MERS-CoV, the Middle Eastern Respiratory Syndrome coronavirus, continues to cause infections (often fatal) and confusion. For a while now, there's been speculation that camels are the source of this virus, based in part on how commonly antibodies against the virus (or a related virus) are found in healthy camels. It always seemed strange, though, for camels to be the ultimate source, leaving lingering questions about whether there is another source or where camels got exposed to the virus in the first place.
Some have focused their attention on bats (which were ultimately the source of the related SARS-coronavirus). A recent paper in the Journal of Virology (Corman et al 2014) helps answer some of those lingering questions questions. The researchers found a coronavirus in the feces of a South African Neoromicia capensis bat. When they looked at the sequence of the virus' genome, it was quite similar to that of MERS-CoV - close enough that the two viruses would be considered the same species. There were some differences, though, indicating there appears to be a "bat type" and a type that infects people and camels.
Relatedness is one thing, but figuring out how viruses are different and when they diverged is important (i.e. did the camels get the virus from the bats, or did the bats get it from the camels?). From an evolutionary standpoint, the bat virus "roots" the phylogenetic tree of human and camel MERS-CoV, meaning that when the different viruses are shown in their "family tree" based on their genetic makeup, the bat coronavirus is the one that comes up at the common ancestor. So, it appears that MERS-CoV originated from this bat virus.
The genetic relatedness of these viruses, the fact that the bat virus appears to be the ancestor, and the evidence for circulation of MERS-CoV in camels for at least 20 years suggests that:
- The virus jumped from bats to camels in the southern part of Africa a few decades ago,
- It was imported to the Arabian peninsula (since that is a common route of camel movement), and
- It recently started to infect people.
There was also the suggestion that camels may be a "mixing vessel" for different coronaviruses, like pigs are for influenza viruses, but I think that's pretty speculative.
For me, a few questions remain:
- Why is MERS not detected in southern Africa, if that's where the related virus is present in bats and where it presumably made the jump to camels?
- Why has MERS only recently been identified in people when its been present in camels for a few decades?
As is typically the case with infectious diseases, a few nice answers lead to many more questions. Presumably, lots of camels, bats and other species will continue to be tested in Africa and the Middle East to see what other information can be learmed.
Camels are getting a lot of bad press on the infectious disease front lately. There’s been the ongoing question of their role in the epidemiology of the very serious Middle Eastern Respiratory Syndrome coronavirus (MERS-CoV). This enigmatic virus (like the similarly deadly SARS coronavirus) is a tremendous public health concern, with high deaths rates in infected people, and its origins remain unclear. Recent studies have found the MERS-CoV virus in camels, and that, along with finding that a large percentage of healthy camels harbor antibodies against the virus, has lead to suggestions that camels might be the natural hosts for the virus. (They could still be innocent bystanders, infected from the same source(s) that infects people, but evidence implicating camels is increasing.)
On top of that, H3N8 equine influenza virus has recently been found in camels from Mongolia. The camels weren’t sick, but it raises some interesting questions. The H3N8 equine flu virus has been relatively stable for decades, with only minor changes compared to the degree of variability found in typical human influenza viruses. While there’s lots of concern about influenza viruses moving to humans, this particular one hasn’t raised much attention. It made the jump to dogs a few years back, resulting in emergence of H3N8 canine influenza, but not much remarkable has happened with it outside of horses. Presumably, the finding of H3N8 flu in camels is a result of transmission of the virus from infected horses. However, what remains to be seen if whether this virus can/will cause problems (e.g. illness) in camels, whether it frequently moves from horses to camels, and whether camels can then infect horses or other species.
Presumably, these two issues (particularly the MERS-CoV problem) will lead to more attention to various infectious diseases in camels. In general, the more you look, the more you find, so it’s likely that other potential infectious disease issues will be identified. Whether this means there are truly emerging issues in camels or whether some of these issues have been going on under the radar for some time remains to be seen.
Photo credit: S. Taheri (own work)(click image for source)
That’s a great title that I can’t take credit for. A colleague (and regular supplier of papers for blog posts) Dr. Stephen Page send me a paper from the Journal of Clinical Microbiology with a more convoluted title “The Capnocytophaga canimosus isolate that caused sepsis in an immunosufficient man was transmitted by the large pine weevil Hylobius abietis” (Tuuminen et al 2014).
I often talk about the bacterium C. canimorsus, and any mention of it is usually greeted with either blank stares or the "what the heck was that bacterium called?" look. It’s an obscure bacterium that’s found in the mouths of pretty much all dogs, as well as some other species. While it rarely causes disease, when it does, it can kill quickly.
This report is noteworthy from a few standpoints. One is the source of infection, as it was associated with a pine weevil, an insect. Insects have not been linked C. canimorsus infections in the past, although I’d wager that little is known about their normal mouth microbiotas. The affected person was a 44-year-old sawmill worker in Finland, with no remarkable health problems. That’s important because C. canimorsus infections almost always occur in people without a functional spleen, alcoholics or people with compromised immune systems. He seemed to have none of those risk factors. While this has been reported before, it’s quite rare.
So, should pine weevil bites be added to the list of things that indicate a need for high-risk people to seek medical care? Well, that seems extreme but it shows the unpredictable nature infectious diseases.
Another question, though: where did the insect get the bacterium (i.e. where did the bug get the bug)? Does C. canimorus actually have a much broader host range? Did this insect recently bite a dog in the mouth? Or, did the person have some other form of exposure? The paper’s title is probably more definitive about the source of infection than it should be. He didn’t own a dog or report being bitten, but could C. canimorsus have been inoculated into the bug bite lesion from some other source?
Who knows? Sounds like a good excuse for a field trip to Finland to look at the microbiota of the pine weevil.
Photo credit: http://en.wikipedia.org/wiki/Hylobius_abietis
Following the Canadian Food Inspection Agency's (rather mind-boggling) abandonment of the rabies response portfolio, there's been a scramble by provinces to figure out what to do. The CFIA will still perform testing, but will not have any role in sample collection, sample shipping or investigation. I'm not sure what most provinces are doing (and based on the calls I get from people in different provinces, I'm not alone) but in Ontario, a lot of effort has been put into working out a new system. Ontario's Ministries of Health and Long-Term Care (MOHLTC) and Agriculture and Food (OMAF) have taken on different components of the void left by CFIA. A lot of work has gone into this transition, but there's still a lot of confusion (and some misinformation).
April showers bring May flowers.
…and I can’t come up with a good rhyme for salmonellosis.
Nonetheless, it’s Salmonella season, courtesy of cute but biohazardous baby poultry.
You can buy chicken, turkey and other bird eggs to hatch every spring. Our local feed mill had the order forms out a while ago, and you can also buy them over the internet. Some schools still buy them.
The problem is baby poultry are high risk for shedding Salmonella (and Campylobacter, another problematic bacterium). Every year, outbreaks of disease in people occur from contact with hatching chicks, so the message isn’t getting around or getting through to people.
In the latest CDC report, 60 people in 23 US states have been diagnosed with salmonellosis linked to a single hatchery that "has been associated with multiple outbreaks of salmonellosis linked to live poultry in past years, including in 2012 and 2013." (How many outbreaks does it take to tell you your company is probably doing something wrong, or in the wrong business?)
The figure of 60 infected people is probably an underestimate, since it’s expected that many people were probably sick but didn’t go to a doctor or submit a stool sample for testing. Of the 60 diagnosed cases, 31% ended up hospitalized, re-enforcing that fact that this is a serious problem.
While the hatchery said they are “working collaboratively with authorities at the Ohio Department of Agriculture and CDC as they proceed with their investigation,” the Ohio Deptartment of Agriculture tellingly stated “The more accurate description of our relationship with that company has been we have tried to provide guidance through the years, but I don't know how many of the recommendations that we have brought to them have actually been implemented.”
Sadly (and bizarrely, from my standpoint) the agiculture department doesn’t have any authority to require the hatchery to implement recommended changes. "We're trying to tell them what they need to do in order to keep this from happening every year." How many people does one company need to sicken before they are forced to do things right (or shut down)?
This report shows a few things.
- Some people just don’t learn (sellers and buyers alike)
- Regulation of animal production for sale to the general public is horribly lax
- Contact with young poultry is a major risk factor for salmonellosis.
- The industrial scale of production of eggs for hatching chicks (and some pet species) means that a problem with a single facility can lead to widespread disease.
- It’s a "buyer beware" world. Don’t trust that the critter you just bought is pathogen free, and take measures to protect yourself.
- High-risk individuals should not be around hatching chicks because of the risk of salmonellosis. This includes kids less than 5 years of age (a key target group for sellers), elderly individuals, pregnant women and people with compromised immune systems.
Photo copyright: piep600 / 123RF Stock Photo
Let’s put this one in the "smart people doing stupid things" file.
Some well-intentioned people at Washington University in St. Louis thought they'd help relieve stress during exam time by bringing in a petting zoo - that unfortunately included "Boo Boo" the biting bear. As you can likely guess, problems ensued.
18 students sustained skin-breaking bites from Boo Boo.
- You’d think someone would clue into there being an issue after, say, a few bites. Once it hit a dozen, I would have thought anyone with common sense would get concerned. But 18??? Did they even pull Boo Boo out of the petting zoo by then, or did he just get tired of biting people? (Or did he simply run out of willing victims?)
Local public health officials originally mandated euthanasia and rabies testing.
- Because Boo Boo is a wild animal species, there are no quarantine provisions after potential rabies exposure. Because of that, standard guidelines are to euthanize the animal for rabies testing. This didn’t go over well (not surprisingly), and they eventually relented. From a practical point, it’s reasonable since Boo Boo’s not likely rabid, he’s just not a good petting zoo critter. However, the decision was probably more PR than science and they’ve gone against standard rabies prevention practices. This is one reason why wild species aren’t supposed to be in petting zoos.
It was reported that "This year, without the university's prior knowledge, the petting zoo included in the experience a 2-month old bear cub,"
- Easy way to deflect blame but no excuse. The University brought in the animals. They had a duty to know what was happening.
Petting zoos can be fun and entertaining. Bear bites and rabies scares aren’t. A little common sense goes a long way. Unfortunately, common sense isn’t always very common.
There’s been some controversy in the past regarding allowing pets to sleep in or on the bed. I don’t get too worked up about it, since I think it’s very low-risk in terms of disease transmission for most pets and households, but a variety if reasons for prohibiting this practice have been given.
I haven’t previously heard the reason: “Don’t do it because you might think you’re petting your cat when you are actually mistakenly pissing off the rabid raccoon that’s dozing beside you.”
Maybe that should be added to at list.
A Massachusetts woman learned this one the hard way. The woman was asleep one night a few weeks ago and reached over to pet what she thought was her cat. Unbeknownst to her, the critter beside her was actually a rabid raccoon that had come into the house through a cat door. Unhappy at being disturbed (and with a less-than-functional brain from rabies), the raccoon attacked, jumping on the woman's face and biting her lip, refusing to let go. She managed to pry the creature off her face, whack it with her phone and call 911. Animal control caught the raccoon, which was subsequently euthanized and confirmed as rabid.
From a more serious standpoint, this case highlights one of the big drawbacks of having a cat door that allows entry and exit of any cat-sized animal. Keeping cats indoors is a good idea for the cat’s health, the family’s health and the wild bird population (and avoids the cat door issue entirely!).
The University of Guelph’s Animal Health Laboratory recently published a summary of selected zoonotic disease diagnoses in its monthly newsletter. It’s an interesting summary of what’s gone through the lab in the last year. It also helps to remind us of the zoonotic potential of all of these pathogens, some of which are relatively common and can be found in a variety of species.
The first North American case of H5N1 avian influenza ("bird flu") was confirmed in an Alberta resident last night, causing much concern but posing little true risk. The affected person had just returned from a trip to China and began showing signs of illness during the flight from Beijing to Vancouver. After spending a few hours in the Vancouver airport, the person continued on a flight to Edmonton. The person's condition continued to deteriorate after returning home, and the patient was admitted to hospital on January 1, dying two days later.
H5N1 flu is a big deal. This bird-origin virus has only been identified in 648 people, mainly in Asia. However, 384 of those have died. Fortunately, it’s not transmitted very easily to people, and almost all human cases have occurred following close contact with infected poultry.
So, the risk posed by the Alberta case is very low, even to people who shared the long plane ride.
There are some strange aspects of this case though. The affected person didn’t have any known contact with live poultry, which is unusual. It’s even more unusual that the person reportedly only visited Beijing, where no cases of H5N1 have been detected, and did not travel to other areas of China where the virus has been found before.
As reported by the CBC, “China is going to be very interested in this,” said Dr. Gregory Taylor, deputy chief public health officer for Canada.
True. I think Canada should be interested in this too.
A case that’s unusual is a concern. Most often, things that appear to be strange or new don’t end up being anything remarkable. However, a disease that was potentially acquired in an area where it has not been found before, and not necessarily from the known main source means that you have to think about other sources (including humans). If this came from another source, maybe there is more risk. It’s very unlikely though, and chances are it will be eventually be explained (e.g. perhaps the person was in a restaurant that kept live poultry on hand which came from an area where the virus has been present).
I assume this H5N1 virus will be sequenced in the next day or so to see how it compares with other known H5N1 viruses. That will answer some questions.
Despite its high mortality rate, the H5N1 virus isn’t really the major concern here, because it’s rare and poorly transmissible between people. The concerning situation is if H5N1 gets together with human seasonal flu and ends up becoming a virus that is both highly transmissible between people (like seasonal flu) and highly fatal (like H5N1). The odds of this are limited, but the pandemic potential of a new virus of this kind is why there’s a lot of flu surveillance.
These days, there’s more and more doom-and-gloom information about multidrug-resistant bacteria. They’re in our hospitals, medical tourists, people on the street, our pets, our food, and pretty much anywhere else you can think of. We can now add crow poop to the list too.
It’s almost to be expected, really. We know that birds can carry various resistant bacteria, and the more contact birds have with human environments and food animal environments, the greater the chance these bacteria are going to be transmitted between them (in one direction or another). It's important to remember that resistant bacteria are also present in nature, independent of human activities.
A recent report of a pretty high profile multidrug-resistant bacterium - vancomycin-resistant Enterococcus (VRE) - in birds wasn’t all that surprising. The study (Oravcova et al, Environmental Microbiology 2013) reported finding enterococci carrying the vanA resistance gene in 2.5% of 590 crows sampled in multiple US states. It was quite interesting though, because VRE is (in North America) a human-associated bacterium. It’s a little more muddled in Europe where VRE was an issue in food animals, in part due to former use of a drug related to vancomycin (avoparacin) in some food animal species. Here though, we rarely see VRE in anything species but humans. This raises some interesting questions about where these crows picked up VRE, if they are able to carry the bacterium for long periods of time, and if they can act as a source of human or animal infection.
Does this bother me? No. It’s of academic interest, but not something that’s going to pose a real risk to me. I tend not to walk under trees full of crows with my mouth open, and I’m pretty sure I’d wash my hands if a crow pooped on them. Yes, there’s the chance that I could have unnoticed contact with contaminated crow poop remnants on an outdoor surface, but the odds of it containing viable VRE are pretty low, and there are lots of other things that I’m more likely to pick up in my daily activities. In terms of VRE, I’m presumably more likely to be exposed in other ways than from crows. However, the study is still important in that it shows how widespread antimicrobial resistance is, how complex the issue is and how we need to do more to understand the ecology and epidemiology of various resistant bugs.
There's no need to go exterminating crows, but Johnny Depp may want to consider an alternative style of hat.
A little knowledge can be a bad thing. We see that with zoonotic diseases. Awareness is great. However, a little bit of awareness can be a problem if it’s enough make people paranoid but not enough to help them understand the real risks. This can lead to excessive and illogical responses (often ending with "...get rid of the cat").
Sound guidelines for preventing infections written by authoritative groups help a lot. An example of that is the recently updated Guidelines for the prevention and treatment of opportunistic infections in HIV-infected adults and adolescents. As a collaborative set of guidelines from the US Centers for Disease Control and Prevention (CDC), the National Institutes of Health, and the HIV Medicine Association of the Infectious Diseases Society of America, it carries a lot of weight - as it should.
It’s a monster of a document of 416 pages. Pet contact gets a little bit of room and probably just the right amount. Enough to say "it’s something to think about," "we’ve considered the issues" and "here are some basic things to consider.”
Here are their specific recommendations:
Hand-washing also should be recommended in association with the following activities: after handling pets or other animals, gardening or having other contact with soil; before preparing food or eating; and before and after sex (BIII).
HIV-infected individuals—particularly those with CD4 counts <200 cells/μL [i.e. people who have advanced disease]—should avoid direct contact with diarrhea or stool from pets (BIII).
Gloves should be worn when handling feces or cleaning areas that might have been contaminated by feces from pets (BIII).
HIV-infected individuals also should avoid other sources of Cryptosporidium oocysts as much as possible (BIII). These include working directly with people with diarrhea; with farm animals such as cattle and sheep; and with domestic pets that are very young or have diarrhea. If exposure is unavoidable, gloves should be used and practices for good hand hygiene observed.
The letters and numbers indicate the strength of evidence. B means there’s moderate evidence supporting the recommendation and III means it’s based mainly or exclusively on expert opinion, not research trials.
Note that nowhere does it say "get rid of the pet" or "avoid contact with animals altogether." Rather, it endorses the use of basic hygiene practices and common sense. In reality, all these recommendations could apply to any individual, not just people with HIV infection.
The preamble to the pet section includes a great statement:
Health-care providers should advise HIV-infected persons of the potential risk posed by pet ownership. However, they should be sensitive to the psychological benefits of pet ownership and should not routinely advise HIV-infected persons to part with their pets. Specifically, providers should advise HIV-infected patients of the following precautions.
…and those precautions are:
HIV-infected persons should avoid direct contact with stool from pets or stray animals. Veterinary care should be sought when a pet develops diarrheal illness. If possible, HIV-infected persons should avoid contact with animals that have diarrhea.
When obtaining a new pet, HIV-infected patients should avoid animals aged <6 months (or <1 year for cats) and specifically animals with diarrhea. Because the hygienic and sanitary conditions in pet-breeding facilities, pet stores, and animal shelters vary, patients should be cautious when obtaining pets from these sources. Stray animals should also be avoided, and specifically those with diarrhea.
Gloves should always be worn when handling feces or cleaning areas that might have been contaminated by feces from pets. Patients should wash their hands after handling pets and also before eating. Patients, especially those with CD4 cell counts < 200 cells/μL should avoid direct contact with all animal feces to reduce the risk for toxoplasmosis, cryptosporidiosis, salmonellosis, campylobacteriosis, E. coli infection, and other infectious illnesses. HIV-infected persons should limit or avoid direct exposure to calves and lambs (e.g., farms, petting zoos). Paying attention to hand hygiene (i.e., washing hands with soap and water, or alcohol-based hand sanitizers if soap and water are unavailable) and avoiding direct contact with stool are important when visiting premises where these animals are housed or exhibited.
Patients should not allow pets, particularly cats, to lick patients’ open cuts or wounds and should take care to avoid any animal bites. Patients should wash all animal bites, animal scratches, or wounds licked by animals promptly with soap and water and seek medical attention. A course of antimicrobial therapy might be recommended if the wounds are moderate or severe, demonstrate crush injury and edema, involve the bones of a joint, involve a puncture of the skin near a joint, or involve a puncture of a joint directly.
Patients should be aware that cat ownership may under some circumstances increase their risk for toxoplasmosis and Bartonella infection, and enteric infections [although I’d argue data supporting a broad statement of cat ownership increasing those risks that are largely lacking]. Patients who elect to obtain a cat should adopt or purchase an animal aged >1 year and in good health to reduce the risk for cryptosporidiosis, Bartonella infection, salmonellosis, campylobacteriosis, and E. coli infection.
Litter boxes should be cleaned daily, preferably by an HIV-negative, non-pregnant person; if HIV-infected patients perform this task, they should wear gloves and wash their hands thoroughly afterward to reduce the risk for toxoplasmosis. To further reduce the risk for toxoplasmosis, HIV-infected patients should keep cats indoors, not allow them to hunt, and not feed them raw or undercooked meat. Although declawing is not usually advised, patients should avoid activities that might result in cat scratches or bites to reduce the risk for Bartonella infection. Patients should also wash sites of cat scratches or bites promptly and should not allow cats to lick patients’ open cuts or wounds. Care of cats should include flea control to reduce the risk for Bartonella infection. Testing cats for toxoplasmosis or Bartonella infection is not recommended, as such tests cannot accurately identify animals that pose a current risk for human infection.
Screening healthy birds for Cryptococcus neoformans, Mycobacterium avium, or Histoplasma capsulatum is not recommended.
HIV-infected persons should avoid or limit contact with reptiles (e.g., snakes, lizards, iguanas, and turtles) and chicks and ducklings because of the high risk for exposure to Salmonella spp. Gloves should be used during aquarium cleaning to reduce the risk for infection with Mycobacterium marinum. Contact with exotic pets (e.g., nonhuman primates) should be avoided.
In my line of work, I deal with feces from a lot of different species. Never once, however, have I thought to model defecation pressure and distances.
Maybe I’m just strange.
A few years ago, German researchers felt the need to model the defecation habits of penguins. The title of the paper, published in Polar Biology, was “Pressures produced when penguins pooh - calculations on avian defaecation" (Meyer-Rochow et al 2003).
The authors considered the fact that penguins don’t leave their nests to defecate (probably preferring not to freeze every time they need to poop). Rather, they observed that penguins move to the edge, “stand up, turn their back nest-outward, bend forward, lift their tail, and shoot. The expelled material hits the ground maximally 40±12 cm away from the bird and then leaves behind a whitish or pinkish streak that can end a few centimetres from the nest’s periphery and may be up to 1 cm wide.”
That observation lead (perhaps fostered by some alcohol?) to questions about the exit velocity of the feces.
Given their protected status, you can’t run around poking and prodding penguins, so much of the research is done from a distance. The researchers in this case used pictures to estimate the "aperture" and determined it to have a "maximal diameter of 8 mm at the moment of "firing"."
Using the size of the "exit" and an estimate of average penguin poop viscosity, along with the angle and distance of firing, they used mathematical models to determine the "penguin-generated pressures" associated with defecation.
I won’t get into all the of the calculations. Suffice it to say, the image at right will probably not been seen in too many other scientific papers.
They concluded that "fully grown chinstrap and Adelie penguins generate pressures between 10 kPa (77 mmHg) and 60 kPa (450 mmHg) during the evacuation of their faeces on land. The process of defaecation commences with the highest pressure initially and then rapidly drops to zero, hence the production of faecal streaks (and not ‘‘blobs’’). In water, different parameters would apply, although (as in air) the smaller the cloacal diameter, the higher the pressure."
And to wrap it up…
"All birds, penguins included, spend a considerable time preening and cleaning their feathers. It seems therefore that these birds propel their faeces as far away as possible (with a minimum amount of effort) lest they soil their plumage. Birds could theoretically increase their projectile defaecation range by squirting 45° up-wards. However, their upright posture and position of the vent prohibit this in penguins, but in eagles and other birds-of-prey the squirt is, indeed, directed upward by ca. 15–30° (unpublished observation). The forces involved apparently do not lead to an energetically wasteful turbulent flow. It is interesting to note that the streaks of the faecal material radiate from the edge of the nest into all directions (no preference is noticeable). Whether the bird deliberately chooses the direction into which it decides to expel its faeces or whether this depends on the direction from which the wind blows at the time of evacuation are questions that need to be addressed on another expedition to Antarctica."
Photo: Adelie penguins, Antarctica (credit: JHB Anderson)
Australian Elmer Fudds beware… there are concerns that feral pig hunting is a risk factor for brucellosis in New South Wales. Brucellosis is a rare disease, but a report like this raises concern because it can be nasty, and it can also be hard to diagnose (or it's not considered right away).
We don’t have feral pigs in Ontario, but they are common in many areas, including parts of the US. In Australia, it’s been estimated that there are over 13 million feral pigs ranging over approximately 38% of the country. Any contact with animals carries some degree of infectious disease risk, and hunting is no exception. In fact, some risks are higher because of the close contact with the target animal and its bodily fluids after its been killed.
The brucellosis story is a bit old, and relates to a NSW Public Health Bulletin from a few years ago (Irwin et al. 2009) of four cases of this bacterial infection detected between December 2006 and September 2009. The infected individuals, all men, reported having hunted feral pigs before the onset of disease, and they all butchered the pigs without any protective gear (e.g. gloves). They didn’t have any of the common risk factors for brucellosis, such as overseas travel or consumption of unpasteurized milk from areas where the disease is endemic in dairy animals, so it was likely that the pigs were the source. Public health authorities trapped and tested 200 pigs, all of which were negative. However, 200 negative pigs from a multimillion population certainly doesn’t mean the pigs are Brucella- free, as was shown when Brucella suis was found in testicular samples of pigs from southern Queensland in a separate investigation.
All of the men reported typical symptoms including fever, sweating, abdominal pain, vomiting, back pain and "loin" pain (a term that’s not typically used since it’s not very descriptive - brucellosis often causes testicular swelling so maybe that’s what it means. Either way, it doesn’t sound pleasant).
Brucellosis is a disease that warrants some attention because it can be nasty and it can take a while to diagnose. Fortunately, it’s rare in most developed countries, although the same link between brucellosis cases and hunting feral swine has been seen in the US as well. Hunters need to be aware of a wide range of potential zoonotic diseases. Additionally, brucellosis is a concern for pet owners since sporadic human cases associated with transmission from pets have been reported, and this may be an emerging or previously overlooked problem.
It's that time of year again… time for the US annual rabies surveillance report in the Journal of the American Veterinary Medical Association (Dyer et al 2013).
- There were 6162 cases of rabies diagnosed in animals in 2012. (This is a 2.1% increase from 2011, but I don't put much stock into changes like that when the tested cases only represent a minority of the animals with rabies.)
- The vast majority (92%) of rabid animals were wildlife, with raccoons "winning" at 32% of all animals diagnosed. They were followed by bats (27%), skunks (25%), foxes (5.5%), cats (4.2%), cattle (1.9%) and dogs (1.4%)
- A variety of other animal species were also diagnosed as rabid, including bison, llamas, bobcats, deer, a cougar, a mink, groundhogs, opossums and beavers. That just shows how any mammal is at risk. I was surprised at the number of rabid groundhogs (42 in 10 states).
- While dogs accounted for only 1.4% of cases (84 animals), a disproportionate number were found in Puerto Rico (18), with relatively large numbers also in Texas (16), North Carolina (9), Georgia (7) and Oklahoma (7). Presumably this relates to a combination of lower vaccination rates and a higher level of endemic rabies in the wildlife population in these areas. It appears that none of the rabid dogs were properly vaccinated against rabies, although vaccination history was not known for many.
- Rabid cats were mainly found in areas where raccoon rabies was common. Pennsylvania had the most rabid cats (15.6%). Other commonly affected areas were Virginia, North Carolina, New Jersey and Georgia.
- The distribution of rabies virus types was pretty much as expected. Raccoon rabies virus predominated on the east coast. Skunk rabies covered the central US, overlapping with fox rabies in the southern regions. Fox rabies was also dominant in the Nevada and Arizona area, while skunk rabies predominated in central to northern California. Fox rabies dominated in Alaska and the mongoose rabies virus strain was found in (not surprisingly) Puerto Rico.
Some Canadian data were also reported:
- There were 142 confirmed rabies cases in animals, 84% of which were wildlife.
- There were 18 rabid cats and dogs, 4 livestock and one person. The person was infected with rabies while abroad, in Haiti.
- No rabid raccoons were found - something that has been the case since 2008.
And in Mexico…
- There were 12 cases of rabies in dogs, and those involved the canine rabies virus variant which is not present in Canada or the US.
Take home messages:
- Rabies... still here (and not going away any time soon).
- Vaccinate your animals.
- Stay away from wildlife.
Image: Distribution of major rabies virus variants among mesocarnivore reservoirs in the United States and Puerto Rico, 2008 to 2012. (click for source: Dyer et al. J Am Vet Med Assoc 2013)
Antibiotic use in animals, and the impact on humans is a controversial area. At a conference a few years ago, one of the organizers posed the question, "What percentage of resistance in human pathogens is attributable to antibiotic use in animals?" They had people write their answers on cards, and later in the day they gave a synopsis of the results. Basically, the responses ranged from 0-96% (or something like that). That's not surprising really, as there are a lot of opinions but there's been a lack of good data. Clearly, use of certain antibiotics in animals in certain situations can lead to increased resistance in some human pathogens. Sorting out the "certains" and "somes" is the problem. It's also clear that there's massive overuse (and abuse) of antibiotics in human medicine that leads to lots of resistance.
The biggest problem is our current lack of data. It's not for lack of trying, but it's an extremely complex area. A study in the upcoming issue of Emerging Infectious Diseases (Collignon et al. 2013) starts to put some more solid numbers behind the concerns. The study took data from a variety of sources and attempted to figure out the number of human deaths from resistant E. coli (just one of the bugs we're concerned about, but a big one) that is attributable to antibiotic use in animals. Their conclusion was that infections with E. coli resistant to 3rd generation cephalosporins (an antibiotic group which is used in some animals and is also important in humans), in which resistance was attributable to antibiotic use in poultry, accounted for 21 deaths and 908 hospital bed-days in the Netherlands in 2007. If this is extrapolated to Europe (which can only be done loosely because of differences in antibiotic use and infection trends between the vastly different EU countries), it would mean 1518 deaths and 67 236 hospital admissions. That's a very small percentage of people in Europe overall, and a small percentage of all the people in Europe who die of resistant infections, but it's still a lot and it's therefor still a concern.
What does this mean more broadly for other countries, other bugs, other drugs? It's hard to say. To quote the authors, "To more accurately estimate the associated increased deaths among persons resulting from third-generation cephalosporin use in poultry, detailed data from more countries is essential." I'd substitute "third-generation cephalosporin use" with "antibiotic use," since we also need to know about other drugs. It's always amazed me how hard it is to get even a basic idea of how much antibiotic use occurs in people and animals, with profoundly different estimates by different groups (often driven by different agendas).
Antibiotic use is a necessity in some situations. We have a moral obligation to keep animals healthy, and healthy animals help make healthy food. However, at the same time, we need to think about standard practices and make sure antibiotics are truly being used wisely in both people and animals. Stopping all antibiotic use isn't practical at this time, nor will it eliminate resistance. Knee-jerk reactions like simply banning antibiotics might actually make some things worse, if they result in other practices that also drive resistance (e.g. adding heavy metals like zinc to animal feed to help prevent diarrhea, resulting in the same pressure for antibiotic resistance, or replacing prophylactic treatment using drugs that are of limited concern in people with later use of therapeutic drugs that are important in humans). However, the use of antibiotics as a replacement for good management practices needs to end, and more thought needs to be given to how to use antibiotics wisely, effectively and sparingly - in all cases (animals and people).
Darwin's back in the news. He’s a young macaque who is often called the "Ikea Monkey" since he was found wandering around a Toronto Ikea parking lot one day last winter in a designer winter coat. He was seized because of a Toronto bylaw prohibiting monkeys as pets, and transferred to a local primate sanctuary. His owner, Yasmin Nakhuda, has been waging a high profile battle to get him back. There are numerous Facebook pages dedicated to freeing Darwin, and she apparently sent him a birthday greeting (perhaps not realizing it's unlikely that he had internet access at the sanctuary... or can read).
Anyway, Ms. Nakhuda is suing for custody and the trial is currently underway. Needless to say there's a lot of drama in the courtroom as Ms. Nakhuda tries to regain custody of the animal she calls her "son." Much of the trial has centred around issues of property, which I guess makes sense since that’s the main legal avenue.
However, what’s not been mentioned are the greater concerns, namely does Darwin pose a risk to the public and does Ms. Nakhuda pose a risk to Darwin? I think the answer to part 1 is certainly yes, and the answer to part 2 is maybe.
The first question (does Darwin pose a risk to the public) is easy. There are a variety of issues with keeping non-human primates as pets. They can be destructive, they are surprisingly strong for their size, and macaques are notorious for being aggressive, so the risk of trauma alone is a major issue. Disease is another concern, and the big problem in this case is herpes B virus. This virus can be found in most healthy captive macaques and can cause fatal infection in people. The fact that it’s been reported that Darwin was prone to biting makes me cringe, since that’s a huge risk for herpes B transmission. Among the trial testimony was an email Ms. Nakhuda sent to a US primate trainer in November documenting her struggles. Among the problems was aggression that Darwin had towards her son and co-workers.
It’s bad enough that she’s exposing herself and her family (including her human chldren) to Darwin. Exposing people with whom she works (and perhaps people who work for her, and would have a hard time raising any concerns they had) is completely inappropriate, as is taking Darwin out in public (apparently "everywhere," including the gym, grocery store, and obviously Ikea). Ms. Nakhuda either doesn’t understand the issues or doesn’t care. Either way, it’s not good.
I don't doubt that Ms. Nakhuda cares for Darwin. However, as the primate sanctuary lawyer Kevin Toyne said "This is not about who loves Darwin the most." For me, it should be about protecting the best interests of the public and Darwin, neither of which would result in him being returned to his previous owner.
I’ve written about the African dwarf frog and Salmonella issue before, but it’s worth a recap since an overview of the 2008-2011 outbreak was recently published in the journal Pediatrics (Mettee Zarecki et al 2013). The fact that reptiles and amphibians can carry Salmonella is nothing new, nor is the fact that outbreaks of disease can occur in people who have contact with them. However, the scale of outbreaks associated with pets can be impressive.
Here are some highlights from the paper:
- Between January 1, 2008 and December 31, 2011, 376 people were diagnosed with salmonellosis caused by the outbreak strain, a type of Salmonella Typhimurium.
- As is common in pet-associated outbreaks, kids bore the brunt of this one. The mean age of infected individuals was 5 years, and 69% were children under the age of 10.
- Severe disease wasn’t uncommon - 29% of people were hospitalized, half of those being kids less than 5 years of age. Fortunately, no one died.
- During a preliminary study, when they compared people who got sick with a group of healthy controls, they found that people who reported exposure to any aquatic pet were almost 5 times as likely to have salmonellosis. When that was narrowed down to exposure to just frogs, the risk went up to 12.4 times higher than healthy controls.
- When they looked at people who were sick and reported exposure to frogs, only 27% reported having touched a frog, with 46% reporting having fed a frog, 59% having had contact with a frog’s habitat and 60% having had contact with water from a frog’s habitat. Twenty-three percent (23%) reported cleaning the frog’s habitat in the kitchen sink, and 35% in the bathroom sink. This tells us some very important information. It tells us that direct contact with frogs or their environment is a high risk behaviour. However, direct contact isn’t required to get sick. While the frog may stay in its habitat, Salmonella may not. Cleaning habitats in kitchen or bathroom sinks is a high risk activity, because it can result in contamination of common human-touch surfaces and items that go into peoples’ mouths (e.g. toothbrushes, cups).
- Often, disease occurred not long after a new frog was obtained. The median time from purchase of a frog to disease was 30 days (range 5-2310 days).
- Only 17% of people interviewed reported knowing that frogs can carry Salmonella. Over twice as many knew there was a risk from reptiles. This shows there needs to be more education of people who buy animals such as frogs. Pet stores should be required to provide some basic public health information. Pet owners should also take initiative and research potential new pets, including how to care for them and how to reduce the risk of zoonotic infection.
- The outbreak Salmonella strain was found in the environment of some patient homes (not surprisingly), an African dwarf frog vendor (potential source of infection), a large-scale African dwarf frog distributor (a great way to spread an outbreak across the continent) and a daycare centre (that never should have had an amphibian in the first place!).
- One breeding facility in California was the likely source. With centralized, large-scale breeding and warehouse-style distribution of pets (of various species, not just frogs), we’re seeing more large-scale outbreaks like this.
More information about African dwarf frogs can be found on the Worms & Germs Resources - Pets page.
I've been bitten lots of times, some on the job (including the last dog I saw when I was in general practice) and some off (including a dog down the road a couple of years ago). Fortunately, I haven't suffered any serious consequences. That's what happens most of the time. However, bad things can and do occur after bites.
A paper in BMJ Case Reports (Tumram et al 2012) describes a rather unusual and unfortunate situation. It's about a fatal infection in a 55-year-old Indian woman who was bitten by a mongoose. She was bitten (unprovoked, it seems) on the leg by the mongoose while washing dishes. She went to the hospital a couple of hours later because of pain and swelling in her leg. It's not clear what happened there, but she went back to hospital the next day, and then received antibiotics. However, that same day, she suffered cardiac arrest (a heart attack) and died a few days later. The bacterium Streptococcus pyogenes (Group A Streptococcus) was isolated from some lesions on her legs, leading to a suspicion that she developed a severe and rapidly progressive infection from the mongoose bite.
Various aspects of this case are unusual. Fatal bite infections occur, but they are rare. Involvement of streptococci is rarer still.
Why did this woman develop a fatal infection, especially when she sought prompt medical care? It's hard to say, and there is a "bad luck" component of infectious diseases. She had diabetes and high blood pressure, which probably increased her susceptibility to infection (but lots of other people who get bitten also have these conditions and suffer no consequences). It doesn't appear that she received antibiotics when she went to the hospital originally, but a bite over the leg isn't one that would always be treated prophylactically with antibiotics.
Why did the mongoose bite? That's another good question. Unless you're a snake, mongooses are typically not aggressive.
Where did the bacteria come from? We don't know much about the oral bacterial population of mongooses, but Streptococcus pyogenes is a human-associated bacterium. It's rarely found in animals and I suspect that the strep didn't come from the mongoose. Rather, it was probably already on the woman's skin and introduced into her body by the bite, or she contaminated the wound after being bitten. It's just a guess, and it doesn't change anything, but it makes sense.
This report shouldn't make people freak out over a bite. However, it should serve as a reminder that bad things can happen. More information about dealing with bites can be found on the Worms & Germs Resources - Pets page.
Image: Dwarf mongoose (Helogale parvula) in Korkeasaari zoo (photo credit: Miika Silfverberg, click image for source)
Allegedly, spring is here. The foot of snow on the ground and minus double-digit temperatures don’t really convince me, but the calendar can't lie, I guess.
Anyway, spring brings with it many things, one of which is hatching chicks. I saw signs for them at a local farm supply store a couple of days ago, and perhaps not coincidentally, this week’s edition of CDC’s Morbidity and Mortality Weekly Reports provides an update on the 2012 human Salmonella outbreak that was linked to contact with chicks and ducklings from a single supplier.
This outbreak has been talked about before, but this report gives some final numbers.
- Ultimately, 195 people infected with the outbreak strain of Salmonella Infantis were identified. (That’s probably a major underestimation too, since in outbreaks like this lots of people get sick but don’t have fecal cultures for Salmonella performed.)
- 33% of affected individuals were children 10 years of age or less.
- 79% of people who got sick reported contact with poultry in the week before illness started.
- Birds were obtained from various feed stores or directly from hatcheries, and 87% of people that provided information about chick or duckling sources reported getting them from a single mail-order hatchery in Ohio.
Chicks and Salmonella go hand-in-hard. Chicks are high-risk for shedding the bacterium, and people can get infected by handling chicks or having contact with their environment. Children are at high risk for infection since they tend to have closer contact with chicks and because they are more susceptible to Salmonella. That’s why it’s recommended that kids less than 5 years of age not have contact with young poultry. Day cares and kindergartens planning on their annual hatching chick programs… please take note.
The article includes some more recommendations.
- Feed stores should use physical barriers (e.g., a wall or fence) between customers and poultry displays to prevent direct contact with poultry.
- Educational materials warning customers of and advising them on how to reduce the risk for Salmonella infection from live poultry should be distributed with all live poultry purchases
Part of the last point is keeping young kids away from chicks and stressing good hand hygiene practices. Like most things in infection control, a little common sense goes a long way.
Today, we went to the University of Guelph's annual open house, College Royal. As per usual, we only covered a fraction of the events, but had to do the traditional visits with the animals and get some of the Food Science milkshakes (even thought it was -2C outside). Animals are a big part of College Royal. In most cases, you can look but not touch (e.g. Old MacDonald's barn, livestock shows), but there is a petting zoo.
The petting zoo has evolved a lot over the years. I was in charge of it for a couple of years when I was a veterinary student, but what we do now is very different from what we did then (in the mid 1990s).
- We've stopped using certain kinds of animals. Most notably, the calves (i.e. baby cows) are gone, since they're considered high risk for transmitting a few important microorganisms. The thing that triggered that was the year we decided to test fecal samples from the calves and found out (not too surprisingly, really) that all of them were shedding Cryptosporidium.
- We've changed the location, for a few reasons. The old location was in a ward in the large animal hospital, which therefore had the potential to impact patient care. The current setup is outside of patient care areas, and makes it easier to contain activities and visitors, and to organize overall.
- Signage has been improved. We used to have many signs, but they mainly provided just basic information about the animals (e.g. "Hi, my name's Betsy. I'm a Holstein cow.") I don't remember having many signs (if any) about hand washing, no food or drink, and other public health measures, but thankfully they do now.
- Hand hygiene is a priority. We didn't really do anything in terms of promoting hand hygiene at the event in the 1990s. Now, we have multiple hand hygiene stations, signs to tell people to wash their hands, people reminding visitors to wash their hands, and a structured flow of traffic through the petting zoo that leads people out past the hand hygiene stations.
Big changes, and for the better.
Has anyone ever gotten sick from the College Royal Petting Zoo? Not that I know of, but it's certainly possible.
Have we eliminated all risk? No. That's not possible. What we try to do is to reduce it as much as we can.
Are all petting zoos like this? Unfortunately no, they are not. Things at other petting zoos are much better overall than they were even five years ago, but there's still lots of room for improvement and still an unnecessarily high risk of infectious diseases.
A lawsuit filed recently in North Carolina highlights some of the issues around petting zoos. The suit was filed in response to a 2011 E. coli outbreak associated with the NC State Fair that sickened more than 100 visitors and killed a two-year-old boy. Among the claims in the suit are:
- animal areas were cleaned in such a manner that E. coli was spread around
- eating and drinking were encouraged in the animal area (presumably, the actual issue is that eating and drinking were not prohibited. I doubt the fair said "please eat and drink in this area")
- there were inadequate hand hygiene stations
- they failed to follow the State Fair's own guidelines
If these claims are true, that's a pretty big "oops" and someone is probably going to be writing a very large cheque.
On a similar note, a UK petting farm was recently found liable for a 2009 E. coli outbreak that sickened 93 people.
Petting zoo design and operation aren't foolproof, but it's not rocket science either - it's largely common sense. There are clear guidelines covering the basics, and adhering to them should greatly reduce any risk of illness or injury. Failing to do so leads to trouble, of both the infectious disease and legal kind.
I'm just back from vacation (luckily, with no infectious disease stories to write), but now I have to catch up on a few posts. One easy one that was waiting for me in my inbox was about Salmonella and hedgehogs.
I've written before about biohazardous hedgehogs, and more details about the US 2011-2013 multi-state Salmonella outbreak were reported in a recent edition of CDC's Morbidity and Mortality Weekly Reports. The outbreak was identified through recognition of a cluster of infections in people caused by the same, historically rare strain of Salmonella Typhimurium. Finding a cluster of the same strain, especially a rare one, suggests that there might be a common source, so an investigation ensued. Here are some highlights:
- Twenty people from 8 states (Alabama, Illinois, Indiana, Michigan, Minnesota, Ohio, Oregon and Washington) were affected, although (as is typical) it's almost guaranteed that many more people were affected but not tested.
- Young people were more often affected, with the average age being 13. The age range spanned from less than 1 year to 91 years of age.
- Four people were hospitalized and one died.
- 14/15 (93%) people interviewed reported direct or indirect contact with a hedgehog. That's a pretty strong indication that hedgehogs might be involved, since that number is wildly disproportionate to the percentage of people in the general population that have contact with hedgehogs.
- Hedgehogs were obtained from various breeders, not from a single source.That's not uncommon since breeders often get animals from other breeders or suppliers and a point-source of infection further up the supply chain is likely.
For some reason, hedgehogs are high risk pets when it comes to Salmonella. High Salmonella shedding rates have been identified in studies of healthy hedgehogs and it's clear that contact with healthy carriers can lead to human infection. Hedgehogs should be considered alongside reptiles in terms of pets that should not be present in high risk households (households with kids less than 5 years of age, elderly individuals, pregnant women or people with compromised immune systems). Hedgehog owners should take care to avoid direct and indirect contact with feces and use good hygiene practices to reduce the risk of infection.
One on the things we try to do with the blog approach to getting zoonotic disease and infectious disease information out is to put a personal spin on stories. Whether it's new puppy issues, a rabid bat in my house, zoonotic disease issues at my kid's daycare or something more mundane, that personal touch sometimes helps keep things in perspective.
Knowing more about what we do and why might also help with understanding how our thoughts and opinions come about. An article posted on atGuelph details our own Dr. Maureen Anderson's ascent in the veterinary world from undergrad to infection control researcher, including her groundbreaking infection control surveillance in veterinary clinics. I'll let you read the story yourselves through the link highlighted above...
Santa gives the reindeer a few months off every year, so inevitably they're going to cause trouble.
A health board inquiry is under way after a young reindeer was taken into a Glasgow Children's Hospital and allowed to interact with patients. The reindeer fawn, from a local reindeer farm, was paraded around the hospital grounds as part of an organized event. That's great. The kids could see something unique. However, the problem occurred when a staff member decided to take the fawn inside so more young patients could see it. By doing that, the fawn was turned into a "therapy animal," meaning all the various recommended precautions for a therapy pet should apply (including a prohibition on bringing farm animals into a hospital).
It essence, good intentions + lack of critical thought + lack of clear local guidelines lead to this situation, which has caused an outcry amongst some groups (and probably a similar "so what?" amongst others).
Here are some interesting bits from the article:
"It had been checked by a vet..."
- Okay, good start, but for what was is checked? You can't tell what infectious agents an animal carries by looking at it. We know that young animals are more likely to shed various potentially harmful microorganisms, and deer can be sources of very harmful bacteria like E. coli O157.
"It is understood that the patients who did pet the fawn were later given antiseptic wipes with which to clean their hands."
- I wonder what "later" means. I suspect it wasn't right after animal contact.
“I don’t suppose any animal, no matter how well shampooed and clean it was, should be allowed into a hospital without prior knowledge and the correct arrangements made,” [Dr. Jean Turner of the Scotland Patients' Association] said.
- A reasonable statement. She's not saying "no animals," she's saying "no animals without a proper plan."
"I think it was well-intentioned, but I don’t think anyone was thinking about the consequences of taking a live animal like that to a hospital.”
- That sums it up nicely.
Every animal (and person) is carrying multiple microorganisms that could make someone else sick. Usually that doesn't happen, and we need to live life, not stay locked up in our bedrooms. However, some animals are at higher risk of shedding pathogens (e.g. young animals, farm animals), some situations make it more likely that an individual animal will contaminate the environment of patients (e.g. interacting with a farm animal, taking a non-house-trained animal inside) and some people are at much higher risk of serious disease when they encounter various bugs (e.g. hospitalized kids).
I'm sure some kids had a great time, and the overall risk was probably low. However, was there really any benefit here beyond a properly run pet visitation program with appropriate animals, established protocols, good hygiene practices and proper handler training?
Pet therapy programs are too important to be compromised by illogical events like this that sometimes cause a knee-jerk "no animals in the hospital" response. That's why there are good international pet visitation guidelines and why people need to follow them.
The 15 cm of snow that fell last night is as good of an indicator as any that agricultural fair season is over in this region. But, planning ahead is important (and often not done well with fair petting zoos), so it's never to early to make a plan for next season. Petting zoos can be fun and educational, but are also associated with infectious disease risk. There's always some inherent risk with any kind of animal contact, since all animals (and people) carry a multitude of infectious agents. However, understanding pathogen shedding patterns is useful to help determine the best control measures.
A recent study in Comparative Immunology, Microbiology and Infectious Diseases (Roug et al 2012) looked at shedding of selected pathogens by cattle, sheep, goats, pigs, poultry, rabbits and horses at a California county fair. Here are some of the highlights:
- E. coli O157 was found in one animal. This is the main outbreak concern when it comes to petting zoos, because very low numbers of bacteria are required to cause disease and human infections can be very severe. Surprisingly, the positive animal was a pig, not a ruminant, as would be typical.
- Salmonella was isolated from feces of 3 animals: 2 pigs and 1 chicken.
- Campylobacter jejuni, another potential cause of diarrhea in people, was found in 3 animals: 2 cattle and 1 sheep. The 2 positive cattle were adult dairy cattle and they represented 17% of all tested cattle. That's a surprisingly high rate for adult dairy cattle, in my experience.
- Other Campylobacter species were found in 2 cattle, 3 goats (30% of all goats tested) and 1 chicken.
- Antibiotic-resistant E. coli were common, particularly in pigs.
- The parasites Cryptosporidium and Giardia, and the bacterium Vibrio, were not found.
The study didn't look at other aspects of the petting zoo, such as the types of contacts that were allowed, but based on the pictures that were included with the paper, they weren't optimal. Given the results, the picture of two children in the pen with the pigs (including one child who was sitting on the ground leaning against a pig) should raise some concern.
Does this study change anything? Not really, but more information can't hurt. We know that petting zoo animals can carry pathogens, and we have to assume that every animal in a petting zoo is carrying something that could cause an infection given the "right" circumstances. That's why there's a focus on good general hygiene and infection control practices (especially hand hygiene), along with excluding animals that are at particularly high risk. As the authors say "The study findings should not be interpreted as a deterrent to visit agricultural fairs, but as a reminder that good hygiene and sanitation are critical in these settings."
Following up on my recent post about MRSP in rats, here’s a story about MRSA in an alpaca (Stull et al, Can Vet J 2012). As far as we know, it’s the first report of MRSA in an alpaca (or any camelid).
The report relates to our large animal hospital, where we perform MRSA screening of all horses at admission, weekly during hospitalization and at the time of discharge. It's all part of our infection control program, and the screening is designed to help reduce the risk to horses and our hospital personnel, since this multidrug-resistant bacterium is endemic in the Ontario (and broader) horse population, and outbreaks can occur in equine hospitals.
While alpaca’s aren’t horses, and we don’t see that many of them here, they sometimes get screened anyway since screening is being done on most of the other patients.
This case involved a neonatal alpaca that was admitted with its mother because of severe respiratory disease. The cria (baby alpaca) was very sick and was ultimately euthanized about 36 hours after admission.
Surprisingly, the admission MRSA sample from the cria was positive. In this case, MRSA wasn’t involved in the animal's illness. The cria didn’t have any evidence of bacterial infection, so this was an incidental (but interesting) finding.
When the bacterium was tested further, it was classified as CMRSA-5 (Canadian epidemic MRSA-5), a human strain that also predominates in horses in North America. The mother alpaca was MRSA negative. Presumably, the cria picked up MRSA from the farm environment or a person shortly after birth. MRSA (especially CMRSA-5) carriage rates are high amongst horse owners and horse vets compared to the general public, and it would have been nice to have determined if there were any horses on the alpaca’s home farm, but we couldn’t get any follow-up information.
This single case is probably of limited concern in the grand scheme of things. It’s likely an "oddball" infection rather than an indication that MRSA is a serious threat to alpacas, or that alpacas are a relevant source of human MRSA infection. However, that’s largely what was said when MRSA was first found in horses in the late 1990's and early 2000's, and it has since become a significant issue in that species, so the potential for MRSA to become a problem in alpacas can’t be completely dismissed.
If nothing else, the occurrence of this case is an indication of the need think broadly when it comes to infectious diseases, since many pathogens don’t have species boundaries. CMRSA-5 is a human-origin MRSA strain, but it’s worked its way outside of its natural host. It’s not the first and certainly won't be the last bug to make its way from people to animals.
This story's a couple of weeks old, but Sonoma County (California) residents have been warned about an outbreak of salmonellosis in songbirds. Outbreaks of salmonellosis occur occasionally in songbirds such as finches, and can result is lots of sick and dead birds. There are also risks to other species, including cats and people.
Why cats? Cats can be exposed to Salmonella from eating infected songbirds, and sick birds are typically a lot easier to catch than healthy ones.
Why people? People can be exposed to Salmonella from areas the birds have contaminated, particularly bird feeders and their vicinity. People have been advised to remove bird feeders or clean them regularly, and to promptly remove dead birds from under feeders.
- Removing bird feeders temporarily might help keep birds (including sick birds) farther away from people. It's not going to hurt the birds since other food supplies are typically abundant.
- Washing feeders can reduce the Salmonella burden but it could also increase the risk to people if they contaminate themselves while washing them. Certainly, people should not wash bird feeders inside the house, especially not in the kitchen sink. They should also take care to avoid contaminating their clothing and make sure they wash their hands thoroughly after finishing with the feeder.
"Songbird fever" is a colloquial name for salmonellosis in cats - a testament to the potential for feline infection. It's uncommon but can be severe, and cats can act as a bridge between sick birds and people by bringing Salmonella into the household. This is just one of many reasons why domestic cats are better off living indoors.
A year or two ago, I received an email from Dr. Chelsea Himsworth, who was doing some interesting work looking at different bacteria found in rats in Vancouver's Downtown Eastside. This is an impoverished urban neighbourhood with lots of homeless people, IV drug users and HIV-infected individuals... and lots of rats. Dr. Himsworth, a veterinary pathologist working on a PhD at the University of British Columbia, is assessing potential health risks posed by rats to this type of population. The reason she got ahold of me was to see if I was interested in looking for some different bacteria, like methicillin-resistant staphylococci, in these rodents.
If you look, you often find, and that was the case here with methicillin-resistant Staphylococcus pseudintermedius (MRSP). This multidrug resistant bacterium was found in nasal or oral swabs from 2.1% of rats (Himsworth et al, Emerging Infectious Diseases 2013). So it was relatively uncommon but certainly present.
One question: from where did it come? Most MRSP isolates found were the same as the most common strain found in dogs, so presumably the rats picked it up directly or indirectly from pets or stray dogs. However, there was also a type we've never run across before. That could mean that there is a separate rat-associated MRSP strain, but more likely it means this strain is present in dogs in Vancouver and we just haven't found in dogs elsewhere yet (there aren't many of us typing MRSP, and we find new strains not uncommonly). While dogs and rats presumably don't spend time lounging around together, there is certainly potential for direct or indirect contact between dogs and rats, and rats have been found to harbour dog-associated oral bacteria in the past.
Another question: what's the risk to people? The risk of infection is probably limited, but not zero. MRSP can cause infections in people but doesn't do so very often. MRSP is unfortunately becoming fairly common in dogs, so people are commonly exposed, yet human infections are still rarely diagnosed. So, the risk to humans from these rats carrying MRSP is pretty low overall, although we'd rather not see new reservoirs for this bug.
What about the rats? Rats may be the innocent bystander here, having been infected by dogs. We don't know whether MRSP causes infections in rats. It probably can in certain circumstances.
Can rats spread this to dogs? I guess it's possible. Rats are probably not contaminating the environment too heavily with this bug from their noses or mouths (compared to dogs), but direct transmission if a dog caught a carrier rat could certainly be possible. The risk to the dog population is pretty low since this pathogen is well established in dogs already and there's a lot more dog-dog than rat-dog contact.
Why does an antibiotic-resistant bacterium live in these rats when they're not receiving antibiotics? Good question. Antibiotics certainly help when it comes to selecting for resistant bacteria, but they're not absolutely required. There are a lot of other factors that can also play a role, so rats don't need direct or indirect exposure to antibiotics to acquire MRSP (or other multidrug-resistant bacteria). It could be that they are just commonly exposed and the bacterium only hangs around for a short period of time, or that there are some other factors in the rats, their food or their environment that select for these resistant bacteria.
If you're in Toronto (or probably anywhere in Canada), you've probably heard a lot about Darwin, also known as the "Ikea Monkey". Darwin is a seven-month-old rhesus macaque (Macaca mulatta) that was found wandering around an Ikea parking lot on December 9 in a designer winter coat. He was seized by Toronto Animal Services since non-human primates aren't legal pets in Toronto, and the owner has been fighting to get him back ever since. She has organized protests. She's filed lawsuits. She's planning on moving to a neighbouring region that currently does not prohibit non-human primates as pets. Of course, not wanting to be known as the home for wayward monkeys and their wayward owners, that very region is in the process of enacting a bylaw banning such pets. Darwin's owner is trying to get him back and move ASAP because the bylaw will not apply to existing pets already living in the region when it comes into effect.
For this post, I'll stay away from some of the stranger aspects of this fight and the exotic pet issue in general, and address one basic question: are rhesus macaques good pets?
That one's easy. No.
Why? There are a variety of reasons.
Number one on the list is Cercopithecine herpesvirus (also known as herpes B, herpesvirus simiae or simply B-virus). This is the macaque version of the herpesvirus that causes cold sores in people. It's very common in macaques, and the vast majority of captive macaques are infected. A problem with herpesviruses is that they hang around for life, being shed intermittently and unpredictably. While this virus doesn't cause a major problem in the monkeys, it can cause fatal encephalitis (brain swelling) in people, most commonly after being transmitted by a monkey bite.
Other infectious diseases are also of concern. Bites are a major issue, both from the trauma associated with them and bite infections from the range of bacteria present in the animal's mouth.
Other injuries can be a problem too. While macaques aren't very big, they're strong and they can be aggressive. Injuries to people can happen from aggressive behaviour or over-exuberant play.
The animal welfare aspect can't be ignored either. These animals have complex care requirements. You can't just lock them in a room, toss in some monkey chow every once in a while, and take off for the weekend leaving the neighbour's kid in charge. These animals need a proper diet and care, and that's not something everyone provide. Stress-associated health and behavioural problems are quite common in pet macaques.
The lifespan of these monkeys also needs to be considered. If properly cared for, they can live up to 25 years. That's a long time to deal with a high maintenance animal. What happens if the owner gets sick or dies, moves somewhere that the animal's not allowed, or for whatever reason can't take care of it anymore? That's true for all pets, but the longer the lifespan, the greater the chance of one of these things happening, and harder it is to get someone to take the animal. It's not too hard for someone to adopt Aunt Edna's 15-year-old cat that rarely leaves the couch and isn't going to be around that long. It's different with a young macaque that's going to live many years and require intensive effort for that entire time.
Similarly, a paper co-authored by people from CDC (Ostrowski et al, Emerging Infectious Diseases 1998) states clearly "The extremely high prevalence of B-virus along with their behavioral characteristics make the macaque species unsuitable as pets."
Darwin needs to go to a good sanctuary or zoo, where he can be a monkey, interact with other monkeys, and have a happy, healthy and species-appropriate lifestyle.
I write a lot about animal bites, and for good reason since they are common and can be very severe. Usually, it’s dog bites. Sometimes it’s cat bites, or more rarely injuries from birds or other critters. Monkey bites not so much, but they happen. I had an email question about rabies exposure from a monkey bite the other day, and there was a paper in the October edition of Emerging Infectious Diseases about monkey bites amongst US military personnel in Afghanistan.
Some highlights of that paper:
From 2001-2010, 643 animal bites were reported by US military personnel.
- More probably occurred since bites are often underreported.
Dogs accounted for 50% of bites, but many other animals were also involved, including rhesus macaques, a type of primate that is present in the wild and also kept as pets in Afghanistan.
- Macaque bites are even more of a concern than dog bites. In addition to the ever-present risk of rabies exposure, these animals can also transmit Macacine herpesvirus B, which is a very serious pathogen that can kill people. Like any animal, macaques also have a wide array of bacteria in their mouths that can cause infections after a bite.
10 monkey bites were reported in this series.
- Most people who were bitten were young (less than 30 years of age) and male. All were junior enlisted personnel or non-commissioned officers.
- Eight of the monkeys that bit were pets, including one that somehow belonged to US military members (despite orders that US military personnel not adopt or interact with local animals or pets).
- Appropriate wound care was provided following only six of the bites. So, there are deficiencies in understanding basic first aid following bites.
- Only five people received appropriate treatment for herpes B exposure. That’s a concern because of how serious this infection can be.
- Eight received antibiotics. Antibiotics are only indicated in a subset of bites, mainly based on what part of the body is bitten, so it's not clear whether this was really needed (while more concerning issues went unchecked).
- Eight received treatment for rabies exposure.
- No one got sick, fortunately.
Monkey bites aren’t something that most people need to be concerned about in their daily lives, but they are a concern for people living in areas where there are monkeys, as well as those who visit such areas. (I have a vivid memory of swinging a camera case at a monkey in Barbados that for some reason seemed to be less than impressed with my existence).
Bites happen, but some are avoidable. Common sense can reduce the risk. If common sense isn’t enough and you’re bitten, don't panic, but you also can't ignore it. After thoroughly cleaning the wound, it's important to get medical advice about what diseases are of concern and whether anything else can or needs to be done. Physicians working in foreign countries also need to be trained on geographically-relevant risks. Monkey-associated infections are not high on the curriculum of US medical schools, so geographically-relevant training is required for people heading elsewhere to work.
With the lingering NHL strike, TV networks are looking for replacement sports. One of my PhD students (who claims he doesn't spend too much time playing around on the internet but keeps coming up with these gems) sent me information about one sport that's not coming to a network near you.
Yes, it's ferret legging. That doesn't really seem like a sport to me...more like a fetish or something someone might do when they're really (really!) drunk. Yet, it apparently exists, evolving from its origins amongst Yorkshire coal miners to a not-much-broader audience.
The rules are pretty simple:
- Tie your pant legs securely around your ankles
- Let someone toss two ferrets down your pants.
- Secure your belt.
- Stand there until you can't take it any more.
"Clean the abrasions thoroughly and hope they don't get infected" is the step no one describes. Wounds are, not surprisingly, common, and some people, like world record holder Reg Mellor, wear white pants to show off the blood strains. Mr. Mellor's world record? 5 hours and 26 minutes.
Interest in ferret legging is dwindling, which is probably a good thing for both ferrets and competitors. There's no mention about whether there are any ferret legging family dynasties, but I suspect that regularly shoving sharp-toothed ferrets down your pants severely limits one's chances of reproducing. That's also good for ferrets and humans alike.
An attempt to be inclusive and create a women's competition involving sticking ferrets up a blouse apparently failed - likely due to relative differences in common sense amongst the genders.
Earlier this year, a troop of Boy Scouts in the US beat off a rabid beaver that was attacking their leader (I wonder if there's a badge for that). Boy Scouts and infectious diseases are in the news again, but not with as happy a story.
In the recent incident reported on ProMED, ten Boy Scouts that attended a camp on the banks of the Semois River in Belgium developed leptospirosis - a potentially severe bacterial infection caused by Leptospira bacteria. The bacteria are shed in the urine of a variety of animal species, and people can become infected through contact with contaminated water or animals. The boys reported having played with a rat, which was likely actually a muskrat, based on the description of its size.
Three of the boys were hospitalized. Hopefully all are on the way to recovering.
This is yet another reminder that wildlife should be left alone. It's possible the boys were infected from the environment, but handling a muskrat (which was presumably sick if they were able to get that close to it) certainly increases the risk of exposure to a variety of infectious diseases.
Image of a North American muskrat (photo credit: Linda Tanner)(click image for source)
a) there are more rabid beavers these days,
b) rabid beavers have always been around in these numbers but they have recently acquired a taste for human flesh, or
c) it's just a fluke,
The latest incident involved a beaver in West Springfield, Virginia that chased after some kids at a nature centre. The kids had been swimming and saw a beaver swimming towards the dock. It's not that unusual to see beaver's swimming around in some areas, but like most wildlife, they typically stay away from people. Not this one though. It "leaped out of the water onto the dock, acting aggressively and chasing the children." Police shot the animal and testing confirmed it was rabid. Presumably, no one required post-exposure treatment since there were no bites.
While rabid beavers are rare, this and earlier incidents involving attacks by rabid beavers, otters and other critters highlight some basic principles regarding rabies safety:
- Stay away from wildlife.
- Mammalian wildlife that are acting abnormally, including displaying no fear of humans, should be considered rabid until proven otherwise.
- Any bite by a wild mammal should be considered a potential rabies exposure. The animal should be tested whenever possible and if it can't be shown that the animal wasn't rabid, it must be assumed that there was rabies exposure.
Common sense goes a long way toward avoiding rabies exposure, but sometimes it's not avoidable. Knowing what to do in the event of a bite from a wild and potentially rabid animal is important. The key is involving physicians and public health personnel who understand rabies exposure risks, so that a proper risk assessment can be done and treatment can be started promptly if it's indicated.
Image: A North American Beaver (Castor canadensis), by Laszlo Ilyes (click image for source)
The annual US rabies surveillance report has been published in the latest edition of the Journal of the American Veterinary Medical Association (Blanton et al 2012). There's not really anything earth-shattering in it, but it's a good overview of the rabies diagnoses in the US from 2011. As always, it only provides a peek into rabies in wildlife (since only a small percentage of wildlife with rabies get diagnosed and reported) but numbers and trends in domestic animals, along with general wildlife data, provide useful information about the state of this virus in the US. Among the highlights:
- Rabies was diagnosed is 6031 animals and 6 people, from 49 states and Puerto Rico (Hawaii remains rabies-free). This is a 2% drop in animal cases from 2010, but I don't put much stock in that because the numbers are weighted towards wlidlife cases, and it's hard to have confidence in year-to-year numbers of rabid wild animals (because it's so dependent on what actually gets tested).
- The main wildlife species that are involved in maintaining the rabies virus in the US (reservoir species) continue to be raccoons, bats, skunks and foxes on the mainland, and mongooses in Puerto Rico. The relative importance of these species varies between regions.
- Raccoons were the most commonly affected species, accounting for 33% of all rabid animals reported. Other leading species were skunks (27%), bats (23%) and foxes (7%). Less common species included coyotes, bobcats, javelinas, deer, otters, mongooses, wolf hybrids, groundhogs and beavers.
- Cats were the leading domestic animal, with 303 diagnosed cases. Dogs came in next with 70, followed by cattle (65), horses (44), and goats and sheep (12). There were also single cases in a domestic bison and an alpaca.
- The six human cases represent the highest annual number of cases since 1994, if you exclude 2004 where four cases were associated with transplantation of organs from a single infected person. In a review of the 24 domestically-acquired human cases from 2002-2011, 88% were linked to bats.
- Three of the six 2011 human cases were acquired outside of the US; one each from Haiti, Afghanistan and Brazil - and all from dogs.
- Two of the three domestically-acquired cases were associated with bat contact. The source of the remaining case, an eight-year-old girl, is unknown, but contact with cats from a feral colony near the girl's school is a possibility.
- 5/6 people with rabies died. That's actually an impressive survival rate, since any survival is still a very noteworthy event when it comes to rabies. The survivor was the eight-year-old girl, and she apparently has suffered no longterm cognitive impairment.
Interestingly, we get a good synopsis of Canadian rabies data in this report too:
- 115 rabid animals were identified, with 92% being wild animals.
- There were three rabid livestock (two of which were horses) and six dogs and cats.
- No rabid raccoons were identified, continuing a trend started in 2009.
And regarding rabies in Mexico:
- 148 rabid animals were identified, mainly cattle (82%).
- Rabies was diagnosed in 20 dogs, with evidence that the canine rabies virus variant (which has been eliminated from Canada and the US) is circulating in some regions.
- There were three humans cases: two acquired from vampire bats and one from a skunk.
- The Indian River Reptile Zoo near Peterborough, Ontario, rushed some of their stock of snake anti-venom to Brantford General Hospital (about three hours away) to aid in the treatment of a woman who had been bitten by a Copperhead snake. Hospitals in Ontario don't tend to stock anti-venom for snakes that don't live anywhere near here, and it's fortunate for the woman that a couple of zoos in Canada stock anti-venom and are willing to share it (and that those zoos happen to be in Ontario and not the other side of the country). Circumstances of the bite aren't clear but the woman or someone she visited a) is obviously keeping a dangerous snake and b) obviously isn't handling it properly. Indian River Reptile Zoo president Bry Loyst sums up some of the problems with snake bites, saying "Hospitals are amazing but they don't have the expertise right there,” and “You'd be surprised at how many venomous snakes there are out there [in Ontario homes].”
- JayJay, a pet macaque (a kind of monkey) from Okeechobee, FL, was shot after "flipping out" and attacking its owner, "ripping apart his hand." The primate, who wore diapers and played with kids, had lived with the family for nine years, having been acquired at three weeks of age. He got out of the house and his owner was trying to catch him with a net. Whether it was the net, the joy of freedom or some other reason, JayJay lost it and clamped down on his owner's buttocks, thigh and hand, respectively, refusing to let go. A friend had a gun handy (no comment) and shot the monkey at the owner’s behest. The bite on the hand (in particular) was severe and deep, damaging tendons and a nerve, requiring surgical repair. This is another example of the "loving" exotic family pet going berserk for some unknown reason. The macaque often played with kids and the owners took him out in public (e.g. dressing him up and taking him trick-or-treating at Halloween). If we can say anything good about this, it’s good that it was the adult owner who was attacked and not a child. Fortunately, unlike a large percentage of captive macaques, JayJay wasn’t a carrier of herpes B virus, a virus that can rarely cause fatal infections in people. A good closing statement was made by Lion Country Safari wildlife director "Anybody that keeps a monkey is going to get bit... I haven't heard of a monkey that wouldn't bite someone."
- A zookeeper in Berlin, Germany, was killed by a Siberian tiger that had escaped its enclosure. While not a pet, it’s another example of a fatal attack by a captive large cat. As with venomous snakes, there is a remarkably large number of these animals that are privately owned, and attacks certainly happen. Usually, the lucky survivors say it was a "freak incident" and totally unexpected because the animal was like a pet cat. The unlucky ones can’t talk, but often the same story comes from friends and family… the animal was this apparently loving, docile large cat that for some reason attacked. You can never be confident that these animals are safe, because fatal injuries can occur not just with attacks, but with playful behaviour given their size and strength.
- In a related theme, a cougar was shot and killed in Muskoka Lakes, Ontario, after attacking a pet dog. The fact that the cougar had been declawed was a pretty good indication that it was an escaped pet. The owner of Guha's Tiger and Lion Farm, an "exotic animal menagerie" located down the road from where the cougar was shot, says he is not missing any of his cougars, which would "never want to escape" (except, I guess, for the jaguar that was shot by police after escaping in 2008). Since there's no regulation of exotic animals in the province, no one will know for sure from where the cougar came, how many cougars are present in Ontario and how they are being managed. Hopefully Mr. Guha has a containment plan for his other cougars, lions and jaguar that goes beyond assuming they'd never want to leave. If I was a neighbour, I wouldn't be too confident, however, when he says things like "If I leave the gate open for some reason — like I unlock it, then the phone rings so I pick up the phone — if they do get out they’ll go sit by (my front door) and wait for me."
Rabies is most commonly reported in dogs, skunks, raccoons, bats and a few other species. However, any mammal is susceptible, and sometimes unusual cases are identified.
1. In a serious take on Monty Python's "killer rabbit," a rabid bunny has caused a lot of problems in Chom Thong, Thailand.
The pet rabbit, Poko, had been purchased last year and starting biting the feet of people in the family on June 10. The rabbit was eventually put in a kennel and died July 28. The other rabbit in the house died the next day (no word on why). The time frame is a bit strange, since if the rabbit was biting because of rabies, it should have died a lot quicker. Once an animal is showing signs of rabies, death occurs quite quickly (usually within 10 days), not over a period of 7 or 8 weeks. So, most likely the rabbit wasn't biting because of rabies, at least at the start.
In response to the diagnosis, authorities have launched an investigation and 120 health officials are fanning out in the area to look for other rabid animals, since where there is one, the are others. Dogs and cats within 5 km of the rabbit's home are being vaccinated against rabies. Family members are being given post-exposure prophylaxis. The father has expressed concern that the treatment was too late since they were bitten several days before, but it's not really much of a risk. Rabies typically has a long incubation period, especially with bites to lower extremities, and starting treatment a few days (or even weeks, in some situations) after exposure can still be effective (albeit the sooner the better). The key is for treatment to be started before any signs of rabies develop - after that happens there's very little that can be done.
The source of rabies isn't clear and I haven't seen any speculation. If the rabbit was caged, then there aren't too many possible sources, with bats probably being the most likely.
2. Swimmers beware... it's not just rabid otters you need to worry about.
A man swimming in eastern Pennsylvania was bitten by a beaver that was subsequently identified as rabid. The beaver apparently attacked a canoeist earlier that day, before encountering the swimmer, a Boy Scout leader. The man suffered 15 lacerations from the attack, and the beaver remained firmly attached to the man's arm as he was helped to shore. The stubborn critter wouldn't let go until the resourceful (and brave) Scouts got it off by hitting it with "anything they could find around them, sticks, rocks..." The beaver was killed and confirmed as rabid.
It's another reminder that any bite from a mammal should be considered a possible rabies exposure. It's also a reminder to avoid contact with wildlife, although that can be easier said than done when a rabid animal is involved.
We’re fully into petting zoo season now, with these types of exhibits appearing at a variety of agricultural fairs and similar events. This also unfortunately means that we’re into petting zoo outbreak season, since there’s always some risk of disease associated with the type of animal contact people have at these displays. There are some basic measures that can and should be taken to reduce the risk of disease transmission, including proper facility design, selection of appropriate animals, good animal health monitoring, sufficient supervision, and above all, providing adequate hand hygiene facilities. Unfortunately, these measures aren’t always implemented - even the really easy ones - be it due to lack of knowledge, lack of interest or downright negligence.
A recent study in Zoonoses and Public Health (Erdozain et al. 2012)(completed under the guidance of Doug Powell and Ben Chapman of BarfBlog fame… or infamy, if you're a particularly slack regulator or politician) evaluated some important public health-related behaviours and factors at petting zoos in Kansas and Missouri in 2010-2011. They found:
- Handwashing stations and signs were present at the exit of 7/13 petting zoos. Yes, it means the majority had them, but it’s a pretty disappointing number. Providing proper hand hygiene stations is easy to do and there’s no excuse for not having them at the exit. The other 6 petting zoos at least had hand hygiene stations within or near animal contact areas, but that’s not ideal. People need to be able to clean their hands on the way out. Doing it in the middle doesn’t help much, and if people have to go out of their way to perform hand hygiene after leaving, it will rarely get done.
- At one event, there was only a sink with no soap, and at another, 2/3 hand sanitizer bottles were empty and there was no area to wash hands. Having hand hygiene facilities is only useful if they are actually appropriately stocked.
- Signs encouraging hand washing were present at the exit of 10/13 petting zoos, but no signs were present at the entrance or entrance to eating areas at any of the venues.
- There were staff monitoring activities at only 6/13 events. At one unsupervised facility, kid goats were able to escape through the fence and were roaming freely.
- When the researchers observed zoo visitors, they noted that only 37% of individuals washed their hands or used a hand sanitizer when leaving. That’s not really surprising, but it’s disappointing nonetheless. People are skipping the best and easiest way to mitigate what is typically the biggest risk factor for pathogen transmission in petting zoos (i.e. contamination of hands ultimately leading to ingestion of pathogens).
- Visitors were almost 5 times as likely to wash their hands when a staff member was present. That’s consistent with a study we published last year and shows the importance of a little encouragement.
- High-risk animals were present in some petting zoos. These included chicks, young ruminants (kid goats) and (a new one for me) a petting zoo that allowed people to enter an area and pet and sit with tortoises.
- People were allowed into animal enclosures in 7 petting zoos, and not surprising, fecal contamination of the ground was common (petting zoo animals not being house trained).
- Various behaviours that might increase the risk of disease transmission were observed, including kids (the human kind, not the goat kind) touching their faces (77% of events), kids eating or drinking in the petting zoo (15% and 38%, respectively), kids eating petting zoo food (7%) and kids sucking on pacifiers (23%). Children were also seen picking up animal feces at one event.
Overall, despite the lessons that should have been learned from various past outbreaks, numerous deficiencies were present, including many that would take little effort to rectify.
The state of petting zoos, at least around here, has certainly improved over the past decade, in part due to more attention from local public health officials, but how do we get more, sustained and widespread improvement?
More strict governmental regulation and enforcement is one way, but that tends to be slow. The more effective approach is probably one that involves the almighty dollar. Most petting zoos are there to make money or bring people to a bigger event that makes money. Like many issues, if consumers start demanding change, change will occur quickly. Maybe that’s easier said than done, but the more pressure that’s put on petting zoo operators and people who run events where petting zoos are present, the more likely it is that change will occur. Visiting a petting zoo can be a great experience, particularly for kids, but we need to make them as safe as possible. Providing hand hygiene stations, some appropriate well-placed signs, having staff supervise, avoiding high-risk animals and logical facility design are easy and inexpensive, and not employing such simple measures is inexcusable.
In response to Salmonella outbreaks linked to these critters, their popularity as pets for young kids, and efforts to ban them in some areas, we've developed an info sheet regarding African Dwarf Frogs. As with our other info sheets, it discusses the good and bad points of owning these little guys, things to consider when deciding whether to get one, and measures to reduce the risk of infection.
This info sheet, along with many others, can be found on the Worms & Germs Resources - Pets page in the Information Sheets for Pet Owners section.
The old saying is "when you hear hoof-steps, think horses, not zebras." In a medical context, it means common things occur commonly, so don't start off thinking about wild and bizarre conditions before you've ruled out the usual suspects. Along that line, when I hear "rabies," I think "bats, raccoons, dogs, cats, foxes..." I don't think about... zebras.
Considering there aren't that many zebras in Ontario, and even in places where there are zebras, most people don't have a lot of contact with them, it makes sense that zebras don't typically make the rabies suspect list. But that doesn't mean zebras can't get rabies.
A Letter in Emerging Infectious Diseases (Lankau et al, 2012) describes one such unusual scenario. In January of 2011, an orphaned zebra foal was taken in by a safari lodge (that's probably not too unusual of an occurrence), and not surprisingly, tourists were allowed to handle and feed the foal. Unfortunately, the foal was bitten by a dog at the end of July. The dog was suspected of being rabid but it doesn't seem like any changes were made to how the baby zebra was handed. Unfortunately, the foal died at the end of August and rabies was confirmed. Lodge staff tried to contact people who had visited during the July-August time period, mainly through emails to travel-booking agents who (it was hoped) forwarded the information to travelers.
Several US travelers contacted CDC after getting the email and their risk of rabies exposure was investigated.
- CDC obtained names of 243 travelers who were at the lodge, 136 of whom were from the US.
- They worked with the assumption that the outside window for rabies virus shedding by the zebra was a 14 day period leading up to its death. Seventy-seven (57%) of the US visitors had been there during that period.
- Twenty-eight of those visitors had already started post-exposure treatment for rabies. None of those individuals had high-risk exposures, 2 had moderate-risk exposure while the rest had low or no-risk exposures, so treatment would not have been recommended for most of them. That's probably because the information went from the lodge to travel agents to travelers, and then to the peoples' general physicians (who are generally less well versed in rabies exposure issues) rather than through public health.
- The cost of rabies post-exposure treatment is at least $4000/person in the US (although I know of cases where the cost was much higher), so at least $100 000 was wasted, in addition to stress and other factors.
Some take home messages
- People need to think about animal contacts when on vacation. Travelers that go to rabies-endemic areas need to pay particular attention to avoid high-risk contact with animals.
- Facilities that allow animal contact need to protect the public. Rabies vaccination of this foal might have prevented its infection and the subsequent human exposures.
- If an animal has been attacked by a rabid animal, don't let people come into contact with it!
- Rabies exposure is a medical urgency, not an emergency. There's time to make sure things get done right, and public health personnel should be involved in discussions of exposure and treatment.
The outbreak stretched over a long period of time, from 2007-2009, and involved a strain of Salmonella called Salmonella Java. During the course of the investigation, 75 people with S. Java infection were identified, although there were probably many more infected since diagnosed cases are usually the minority of the true total.
Individuals affected ranged in age from 1 month to 60 years, but the median age was only 2 years, which means the majority were very young children. The investigation started to focus on playgrounds and ultimately 207 sand samples were collected from 39 locations. Thirty-five isolates of S. Java were found, all from 6 playgrounds. These playgrounds had all received sand from the same depot over the preceding year, but Salmonella wasn't found in samples from the depot.
To try to find a source, they started testing critters living in the area of parks, and found S. Java in 34 of 261 animals, mainly from long-nosed bandicoots (a marsupial indigenous to Australia).
It's possible that this Salmonella strain is widely present in bandicoots (and other critters) in the area. I don't know their defecation habits, but if they have a preference for pooping in sandboxes (like cats do), they could be contaminating play areas. The other possibility is that the sand was contaminated from some other source and the bandicoots were infected from the sand just like the people. There's not really any easy way to figure that out.
Sandboxes have been associated with various disease outbreaks, but the overall risk is low and it's certainly not a reason to keep kids away from them. Some things that can be done to reduce the risk of potential disease transmission from things in the sand include:
- Supervising kids to prevent them from sticking things in their mouths.
- Making sure they don't eat or drink in the sandbox/playground.
- Making sure they wash their hands after playing in the sand.
- Covering the sandbox whenever it's feasible (not always an option but good if it can be done) to help prevent animals from defecating in the sand.
More information about sandboxes and potential disease risks can be found on the Worms & Germs Resources - Pets page.
Image: Long-nosed bandicoot from Eastern Australia (Perameles nasuta)(click image for source)
Q-fever, a serious disease caused by the bacterium Coxiella burnetii, is an important concern at petting zoos because small ruminants (sheep and goats) are commonly present at these events and they are the major source of this pathogen. The risk is greatest around adult animal at the time of birthing, and around the new lambs and kids (baby goats), because this is when large numbers of highly infectious Coxiella can be shed. That’s one of the reasons why pregnant small ruminants shouldn’t be part of any petting zoo, but unfortunately this particular recommendation is widely disregarded.
Other than petting zoos, the general public can also have contact with small ruminants through various other routes. An outbreak of Q-fever in the Netherlands (a country with serious Q-fever problems) was reported in association with one of these atypical events, namely "lamb viewing days" on a farm (Whelan et al, Epi Infect 2012).
This farm was open to the public every year during lambing season, and attracted about 12000 visitors from the area annually. Visitors could watch lambs being born (if the timing was right) and interact with young lambs. After finding a cluster of Q-fever cases in the region, an investigation ensued, which compared people who were diagnosed with Q-fever in the region to a group of people without Q-fever. Here are some of the highlights:
- 21% of people with Q-fever reported visiting the farm compared to just 1% of controls.
- When various other factors were controlled in the analysis, having visited the farm meant someone was 43.3 times as likely to have Q-fever compared to someone who didn’t visit the farm.
- Coxiella burnetii was identified in numerous sheep, as well as from 7 of 8 air samples collected on the farm. (Coxiella is a very small, hardy organism that can resist drying, and it can therefore often be found in the dust in the air in areas that have a lot of environmental contamination, like pens where goats and sheep give birth.)
- Specific contacts (e.g. holding a lamb, witnessing a birth) were not identified as risk factors, but the small sample size of people that reported what types of contact they had may have limited the ability to detect a difference.
Visiting farms and having contact with farm animals shouldn’t necessarily be considered a high-risk behaviour. In fact, in some ways it’s a good thing. Greater contact between people and animals and a better understanding of farm animals can be very beneficial. However, we’ve known for a long time that some situations pose an increased and unnecessarily high risk. People organizing farm encounters or petting zoos need to take some basic precautions to reduce the risk to visitors. These are pretty simple and can be done without significantly affecting the visitors' experience. Visitors also need to take some responsibility themselves and follow recommendations, like practicing good hand hygiene and keeping food and drink out of animal areas (just to name a couple). Additionally, the more visitors know about risks and preventive measures, the more they can pressure facilities into doing things right. Public health personnel can work hard to try to improve petting zoos and other events, but nothing will change things quicker than an informed public withholding their money from places that put them at unnecessary risk.
Markham, Ontario's city council has passed a bylaw prohibiting the keeping of African Dwarf frogs. While in reality more of a ban on the sale of frogs in the city (since I doubt there will be any effort to search for contraband frogs in households), and perhaps of somewhat limited impact because of the availability of the potentially Salmonella-laden critters in neighbouring areas, not to mention the common practice of pet retailers flouting laws like this, it's nonetheless a step that will hopefully reduce the number of these animals in households.
Why the fuss about African Dwarf frogs?
- Mainly, it's because of the risk of transmission of Salmonella from these frogs to people. Large numbers of Salmonella infections have been linked to these frogs internationally, and the risks are amplified with pets like this that are marketed toward young kids (especially as pets to keep in their bedrooms) and for schools and childcare facilities, because children are one of the highest risk groups for developing salmonellosis.
- The other important issue is animal welfare, since these frogs are often sold in unsuitable habitats and have a fairly limited lifespan in captivity.
Not surprisingly, the owner of the US company that is one of the main distributors of these animals is unhappy with the decision. It's hard to be sympathetic given the fact that they essentially ignore the risks these animals pose to people, at least in the materials they present to the public. Despite the fact that they are marketing what is considered a high-risk animal as a pet, there's little effort put into providing information about that risk or risk mitigation. Looking at their promotional materials, I can find lots of information about how to care for the aquarium. Yet, none of it mentions Salmonella. There's no statement about keeping young kids away from frogs. There's no mention of washing hands after contact with frogs or their environment, or that aquarium water shouldn't be dumped down bathroom or kitchen sinks... or any other basic, relevant infection control practices. They do have some CDC information on their website if you look around, which is better than nothing, but it needs to be more prominent. Everyone that purchases one of these frogs should get a clear information sheet that explains the risk of Salmonella transmission and how to avoid getting sick. Yes, it puts a bit of a damper on the new pet, but a lot less than being hospitalized.
Back in Markham, it's hard to say whether the ban will have an impact on frog ownership because of the ability to buy frogs a few minutes away in neighbouring municipalities, and the likely lack of any real enforcement effort. However, it's a start and if nothing else, and publicity associated with the ban may help educate people. African Dwarf frogs that are already in households are exempt and can live out their natural (albeit often short) lifespans, but people can't replace them when they are gone.
More information about Salmonella can be found on the Worms & Germs Resources - Pets page. We don't have a dwarf frog info sheet (it's coming) but most of the information on the Reptiles info sheet equally apply to frogs.
This time of year, it's very common around here to see young raccoons wandering about. It's also still pretty common to hear about people keeping a litter of baby raccoons in their house. I can understand the appeal - they're cute and entertaining. However, in addition to being illegal in many regions, handling young raccoons also poses a risk of exposure to a variety of infectious diseases.
Chief among the infectious disease risks of handling young raccoons is rabies, as a Walker County, Alabama, family found out. Two baby racoons were found in someone's attic, and another two littermates were found a little while later. The person who found them gave two each to two separate people. As is often the case, they were handled by many different individuals before one of the raccoon kits was found to be rabid. Now more than 20 people are facing post-exposure treatment. It's one of the larger reported exposures from a single rabid raccoon, but it's far from unprecedented.
Beyond the obvious public health concern, this situation demonstrates another possible issue. Rabies is sporadically distributed in some regions, and moving wild animals around leads to the potential for dissemination of rabies, as well as other infectious diseases. Raccoon rabies is present in the area where the baby raccoons were found, but has not been found in Walker County, even though it's not far away. If the rabid raccoon had escaped (or was released), it could have potentially spread rabies into an area where it's currently not well established, thereby increasing the risk of exposure to everyone (animals and people) in the county.
As mentioned above, it's also illegal to harbour wildlife in many regions if you are not a licensed rehabilitation facility. While getting fined seems to be uncommon, four people in this incident have been charged with unlawful possession of a protected animal. Just one more reason not to do this.
While baby raccoons may have some appeal, as Alabama's state veterinarian Dee Jones says, "...people just need to stay away from them."
Ichthyotherapy is a fancy name for sticking your feet in a bucket of doctor fish (Garra rufa) and letting them gnaw on your dead skin. While it's not something I'm planning on doing (for various reasons), it's a popular spa treatment in some areas. It's also spawned (pardon the pun) controversy because of infectious disease concerns. Specifically, spa "instruments" are supposed to be cleaned and sterilized between clients, but you can't really autoclave fish. (Well, you can autoclave fish... just don't expect them to do any more foot grazing when you're done.)
Some people have pushed back, saying there's no evidence that these fish pose any risk, although some infections have been reported. A paper published in the latest edition of Emerging Infectious Diseases (Verner-Jeffreys et al. 2012) provides some interesting new information. It involves an investigation in 2011 by the UK's Fish Health Inspectorate into an outbreak of disease amongst 6000 doctor fish that had been supplied to spas in the UK. The outbreak had a high mortality rate (amongst the fish, not the spa clients) and the bacterium Streptococcus agalactiae (a Group B Streptococcus species) was isolated from sick and dead fish. This bacterial species can cause a range of illnesses in people, but the strain that was found was most closely related to a strain previously found in a sick fish and is not necessarily a risk to people. However, it raised questions about the bugs that may be found in these fish.
Researchers followed this up by doing checks of doctor fish arriving at Heathrow Airport from Indonesia. A variety of different bacteria known to cause disease were isolated from the fish, including some multidrug-resistant bacteria. While it's not particularly surprising, this provides more evidence that most or all of these spa fish are carrying bacteria that can cause disease in people. When people put their feet in water containing these fish (and the fish feces), there's a chance of exposure. Disease seems to be rare, but it can happen, and the risk is probably highest is people with underlying skin disease, as well as people with compromised immune systems.
The easiest way to avoid these risks is to avoid ichthyotherapy. But, if you can't go without your foot fish treatment, how can you reduce the risk? There's no solid information but the following precautions and measures make sense:
- People with cuts, scrapes or other foot lesions should not undergo ichthyotherapy.
- People with diseases that affect their immune system (including diabetes) should similarly avoid close encounters of the fishy kind.
- Consideration should be given to commercially raising pathogen-free doctor fish for spa use under high standards of infection control and hygiene.
- Good management practices to deal with cleanliness of water and health of the fish should be developed and followed.
Fox / dog / human, North Carolina
In this case, a rabid fox had a "direct encounter" with several people, then it was killed by a dog. Three people have started post-exposure treatment.
- The article states that the dog was vaccinated against rabies, which is good to hear. However, it goes on to say that exposed pets need to be euthanized or have a 6 month quarantine. In reality, standard guidelines are that unvaccinated pets are treated like this while vaccinated pets undergo a less rigourous 45 day observation at home. Hopefully the discrepancy is simply due to inaccurate reporting and not misinterpretation of guidelines by local officials.
Cat / human, Maryland
A rabid stray cat scratched five people, who have been urged to undergo post-exposure treatment. Officials are calling for anyone who potentially had contact with this cat go to an emergency room.
- However, odds are if someone goes to an emergency room and says they might have had contact with this cat, they're just going to sit around until someone tells them they don't know what needs to be done, or to go home and deal with someone else. Rabies exposure is a medical urgency, not an emergency. People should take a little extra time to work with their physician and/or public health rather than go to the emergency room.
- People who may have had contact with the cat need a proper assessment to determine if they were potentially exposed to rabies, since just being around the cat or having casual contact is not a risk. Scratches are a bit controversial since they are low risk for rabies transmission (unless the scratches become contaminated with saliva from the animal), and there are conflicting guidelines regarding what to do for a person who is scratched.
- This is also a good reminder to stay away from stray cats.
Fox / human, Pennsylvania
In this report, authorities are trying to find a person that cradled an injured fox in a blanket. The fox was subsequently identified as rabid and they need to determine whether the person was potentially exposed to the virus.
- Again, another reminder to stay away from wildlife, and if there is contact with wildlife, make sure rabies exposure is considered.
Bat / human, Indiana
A student was bitten by a rabid bat while he slept in an Indiana University dorm room. He woke up after being bitten (good thing, since he probably wouldn't have noticed otherwise due to the often tiny marks left by a bat bite). He is now receiving post-exposure treatment.
Rabies isn't going away, at least any time soon. People need to be aware of the risks in rabies-endemic areas, take care around wildlife and vaccinate their pets.
Photo credit: Rob Lee (click for source)
Don't tell Samuel L. Jackson (Snakes on a Plane was bad enough), but on August 2011, a bat was found flying through the cabin of a plane shortly after take-off from Wisconsin. Failing to heed the seat belt sign, it flew around the cabin a few times before it was eventually trapped in a bathroom. The aircraft then returned to the Wisconsin airport...vnot sure whether that was because they were worried about the bat or because they didn't have an available bathroom any more.
Unfortunately, when they got back to the airport, no one thought to close the plane door before opening the bathroom door, so the bat flew out of the bathroom, out of the plane, down the jetway, through the airport and was last seen exiting the airport via automatic doors (smart bat). The problem with the bat's escape is there was then no way to determine whether it was rabid, since even bats with a good sense of direction can be shedding the virus. Because of that, it had to be assumed that the bat was rabid and an investigation ensued.
The Wisconsin Department of Health called the CDC for assistance and a standard investigation was undertaken. A key component was to determine who, if anyone, was potentially exposed to rabies, assuming the bat was carrying the virus. Rabies is spread through direct contact of saliva from an infected animal with broken skin or mucous membranes (e.g. mouth, nose). Most often, this occurs via a bite. Being in the same area as a bat doesn't constitute a risk.
A rabies investigation typically involves interviewing people who were in the same area as the bat to see if they had any contact with it. That was done, but it was complicated by "difficulties obtaining an accurate passenger manifest...". (Considering it seems like I have to do everything short of depositing a DNA sample to fly to the US these days, I can't fathom how they couldn't have a list of who was on the plane.)
Anyway, the airline gave the CDC a list of 15 people that they knew were on the plane and 33 who had reservations (but apparently they didn't know for sure whether they were on the plane). Considering 50 passengers were on the plane (not counting the bat), that left a few unknowns, which was compounded by their finding that some people who had reservations confirmed they were not on the plane. They tried various ways to contact people, but ultimately ended up with 5 mystery passengers.
Fortunately, the risk of rabies exposure in this case is low. All 45 of the contacted passengers reported having no direct contact with the bat, and it's very unlikely anyone else did given the description of what happened. Similarly, none of the pilots (hopefully it was easy to figure out who they were) and other flight or ground crew reported any contact.
An environmental assessment was performed to see if there was a bat problem at the facility, and nothing out of the ordinary was found. They made a few recommendations to reduce the chance of this happening again:
- Use of netting to cover crevices in the airport where bats might roost.
- Extending and retracting jetways before the first flight of the morning (I guess to scare the bat out before a plane is hooked up).
- Training employees on bat capture methods.
- Testing any bats for rabies.
So, it was more of an interesting story than a true disease concern, but with rabies, you have to be thorough to convince yourself that there's no risk.
It also seems like this bat was much more organized than the airline.
Max, a 12-year-old Chihuahua from Greenfield, New Jersey, was euthanized recently after he was exposed to rabies. While far from unusual, the case highlights the ongoing risk of rabies exposure as well as issues with understanding of rabies guidelines and communication.
Max was attacked by a rabid raccoon - an ever-present risk for animals that go outside (or get outside) in many regions. Animal control was called and the raccoon was caught. It was euthanized and rabies was confirmed, indicating that Max was very likely exposed to the virus.
Here's where things seem to get strange. The paper reports:
"Once exposed to a rabid animal, a six-month quarantine is required for the exposed animal, even those animals that have been inoculated with a rabies vaccine."
- Not really. In Canada, standard guidelines are for a 6 month strict quarantine for dogs (and cats) that are not properly vaccinated, but only a 45 day observation period is required for vaccinated animals. I don't know if in this jurisdiction they made up their own different rules, whether someone doesn't know what's supposed to be done or whether it's poor reporting, but it's a concern because it can be a difference between life and death... not necessarily from rabies, but from the quarantine requirements alone. People are often unwilling to undertake a strict 6 month quarantine and choose euthanasia (as was the case here), while the 45 day observation period is much more acceptable.
The attending veterinarian stated "Because of the way it was exposed and because of the positive, I think there was a really good chance this dog was going to get rabies".
- It's certainly possible, and nowhere does it say whether Max was properly vaccinated. However, there's a reason we vaccinate. It's a highly effective vaccine and we're trying to prevent disease. Nothing's 100%, but with proper vaccination, the risk of rabies is greatly reduced.
It's also stated that "due to the nature of rabies, until behavioral changes occur, the animal is not infectious".
- While this doesn't have anything to do with Max's situation, it's not true. Animals can shed the virus for a short period before they show signs of illness. That's the reason there is supposed to be a 10 day quarantine period after a dog bites someone - to see if the dog develops signs of rabies (which would have major implications for the person who was bitten).
Curiously, the article ends with a reminder to vaccinate pets, which seems kind of strange if their assumptions are that an exposed animal will get sick irrespective of vaccination status and that vaccination will have no impact on what happens to an animal after exposure.
However, despite the miscommunication, the take-home message emphasizing the need for vaccination should be heeded. As well, people making decisions about what to do after rabies exposure should make sure they do so based on the best evidence that's available, namely the Compendium of Animal Rabies Prevention and Control.
At this time of year, I start to see ads from local feed supply stores about annual chick sales. Overall, it's not a big deal and most people that buy chicks don't have problems. However, it can be a particular concern for certain high risk groups, particularly young children, and outbreaks of salmonellosis are a recurring issue.
Contact with young poultry is considered very high risk for Salmonella exposure, since Salmonella shedding rates amongst the little guys are pretty high. Most outbreaks of salmonellosis disproportionately involve young kids, due to a combination of increased handling, poor hygiene and inherent increased susceptibility of young kids to infection. The problem is that sometimes people buy chicks because their young kids want to raise and handle them. Outbreaks associated with sales of young chicks, as well as hatching chicks in schools and daycare, have been reported.
A recent CDC report describes yet another multistate outbreak of Salmonella, this time associated with a mail-order hatchery.
The outbreak occurred from February to October 2011 and was first noticed through lab-based identification of clusters of Salmonella Altona and Salmonella Johannesburg. Ultimately, 68 cases of S. Altona and 28 of S. Johannesburg infection were identified in 24 states. Here are some highlights:
- 32% of people with S. Altona and 75% with S. Johannesburg were kids 5 years of age or younger.
- 74% of people with S. Altona and 71% of people with S. Johnannesburg reported recent contact with young poultry.
- Most people that had poultry contact reported purchasing chicks or ducklings at local agricultural feed stores. These stores got the chicks and ducklings from a single mail-order hatchery.
Mass production of animals for widespread distribution, whether it's guinea pigs like I wrote about the other day, or chicks and ducklings here, increases the risk of widespread outbreaks because a single focus of infection can have far-reaching effects.
Mass production and mail-ordering of chicks isn't likely to stop, so what can people do to reduce the risk?
- Keep high-risk people (that is kids 5 years of age or less, elderly individuals, pregnant women and people with compromised immune systems) away from young poultry. This includes keeping chicks out of schools, where hatching chicks is still performed in some areas.
- Use good hygiene practices when handling chicks or anything in their environment. Assume that all of the chicks are shedding Salmonella and treat them accordingly. By that I mean use good general hygiene practices, particularly hand hygiene, to reduce the risk of exposure.
- Stores selling chicks should also provide basic safety information to inform and remind people to use appropriate practices to reduce the risk of infection.
It's been a while since I wrote about petting zoos. Part of the reason is that the state of petting zoos in this area has improved quite a bit over the past few years, so I haven't been coming home from fairs or other events with a need to vent. However, improvements are not universal, and even with improved conditions, there are always going to be disease risks associated with petting zoos and other events where people have contact with animals.
This week's edition of Morbidity and Mortality Weekly Reports (a rather gruesomely named but very interesting publication by the US CDC) describes a 2011 outbreak of E. coli O157 from a North Carolina State Fair. After receiving reports of infections in four people who had attended the fair, an investigation was launched. Here are the highlights:
- A total of 25 suspected cases were ultimately identified. (Usually, there are many more milder cases that go undiagnosed). Stool samples were collected from 19 of these individuals and the same strain of E. coli O157 was confirmed in 11 of them.
- Affected people ranged from 1-77 years of age.
- Eight people (32%) were hospitalized. Four of those had hemolytic uremic syndrome (HUS), a severe form of disease caused by E. coli O157.
- When compared to people who did not get sick, having visited one of the buildings were sheep, goats and pigs were housed for livestock competitions was the only risk factor identified. While the public was not supposed to have contact with animals in those buildings, 25% of people reported having had direct contact with animals anyway.
An investigation like this often can't determine the source of the pathogen with 100% accuracy, because the investigation occurs after the fact (sometimes long after). That means the animals aren't around anymore for testing, the area/fair may have been cleaned up already, and people may not completely (nor accurately) recall exactly what they did. Regardless, it's quite suspicious that contact with this particular building was the root of the problem. How people became infected isn't clear. Some had direct contact with animals, and that's an obvious potential source. Cattle are the most common source of E. coli O157, but it doesn't appear that any were present in the building. Sheep and goats are a more likely source than pigs. Other people could have been infected through contact with contaminated surfaces in the building, something that has been documented in other outbreaks.
After a large 2004 petting zoo outbreak at this same fair, the state passed a law (named Aedin's Law, after a child who became seriously ill) that set strict requirements for animal exhibits where contact with the public is intended. This facility was not subject to Aedin's Law because animal contact was not intended (even though it was apparently common) and a multiagency task force is looking into additional measures for exhibits where animal contact might occur.
Cost/benefit is an important issue when it comes to infectious disease control. There will always be some risk of disease when interaction with animals is allowed. We can take measures to reduce the risk, but never eliminate it. Therefore, the key is maximizing the benefit and minimizing the risk. Animal contact at fairs and similar events can be very rewarding for some people, so most people will accept some degree of risk. This outbreak involved a relatively small number of people, particularly when you consider approximately 1 million visitors attended the fair. The infection rate was really very, but with a potentially life-threatening disease, it's not something that should be ignored.
As is the case here, infection control is often reactionary, with changes only taking place after problems occur. However, it's good to see that actions are being taken (at least in NC) to reduce the risk of this happening again.
Sometimes poor quality papers get published, like the one I wrote about yesterday. Other times, published studies have no impact on science… and occasionally, that’s done on purpose. Two recent studies highlight the latter group and show that, while surgeons may have too much time on their hands, some at least have a sense of humour.
A "groundbreaking" study by Dr. Denis Verwilghen and friends was just published in the Veterinary Record, entitled “Investigation of the best suture pattern to close a stuffed Christmas turkey”. Their randomized trial involved assessing skin disruption scores and the cosmetic appearance of 15 stuffed turkeys that were closed with one of five different methods. Their conclusions: Before cooking, both the Utrecht suture pattern and surgical staples provided the best cosmetic result. However, after cooking and removal of the suture or staples, the skin only remained intact in the surgical staple group. Surgical staples are also a lot easier and quicker to place, so if you have a surgical stapler on hand, pull it out for your Christmas turkey. Beware though: the authors made sure to remind everyone that skin staples are not digestible. Maybe we need a surgical checklist for turkey preparation that requires the cook to record the number of staples that go in and are later taken out.
There was also a study published in the British Medical Journal (Subramanian et al, 2011) entitled "Orthopedic surgeons: as strong as an ox and almost twice as clever? Multicentre prospective comparative study." This authors investigated the standard claim that orthopedic surgeons are "strong as an ox but half as smart." The study (conducted by surgeons, so I have to wonder if they made up some of the data) involved comparing dominant hand grip strength and intelligence test scores of orthopedic surgeons and anesthetists. The end result? Orthopedic surgeons have a higher mean intelligence score and higher mean grip strength.
There are 3 possible explanations:
- Surgeons really are smarter than we think. That may not be an acceptable answer since, as an internist, I’d have to make up a new series of surgeon jokes.
- Anesthetists were a bad control group. The surgeons may have feared going up against their internal medicine counterparts, and therefore decided to compare themselves to the anesthetists instead.
- They lied. Although, if they really are only half as bright as an ox, they must have had help.
A South Carolina woman has been identified as the first case of human rabies in the state in the past 50 years. Very little information has been released, including whether or not she is still alive. Unfortunately, the odds are quite low that she survived. Successful treatment of a Wisconsin girl in 2004 using a radical new protocol was accompanied by much optimism for treatment of this disease, which at the time was described as invariably fatal. While a few other survivors have been reported, rabies is now often referred to as almost invariably fatal, since the protocol has not been the panacea that it was hoped to be, and death is still the typical outcome.
In the latest case, exposure to a bat in the home a few months earlier was the suspected source of infection. This is a common source of exposure and a typical time frame. Few details are presented, so it's not clear whether the woman was known to have been bitten by the bat or whether that's suspected for some other reason (such as lack of other possible sources).
This is another indication of the care that needs to be taken around bats. While human rabies is fortunately very rare in Canada and the US (it causes tens of thousands of deaths each year worldwide, mainly from dogs in a few developing countries), bats are an important source of exposure. Any encounter with a bat needs to be accompanied by a determination of whether there is a risk of rabies exposure. Anyone bitten by a bat should try to make sure the bat is caught and tested for rabies, because otherwise there's no way to prove it wasn't rabid, and post-exposure treatment would be indicated.
Image: Bat bites can be very dangerous, because they carry the risk of rabies transmission, but they can be so small that they may not even be detected. (Image source: http://agrilife.org/batsinschools/responding-to-a-bat-bite/)
One problem with keeping uncommon animal species as pets is that we don't know much about them from an infectious disease standpoint. Some species end up being pretty low risk while others end up causing unexpected infectious disease challenges.
A Texas family found this out the hard way, after their 16-year-old daughter got sick after being bitten by a kinkajou. Kinkajous are strange little critters that are somewhat related to raccoons. Paris Hilton helped fuel the kinkajou fad a few years about after she adopted one (and was bitten by it shortly thereafter). They tend not be be good pets because they are nocturnal and can be antisocial or aggressive during the day (like a lot of people that are kept awake when they want to be asleep).
I wrote earlier this year about concerns regarding the raccoon roundworm, Baylisascaris procyonis, in kinkajous. This more recent report involves an infection that set in after the Texas girl was bitten by her aunt's six-week-old kinkajou. Within 24 hours of being bitten, the girl was severely ill and ended up in hospital for six days. She was treated with antibiotics and responded to treatment.
Because "kinka-what?" was the response to being told that the girl had been bitten, the family and their doctors researched diseases that might be associate with kinkajou exposure. One thing they found was a bacterium called Kingella potus, which was recently found in kinkajous (and subsequently in people with kinkajou bites). Nowhere in the news report does it actually say that this bacterium was identified in the girl, so it's unclear what really happened.
This is yet another example of what can happen when people buy pets that neither they nor the veterinary and medical communities know much about. The recent debacle in Ohio that culminated in the deaths of a large number of exotic animals was a high profile example of the weak to non-existent laws (or enforcement) pertaining to exotic animals in many areas, something that continues to put both animals and people at risk.
We seem to be seeing more canine papillomavirus cases in dogs in the area as of late. It isn't a high profile disease - the virus doesn't typically make dogs sick, it usually just causes warts. Whether there is actually an increase in cases or we're simply looking for them more carefully is unclear, but it may genuinely be on the rise.
Canine papillomavirus can cause a range of skin problems in dogs, typically warty lesions (papillomas) that go away over time without specific treatment. Usually, a small to moderate number of warts are found in the mouths of infected dogs (see picture right). Sometimes, the lesions can be large and extensive, causing problems and requiring surgical removal. Most often (like warts in people), it's merely a cosmetic issue that goes away eventually, but it may take months. Depending on the size and extent of the lesions, and whether they are growing or causing problems, treatment may be recommended. This can include crushing a wart to try to stimulate the body's immune response, or topical administration of certain drugs. Complete removal of the lesions surgically should be curative.
Canine papillomavirus is spread by direct contact between an infected dog and a susceptible dog. However, because it tends not to cause severe disease, this virus doesn't get a lot of attention in the research world. However, a recent study (Lange et al J Clin Microbiol 2011) has provided more insight into the virus. In the study, researchers evaluated different ways to identify the virus. They then tested 95 healthy dogs at the University of Zurich and identified viral DNA on the skin or in the mouth of over 50% of the dogs. Whether these healthy dogs pose a risk to others is currently unclear, but it suggests that the virus could be transmitted not only from dogs with skin lesions, but from a large number of normal, healthy dogs. If that's the case, control will be a lot harder, since focusing on just the "sick" dogs (the ones with skin lesions) would miss a big pool of potentially infectious animals.
It's important to note that people cannot be infected with canine papillomavirus, nor can dogs be infected by papillomaviruses from other species.
Image from: www.marvistavet.com
Here’s a recent question I received:
"My problem is that the raccoon broke a window, came into my house, ate the cat food and then defecated on the kitchen floor. Since they went a day without food, the cats may have eaten the few bits of food that were left behind. How can I tell if they got the roundworm?"
It’s a reasonable question given the concerns about Baylisascaris procyonis, the raccoon roundworm. However, there’s basically no risk. While it is very likely that the raccoons were shedding roundworm eggs in their feces, those eggs are not immediately infective. Ingesting a "fresh" roundworm egg isn't a risk. Eggs have to sit around in the environment for at least 11 days (typically 14-28 days) before they become infective. Therefore, unless the feces are allowed to sit around in the house for a couple of weeks, roundworm infection isn’t a concern in such a case.
Having pets in school classrooms is a somewhat controversial subject. For every good point that's raised (e.g. promoting empathy, entertainment, learning about animals and their care) there are bad points (e.g. poor environment for the pet, rough handing, disorganized or absent medical care, disease transmission, fear, allergies, distraction). Some organizations have developed detailed guidelines for using animals in classrooms, but animals are often in classrooms with little consideration of the issues. Little is known about what happens with these pets. We tried to do a survey of teachers from some school boards a few years ago and only ended up getting about two responses out of hundreds of eligible teacher participants (the overall lack of support from board administration didn't really help get the survey out and get teachers interested either, but that's another story). So, we really don't have a good idea of the types of animal contact that occur in classrooms or the problems that result, but we know from various case reports that complications like infections can and do occur.
PetSmart and the Pet Care Trust have a "Pets in the Classroom" program where kindergarten to grade six teachers can get support for having a pet in the classroom. Their release outlines a few of their perceived benefits, and some of the complexities of having pets in classrooms. Their points are in italics, with some comments from me.
Hamsters make fun classroom pets because they are active and teach children the importance of schedules and responsibilities.
- Yes and no. They can be entertaining, but they can also be distracting. You have to differentiate something that's a novelty from something that is being used as part of the educational curriculum. Hamsters can be injured with rough handling by young children and close supervision is required. They may also bite when handled, especially when handled by young kids who don't know what they are doing. Plans to take care of the hamster over holidays and the summer are needed, and are often not considered in advance. The disease risks of hamsters are relatively low, but not non-existent. Having nocturnal animals in a busy daytime setting is also questionable ethically.
Guinea Pigs are easily handled and encourage children to follow a regimented routine.
- They are similar to hamsters in their benefits and risk, but their larger size makes them more robust and less prone to handling injury. They are probably one of the better mammals to have in a classroom, but still require good organization, planning and practices.
Fish are a great way to illustrate basic chemistry and biology principles while students follow regularly scheduled water changes.
- Fish can be great classroom animals. There are ways to incorporate them into the curriculum, from behaviour to animal care to feeding to water quality and environmental concerns. They need some care, with regular feeding and proper water maintenance, but with basic supervision and planning, the risks to the animals and people are minimal and they can be of benefit educationally.
Bearded Dragons depend on their environment for heating and cooling and are a great way to teach about geography and the environment.
- Bearded dragons (see image) are great little reptiles with a lot of personality. However, they have specific requirements for care and feeding, something that cannot be easily fulfilled in a lot of classrooms. Also, being reptiles, they are high risk for Salmonella shedding. In a low risk household, it's not a big deal with basic hygiene practices. However, in a classroom with lots of kids, perhaps limited enforcement of hygiene, and kids eating in the area where the reptile is, the risks get higher. General guidelines are that children less than five years of age and people with compromised immune systems should not have contact with reptiles. This means they should not be in kindergarten classrooms or rooms where such students may spend time. More complicated is the issue of immunocompromised individuals. I'm not convinced that teachers always know when one of their students is immunocompromised, and what happens if there's an established pet and a student becomes immunocompromised? Bottom line: Reptiles shouldn't be in classrooms.
Leopard Geckos are docile in nature and teach children about different nocturnal behaviors.
- These are interesting little critters, but not good classroom pets, like other reptiles, for the reasons outlined above. Nocturnal pets may not be great for classrooms either since the daytime activity and disruption may be harmful to them in the long term.
Certain pets can be good additions to certain classrooms, with some logical planning and common sense, but poor planning and bad animal choices can be harmful to students and animals. School boards should be proactive and develop or adopt sound protocols for classroom pets.
I've written numerous times about risks (mainly infectious disease risks) associated with some types of exotic pets. I'm not against all exotic pets, but I am against keeping improper pets and doing so in improper situations. The latter largely involves keeping species at high risk for certain pathogens like Salmonella in households with high-risk people (e.g children under five years of age and people with compromised immune systems). The former involves keeping pets that are just not appropriate as pets because of they are large, hard to care for or venomous, or where keeping them in captivity is otherwise risky to either the owner or the pet.
Some good examples of these issues were reported this week:
- English snake "expert" Luke Yeomans died after being bitten by one of his pet king cobras. He kept 24 snakes in a compound behind his home and was planning on opening the space up to the public. He had stated that the trust he had built up with the snakes by feeding and caring for them ensured they would not turn on him. Famous last words.
- A South Dakota man was bitten by his (or a visiting relative's... there's some controversy) pet copperhead snake. Along with what was characterized as an "exceedingly painful bite" he could face criminal charges for owning a dangerous animal. Fortunately, copperhead bites are rarely fatal, but they are far from pleasant. One expert described it as "go ahead and light your hand on fire and put the fire out with a hammer for several weeks."
- A Florida man (note a gender bias here?) was bitten by his African Puff Adder. Neighbours heard his screams of "Help, my fingers are turning black!" as the ambulance arrived. Fortunately, a local serpentarium met them at the hospital to provide anti-venom to counteract the venom from this somewhat small but bite-prone snake that accounts for more than 50% of snake bite deaths in Africa.
- A Putnam Lake, New York woman was found dead in her bedroom, with the prime suspect being a pet Black Mamba, one of 75 snakes she and her boyfriend kept. Black Mambas are described as one of the fastest and most venomous snakes in the world, a great combination for a predatory snake, not a good combination for a pet.
Some people may argue that these incidents are Darwin-in-action. However, while people have some degree of right to be stupid, they don't have the right to put other people at risk. There are too many instances of dangerous exotic pets escaping, with potential risk of exposure of members of the general public. At the moment, Ipswich, UK police are on the search for a 7.5 foot boa constrictor that's on the loose. They've warned that children and pets should be kept indoors, particularly since the owner describes the snake as "unfriendly" at the best of times and, having last been fed 3 weeks ago, "is due a feed." The risks to the public are limited, but people have been killed by pet constrictors in the past, so erring on the side of caution and awareness is justified.
Yes, exotic pets can be interesting and unique. People are sometimes attracted to something new and different, but often it's the 'look at me!' aspect of having something completely different. However, novelty should not be a justification for keeping pets. Our ability to safety and humanely take care of them, and manage potential risks to the public have to be part of the equation.
Image: A Black Mamba (Dendroaspis polylepis) (source: http://en.wikipedia.org)
The Tennessee Aquarium in Chattanooga is being sued for $2.4 million by the parents of a child who allegedly acquired an infection after petting stingrays and sharks. The news report contains very little information, but the reference to "fish-handler's bacteria" means the infection was presumably caused by the bacterium
The US CDC is investigating yet another multistate outbreak of salmonellosis associated with contact with chicks and ducklings. As of June 18, 39 people have been diagnosed with Salmonella Altona infection (with a large number of others presumably infected, since only a minority of cases tend to be diagnosed). People in at least 15 states have been affected, as indicated by the map on the right.
Reported cases so far occurred between February and the end of May, but the outbreak could still be ongoing. Of all the affected individuals, 28% have been hospitalized but there have been no deaths.
Outbreaks like this lead to investigation of possible sources, starting with the usual suspects of high-risk foods and animal contact. In interviewing people that became sick, 81% of them reported having contact with live poultry before getting sick. In people that identified the type of poultry, all reported contact with chicks, ducklings or both. All 19 people that provided information about the source of chicks or ducklings reported getting them from different locations of a nationwide agriculture feed store (which is not being identified). The same strain of Salmonella was isolated from ill people and chick/duckling displays in two store locations. A single mail-order hatchery was then identified as the source of the animals.
Large distributors of animals, especially high-risk animals like chicks and ducklings, can be the sources of large outbreaks since they can supply large numbers of infected animals to a large region. While cute, chicks and ducklings are high risk for carrying Salmonella and they can shed large numbers of Salmonella in their feces without showing any signs of disease. That's why standard recommendations are that high risk persons (e.g. children less than 5 years of age, immunocompromised or elderly individuals) should avoid contact with baby poultry.
In the context of this outbreak, since the store is not being named (and since it's possible the hatchery sent chicks to other sources), anyone who has had contact with chicks and ducklings needs to be aware of the potential for Salmonella exposure. In reality, this is also true outside of the context of this outbreak, since Salmonella exposure needs to be considered after any contact with chicks and ducklings. It doesn't mean that people who have had contact with baby poultry should go to the doctor, get tested, or do anything different. However, it is important that people notify their physician about poultry contact should they get sick. For more information about reducing the risk of Salmonella exposure from poultry, click here.
An article in the May/June edition of Canadian Vet Newsmagazine (a magazine, not to be confused with Canadian Veterinary Journal, a scientific journal), described an interesting case of an indoor pet bird acquiring an infection from a wild raccoon, despite no direct contact.
The bird was an African Grey Parrot that was admitted to the Ontario Veterinary College because it had developed neurological abnormalities over the preceding few weeks: a head tilt, unsteadiness and problems climbing. Infection of the brain caused by the raccoon roundworm Baylisascaris procyonis was suspected and treatment was started, however unfortunately (but not surprisingly) the bird continued to deteriorate and was eventually euthanized. Baylisascaris infection was confirmed at necropsy.
Baylisascaris procyonis, the raccoon roundworm, is extremely common in raccoons, with the majority of raccoons in some areas shedding the eggs of this parasite in their feces. The eggs are extremely hardy and can survive for long periods of time in the environment. The tendency of raccoons to defecate in the same areas (raccoon latrines) means that very high concentrations of eggs can be found in some spots. While this is a raccoon-origin parasite, it can occasionally cause infection in other species (including people and dogs, albeit very rarely). After ingestion of the parasite eggs, the eggs hatch and parasite larvae migrate through the body, causing damage to various tissues as they go. If they migrate through the brain, severe neurological disease can occur.
An interesting aspect of this case is the fact that it was an indoor parrot. If this was a dog that had been exposed to a raccoon latrine, while it would have been a rare occurrence of disease, the origin of infection would have made sense. Here, the parasite eggs had to somehow make it into the house and then into the parrot. The suspected source was branches that were collected from the backyard and placed in the bird's cage. The branches were presumably contaminated with Baylisascaris eggs, and the bird ingested some while chewing on the branches.
This is a very rare situation, but the article includes some basic recommendations:
- Never adopt a raccoon (for many reasons beyond the Baylisascaris risk to pet birds).
- Don't keep parrots in outdoor enclosures where raccoons have access.
- Don't put parrots in outdoor enclosures that may have previously housed raccoons.
- Avoid putting objects from raccoon-inhabited areas into parrot cages or treat them to kill eggs. Heating objects to 62C for 1 minute should kill any eggs that are present.
- Ensure that cage bedding and bird feed are not potentially contaminated with raccoon feces.
A California teen has been battling a chronic and severe infection acquired from a fish tank. Five years ago, Hannele Cox cut her hand when she pulled it out of an aquarium. It sounds like it was a pretty minor scratch, but it doesn't take much to cause an infection under the right circumstances.
A while after the injury, infection was apparent. A round of antibiotics didn't fix it (no word on whether any bacterial cultures were performed at that point). Eventually, a dermatologist diagnosed the problem: Mycobacterium marinum infection. One problem with infections like this is that they are sometimes not diagnosed until they are quite advanced. If the patient doesn't mention the aquarium exposure and/or the physician doesn't ask about pets, an infection like M. marinum might not be considered.
Mycobacterium marinum infection is sometimes called "fish tank granuloma" in testament to its common association with fish tanks. It can be found in both freshwater and marine fish (and the water in their tanks), and most often infected fish don't have any signs of disease. Therefore, you have to assume that any fish and any aquarium could be infected, and therefore a potential source of human infection.
Infections with M. marinum usually develop a couple of weeks after exposure and are characterized by small bumps (papules) on the skin that progress to shallow ulcers. Typically, infection is not very invasive and responds to treatment, although months of treatment may be required. Sometimes, the infection can spread to deeper tissues, making it much harder to treat. Unfortunately, that's what happened to Hannele Cox. Her infection has not responded well to treatment and has spread to deeper tissues, including bone. She's had two surgeries to try to save her hand, and at least one more is planned. Amputation isn't outside of the realm of possibility, but will hopefully be avoided.
Fish owners should be aware of the risk of M. marinum infection. While fish are often ignored as a potential causes of infection and the overall risk is low, there are simple measures that can be undertaken to reduce the risk of acquiring an infection from fish tanks. These mainly involve limiting contact with fish tank water and the use of good general hygiene practices:
- Contact with aquarium water should be minimized
- Never dump aquarium water into kitchen or bathroom sinks.
- Promptly clean up any aquarium water spills.
- Take care when putting your hands in the aquarium, especially if there are sharp surfaces (e.g. rock, coral) that might result in cuts or abrasions.
- Hands should be washed thoroughly after contact with aquarium water.
- People with compromised immune systems should not have contact with aquarium water. They should have someone else clean their fish tank.
As I mentioned in an earlier post, there's been a large and ongoing outbreak of salmonellosis in people across the US associated with pet aquatic frogs (such as African dwarf frogs). A recent edition of Morbidity and Mortality Weekly Reports provides an update on this large and concerning outbreak. Here are the highlights regarding infections reported between April 1, 2009 and May 10, 2011.
- 224 infections with the unique outbreak strain of Salmonella Typhimurium have been identified in 42 US states. Since it is estimated that only ~3% of Salmonella infections are laboratory confirmed, this means that the number of true cases is probably much higher (e.g. >8000, if the 3% estimate is accurate).
- The median age of affected people was 5 years, with a range of <1-67 years. The young age bias may be because of increased susceptibility to infection, increased likelihood of severe infection (which would more likely result in testing) or more common exposure.
- 30% of affected individuals were hospitalized. There were no deaths.
- 65% of affected people reported contact with frogs in the week before illness. 18% of those occurred outside the home (which is why we need to make sure that even non-pet-owners are educated about zoonotic disease risks associated with pets).
- The median time from acquiring a frog to onset of disease was 15 days. This means people often got sick fairly soon after acquiring their new pet.
- One breeder in California has been implicated as a common source of infected African dwarf frogs. As with many kinds of small pets (e.g. rodents, reptiles), this is a large breeder that sells to distributors who then sell to pet stores and elsewhere. This type of mass production and distribution system means that a problem with a single breeder can result in widespread disease. This has been clearly shown previously in various other outbreaks, especially with pet rodents.
What should the average pet owner know?
- High-risk households - those including kids under the age of five, elderly individuals, pregnant women or individuals with a compromised immune system - should not have pet aquatic frogs.
- High-risk people (as describe above) should not have contact with aquatic frogs in other places.
- People with aquatic frogs should consider the frogs to be infected with Salmonella until proven otherwise. Since we don't know how to prove otherwise, that means treat all pet aquatic frogs as infectious.
- Frog owners should avoid direct contact with the frogs and their water. Hands should be washed thoroughly after contact with frogs or their environment.
- Frog owners should never dump aquarium water into kitchen or bathroom sinks.
- Any spills of water during aquarium cleaning should be promptly and thoroughly cleaned up.
- Other pets should be kept away from aquaria (I remember when I used to have aquatic turtles and a cat. The cat used to drink from the aquarium and occasionally bat at the turtles. Not something I'd endorse now, but that was in my pre-DVM era).
This outbreak doesn't mean that aquatic frogs can't be good pets. It means that they shouldn't be pets for certain people, that good routine infection control practices need to be used by frog owners and that consideration needs to be given to whether mass production of pet frogs (and other species) is appropriate.
Photo: An African dwarf frog (Hymenochirus boettgeri) (photo credit: James Gathany, CDC Public Health Image LIbrary #11831).
Rabbit hemorrhagic disease (RHD), a rare and reportable disease, has been identified in a pet rabbit from Winnipeg, Manitoba. The affected adult male rabbit was taken to a veterinary clinic in March after being lethargic for a short period of time. It was diagnosed with liver failure and subsequently died. The rabbit's body was forwarded to the Manitoba Ministry of Agriculture, Food and Rural Initiatives animal health laboratory. Various tests were performed and rabbit hemorrhagic disease was identified.
Rabbit hemorrhagic disease is a viral disease caused by a calicivirus. It is a serious infection that has high death rates and spreads very rapidly between rabbits through direct contact and through contaminated items such as cages and bedding. It does not affect people. Caliciviruses are non-enveloped viruses - viruses of this kind are very hardy, and can survive in the environment for long periods of time. RHD is reportable in Canada, and has not, to my knowledge, been identified in the country before. It's endemic in wild rabbits in many countries, and is thought to have made its way to North America in 1988 in a shipment of frozen rabbits from China to a supermarket in Mexico City. It's been found in the US in sporadic outbreaks since 2000.
Finding RHD in a Canadian rabbit perhaps isn't too surprising, since it's been identified in the US periodically over the past decade. However, this is a strange situation. The affected Manitoba rabbit lived in an apartment with two other pet rabbits, and did not have any outdoor access or contact with any other rabbits (or any other wildlife). These other two rabbits were fine. They were quarantined initially but have since been released from quarantine since they stayed healthy and tests for the virus were negative.
So, where did the virus come from? That's a baffling question, because this virus is a rare and exotic disease that is not known to be elsewhere in Canada. It would have been a lot less surprising if this was in a rabbit with outdoor access or that had had contact with other rabbits (outside of a confined household group). No source has been reported, but I assume authorities have looked at aspects like the owner's contact with rabbits or wildlife, the owner's contact with areas where wild rabbits might live, when the other rabbits were obtained and from where, and whether the owner has brought rabbit meat into the house. Although mice and similar rodents aren't known to be susceptible to the virus, checking for a rodent infestation in the house would be another consideration at in a strange situation like this.
Why were the other rabbits unaffected? That's surprising as well, considering how easily the virus is normally transmitted.
Another thing this story highlights is the usefulness of diagnostic testing. I'm impressed that the owners and veterinarian submitted the rabbit's body for testing. Too often, an animal that dies of a strange disease is just buried or cremated. That's understandable from an emotional aspect, but often it occurs because testing is not even discussed after an animal has died, or because people don't think about why it might be useful. Cost is an issue, as testing is not typically subsidized for non-food-animals (in this case, even though it was a pet, I presume the rabbit was treated as a food animal, with a lot of testing done for free). While testing won't help the dead animal, it can provide useful information at times, beyond finding a rare foreign disease. It's not uncommon for me to get a call from someone saying "my dog recently died of some strange disease, is it safe for me to get a new puppy or do I have to do something first?" or less commonly "I'm sick and the doctors haven't figured it out. My dog died last month of something strange, do you think they could be linked?' With only a vague clinical description, there's often not much I can say.
Rare diseases are just that - rare. The odds of encountering one are quite low, but they do happen. Arriving at a diagnosis can help identify risks to other pets and people, and it is often money and time well spent.
As petting zoo season approaches (along with petting zoo-associated disease outbreak season, unfortunately), it's important for people who run petting zoos and other animal contact events to think about what they do to reduce the risk of infecting visitors. No petting zoo will ever be 100% safe, because any person-animal contact (just like any person-person contact) carries some degree of risk. However, the risks can be greatly minimized by some basic measures, such that the benefits of animal contact can greatly outweigh the risks for most people.
One of the standard guideline documents for managing public person-animal contact is the National Association of State Public Health Veterinarians (NASPHV) Compendium of Measures to Prevent Disease Associated With Animals in Public Settings, which has just be updated again for 2011. Anyone planning a petting zoo or similar event should know this document well and ensure that their event fulfills all the recommendations within it.
Hopefully, petting zoo operators will pay attention to these guidelines out of a desire to safeguard the health of their visitors. If that's not enough motivation, the liability aspect should be considered. Since there are well established and readily available guidelines, failing to use them could certainly increase the legal liability risk.
Easter is one of those holidays when there are concerns about dumb pet purchases. Spur-of-the-moment purchases of inappropriate pets can lead to animal suffering and death, and risk of human infection. Easter's problems: baby chicks and rabbits.
Rabbits can make great pets. They're a long-term commitment, but they’re relatively low maintenance, a lot is known about how to raise them and they are generally low risk for transmission of infections to people. Chicks are a different story. Chicks are notorious Salmonella vectors and have been linked to numerous outbreaks. They are easily injured and often improperly raised. They also grow up (well, some of them do, at least) to be full sized poultry, something that most people don't really want.
A story from Vidalia, Georgia highlights some of the issues with Easter pets. In it, Tracy Gunn describes his need to buy a chick for his daughter - and not just any old chick, but a dyed chick, something that’s illegal in 36 US states, but not Georgia. Gunn states "I don't know what she's going to do with it." Sounds like a recipe for a few minutes of novelty, followed by a relatively short life for the chick. At least his daughter’s 17, and not in the high risk group for salmonellosis.
Alongside the cage full of multicoloured chicks was a collection of rabbits.
“The bunnies sell real good for Easter. We've been selling a lot of them about the last month. Can't keep enough of them.” said a store employee.
He followed that up with “They buy (rabbits) for their kids for Easter, then they take Easter pictures and stuff like that with them, I'm not sure about what happens to them afterward.”
That’s the problem. Kids get a few minutes of novelty enjoyment, but then a lot of those animals end up dead, released into the wild (not a good thing) or dropped off at an animal shelter, because people don't think about the "afterward" part before they buy.
Pet purchases need to be made with thought and foresight:
- Do I really want this pet?
- Am I committed to taking care of it for its entire life?
- Can I take care of it properly with my current living situation?
- Can I afford to take care of it properly?
- How do I take care of it?
- Are there any disease risks that I need to be concerned about?
- Are there any people in the household who are at high risk for disease caused by this type of animal?
If you can't answer these questions, don't buy or adopt an animal - of any kind.
A Montreal pediatrics resident has expressed concern about rat bite fever in kids. Dr. Karine Khatchadourian described three cases of this bacterial infection in a paper called "The rise of the rats: a growing paediatric issue," published last year in the journal Paediatrics and Child Health. The article didn't really present any evidence that this is a "growing" issue, but it is a disease of concern.
Rat bite fever is a bacterial infection most commonly (but not exclusively) associated with bites from rats. Healthy rats often carry the bacterium that causes the disease (Streptobacillis moniliformis in North America), and infection can occur when the bacterium is inoculated into the body by a bite, or when it's spread to mucous membranes like the mouth through direct mouth-mouth contact with pet rats (yes, some people kiss their rats).
The disease can be serious, and even fatal, if not properly diagnosed and treated. It's also a classic example of why physicians need to ask their patients about pet contact and why people need to take bites from pets seriously. Knowing that a rat is in the house, and particularly if a bite has occurred, is a key factor in helping make the diagnosis. If the physician doesn't ask the question, this critical piece of information may be missed, along with the diagnosis.
Being concerned about rat bite fever (and other zoonoses) is good, and ways to educate pet owners and physicians about such diseases are needed. However, extrapolating "rat bite fever is bad" to "rats are bad" is a stretch. The statement in the paper "Should we, as health care professionals, advocate to have rats banned from being sold in pets stores?" is over the top.
Every animal carries many microorganisms that can cause disease in people, given the right circumstances. Similarly, every person you meet is carrying something infectious. The key things to consider are:
- What is the likelihood of infection?
- How severe is the disease that may occur?
- What can be done to reduce the risk of infection?
- What is the cost-benefit, i.e. how do the potential risks compare to the potential benefits?
How can the risks be reduced?
- Rat owners need to be aware of the disease.
- Good handling practices are needed to reduce the risk of bites.
- Any bites that occur should be promptly cleaned and a physician contacted if there are concerns.
- Contact of rat saliva with broken skin or mucous membranes (e.g. kissing the rat) should be avoided.
- Physicians need to know whether their patients own pets, including rats, and know what diseases may be associated with those types of animals.
With this type of approach, the risk of infection can be reduced and the ability to properly and promptly diagnose the disease, in the odd case that it occurs, can be maximized.
I don't want to downplay rat bite fever. It certainly can cause illness, particularly in children under the age of 12. A recent paper reported a fatal case in a 14-month-old boy, however in that case the infection was associated with ferrets, not a rat.
Parents of small children need to think about the risks of zoonotic diseases, as well as injuries (e.g. bites) when deciding whether to get a pet, and what type of pet to get. If people like rats, take care of them properly and communicate well with their physician (and if their physician is aware of the issues), then the risks of serious disease are quite low.
Dr. Khatchadourian suggests that parents "should stick to cats and dogs, and steer clear of rats." However, that's no assurance that a zoonotic infection will not occur. There's no evidence indicating the risk of disease is less with those species. It doesn't even eliminate the risk of rat bite fever, since Streptobacillus moniliformis can be found in the mouths of dogs too.
Rather than banning rats from pet stores, we should focus on educating pet owners, veterinarians and physicians about zoonotic diseases.
The latest edition of CDC's Morbidity and Mortality Weekly Reports describes a case of rabies in a Michigan man from 2009. While human rabies in most developed countries is very rare, this is yet another reminder of the ever-present risk of rabies exposure in many regions, and the ongoing need to be proactive to avoid this almost invariably fatal - but almost completely preventable - disease.
In the 2009 Michigan case, the man woke one day with a bat on his arm. Bats are classic rabies vectors, and you have to assume that any bat has rabies until proven otherwise. If you can't be sure that you weren't bitten or scratched (something that may be easier said than done, because bats bites can be very tiny), then you have to consider yourself exposed if you've had contact with a bat and the bat wasn't tested and rabies-negative.
Unfortunately, the Michigan man did not seek medical attention, and nine months later he started to develop signs of rabies. It started off with pain and progressive numbness in his left hand and arm, and pain in his neck and back. He developed weakness in his left hand and soon could not grip anything or raise it more than a few inches.
While he was being evaluated in hospital, he developed breathing difficulties and had to be placed on a ventilator. Various diseases were considered and numerous tests were run. After a little initial improvement, he began to deteriorate, with more profound neurological signs.
Five days after he was admitted to hospital, his wife was asked about possible animal bites, but she didn't know of any. A couple of days later, a relative recounted being told about the bat encounter, but there was little that could be done at that point, and the man died three days later. Rabies was eventually diagnosed.
Because of the potential risk of exposure, 11 family members that may have had contact with the man's saliva received post-exposure treatment.
Sadly, you can almost guarantee that rabies could have been prevented if he had reported the bite and received post-exposure treatment (even months later). Rabies education is critical so that people know the risks of exposure and know to get medical advice after any encounter with a wild animal.
People for the Ethical Treatment of Animals (PETA) is battling Ringling Brothers and Barnum and Bailey Circus because of Karen, an elephant with tuberculosis (TB). The animal rights group is claiming that the elephant poses a public health risk because she has TB, and it appears that their appeal had initially convinced Baltimore city council to bar the animal from performing.
However, while Karen does have TB (along with about 12% of all Asian elephants in captivity in North America) she does not have active disease. This means she is not known to be shedding Mycobacterium tuberculosis, the cause of TB. Standard protocols are for captive elephants to be tested each year for TB shedding through culture of trunk washes, whereby the elephant essentially sucks some fluid into its trunk and blows it back into a collection bag. If TB is grown from that sample, the elephant has active disease and needs to be quarantined. Since Karen does not have active disease (and because close and prolonged contact are needed for transmission of TB), she is not believed to pose any public health risk.
Recently, I wrote about an outbreak of TB in people that worked with infected elephants at a sanctuary. That was a totally different situation from this one. The major differences, particularly with regard to the risk of transmission, are perhaps best explained by one of the authors of that report, Dr. William Schaffner, who said "If you're at a circus, you're at a great distance from the elephants. You do not have genuinely prolonged contact with them. You're there for 2 hours of the show. That sort of exposure should not put people at risk. I would let my grandchildren attend."
A month or two ago, there was a lot of press about the risks of pets sleeping in beds. It was in response to an article in the journal Emerging Infectious Diseases that didn't put forth any new information, but summarized a few diseases that could potentially be transmitted by pets. Unfortunately, the relative risk of those diseases wasn't really explored, and some media reports latched onto diseases like the plague, transmission of which can occur between pets and humans but the likelihood of this in most areas is essentially nil.
Anyway, an article at Scienceline.org has taken a more balanced approach towards the subject. One sentence perhaps say it best: "Many of those scare headlines, however, missed the main point of Chomel’s work: For most people, the risks are minimal, and there are easy ways to go about preventing pet-to-owner disease sharing."
I won't go into details here, since you can read the article yourself, but a key component is that pet ownership is never no-risk, but is usually low-risk. Basic hygiene practices and common sense can reduce the risks further. The cost-benefit needs to be considered, and while we can never completely eliminate the "cost" aspect, the benefits of pet ownership certainly outweigh the costs in the vast majority of households.
The US CDC is investigating a large, long-lasting and widely dispersed outbreak of salmonellosis that has been linked to contact with pet frogs, such as African dwarf frogs (see image). Between April 1, 2009 and April 5, 2011, 217 infections were identified in people in 41 states. A strain of Salmonella Typhimurium has been implicated.
Of the 217 infected people, 34% were hospitalized, which is quite a large proportion, but is probably due (at least in part) to the fact that stool samples aren't often cultured from people with milder disease (who don't go to the hospital). If you have severe diarrhea and are in hospital, you're more likely to be tested. As with most outbreaks, the 217 diagnosed cases presumably represent only the tip of the iceberg.
Of the people who got sick, 64% reported contact with frogs in the week before their illness began. Of these, 84% had contact with African dwarf frogs. This type of widespread outbreak with a single strain and a fairly clear link to a specific type of animal raises questions about whether there's a major breeder or supplier that is the source of the problem. Not surprisingly, the investigation identified a single water frog breeder in California as the source of frogs associated with this outbreak. Salmonella was identified from environmental samples at the breeder's facility. Testing is still apparently underway to confirm whether it's the outbreak strain, but it's pretty likely.
As with any other reptiles or amphibians, there are standard recommendations to avoid infections from aquatic (water) frogs:
- They should not be in households with high-risk people: children less than five years of age, the elderly, pregnant women and immunocompromised individuals.
- Care should be taken to prevent contamination of the house from aquarium/terrarium water.
- To avoid contamination, aquarium water should not be dumped down kitchen or bathroom sinks.
- Hands should be washed thoroughly after contact with aquarium water or the frogs themselves.
Photo: An African dwarf frog (Hymenochirus boettgeri) (photo credit: James Gathany).
A sure sign of spring is the proliferation of classrooms hatching out chicken or duck eggs. While chicks may be cute and entertaining, they are also high-risk sources of Salmonella and some other infectious microorganisms. Numerous Salmonella outbreaks have been linked to contact with hatchling chicks, and care must be taken if teachers are considering having chicks in classrooms.
Things to consider:
- Who will be in contact with the chicks? Children under 5 years of age, pregnant women and people with compromised immune systems should not have contact with young chicks. This rules out having chicks in preschool and some kindergarten classes, however not everyone follows those standard recommendations. It's also very hard to know whether there may be immunocompromised kids in the classroom. Unless a teacher/school is sure that there are no high-risk children present, they shouldn't have high risk animals.
- Where will the chicks be hatched and raised? Is it in a contained area?
- Is the chick area easily and always supervised to ensure that rules are followed? This is important for both children and chicks, since chicks can easily be injured or killed through improper handling.
- Are protocols in place regarding safe handling and hygiene?
- Are the chicks going to be in an area where students eat?
- Are parents going to be notified in advance?
- Are there plans for sending the birds to an appropriate home when they're done in the classroom?
- Are the chicks there for a true educational purpose, or just as a novelty?
Hatching chicks can be done relatively safely in appropriate classrooms, with older children, no high-risk individuals, easy access to hand hygiene stations, appropriate protocols and proper supervision. The problem is, these aren't always (or even often) present, and inadequate thought often goes into bringing chicks into classrooms.
The pandemic H1N1 influenza virus continues to circulate, although the hype has certainly died down. During the original 2009 pandemic, there were a few reports of infection of domestic animals, particularly ferrets and cats. This wasn't particularly surprising since we know these species are susceptible to human influenza viruses, and with so many people infected and so many people owning pets, a large number of pets were presumably exposed, and a few got sick.
Three animals from the San Diego Zoo also developed H1N1 influenza in the fall of 2009: a badger, a Bornean binturong (also known as a bearcat, see photo) and a ferret. The badger and binturong had severe pneumonia and had to be euthanized, but the ferret survived. Presumably, these animals were infected by an infected person, probably a caretaker. This report just provides more evidence of the ability of this virus to infect a diverse range of species, and the need to consider both the potential role of various animal species in human influenza transmission and the potential for animal disease from contact with infected people.
Photo: A binturong (Arctictis binturong) at Overloon, NL (photo credit: Tassilo Rau, source: http://en.wikipedia.org)
Kinkajous are strange little mammals from the Procyonidae family - the same family to which raccoons belong. Kinkajous are native to Central and South America and are occasionally kept as pets, but they don't make great pets because they are strictly nocturnal, can be cranky when woken during the day, and can sometimes be aggressive. Regardless, there is a niche pet trade, particularly in the US.
A recent report in Morbidity and Mortality Weekly Report describes detection of Baylisascaris procyonis (the raccoon roundworm) in pet kinkajous in the US, including:
- A 10-week-old kinkajou in Tennessee in which Baylisascaris procyonis was found during a routine fecal examination.
- Detection of Baylisascaris eggs from soil samples under the cages of a kinkajou breeder in Florida (the breeder from which the Tennessee animal was obtained).
- An unrelated case (11 years earlier) in which adult Baylisascaris worms were found in the intestinal tract of two adult kinkajous that died of other causes.
No human infections (i.e. cases of larval migrans) were linked to infected kinkiajous.
Baylisascaris is a parasite that's extremely common in raccoons, rare (but concerning and sometimes over-hyped) in dogs, and an extremely rare cause of disease in people. While rare in humans, it still gets a lot of attention because when disease does occur, it can cause serious neurological damage, typically in children. The damage is caused by migration of parasite larvae through the body, and through the brain. This can occur after someone swallows infective parasite eggs, which then hatch in the intestinal tract and then embark on their journey through the body.
It's unclear whether Baylisascaris is a common problem in kinkajous (like it is in raccoons) or a rare finding (like it is in dogs), since this report only describes the parasite in a small number of animals, and no larger studies of intestinal parasites in kinkajous have been reported. It would be useful to know whether kinkajous are true reservoirs of this parasite (and therefore whether we should consider all kinkajous to be carriers) or whether infection is just an unusual finding.
Overall, the public health risk is likely limited.
- There aren't that many pet kinkajous around, as far as I know.
- While Baylisascaris is nothing to dismiss, to get infected, a person still has to eat infective eggs from feces. The likelihood of transmission from a pet to a person is therefore low if good basic hygiene measures are used.
- The parasite eggs are not immediately infectious. They have to sit around in the environment before they are infectious, usually for 2-4 weeks. Therefore, prompt removal of feces and careful attention to basic practices like hand hygiene should greatly reduce the risk of transmission.
- Routine testing and deworming of pet kinkajous should reduce the risk even further.
What does this mean for pet kinkajou owners? Not a lot beyond what would normally be recommended. Pet kinkajous should have good veterinary care and regular fecal examinations. Regular deworming should be discussed with the attending veterinarian, and good hygiene practices should be used to avoid contact with feces, especially old feces.
- Like all mammals, donkeys are susceptible to rabies virus but infections are not particularly common. Raccoon rabies has also be identified in the area, and a bite from a raccoon may have been the source.
- A York County woman was bitten by a kitten that ran into her house when the door was opened for someone else. The kitten bit her when she grabbed it to throw it (hopefully not violently) back outside... an understandable reaction but not what you want to do in a case like this. You need to know whether a wild animal that bites is rabid, and if it gets away, you can't test it. You need to get away from it but keep it contained until someone can come get it. The other problem with people getting rid of the animal is that they might not recognize the risk of rabies. In this case, the kitten was hit by a car after being removed from the house, which allowed for it to be tested.
Yet another report of a dog being exposed to rabies through contact with wildlife, then being euthanized because it was not properly vaccinated.
- An unvaccinated animal that has been exposed to a rabid animal has to be euthanized or undergo a strict six-month quarantine. A vaccinated animal only needs a 45-day observation at home.
- Encountering a manic bobcat isn't something I'd like to do, and a LaCrosse, Florida woman spent nine days in hospital after being attacked by one. The 25-pound cat was trying to get the family's cat, then lunged at the woman when she came outside the house, aiming for her neck. Her husband then shot it. They knew that the bobcat needed to be examined, and took the rather unusual approach of bringing it to the hospital emergency room with them (I'd love to have seen that). I don't imagine hospital personnel did anything, but Florida Fish and Wildlife Conservation Commission personnel came and got it, and later confirmed that it was rabid. (Image: Lynx rufus, US Fish & Wildlife Service)
Raccoons are fascinating critters but they don't make good pets. Their curiosity makes them quite disruptive and damaging, and they have seriously injured people (particularly infants). They are also rabies vectors, and in many regions raccoon ownership (along with other wildlife species) is illegal (or only legal with a license). Despite all this, some people continue to keep raccoons as pets, and injuries continue to happen. Unfortunately, it's often not the owners that suffer the consequences, but children.
A one-week-old Griggville, Illinois baby is in hospital after being attacked by her grandparents' pet raccoon. The baby was in a room with the raccoon (not a good idea to start with), when the raccoon starting biting and scratching the baby's face and head. The raccoon's owner thinks the raccoon wasn't being vicious, just curious and trying to get a ribbon off of the baby.
"Rampy was trying to get the bow off the baby's head and it's got long claws and he was scratching up the head trying to get the bow off," said the owner.
Regardless, the fact that it caused severe injury indicates it's a hazard. (Wounds caused by accidents heal at the same rates as those caused my malice.)
Euthanasia of the raccoon was requested to test it for rabies. The owner countered that it had been vaccinated against rabies and dewormed (which raises the question of what veterinarian did this. I'd consider vaccinating and deworming an illegal pet unethical at best). Further, rabies vaccination does not guarantee that the raccoon isn't rabid. A judge eventually ordered the raccoon to be euthanized.
You'd think the raccoon's owners would be aghast at the attack. While I can see how they'd be attached to their pet, typically concern over a grandchild takes precedence. Not here, however, as the owners fought the euthanasia order and are railing against local authorities for having the raccoon euthanized after a potentially life-threatening attack. Even the infant's father is taken back by their attitude, stating "If it was somebody's dog that bit a kid, they'd be held accountable. These people should be held accountable for [the raccoon]."
You can probably tell from various posts that I'm a fan of the CDC's journal Emerging Infectious Diseases. It's a great journal containing interesting infectious disease reports about people and animals (it's free too, which is a nice bonus). In addition to the ferret infection I wrote about, the last edition also has a very interesting report about tuberculosis (TB) in people associated with an elephant sanctuary.
Tuberculosis is a big problem in elephants. It is relatively common in captive elephants in North America (2-12% are thought to be infected), and it It can be a tricky infection to diagnose, so it's very hard to know who's infected an who isn't.
Beyond being a problem for the elephants (because infection can be fatal), elephants with TB pose a risk to people, and there have been reports of human infections associated with elephant contact. Close and prolonged contact is most often associated with transmission of TB from elephants to people, but this recent report shows that indirect transmission may also be a concern.
The report in question deals with an elephant sanctuary in Tennessee. Problems were identified in July 2009 when routine TB skin testing of some workers at the facility indicated exposure to TB. Further investigation revealed that a quarantined elephant had tested positive in December of 2008. The elephant was diagnosed by culture of a trunk wash - to do this, the elephant is trained to suck water into its trunk and then "exhale" it into a plastic bag. The sample is then cultured for Mycobacterium tuberculosis. Animals with positive trunk washes are considered infectious, just like people with positive sputum (spit) cultures.
The TB history at this facility goes back further. In 2004, they took in two elephants that were known to be infected with TB. They were handled as per USDA Guidelines for the Control of Tuberculosis in Elephants (yes, such a document exists). One died of TB and the other was later released from isolation after treatment, according to the guidelines. In 2006, they took in eight more elephants from the same facility. All were considered high-risk for TB and were tested annually. All samples between 2006 and 2009 were negative, except for that one December 2008 sample. There's concern that since the elephants tested negative, people might have become lax with infection control practices. It's a problem beyond elephant facilities, where compliance slips over time since people may not see the need to continue to do what's required.
After being notified of the the 2009 human TB test results, Public Health personnel launched an investigation. They eventually determined that 9/46 people whom they were able to contact had positive TB skin tests during the 2006-2009 period, despite having negative tests before then (confirming that they were truly exposed during this period). The strange thing was that it wasn't only the people with prolonged, close contact who were infected. People who worked in the quarantined area in 2009 were significantly more likely to be positive, but of the 13 people that worked in the quarantine area, only one had close contact with any elephant. Furthermore, three of the people who were infected were administrators.
This is where is gets interesting. Normal cleaning practices included the use of high-pressure washing to clean the barn. We know that this increases the risk of spreading bacteria in the air over long distances, and it's generally frowned upon from an infection control standpoint. People in the quarantine area wore respirators to reduce the risk. However, the administrative area was attached to the quarantine area and investigators subsequently determined that there was airflow from the quarantine area into the administrative area. So, when people were cleaning the quarantine area with high pressure washing, they were creating infectious aerosols that spread into the administrative building. That presumably accounted for infection of the people who had no contact with elephants. Furthermore, one of the investigators was also exposed during time spent in the administrative area before the risk was identified.
This highlights a few issues:
- Infectious diseases continue to surprise us. We may know what they tend to do, but new transmission patterns and new concerns can develop.
- Power washing can contribute to the spread of infectious diseases. This is a concern in many types of facilities.
- Infection control compliance needs to be maintained over time, even if it seems like the risks have dropped.
- Captive elephants continue to pose a risk to people around them, and careful precautions are needed to reduce the risk of exposure to TB.
The three-year-old ferret from Germany was taken to a veterinarian with a five-month history of coughing, recent weight loss, vomiting and mild diarrhea. A chest radiograph was taken and "nodular densities" were found in the lungs (these would show up as white spots on the radiograph). This type of finding is usually an indication of something bad going on in the lungs, such as tumours or granulomas. Because of the poor prognosis, the ferret was euthanized. At necropsy, the lung nodules were confirmed, and there were some other abnormalities such as and enlarged spleen and a lot of enlarged lymph nodes. Using a combination of culture and molecular tests, Mycobacterium celatum infection was identified as the cause.
Mycobacteria are a diverse group of microorganisms, whose most notable member is M. tuberculosis, the cause of (not surprisingly) tuberculosis (TB) in humans. Mycobacterium celatum belongs a large group classified as 'non-tubercular' Mycobacterium species.
Mycobacterium celatum is rather uncommon, being first diagnosed in a person with AIDS in 1993, and only being reported sporadically in people since then. Most human infections have occurred in people with compromised immune systems, but there are some reports of people with apparently normal immune systems becoming infected. There is also one previous report of an infection in a ferret. There is no evidence that the ferret reported here had a compromised immune system, so the reason for the infection is not apparent. The source of infection is also unknown. Since there were granulomas throughout the lungs, it suggests that the ferret inhaled the organism, but that can't be proven and there are no clues even suggesting a possible source.
An interesting aspect of this report is the question about whether the ferret's owner may also have been infected. It's perhaps a bit of a stretch, but there was a suggestion that the owner may have been infected as well because he/she reported a chronic cough. Testing was performed and no Mycobacterium (of any species) was detected, but the person was treated with antibiotics prior to being tested so a false-negative culture is possible. The likelihood that the person was truly infected is probably quite low, but it can't be dismissed.
Ferret owners shouldn't be too worried about M. celatum. This is an example of one of many possible rare infections that can be encountered. Similarly, this report doesn't mean that ferrets should be considered at higher risk for causing human infections. Every animal poses some degree of risk to people, and ferrets are actually pretty low-risk overall. Mycobacterial infections aren't something to be too concerned about, but, as suggested in this report, the general concept of considering human disease when something is diagnosed in a pet is excellent and too often overlooked.
(Photo credit: Luke Rutherford)
We've known for a while that cats and ferrets are susceptible to many human influenza viruses, something that was again demonstrated last year through sporadic (and often fatal) reports of H1N1 influenza in both species. Since H1N1 is still in circulation in the human population, there's still a risk of exposure of cats and ferrets, as was seen in an outbreak at a ferret shelter in Kentucky that began last month.
Over a few weeks, starting in early February, all 17 ferrets at the Ferret Villa Shelter in Erlanger, KY, developed influenza. As expected, coughing, sneezing, fever and lethargy were the first signs of disease, with more severe respiratory disease developing in some. One ferret died, and H1N1 was diagnosed through post mortem testing. Presumably, all of the other sick ferrets had influenza as well. Fortunately, the other 16 ferrets survived with supportive care and should presumably suffer no long-term effects.
There's been no mention of the source of the virus, but it almost certainly came from an infected person. Given the susceptibility of ferrets to influenza and the potential for severe illness, ferret owners should be aware of the risk and restrict contact between their ferrets and anyone with flu-like disease. Ferret shelters or breeders, with larger numbers of ferrets, should take extra precautions.
The risk of transmission from ferrets to people isn't known, but it's logical to assume that there is some degree of risk. An infected ferret could quite plausibly shed enough virus to infect a person under the right circumstances. However, since influenza in a pet ferret most likely came from its owner, and most ferrets don't meet many people outside of their households, the risk to other people in most households is probably limited - most people would probably be exposed via the person who was originally sick before they had a chance to get it from the ferret.
(Photo credit: Luke Rutherford)
Petting zoos can be great events (I've said it before and I'll say it again!). I end up visiting many with my kids every year. Despite the fact that a few petting-zoo-associated disease outbreaks also occur every year, and despite the fact that I deal with infectious diseases every day, I still don't get too concerned about the risk to my family.
The main reason is that I can control one of the most important disease prevention measures: making sure my family washes their hands after being in the petting zoo (along with some other common sense measures).
Hand hygiene is a critical infection control tool, and poor hand hygiene practices are often part of the problem in outbreaks. Figuring out how to improve hand hygiene is an important research area, albeit one in which few people are working.
A paper by Maureen and I, published recently in Epidemiology and Infection, looked at hand hygiene compliance in a petting zoo and how to improve it. The study involved using webcams to remotely and discretely observe hand hygiene practices in people attending a petting zoo. We've previously done observer-based studies, where you have someone standing there watching, but it's possible that this method falsely elevates results because some people might notice they're being watched and be more likely to wash their hands. It's also easier to record a lot of data and evaluate it over time (i.e. by watching it on video), than try to collect everything accurately in real time.
The published study involved a large petting zoo at the University of Guelph's annual open house. It's a well designed and operated event, which needs to be considered when evaluating the results, since petting zoos vary greatly in quality.
Overall hand hygiene compliance at this particular event was 58%. That means 58% of people that came into the petting zoo washed their hands or used a hand sanitizer on the way out. (It doesn't mean they all did it well, but they at least they did something). In some ways, that number's good, when you compare to our earlier petting zoo observation study, (or even to results of hand hygiene rates of physicians in some hospitals). However, for such a short-term activity where there is easy access to facilities to wash hands or use a hand sanitizer, there's much room for improvement.
During the petting zoo, a few thing were changed at defined times to see if they would improve hand hygiene rates. Two things resulted in increased hand hygiene compliance; a combination of petting zoo personnel actively offering visitors hand sanitizer near the exit and improving hand hygiene signs, and having personnel walking through the zoo reminding people to wash their hands. This suggests that people need an active reminder to clean or sanitize their hands. Whether they don't think about it, or can't be bothered unless someone points it out, is unclear, but having personnel encouraging hand hygiene is something to consider to help improve infection control. It's practical for short-term events like petting zoos at fairs and similar exhibits, although perhaps not as practical for permanent exhibits.
People who entered pens or touched animals were more likely to wash their hands than people who didn't. This is presumably because people who had contact with animals were more likely to recognize a risk. However, while people who touch animals are presumably at higher risk, simply being in the area is enough to pick up an infection. In some outbreaks, people who went into the petting zoo but never touched an animal got sick. That's why there is a need to remind people that everyone must wash their hands after leaving a petting zoo, not just those who actually petted the animals.
A few other concerns were noted. Despite warnings on prominent signs, 10% of people carried food or drink into the petting zoo area. This probably increases disease transmission risks since people may eat or drink before they wash their hands, or directly contaminate their food or drink while in the petting zoo area.
Overall, hand hygiene rates weren't bad (and were better than I was expecting), but there is still room for improvement. Considering how quick, easy and cheap it is, there's no reason not to strive for 100% compliance.
In Canada, rabies testing and surveillance is performed by the Canadian Food Inspection Agency (CFIA). National data for 2010 are now available and indicate there were a small number of cases in domestic animals, with more in wildlife, for a total of 123 cases.
Dogs: There were three cases, all in Saskatchewan.
Cats: Four cases, three in Manitoba and one in Alberta.
Horses: One rabid horse in Manitoba.
Cattle: One, from Manitoba.
Skunks: 60 cases, 33 in Manitoba, 17 in Saskatchewan and 10 in Ontario.
Bats: 48 rabid bats, most in Ontario (29) but also in BC, Alberta, Saskatchewan, Manitoba, Quebec, New Brunswick and Nova Scotia.
Foxes: Six from the Northwest Territories or Nunavut.
No rabid sheep, goats, raccoons (down from 58 in 2007), wolves or other species.
Manitoba seems to win the 2010 rabies prize, while Newfoundland and Labrador, Prince Edward Island and the Yukon had no cases.
As with any disease surveillance, these numbers underestimate the scope of rabies. For an animal to appear on the list, rabies had to be considered and testing performed. So, for wildlife, it's a massive underestimation of the number of cases, since most affected wildlife don't get tested. Wildlife testing (and testing in general) is typically only done when there has been the potential for human exposure. Domestic animal cases are probably a fairly close representation of the status of rabies in pet and farm animals, since it's reasonably likely that a domestic animal with rabies would be identified as such and tested (although certainly cases can be missed or neglected). As with wildlife, there is probably an under-identification of rabies in feral/stray dogs and cats, since testing would only be done on these animals if they are caught and if there was potential human exposure.
A recent press release from The Pet Care Trust reported on the status of its Pets in the Classroom program, which provides support to teachers to have pets in school classrooms. On the surface, it seems like a fine concept, helping to enrich school activities. However, it's one of those ideas that can do a lot of good, or it can also be very bad, depending on how the program is run.The Pet Care Trust has some useful information about pets in classrooms, and anyone considering having a pet in a classroom needs to be aware of a variety of concerns, including:
- Welfare of the pets (e.g. minimizing stress, preventing abuse)
- Adequacy of pet care, particularly during weekends and holidays
- Access to and cost of veterinary care
- Distraction of students
- Infectious disease transmission
Given the topic of this blog, I'll focus on the last one.
Infectious disease transmission from pets in classrooms is a real problem. Zoonotic infections can and do occur in these situations. The risks are quite variable, and depending on the animal, children, classroom and pet care, can range from inconsequential to quite serious.
The type of animal is very important. Certain species are very high risk for carrying particular infectious diseases and for transmitting them to people. Reptiles are notorious for Salmonella, so it is recommended that children under five years of age and immunocompromised individuals (among others) not have contact with reptiles. Even with older kids there's a risk, and older kids have picked up Salmonella in classrooms from reptiles or a reptile's food (e.g. frozen rodents).
So, it's concerning that 435 of the 2066 grants handed out by this program were for reptiles, and included kindergarten to Grade 6 classrooms. A lot of reptiles went into classrooms with a lot of young kids. Typically, elementary school children (at least around here) eat in their classrooms, which raises even more concern. While the majority of students would be five years of age or older, immunocompromised kids are not exactly uncommon, and it's unclear whether teachers have adequate knowledge of whether kids in their classes are immunocompromised, nor whether they understand that such children are at increased risk of disease from classroom pets.
I'm not saying pets in classrooms are a bad idea. However, it's often done poorly and with little forethought. To be effective and safe, you need to consider many things, such as:
- What species should it be? From my standpoint, no reptiles or other high-risk species (e.g. baby chicks) should be in any classroom, because you can't guarantee a high-risk person won't be around. The animal needs to be small enough to be properly housed in a classroom. Its care requirements need to be basic and readily met. It shouldn't be a species that gets stressed easily, and it needs to be an animal that can tolerate all the activities that go on around it (e.g. a nocturnal species is probably not a good idea).
- What types of hygiene/infection control practices need to be used around the animal and how will they be enforced?
- What disease or injury (e.g. bite) risks are present and how will they be managed?
- Who will take care of it? This means who will take care of it for its lifespan, not just the upcoming school year.
- Who will arrange and pay for any medical expenses that arise, either for preventive medicine or treatment of disease?
- Will parents be notified?
- What happens if a child in the class is allergic to or afraid of the animal?
- Will proper supervision be available at all times?
- Who from the school or school board must give permission, and is there a standard approval process? (There should be, but there rarely is.)
- Why is the animal going to be there? Will there be any educational use or it is just there for fun/decoration?
If you can answer all these questions adequately, then a pet might be a good fit in the classroom in question. If you can't answer them, or can't be bothered to try to answer them, then there should be no pets in the classroom until you can.
A New Jersey man managed to avoid being a good example of Darwin's "natural selection," thanks to the help of medical professionals and the Bronx Zoo.
Eric Bortz (who, I'm sad to say, works at a veterinary clinic), purchased three snakes - a copperhead (venomous), a timber rattlesnake (venomous) and a monocled cobra (venomous) - a couple of weekends ago. (Sadly, that's not hard to do if you have a few hundred dollars.) The snakes joined his collection of pets, including a tarantula, several scorpions, a king snake, a boa constrictor and a rabbit (no word whether the rabbit was a pet or a snake-snack).
Anyway, the following Monday, he was bitten by the newly-acquired cobra. He had apparently been told that the snake had undergone a procedure to render it non-venomous, but it became apparent that it either wasn't true or it wasn't done right, when Mr. Bortz went into respiratory distress and started seizuring.
Fortunately, he received prompt medical care and his proximity to the Bronx Zoo facilitated access to antivenin. Zoos are often called in to help out when people get bitten by their venomous snakes, since zoos typically keep a supply of antivenin in case their staff get bitten.
Keeping venomous snakes is just stupid - there's no reason to do it, and t puts people at risk. The risk is not just to the owners who made the choice to keep the animals, it's also to other people that might be exposed if the snake gets out, including family members, friends and neighbours, who didn't make the choice... it's something that has happened in the past, and will no doubt happen again. Venomous snakes (and other dangerous animals) are also a potential problem for first-responders if there's been a fire or other incident in the house. There's absolutely no reason for these creatures to be kept as pets, and no reason that keeping and selling them shouldn't be met by large fines or other deterrents.
A recent article in Emerging Infectious Diseases discussed infectious disease risks associated with having pets in the bedroom. It raised awareness about pets and zoonotic diseases, although some of the coverage was a bit over the top. There are risks, but for most people and most pets, the risks are quite low. Some things do increase the risk quite substantially. One is sleeping with a large predatory carnivore.
Large exotic animals such as lions and tigers are surprisingly common in small zoos, animal parks, exhibitions and even private homes. Many people get away it, but all too often it's an accident waiting to happen, as for a 17-year-old Florida girl who sleeps with a tiger in her bed.
Felicia Frisco is part of a family of animal handlers. Her father runs an "institute" that provides animals for movies, TV shows, presentations and for the public to "cuddle." Felicia has been raising Will, a now six-month-old Bengal tiger. Part of Will's training involves sleeping in Felicia's bed every night.
Felicia said her friends "think it's really cool that I have a pet tiger because most of them only have a cat or dog." Other people (the one's with common sense) think it's an appalling example of poor animal handling and weak regulations (along with poor parenting).
Will may be very friendly now, but that doesn't mean he's safe. Many people have been killed by pet lions and tigers. Sometimes it's from attacks, but sometimes it's just the result of normal playful behaviour. A playful swat to the head or neck from a large cat can be fatal. Think how aggressively some cats play. Scale that up a few hundred pounds and you can see the potential for injury or death. As Will gets older, the risks will increase based on his increasing size and natural instincts. Also, there may be behavioural changes associated with sexual maturity that could increase the risks.
Felicia's father, the ringleader of the venture, seems to be in complete denial: "She may have that young cub in her room and be taking care of him and raising him, but her mother and father who are full time professional animal trainers also live there with her and have many other tigers right outside the door that are part of their living."
- Having someone in the next room doesn't prevent an attack. They just get to see the damage first.
- Having other tigers doesn't reduce the risk. It means there are more animals to cause problems and the potential for people to be injured getting into the middle of a cat-cat quarrel.
- Being a trainer doesn't make you invulnerable to teeth and claws (remember Siegfried and Roy?)
He further distances himself from parent-of-the-year honours by saying "That Felicia is risk-free is by no means true but neither are most 17-year-olds behind the wheel of a car... they die like flies across the country. It's like having an extreme sport in your life. The potential for accident and injury is certainly there."
Jack Hanna, a famous animal trainer, summed it up nicely: "Every cat has a different killing ability, the tiger it makes no difference, it's like they can go and it's a bomb going off wherever it hits."
- No? Maybe only if you're a high school wrestler from North Dakota.
On the way to the finals of a tournament, a busload of wrestlers came across a "dead" raccoon. For reasons that are unclear, they thought it would be a good idea to pick up the raccoon carcass and take it with them. They put it in the storage area of their bus and continued on their way.
Not only did that group of students display some questionable judgment by picking up the carcass, they also failed to notice that their "dead" raccoon was not actually dead. When they arrived at the tournament, the raccoon got up and ran away.
So, not particularly bright (or observant), but maybe not that big of a deal. Raccoons are important rabies vectors and a raccoon that allows itself to be loaded onto a bus by a bunch of high school students, and then later runs away, must be considered potentially rabid since you can't prove otherwise. However, you don't get exposed to rabies just by riding in the same bus as a napping raccoon. You have to have close contact with it (e.g. bite that breaks the skin, exposure of an open scratch/wound or mucous membrane (nose, mouth, eyes) to raccoon saliva).
In this case, however, the team was removed from the tournament when officials found out "they had been in contact with the wild animal and feared they may have contracted rabies." This makes no sense.
- If they were exposed, they'd pose no risk to anyone else at that point. You don't become immediately infectious after exposure. These students could not have transmitted the virus to other competitors.
- There was no evidence that they were actually exposed. No one was bitten or scratched.
Carrington school superintendent Brian Duchscherer said: "Once we found out, we didn't know if there was a potential of spreading anything or if the raccoon had rabies or not but we decided to bring our kids home." I would hope that a quick call to public health would have put those concerns to rest. Either they didn't bother to try to get good information or they got bad advice.
When it comes to handling microorganisms, there are 4 biosafety levels.
- Biosafety level 1 (BSL-1) organisms are harmless.
- BSL-2 organisms include most of the commonly encountered bugs, including things like E. coli, Salmonella and Staphylococcus aureus. They can cause serious disease but infections are often treatable and they can be handled safely with standard lab protocols.
- BSL-3 organisms are a relatively small group of bad guys that require more extensive facilities and protocols to handle them. These include Coxiella burnetii (the cause of Q-fever) and Francisella tularensis, the cause of tularemia.
- BSL-4 organisms are the really bad guys that require high level containment like you see in the movies. There are a limited number of BSL-4 facilities in the world and they deal with bugs like Ebola virus.
One of the BSL-3 pathogens I mentioned was a bug called Francisella tularensis, the bacterium that causes tularemia, which is also listed as a potential bioterrorism agent. Tularemia is a very nasty disease. It's uncommon but human infections occur sporadically in many regions, typically associated with wildlife exposure. It's often associated with contact with rabbits, but the bacterium can be found in a wide range of animals (including insects) and in the environment.
Recently, people in Bell and Coryell counties in Texas (between Dallas and San Antonio) were warned about the potential for tularemia exposure from wild hogs, since 15-50% of tested feral hogs in those areas had evidence of current of past infection. While evidence of past infection (the presence of antibodies against the bacterium in their blood) does not mean that they are actively infectious, it indicates that the bacterium is circulating in the area and that hogs are being exposed. If a hog was actively infected, it could be a source of human infection if there was direct contact (i.e. hunting and butchering).
Because of the potential risk of exposure, the following recommendations have been made:
- Always wear rubber gloves and eye protection when dressing (i.e. skinning & gutting) wild game.
- Ensure that game meats are handled carefully and thoroughly cooked.
- Use insect repellent to keep ticks, biting flies and other insects at bay.
- Look for rabbit nests in tall grasses before mowing. (As unusual as it sounds, running over rabbits with a lawnmower has been associated with development of tularemia).
The risk of tularemia is pretty low, but it's a very serious disease and you don't want it. Using these basic precautions should help reduce the risk.
Glanders, a very serious disease of horses, donkeys and mules caused by infection with the bacterium Burkholderia mallei, has made the news again in a rather unusual manner – it has been reported as the cause of an outbreak in lions and a tiger at an Iranian zoo in Tehran.
The story goes that two Amur tigers arrived at the Tehran zoo from Eastern Russia in April 2010 as part of an exchange program between the two countries. The tigers were supposed to be used to help restore the tiger population in northern Iran on the Miankaleh nature reserve, but their living quarters there were apparently still not ready, and thus they were being kept at the zoo. One of the tigers died in December 2010.
And that’s were the story starts to get a little dicey. The Iranians claim the tigers were imported already carrying the disease, and that the last case of glanders at the zoo was 50 years ago. The tigers had already been at the zoo for eight months - although the incubation period for glanders can be months in some cases, it is normally only weeks. The Russians of course insist that the tigers were completely healthy when they were transferred – they’d been thoroughly examined and quarantined prior to being moved. (This makes the most sense to me, since transporting an animal such a long distance is a major stress and increases the risk of illness, and transporting an animal that is already sick would be even more risky. Not a chance I would take with two members of a species of which there are fewer than 900 individuals left in the world.) They also pointed out that a sick tiger from the cold regions of Russia would be much more likely to succumb to illness during the very hot Iranian summer, not during the winter.
Another report said that three lions at the zoo also died from glanders in the last two months, and subsequently another 14 lions were diagnosed with the disease, all of which were put down by the authorities. The main concern seemed to be the spread of the disease from the big cats to the feral cat population, and then to the human population. This second report states that “the tiger died after being fed contaminated meat, though it is possible it could also be related to the glanders.” Yet another report said that the tiger was infected with feline immunodeficiency virus (FIV - the feline equivalent of HIV).
Facts to keep in mind:
- Glanders is an highly contagious disease, and highly fatal (B. mallei is even classified as a Class B bioterrorism agent).
- Animals that do recover from the disease can become long-term carriers of B. mallei, and are a risk to other animals (and people). Prompt euthanasia of affected animals is therefore often the primary means of controlling outbreaks (but the bacterium is susceptible to antibiotics).
- The infection can be transmitted to other animals (and people), usually through close direct contact or contact with oral and nasal secretions and discharge from skin ulcers. It can also be transmitted by eating tissues from infected animals.
- The bacterium is killed by most disinfectants, and UV radiation (sunlight).
Glanders can affect species other than equids, including people and cats, however there is very little information available about glanders in any felids, let alone lions and tigers. Theoretically it might be possible for the disease to spread from the zoo animals to feral cats and then to people, but I don’t know how many feral cats are brave (or stupid) enough to wander into a lion enclosure. There’s also a possibility that a glanders-positive feral cat may have infected the zoo cats (but again, it would have to be very brave, or very stupid). It is also unclear what tests were used to confirm that the big cats were infected with glanders, and it is unknown if other animals at the zoo have been tested. Since this is typically a disease of equids (and has also been found in goats and camels), I would certainly be checking these animals first.
The big question is, where did the glanders come from in the first place? It seems unlikely that the tigers brought it from Russia, when the disease is actually endemic in Iran (even though they’d had no diagnosed cases at the zoo for many years). Is there a carrier animal in the zoo? Were the animals infected by eating contaminated meat? Was it brought in by feral cats? The source needs to be identified and addressed or animals will continue to be infected, which is particularly bad news for the kinds of rare species that may be found in a zoological collection. Some more details about the testing would also be appreciated – given the severity of this disease, and the severity of the consequences for positive animals (euthanasia), one needs to be as sure as possible that these animals are infected with B. mallei and not something else.
Photo: Amur Tiger (Panthera tigris ssp. altaica) (click image for source)
One concern with uncommon pets is our relatively poor understanding of the infectious agents they may carry. For our "established" pet species, we have a reasonable understanding of what bugs tend to be present and which animals may be at higher risk. The less common the pet, the less research tends to be available, making it harder to assess risks and determine what types of prevention programs need to be in place.
A recent study published in Veterinary Parasitology (Levecke et al. 2010) provides information about chinchillas and the parasite Giardia. This Belgian study involved collection of stool samples from 80 healthy pet chinchillas from 4 households and 4 breeders. They identified Giardia in a rather astounding 66% of samples. Young animals were more likely to be infected, as were animals that participated in shows (I didn't realize there were chinchilla shows).
A subset of samples were typed using molecular techniques to determine the Assemblage (strain/type) of the Giardia. This is very important from a human health standpoint, because some types of Giardia can infect both animals and humans, while others are more host-specific. Most samples (86%) contained Assemblage B. However, a combination of different Assemblages was common, and Assemblages C (71%), A (52%) and E (9.5%) were also found. Importantly, all positive samples contained at least one of Assemblages A or B, which are types that can cause disease in people. Assemblage C is typically associated with dogs and Assemblage E with livestock, so those results were a little surprising.
What does this tell us? It tells us that a large percentage of healthy chinchillas may be shedding Giardia in their stool, and that they typically shed types that can cause disease in people.
Does this mean people are getting sick from pet chinchillas? Not necessarily, but it indicates there is a risk.
What can chinchilla owners do? It's pretty straightforward. Giardia has to go from the animal's stool to a person's mouth to cause infection. The use of good general management and hygiene practices (especially handwashing) should greatly reduce the risks. As the folks at Barfblog say, "don't eat poop."
Should chinchillas be tested for Giardia? Probably not. A single negative result does not necessarily mean Giardia isn't there or that it never will be. Given the numbers reported here, it's best to go on the assumption that every chinchilla is (or could be) positive, and take appropriate precautions.
An interesting paper in the journal Emerging Infectious Diseases (Page et al. 2011) describes an impressively large effort to study the effect of anthelmintic (dewormer) baiting on parasite contamination at raccoon latrines sites in Indiana.
Raccoon latrines can be highly contaminated with various parasites, because raccoons congregate at these sites and use them as "communal toilets." Of all these parasites, the raccoon roundworm, Baylisascaris procyonis, gets the most attention. It is very common in raccoons, but it is also a very rare cause of disease in people who swallow the infective parasite eggs from the environment. In some of these people the parasite larvae can cause very serious neurological disease which can be very difficult to treat.
In this study, the research team identified 559 raccoon latrines in north-central Indiana. They removed debris from the areas and used a torch to help kill the parasite eggs that were there (this is one of the very few effective ways to kill the very hardy eggs of Baylisascaris). At a selection of latrine sites, they also collected baseline fecal samples. After this was all done, they distributed dewormer (pyrantel pamoate) baits in half the areas once a month (leaving the other half of the areas as controls). They then collected fecal samples at all the latrine sites approximately 6, 12 and 18 months later.
Fecal samples were tested for B. procyonis eggs. Also, they captured mice from some of the study patches. Like people, mice are intermediate hosts for B. procyonis, and they can be infected in the same manner, so researchers looked for B. procyonis larvae in the brains of the mice.
Overall, they tested 1797 fecal samples. In the first round of sampling, 33% of samples contained B. procyonis eggs. The prevalence of eggs decreases significantly (3-fold) after baiting by the first recheck, and stayed at that level throughout the study. By the one-year sample time, there was also a significant decline in B. procyonis larvae in the brains of mice (27% vs 38%).
This impressive study shows the potential impact of controlled and somewhat practical interventions on the presence of some concerning microorganisms. Certainly, no one is going to be able to treat all raccoon latrines with a torch. However, dewormer baiting might be a consideration in areas that are close to human populations, along with other control measures. Dewormer baiting could be relatively cost-effective in this case. It won't eliminate the problem, but it might help reduce environmental contamination and the associated potential for human and domestic animal exposure.
A recent news report from Berkshire, Massachusetts that was highlighted by ProMed is a strange and concerning story of rabies exposure.
The story involves two people that were stalked and attacked by an aggressive fox. One man was attacked in his driveway. He fought the fox off with a smoker lid, but several hours later it attacked and attached itself to a woman next door who was outside collecting her recycling bin. The fox bit her multiple times, and it took 20 minutes (with the aid of the same smoker lid - apparently a good fox extractor) to remove the fox from the woman’s leg. The man then killed the fox.
The woman’s sister called the police, who dispatched paramedics and suggested they call Animal Control to get the fox tested for rabies.
So far, so good. Unfortunate attack but managed as well as can be expected.
Anyway, when the paramedics arrived, they told the woman that she didn’t need to go to the hospital. A little more information in the article would have been nice here. Based on the severity of the injury, the response of the paramedics probably makes sense. The fox had bitten her, but the bites didn’t appear to be too serious from a trauma standpoint, and racing her off to the hospital in an ambulance was not required. However, rabies exposure is a major concern and this scenario raises a good question: What is the role of paramedics in thinking about and educating people about the risk of rabies exposure? Ideally, paramedics should know enough to tell people that they should seek medical care when there has been potential exposure to rabies. I don’t know whether this is the case, however. If someone isn’t injured enough to require emergency care, is that all that the paramedic needs to assess?
The woman then had a relative drive her to the emergency room. If this was because of concerns about the severity of bites, then that makes sense. If it’s from a rabies exposure standpoint, then it’s overkill. Assessment of rabies exposure and starting treatment is considered a medical "urgency," but not an "emergency." Basically, that means you don’t need to be treated immediately and you have time to go to a regular physician. In this case, going to her physician the next day would have made the most sense, since emergency rooms are not the ideal place for rabies assessment and exposure treatment.
The fox was rabid in the end, and the woman was started on rabies post-exposure treatment. Even if this was an inefficient way of getting care, the key point is that she was treated. Rabies is almost invariably fatal but is almost 100% preventable with proper post-bite care.
The description of her treatment is strange, however. “On Monday she began the lengthy series of anti-rabies vaccinations, which included injections into each bite mark. She returned to the hospital for another shot on Thursday and learned that she has 10 more vaccinations to endure this month, with each hospital visit at a USD 75 co-pay.” This makes no sense. Current-day rabies post-exposure treatment consists of a series of 4 doses, not 10 or more.
Another strange part of this story is the apparent difficulty the two victims had getting the animal tested. The people who were attacked claim “I called a rabies hotline and nobody picked up." As a result, the fox's body sat on the woman's property for three days until they took it to a local vet clinic, that shipped the fox’s body for testing. In another strange twist, it seems the woman had to pay for testing herself. That makes absolutely no sense. This is clearly an animal with a high likelihood of having rabies and a situation where there has been clear exposure of a person. The rabies status of the animal must be determined and requiring people to pay for that themselves makes no sense.
By the time I posted this story, the Berkshire newspaper had pulled the article from its website. I don’t know why. It could because the story was poorly written or the information was incorrect. Regardless, it raises some interesting issues.
Petting zoos are very common in the UK (as in many other regions), where approximately 2 million people visit 1000 different petting zoos every year. While the vast majority of petting zoo visits are simply pleasant outings associated with no problems, some people leave with more than just memories... they leave with an infectious disease. A letter in the latest edition of Emerging Infectious Diseases (Gormley et al 2011) describes one of the diseases people can pick up at petting zoos: cryptosporidiosis.
From 1992-2009, 55 outbreaks of intestinal infections associated with petting zoos were reported in England and Wales. (There were presumably many more unidentified cases or even outbreaks.) Of these, 55% were caused by E. coli O157. The second most common cause was Cryptosporidium, a protozoal parasite that is commonly found in feces of calves and lambs, which was responsible for 42% of the outbreaks and affected 1078 people. (Again, this is probably an underestimation of the true numbers because typically there are many undiagnosed or unreported cases of illness for every case that is identified). The number of people involved ranged from 2-541 per outbreak. Twenty-nine people were hospitalized due to the infection.
Factors associated with outbreaks were things that we know are issues with petting zoos:
- Contact with young lambs, calves or kids
- Inadequate hand hygiene facilities
Cryptosporidium outbreaks were also more common in the spring, as opposed to E. coli outbreaks which were more common in the summer. This may be explained by the association of the pathogen with contact with young calves, lambs and kids, since these animals are mainly born in the spring.
Alcohol-based hand sanitizers, while excellent for most bacteria, are ineffective against Cryptosporidium. This can also be a contributing factor to outbreaks of cryptosporidiosis, particularly if hand washing stations are replaced with hand sanitizers. While alcohol-based hand sanitizers are certainly better than nothing, their usefulness is limited when resistant pathogens (such as Cryptosporidium) may be present, and when peoples' hands might be contaminated with large amounts of dirt or other debris (e.g. feces).
Petting zoos can be great events, particularly for kids. However, kids, especially young kids (less than five years of age), are at high risk for certain infectious diseases they may encounter at such venues. While petting zoos seem to be improving and governments are paying more attention to making them safer, visitors need to look out for themselves.
- Make sure a hand hygiene station, preferably a hand washing station, is available. Do this before you touch animals.
- Always wash your hands after leaving the petting zoo, regardless of whether or not you touched an animal (since other surfaces you touched may have been contaminated).
- Do not have contact with young calves, lambs, kids (i.e. baby goats) or poultry.
- Do not have contact with diarrheic animals, or animals that appear to have any other health problems.
- Don't take food, drink or anything that might go into a child's mouth (e.g. baby bottles) into the petting zoo area.
- Closely supervise children.
- If you see a poorly equipped or run event, don't be afraid to contact your local public health office. While most petting zoos seem to be improving, some are still pretty bad and may need to be forced to do things right.
A dead otter was found floating in a pond in Florida near the site of a recent otter attack that was captured on video. Testing confirmed that the animal was rabid. It's impossible to determine whether this is the same otter that attacked the teenager in Boca Raton last week, but it's likely, and shows that rabies post-exposure treatment of the victim was a good decision.
Numerous rabid otters have been identified in Florida in recent years. I haven't seen any information about the viral types that have been involved or how it is thought that otters are becoming infected. Regardless, these incidents should be a reminder to stay away from wildlife, and to consider rabies exposure any time someone has been bitten by a wild mammal.
A teenager who was filming an otter he spied in a pond now knows more about rabies than he probably ever wanted. The 19-year-old shot the video from the bank of a pond, watching the otter innocently swimming around. After a brief stare-down, the otter did another quick swim, then ran onto shore and attacked! And it was all caught on camera and displayed to the world via YouTube.
This is the third recently-reported otter attack in the area. This type of behaviour obviously isn't normal, and rabies has to be a concern. Rabies has been previously identified in marauding otters in Florida, and since this otter got away, you have to assume that it was rabid. Accordingly, the victim is undergoing rabies post-exposure treatment.
Pardon my straying from the zoonotic disease realm, but here's a little light reading... (for the pdf version with images click here).
Medical Mysteries of the 100-Acre Wood
Children around the world have been entertained by activities in the 100-acre-wood for decades. But at what cost to the animals? What kind of example is this setting given the obvious medical and ethical problems present in these animals? As protectors of animal health and welfare, and fully cognizant of the ethical requirements put upon us by the Veterinarian’s Oath, we feel bound to address these issues and call for immediate action.
Winnie the Pooh may be a lovable creature, but he clearly has numerous health problems. Despite being born in 1926, Winnie the Pooh appears not to have grown to adult height. This stunted size may be the result of a primary growth hormone deficiency, but we suspect that it is solely the result of inadequate nutrition. His body mass index is excessive, in large part from his inadequate diet. A diet based solely on honey is inadequate for a growing bear. The caloric density is a main factor in this animal’s obesity. As well, it is virtually guaranteed that Pooh has, or will soon have, numerous nutritional deficiencies based on this diet. Pooh also seems rather "slow on the uptake" which may be the result of inadequate omega-3 fatty acid intake. Unlike many other bears feasting on wild salmon and other sources of these important fatty acids, Pooh’s omega-3-deficient diet has not provided him with the neuroprotective and developmental benefits that omega-3s provide. Sadly, this is irreversible and Pooh will never be able to obtain his true genetic capacity for intelligence. Despite the irreversible nature of his improper brain development, there are other areas that can be improved and his diet must be addressed immediately. This may not be easy, given decades of inadequate diet and conditioning to only eat honey. While some may recommend the use of mirtazapine to stimulate his appetite along with provision of a normal diet, we disagree and believe that a more natural approach involving complete restriction of honey along with providing an adequate diet will be successful. Use of mirtazapine may be unnecessary, particularly once hunger sets in. Further, this would be an off-label use of the drug and we have little confidence in available ursine dosing data. There is always concern regarding the metabolic efforts of dietary restriction in overweight animals, but we are unable to find any published reports of fatty liver syndrome in obese bears being weaned from a honey-only diet, so this absence of published evidence clearly indicates that this is a completely safe approach. We do, however, recommend a complete hepatic evaluation prior to feed restriction because of the marked yellow pigmentation of this bear.
Eeyore clearly has a significant undiagnosed metabolic disease, given his body condition, poor muscle mass and lethargy. While equine metabolic syndrome has been poorly investigated in donkeys, it is a likely explanation for the excessive body condition. The slow purposeful movements exhibited by this animal also suggest the presence of a primary muscular disorder such as polysaccharide storage myopathy. At a minimum, muscle biopsy is indicated to determine the cause of his unwillingness to move beyond a crawl. Certainly, the slow movement and vocalization could be the result of a brain lesion but, sadly, Eeyore’s girth is too excessive for him to fit into existing MRI or CT scanners. Only with proper control of his metabolic disease and a good nutritional program will there be any ability to diagnose any cerebral component. Blind brain biopsy is not recommended due to the invasive nature of this diagnostic test and the rather low likelihood of actually identifying brain tissue in a donkey.
At the opposite end of the spectrum is Tigger, the hyperactive tiger whose incessant jumping and twitching likely indicates the presence of a cerebellar disorder. In the absence of advanced imaging (which would obviously require travel beyond the 100-acre-wood) one must make a presumptive diagnosis of cerebellar hypoplasia from fetal infection with feline panleukopenia virus. Unfortunately, there are no therapeutic options and there is a grave prognosis for clinical improvement. He must also have an additional neurological abnormality affecting his cerebral cortex since he has repeatedly shown an unwillingness to recognize readily available food sources, most notably a young pig.
Roo is an active young kangaroo. While his excitable, bouncy nature may simply be the exuberance of youth, we are concerned about the sustained energy. This concern is heightened by the fact that all images of this animal show profound papillary dilation to the point that his eyes appear completely black. This sign clearly indicates the potential for illicit drug exposure. Drug testing is required. His mother, Kanga, appears to be a loving, caring mother, with no apparent health problems. Despite this, she must be investigated as a potential source of Roo’s drug exposure because her attitude seems too persistently cheerful for someone spending all her time around a hyperactive youngster.
Piglet’s most obvious abnormality involves vocalization. There are many potential causes of vocalization abnormalities in pigs, including behavioural and neurological etiologies. Piglet appears to be the only piglet left from his litter, so congenital or neonatal infection that killed his siblings and left him with a serious stutter must be considered. We are hesitant to speculate about specific causes or the potential food safety risk. CT or MRI would be required to explore this further, but it is questionable whether this is justifiable given the cost involved for a pig. Further, consumer concerns about irradiated meat may preclude CT scanning.
Rabbit, while exhibiting classical signs of dominance, does not manifest his behaviour in bites or other serious outcomes. His dominating personality is more directed at controlling the daily activities of his cohorts, without obvious negative impacts. That, combined with limited pharmacokinetic or safety data for drugs like fluoxetine (Prozac) in rabbits lead us to recommend no treatment for this disorder. However, given the high prevalence of Encephalitozoon cuniculi shedding by rabbits, we must assume that he is carrying this animal and human pathogen in his kidneys, and ensure that contamination of the environment with urine is avoided. Concerningly, there consistently appears to be a dearth of hand hygiene opportunities in the 100-acre-wood, with few sinks and complete absence of hand sanitizers. This infection control deficiency must be addressed to contain the multitude of pathogens that appear to be present in this toxic environment.
And finally, on to Christopher Robin. While a minor, Mr. Robin is clearly the caretaker of this ragtag group of animals and certainly bears (pun intended) responsibility for their health and welfare. His obvious failure to provide adequate veterinary care is of significant concern and should result in immediate investigation. The potential for Christopher Robin to be the source, intentional or otherwise, of Roo’s illicit drug exposure raises numerous additional concerns. At a minimum, thorough veterinary examination of all animals and review of animal management practices should be mandated by regional authorities to ensure the health and welfare of these animals, as well as children around the world that are learning from Christopher Robin’s example.
The debate about urban (backyard) chickens is again in the news, this time in Windsor, Ontario. The debate was ignited by a recent case in which a Windsor couple has been given one week to get rid of their backyard hens. The couple is preparing to fight the order, stating that the chickens are their pets, and no different than other pet species.
Different cities have taken different approaches to the urban chicken movement. Some allow or even actively support keeping urban chickens. Others ban them outright.
Supporters of the urban chicken movement say that the birds provide local, natural food and that they can be good pets. They say that a few chickens are no more noisy or disruptive than many dogs.
Opponents worry about the mess the birds make, odours, noise, attracting other urban wildlife like raccoons and skunks, and infectious disease risks.
Which position is right? I don't know. Bringing animals into closer proximity to people always increases infectious disease risks, but does it increase them enough to be a concern, and do the positive aspects outweigh the concerns? Even healthy backyard chickens can carry a variety of potentially harmful bacteria that could be spread by direct contact, or contact with the chicken's environment or run-off into neighbouring yards. However, the biggest problem is probably not these small groups of chickens spreading infection - the nuisance factor and attracting other animals (including rabies vectors) into the area might pose the greatest risk. We don't have enough information to make a very informed decision one way or the other. However, if people are going to keep backyard chickens and authorities are going to allow it, some common sense needs to be used in terms of how many birds are kept, how they are raised, how to dispose of manure, how to keep wildlife away, and general hygiene practices.
One more thing to be wary of is statements about food safety regarding urban chicken eggs. People sometime equate organic, backyard, non-intensively farmed animals as being no risk for foodborne pathogens. That's not the case. This type of farming does not necessarily result in safer food, and misconceptions to that effect can increase disease risks if people fail to take adequate precautions. Backyard eggs and poultry products need to be treated the same as products coming from a commercial farm.
A nine-month old Georgia (US) baby is in critical condition after being attacked by two raccoons while sleeping in her crib. The attack occurred in the middle of the night, and the baby ended up with severe bites over her head and other parts of her body.
It's not clear at this point whether these were pet raccoons that were being kept illegally or whether two raccoons broke into the house. If the latter, it's suspected that the family may have been feeding the raccoons, which could have made them less fearful of people than usual. The news clip also shows a large cage outside that could presumably house raccoons (pure speculation on my part here). Authorities are investigating whether these were illegal pets, and if so charges could result.
An unprovoked raccoon attack in a house is pretty strange. Raccoon attacks would be more likely in the raccoon's environment or if they were sick (e.g. rabies). They might also be more likely to try to break into a house if they have been fed by people and lost their fear of humans. Still, attacking a baby seems like a very strange thing for them to do. I also wonder whether an attack like this might be more likely with a pet raccoon, especially if it was an older, established raccoon in a household where a new baby had disrupted the routine.
Rabies has to be a major concern in a situation like this. One of the raccoons was killed by police. The news clip and article on the same website provide conflicting information about whether the other raccoon was caught. Both raccoons need to be tested to determine whether they had rabies. Otherwise, the baby will need rabies post-exposure treatment.
British champion rower Andy Holmes has died of leptospirosis, which was suspected to have been acquired from the water during the annual Boston Rowing Marathon on the River Witham (UK) in September. The 51-year-old Holmes, an accomplished Olympic rower from the 1980s, started to feel unwell in the days after the race, and developed a fever. He was subsequently diagnosed with Weil's disease, a serious form of leptospirosis that can cause liver failure.
In some ways, this is being written off as a very rare and unfortunate event. It's always hard to determine how aggressive to be when making recommendations about avoiding infections that can be acquired from common recreational and occupational activities.
The race's welfare officer stated "Part of any rower's training is being warned about water safety. If you fall into water you must wash thoroughly and if you think you have ingested any water seek medical advice." The problem is, exposure to water during rowing and similar events is basically unavoidable. Splashes of small amounts of water into the eyes, nose, mouth or cuts/scrapes could be enough to inoculate potentially harmful microorganisms into the tissues. People aren't going to run to the physician after every potential exposure. Knowing whether or not the water source has previously been implicated in leptospirosis infections may be useful, but it doesn't tell you anything for certain.
General recommendations for people working around water include:
- Covering cuts and sores with waterproof bandages.
- Washing hands, particularly before eating.
- Avoiding contact of water with the eyes, mouth and nose, whenever possible.
- Avoiding ingestion of any amount of water.
- Ensuring their physician knows about the potential for water exposure should they become sick.
Obviously, complete avoidance of water exposure is impossible for many people, and the overall risk is very low. Weil's disease is a rare condition but it does occur, both as sporadic cases and large outbreaks. It's usually treatable but can be fatal, so it shouldn't be dismissed.
Issues with pets and leptospirosis are similar. Pets, mainly dogs, become exposed from contact with water that has been infected by Leptospira bacteria from the urine of infected wildlife. Infection can cause a broad range of disease in dogs as well, from subclinical to acutely fatal. Vaccines for certain strains are available for dogs who are at higher risk of exposure. Talk to your veterinarian about whether your dog should be vaccinated against leptospirosis. More information about leptospirosis in dogs and cats is available on the Worms & Germs Resources page.
Image: Andy Holmes sits behind Steve Redgrave after winning a gold medal for Britain at the 1988 Seoul Olympics.
A Florida woman is facing criminal charges after biting someone at a vet clinic. Kathleen Minneker took her two dogs to the Affordable Animal Care Clinic in Fort Myers, Florida, for grooming. She showed up an hour late and became irate when the grooming wasn't finished on time. At that point, Ms. Minneker apparently lost it, and attacked clinic owner, Gina Brashear, who ended up covered in bites, bruises and scatches. Brashear explained "a chunk is gone off my finger and a chunk off my toe." All this was from the irate customer, not the dogs. In a bit of an understatement, Brashear said "She's a biter."
Brashear is now receiving antibiotics to prevent bite-associated infection, something that can result from human bites just like from animal bites.
There's no word on whether Ms. Minneker was up to date on her rabies shots. Unlike a dog, Ms. Minneker will not be quarantined for 10 days to make sure she does not have rabies, however she may end up with a somewhat longer confinement period courtesy of the State of Florida.
A somewhat strange report from MSN News India describes measures that are being considered following an outbreak of salmonellosis that killed 3 tigers at Bannerghatta Biological Park. The zoo authority is investigating whether tests used by the Indian army to detect Salmonella in milk and milk products could be used to detect Salmonella in meat.
Testing of meat for Salmonella is a reasonable consideration, but it really depends on how often meat samples are contaminated.
- If most meat samples have Salmonella, what will be done with the results and the meat? The cats have to eat, and unless they have a plan to throw out all positive food or do something to it eliminate Salmonella (like cooking it), testing might be of limited use.
- Also, if Salmonella is usually there at low levels and problems only occur with sporadic high level contamination, or contamination with particularly virulent strains, then using a test that just says "Salmonella yes" or "Salmonella no" may not help much.
It is also reported that "the authority is also in talks with some firms to come up with a microwave which has the capacity to kill microbes in 300-400 kg of meat at a time."
- This is questionable since it's probably a lot of expense to develop a large microwave, and particularly since microwaving is not a reliable method of killing Salmonella. If there is a need to treat the meat to kill Salmonella, there are more reliable measures, such as cooking in a conventional oven, irradiation or high pressure pasteurization.
Another bizarre aspect is someone from the zoo authority stated "In Canada, when 7,000 pet dogs died on being fed infected beef last year, some firms there came up with a microwave with the capacity to kill microbes in 500 kg of beef in three to four minutes. We are exploring the possibility of similar technological innovation being implemented here, for which we are in talks with some technicians".
- I have no idea what this guy is talking about. I am not aware of any outbreak killing 7000 dogs in Canada (and if it really happened, I'm pretty sure I'd be well aware, if not in the middle of it).
On the positive side, all of the tigers that survived have now completely recovered and no new cases have been identified.
A Wisconsin man is recovering after being attacked by a seven-year-old Siberian tiger at The Wisconsin Big Cat Rescue & Educational Center. The victim is a volunteer at the centre, and he was attacked while giving the tiger some water. He was airlifted to hospital but his injuries are described as minor.
As is often the case, it is suspected that the attack wasn't an indication of aggression. Rather, it may have been playful behaviour, something that can quickly become deadly with a large cat. People have been killed before by big cats trying to play with them - all it takes is one misplaced swat from these extremely powerful beasts to do significant harm.
Attacks by big cats are not exactly rare in North America, and are almost always associated with poorly housed "pet" big cats and roadside zoos. It is actually relatively easy to buy a big cat, and many parts of North America have few to no restrictions on ownership. The animals often suffer because of inadequate nutrition or poor housing, and public health is at risk because of inadequate housing and restraint. There's no reason for tigers to be in North America apart from accredited zoos (or similar facilities) with adequate housing for these large animals and properly trained personnel. They are not pets. You can hand raise a tiger and make it pretty tame, but they are never safe. How many cat owners are bitten, swatted, stalked or jumped on by their small-sized pet cats every day? Imagine what happens what those same feline behaviours are exhibited by a tiger that weighs a few hundred pounds.
When I first saw the headline, I thought "here's another person injured at some crappy roadside zoo that has no business keeping big cats." This facility and the circumstances around the attack seem to be different. This does seem to be a legitimate rescue facility (some "rescue" facilities for various species are just people who like to collect animals), although it's hard to say too much about how reputable the place is from a distance, and whether there is any truth to some unflattering internet reports. The attack also occurred through a fence. In properly run facilities, the likelihood of an attack is reduced by restriction of direct contact between people and cats. If someone isn't in a pen with the animal, the chances of injury are much lower. Circumstances regarding this attack aren't clear, so it's hard to say whether there are issues with the design of pens or how people interact with the animals, and whether the person really wasn't in the pen. However, the fact that this seems like a more reasonable facility than your average small zoo and a potentially serious attack still occurred underscores the danger posed by people owning these animals.
ProMed's monthly rabies update contains some recurring themes:
- A couple of incidents of dog versus rabid raccoon. The dog usually comes out on top, but the raccoon can exact revenge at the end of the day through the need for quarantine or euthanasia. If the dog is not vaccinated, a long quarantine or euthanasia is required. If the dog is vaccinated, only a shorter observation period is needed.
- A rabid skunk was found wandering around during the day with a wobbly gait and drooling. Any wild animal that is acting strangely should be considered rabid until proven otherwise. They don't have to be showing signs of severe neurological disease. Something as simple as not being afraid of people or wandering around in areas or at times when they would not usually be found should raise the suspicion.
- A child who was sleeping outside woke up to "find a raccoon, kind of, scratching at his leg." (I assume they mean it was "kind of scratching at the kid's leg," (whatever that means), instead of it was "kind of a raccoon.") The raccoon wasn't caught for testing but the child is undergoing post-exposure treatment because a normal raccoon wouldn't be expected to do that, so there is a significant chance of rabies exposure. Scratches are not high risk since rabies virus does not live in the claws, however it is possible that saliva from the raccoon could have been present on the animal's feet or the raccoon could have licked the child before scratching, such that the scratches could have then inoculated rabies virus into the tissues.
- A couple of reports of rabies in rabid kittens. These cute little rabies vectors cause repeated problems, and lead to public alerts notifying anyone who may have handled the kittens to get evaluated to see if they need post-exposure treatment. Handling of strays should be avoided.
- A family received post-exposure treatment after being bitten by their rabid cat. Vaccination of pets is not just for the health of the pet. It's to reduce exposure of people as well.
2009 animal rabies statistics have recently been published in the Journal of the American Veterinary Medical Association (Blanton et al 2010). Here are some highlights:
- 6690 rabid animals were identified, along with four human cases. (One of those human cases was associated with travel to India, as described as described in a recent post).
- Rabid animals were identified in 49 states and Puerto Rico.
- 92% of infected animals were wildlife. Raccoons were the winners (actually, the losers, I guess) with 2327 cases, followed by 1625 bats, 1602 skunks, 504 foxes, 300 cats, 81 dogs and 74 cattle.
It is important to remember that these are rabies diagnoses, not all rabies cases. Certainly, more animals died of rabies and were not tested. These numbers may represent the "tip of the iceberg," particularly for some wildlife species. This can impact on the accuracy of the relative numbers between species, and year-to-year changes in cases, but doesn’t change the fact that rabies is present, widespread, relatively common and can infect a wide range of animal species, including pets. It also highlights why vaccination of pets is still important.
A Salmonella outbreak at the Bannerghatta Biological Park in Bangalore, India, has resulted in the death of three tigers. The latest victim, a four-year-old female tiger named Minchu, had been critically ill for the past two weeks and died of kidney failure. (Kidney failure is a potential complication of severe intestinal bacterial infections like salmonellosis.) This followed on the deaths of Minchu's older sister Divya and a 45-day-old tiger cub. Fifteen of the remaining 41 tigers are sick, and more deaths would not be surprising.
The source of the outbreak at the Bannerghatta Biological Park hasn't been reported. Likely, it originated from Salmonella in raw meat. Whether the large outbreak indicates a highly contaminated batch of meat, a particularly virulent strain of Salmonella or widespread transmission of Salmonella from an initial case or two is not clear. Regardless, good infection control practices are going to be critical, since the animals' environment is certainly highly contaminated. This poses a risk to all animals and people exposed to the environment. Good infection control is also needed to prevent Salmonella from spreading to other parts of the park. Spread is most likely to occur via peoples' hands or clothing, or through contaminated equipment.
Large Salmonella outbreaks can be very hard to contain. Aggressive infection control, including testing of animals, isolation, thorough cleaning and disinfection, restriction of movement, and re-assessment of various management practices are key aspects of any outbreak control program. Hopefully this outbreak is now under control and Salmonella doesn't "escape" and affect other animals or people at the park.
The Public Health Agency of Canada (PHAC) has issued a public advisory regarding salmonellosis linked to frozen rodents used as pet (reptile) food. The rather vaguely-worded advisory states that there have been seven reported cases of Salmonella caused by a specific strain that has been linked to frozen rodents. No details about the cases or the origin of the rodents are provided, however it presumably involves the large international Salmonella outbreak associated with Mice Direct, a mail-order rodent company. The advisory reminds people to take basic precautions when handling rodents that are used for reptile food.
Basically, the key is to consider all such frozen rodents biohazardous, and handle them accordingly. Remember to:
- Limit contact with the rodents as much as possible.
- Thaw them in a sealed container, preventing any contact with human food.
- Keep them away from kitchen countertops and other food handling surfaces.
- Wash your hands thoroughly after handling them.
In response to a case of plague in prairie dogs in Saskatchewan's Grasslands National Park, park officials are dusting prairie dog burrows with insecticide to try to control fleas. A single case of plague, a serious bacterial infection caused by Yersinia pestis, was identified in a prairie dog in the park earlier this summer. Plague is present in some areas of North America, but it's rare in Saskatchewan. It circulates in wild small mammals, and prairie dogs are particularly susceptible to infection. The main mode of transmission is via fleas, which feed off infected animals, then bite and infect other animals.
Prairie dog numbers at the park have dropped by 50-70% this summer, however it's not known whether plague is involved in this, as there has also been a drought. It's fair to assume, though, that if there has been one case of plague found in the park, there have probably been many other undiagnosed cases. Whether or not plague is responsible for the large drop in prairie dog numbers, measures to try to reduce plague transmission are a good idea because of the impact it can have on the prairie dog population (and those of other wild mammals), as well as people or pets that may venture into the area. Anyone or anything walking through the area could plausibly be bitten by an infected flea. The odds are probably pretty low, but park officials are trying to keep people and pets out of the park to reduce this risk.
A Rosedale, California high school has welcomed a new pet into the classroom: a squirrel. CJ Addington, a physics teacher, caught a baby squirrel that some students spotted outside the school.
I have some (just a few) issues with this:
- In most areas, catching and keeping wildlife is illegal, for good reason.
- A baby squirrel wandering around outside is not necessarily an orphan that needs saving. There's a good chance this squirrel will die now that it's been taken from its habitat.
- I doubt the teacher has a wildlife rehab license and knows how to take care of the squirrel.
- The teacher wants to "take care of it until it's a full grown squirrel and ready to go back in its habitat." Releasing an animal that has been hand-raised in captivity back into the wild is likely going to result in a quick death, and that's completely unethical.
- I have a hard time figuring out how to incorporate a pet squirrel into a physics curriculum.
- The teacher says "The administration did not have any disputes about having the squirrel." The administration, therefore, is clueless about a host of issues, including capture and care of wildlife and CDC recommendations against having wild animals in situations like this.
- Mr. Addington also said, "It is too young of a squirrel to be carrying anything, so I didn't have to vaccinate it or anything like that." Uh...no. This squirrel could be carrying a wide range of pathogens, including rabies. The number of people that have been exposed to rabies through handling baby wildlife is astounding.
- "It's cool to have a squirrel that freaks out at random points of class" said one student. That certainly sounds like a healthy, stress-free animal that is thriving in its environment (note the sarcasm here). Also, it shows how it's a potential classroom disruption.
Pets can be useful additions to classrooms in specific and well-controlled situations. Things to consider when deciding if an animal is reasonable to have in a classroom include:
- Are there any school rules that cover this?
- Are there any students that are at increased risk of infection because they have compromised immune systems? (Part 2 of that question is "If no, are you SURE that you would know if there was an immunocompromised child in the class?)
- Are there any students who are afraid of the animal? (Part 2: are you sure? applies here too).
- Are there any students who might be allergic to the animal? (Part 2 again...)
- Is there an educational value, or is it just a novelty?
- Will children eat in the same room as the animal?
- Can the animal be kept safely and in a humane manner?
- Who will care for the animal on weekends and holidays?
- What happens if the animal gets sick?
- Will protocols be established before the animal arrives, covering the above plus other issues, such as who will have access to the animal, how it will be handled, what type of hygiene practices will be used, etc?
The list goes on. Clearly, having an animal in a classroom is something that requires a lot of thought, time and work. It is possible for animals to be valuable teaching tools in a classroom, as part of the curriculum, as well as providing entertainment and increased empathy towards other species. It's also possible for animals to expose people to serious infectious diseases, to be distracting and to disturb the education of individual students or whole classes.
Wildlife should never be classroom pets.
An attack by a bear that killed a caretaker in a Cleveland, Ohio suburb has ignited discussion about the complete lack of regulation of ownership of large and potentially dangerous animals in many jurisdictions. Despite numerous serious injuries and deaths caused by dangerous exotic animals, some places like Ohio have had no means of restricting who keeps such beasts and how. Some places have no rules because no one has put the effort into developing them, while others have had attempts blocked by agricultural interests - people worried about regulations that could affect housing and care of farm animals. (You'd think that, with the number of lawyers in the US, someone could write some legislation that differentiates a Siberian tiger from a cow). As Wayne Pacelle, president of the humane society of the United States, said "It's just a free-for-all in Ohio... Tigers, wolves, bears in a suburban Lorain County community. It's a disaster waiting to happen."
As reported by the Associated Press, "According to a database of publicized exotic-pet escapes and attacks since 1990 kept by the animal rights group Born Free USA, Ohio ranks fifth in the number of episodes that hurt or killed a human — 14. The leader, Florida, has had 43, followed by Texas with 19, New York with 18 and California with 16. Alabama ties Ohio with 14."
Anyway, the bear in question is one of many large exotic animals owned by Sam Mazzola, a "former bear-wrestling entrepreneur." Since the animals weren't in a zoo or some other place where they were publicly exhibited, USDA rules didn't apply. Since the animals were not native endangered or threatened species, US Fish and Wildlife Service rules were avoided. In a place like Ohio, these are the only lines of protection for both these animals and the general public.
Mr. Mazzola claims that injuries and even deaths are "things that happen when you deal and love these type of animals," while explaining that he's had about 2000 stitches from his time working with animals - so much for the claim that this is a safe situation. You also have to wonder about the ethics of putting young people in a position where they are taking care of large and potentially dangerous animals with, presumably, minimal proper training: the person killed in the Ohio bear attack was 24, and people much younger than him have been killed taking care of other large exotic animals.
Large exotic animals can be very interesting, but the health and welfare of these animals, people working with these animals and anyone that might come into contact with them (including if they escape) need to be considered. Too often, large exotic animals are kept in inadequate facilities, in terms of both animal health and welfare and human safety. Since common sense clearly will not prevail, the only way to control this is with legislation clearly describing which animals can be kept by which people and under what conditions, and through diligent enforcement of the regulations (with adequate penalties for violators to act as a deterrent).
Around here, fall fair season is getting into full swing. Fall fairs can be a lot of fun for kids and adults alike, with midway rides, livestock shows, horse events, lots of good (and bad for you) food... and petting zoos. Petting zoos can be entertaining and educational, but they are also the source of numerous disease outbreaks every year, sometimes resulting in serious illness.
Petting zoos are a concern because even healthy-looking farm animals can be infected with harmful bacteria like E. coli O157 or Salmonella. The odds of getting sick at a petting zoo are low, but there is always some degree of risk. Petting zoos are certainly getting better. I tend to cringe less every year, although it's still not too unusual to see some pretty major issues.
If you are going to go to a petting zoo, think about the following:
- Kids less than five years of age, the elderly, pregnant women and people with compromised immune systems are at higher risk for infections. Particular care must be taken by these individuals, and they should avoid any contact with high-risk species like baby calves, lambs, reptiles or young poultry (chicks).
- Take a look at the animals. Avoid contact with any animal that has diarrhea, skin lesions or that appears sick.
- If you are taking kids into a petting zoo, watch them closely. Make sure they don't put their fingers in their mouths or do anything else that would increase the risk of them swallowing harmful microorganisms. Don't let them carry cups, toys or other personal items that might become contaminated.
- Make sure you don't have any food or drink with you when you enter a petting zoo.
- Above all, wash your hands thoroughly (ideally) or use an alcohol-based hand sanitizer (second best option) after you have had contact with any animal OR been in a petting zoo environment. Even if you didn't touch an animal, you might have contaminated your hands from touching something in the area. In some outbreaks, people that didn't have contact with animals but were in the area have become sick.
By taking these simple steps you can greatly reduce the risks and make it more likely that the petting zoo will be an enjoyable and infection-free event.
At the same time, while it's important to take some responsibility for what we do, petting zoo operators need to ensure that their petting zoos are run properly. If you are at a petting zoo that doesn't comply with expectations, especially if there are problems with access to hand sanitizers or hand washing stations, don't be afraid to contact your local public health department and let them know.
Image source: www.ecoliblog.com
Security screeners at a Thai airport discovered an attempted tiger smuggling, presumably by realizing stuffed animals don't have a skeleton. A 31-year-old Thai national was trying to smuggle a sedated tiger cub in a carry-on bag. As it went through the X-ray machine, screeners noticed an item resembling a real cat. Closer inspection identified the actual item and the individual was arrested.
Unfortunately, this person is presumably among the very small minority of smugglers that actually get caught. Creative smugglers, established smuggling pathways, lucrative markets and extremely lenient penalties combine to make this a pathetic but unfortunately often profitable venture that results in the deaths of huge numbers of animals, and acts as a potential way to transmit various infectious diseases that could affect other animals or humans.
Image: Tiger cub at the Philadelphia Zoo (source: http://commons.wikimedia.org)
Yet again, a large number of people are undergoing rabies post-exposure treatment because they were exposed to a rabid raccoon that was "adopted" from the wild. In this case, a North Carolina family found a baby raccoon at the side of the road and decided to bring it home. Over the next couple of weeks, various family and friends handled the raccoon, and many were bitten or scratched in the process. The raccoon then died and was identified as being rabid. Forty-five people are now being assessed to determine whether they need to be treated for rabies exposure.
The family dog, which was unvaccinated, has been taken by Animal Control and now faces either a six-month strict quarantine or euthanasia. I suspect the dog will be euthanized.
So, this probably well-meaning but misguided action has resulted in:
- the need for costly post-exposure treatment of many people
- presumably a stressful period for many of those people
- probably the death of the pet dog (although not having the dog vaccinated played a big role here too, since if it was vaccinated, it would only face a 45 day observation period at home, not a strict six-month quarantine or euthanasia).
Fortunately, the raccoon was tested. Otherwise we might be talking about human deaths from rabies, instead of people needing post-exposure treatment. The people who took in the raccoon could also face charges since keeping wildlife without a permit is illegal, but it sounds like that's unlikely to occur.
A few take-home messages from a situation like this:
- Leave wildlife in the wild.
- Vaccinate your pets.
- If you are exposed to an animal that is acting strangely, make sure it's tested for rabies (they did this right, at least).
Plague has been identified in a dead prairie dog in Grasslands National Park in Saskatchewan, Canada. This disease, caused by the bacterium Yersinia pestis, circulates in small wild mammals in some regions, and is spread by fleas. While plague is endemic in some parts of North America, it's very rare in Canada. (The last reported human case was in 1939).
Prairie dogs are highly susceptible to plague. The most likely problem with plague occurring in prairie dogs in Grasslands National Park will be the impact on the prairie dog population itself. Outbreaks of plague in prairie dogs can be devastating, virtually wiping out entire colonies.
- Plague can be transmitted to people, but the risk here is quite low. For people to become infected, they have to be bitten by a flea that was infected by biting an infected prairie dog (or other animal). The risk of exposure to a flea infected by wildlife is pretty low if people aren't crawling around prairie dog holes and take some basic precautions.
- The risk to pets is similarly low. Cats are more susceptible to plague than dogs, but they have to be exposed via a flea or, more commonly, from hunting and eating infected wildlife. There presumably aren't too many pet cats in Grasslands National Park, so the risk of exposure is probably limited. Dogs are rather resistant to plague, but they are probably at increased risk of exposure in a situation like this because they are more likely to be taken into areas where infected animals and fleas may be present (e.g. with people going hiking).
The greatest public health and domestic pet concern would be if plague spread beyond prairie dogs and into other small mammal populations that live closer to people or that have more contact with pets. The likelihood of this becoming a major problem is pretty low, but it's a serious disease and this situation certainly needs to be monitored.
In response to this case, park personnel are monitoring prairie dog colonies to look for more cases. They are presumably also keeping a close eye out for any other unexpected deaths of small mammals. Park officials have recommended that people stay away from prairie dog colonies, tuck their pants into their socks (to keep out fleas) and use insect repellent on their shoes. They have also closed some areas to domestic pets.
How likely is E. cuniculi to be trasmitted from an infected rabbit to a dog? My sister has a positive rabbit and my dog was just diagnosed with kidney insufficiency. Now that the dog's kidneys are compromised, should we be concerned?
Encephalitozoon cuniculi is a strange little organism that is now classified as a fungus, but is also similar to some types of protozoal parasites. It is an important (and often overlooked but potentially treatable) cause of neurological disease in rabbits. It is quite common in healthy pet rabbits, and infected rabbits shed the organism mainly in urine.
Less is known about E. cuniculi in dogs. Neurological disease, stunted growth and renal failure are the most common problems that develop. Disease usually occurs in young dogs (less than 1 year of age, with most cases in dogs a couple of months old or younger). Some studies have reported antibodies against the organism in a large percentage of healthy dogs, indicating that they've been exposed at some point, but most studies have found antibodies in few or no dogs.
The risk of transmission from rabbits to dogs is not known. There are a few different types of E. cuniculi, including one type (type I) that is called the "rabbit strain" and another (type III) that is called the "dog strain." The ability of the rabbit strain to infect dogs, particularly dogs with normal immune function, is unclear. Considering the low incidence of infection in dogs (especially older dogs), the different types of E. cuniculi that predominate in dogs and rabbits, and the commonness of kidney disease in dogs, I doubt there's a link between the rabbit's infection and the dog's kidney disease in this case.
I had an advice call the other day about two cats that were found with a dead bat. One cat was vaccinated against something (not sure what or when) while the other cat was unvaccinated. This is a situation that, if managed properly, can be very minor, but if handled improperly, can be a major problem, even resulting in death of the animals.
Bats are notorious rabies vectors. The odds of this bat carrying rabies are probably low, but they are not zero and a rabid bat is going to be more easily caught than a healthy bat. Any contact of an animal with wildlife in areas where rabies is present is considered a possible rabies exposure unless proven otherwise. The only way to do this is to have the bat tested.
If the bat is tested and is negative, then everything's fine. If it's positive, then the vaccinated cat would need a rabies booster vaccine and would have to be observed at home for 45 days. The unvaccinated cat would need a strict six month quarantine or would have to be euthanized. So, it's clear that the rabies status of the bat and the vaccination status of the cats are crucial.
Here's what to do in a case like this:
- Get the bat. The bat needs to be tested so you have to maintain control of it. Don't let the cat eat it or run off with it. Don't leave it outside where a person or animal could walk off with it. Put it in a bag or container, without having direct contact with it (e.g. use gloves or a scoop to pick it up). Be very careful if it's not completely obvious that the bat is dead, because an injured bat might look dead but still be able to bite.
- Submit the bat for testing. In Canada, that's done through the Canadian Food Inspection Agency. Make sure they know that an animal has been exposed to the bat. They would not likely test the bat if there was no exposure. They can be contacted directly or through your veterinarian. There is no charge for testing.
- Find out the vaccination status of the cat(s). You need to know when the last rabies vaccine was given and what type of vaccine was used (1 year or 3 year). You need to be able to demonstrate that the pet is current on its rabies vaccination if the bat is positive and you want to avoid the long quarantine.
- Figure out why/how/where the cat(s) caught the bat, and whether that can be avoided in the future.
Mexican officials searching a man at the airport with a bulge under his shirt identified 18 monkeys hidden beneath his clothes. Apparently, investigators became suspicious when the guy became very nervous when questioned. (I would have thought the stench associated with having 18 monkeys plastered to your body would be another tip-off.)
He was detained for possessing the 18 titi monkeys, a protected endangered species. He claimed they were pets and that he moved the animals from his suitcase to his clothes so the x-ray machines wouldn't harm them. I suspect the fact that an x-ray screener might have flagged the image of a suitcase with 18 monkey skeletons in it as abnormal was another reason.
Anyway, that's one more smuggler caught, but many more to go. Unfortunately, it's probably the stupid, small volume smugglers that get caught most of the time, while the people involved with importing huge numbers of animals go unnoticed.
Why does animal smuggling need to be stopped?
- It's inhumane. A large percentage of animals caught for smuggling die during transit. Many of the "lucky" ones that make it to their new owners die because of illnesses acquired during transit, stress of shipping and adaptation to a new home, and inadequate care by uninformed owners.
- It creates a risk of infectious disease importation. Smuggling is a major risk for introduction of diseases that could hurt (even devastate) animals or humans. Smuggled animals don't go through the same degree of inspection and quarantine as legally imported animals. Smuggling may be the main risk of introduction of various infectious diseases.
- It harms populations. Mass smuggling of endangered species can jeopardize the survival of these species in the wild.
The best way to deter smuggling is to cut down on demand. If people stop buying these animals, people will stop smuggling them because there will be no profit in it. People thinking about getting an exotic pet need to think carefully about from where the animals come. Too often, people put on blinders and conveniently forget the questionable provenance and what they are supporting in their desire to get a novel pet. At the same time, smuggling laws need to have some teeth. Huge amounts of money are made through smuggling, and the penalties need to reflect that. A slap on the wrist doesn't do much to deter someone who's making a lot of money and has little risk of being caught.
Image: Dusky titi monkeys (source: www.bbc.co.uk)
- Roaming pets + wildlife = bad news: One person's dogs killed a raccoon while out for their "romp around the yard." The raccoon was rabid. There's no mention about the vaccination status of the dogs. If they were vaccinated, they probably got a rabies booster and are under a 45-day "house arrest" for observation. If not, they either need to be placed under a strict 6-month quarantine at a separate facility, or they'll be euthanized. Another report describes a different dog that is now under a 6-month quarantine after attacking a raccoon. In yet another report, a North Carolina woman's dog was euthanized because it killed a rabid fox and was unvaccinated (the owner chose euthanasia over quarantine). That dog is now dead mainly because the owner didn't take the simple and relatively inexpensive step of ensuring that her dog was vaccinated.
- Pissed-off wildlife bite. Sometimes they're rabid too. Get too close at your own peril: A South Carolina man is undergoing post-exposure treatment because he was bitten by a raccoon while removing it from a trap. I'm glad that he had the animal tested. It's pretty easy to see someone in a situation like this just yelling at the raccoon and letting it go, thinking they were bitten because the raccoon was upset and not realizing that they might have been exposed to rabies.
- Some people just don't get it: In response to rabies exposure of close to 50 church members from a rabid bat while on a mission trip, the mission leader stated "It's just part of being in rural America, so there's really not a lot to talk about." Ugh. Rabies exposure should not be written off as some benign, unavoidable rural American experience. It's exposure to an almost invariably fatal disease that requires a series of expensive treatments. It's also not a rural thing. Rabies exposures can occur commonly in urban areas as well.
- Stray kittens can be cute but deadly: A rabid cat and kitten were identified in Ocean City, Maryland, and authorities are looking for people that may have come into contact with them. Human exposure to rabies from handling cute but infected kittens is not uncommon, and sometimes involves a lot of people. If you see a stray kitten, it's best to leave it alone. If you feel the need to rescue it, make sure that you get it to a vet for an exam, and that it subsequently goes somewhere where it can be properly observed and taken care of. If you're bitten in the process, make sure the kitten is quarantined for 10 days to see if it's rabid, or euthanized and tested. The worse case scenario is when people play with stray kittens, get nipped in the process, dismiss it as a minor or playful bite, then release the kitten back into the wild, never knowing whether they might have been exposed to rabies.
It's not like we needed any evidence that rabies is still an active, deadly disease, but a recent ProMed-mail posting contains 16 different rabies notices. They include:
- An animal control worker who was bitten by a rabid, stray cat that was trapped by a person in Texas.
- Rabies exposure in an unvaccinated dog in Maryland, that resulted in euthanasia of the dog because the owners didn't want to undertake the required 6 month quarantine for exposed, unvaccinated dogs. The dog was exposed to rabies virus while killing a raccoon.
- Diagnosis of rabies in two trapped raccoons in New Jersey.
- Rabies exposure in an Arizona woman who was attacked by a rabid fox while in her yard.
- More marauding (presumably rabid) foxes attacking people and dogs in Maine and South Carolina.
- Rabid bats and skunks in Colorado.
- A rabid fox in Alabama.
- Rabid raccoons in Virginia.
- A rabid raccoon attacking a vaccinated dog.
- Rabies exposure in people bitten or scratched by rabid stray kittens in New Jersey, Nebraska and Georgia.
Common themes or take home messages:
- Rabies is here (in most areas, at least) and it's unfortunately not going away any time soon. We can reduce the number of affected animals and decrease the risk of exposure of people and domestic animals, however, with good prevention strategies.
- Vaccination of pets is a cheap and effective way of protecting them, and anyone they are in contact with.
- Keep pets away from wildlife.
- If you are bitten by a wild animal, you must consider it a potential rabies exposure unless the animal can be proven not to have rabies.
- If you see an animal that is acting strangely, stay away and call animal control.
A UK man is recovering from a tarantula bite that occurred when he, apparently in a drunken stupor, encouraged the venomous critter to bite him. (I suspect the "victim" has a pretty high endogenous level of stupidity, because I don't think you could get me drunk enough to say "Hey, maybe I should let an enormous venomous spider bite me!")
The character in question, Peter Saunders, stated "It was completely my own fault. I provoked the spider into biting me on my index finger so I can't complain about the consequences at all." At least the statement demonstrates some degree of logical thought. He ended up getting more than he bargained for, since the bite was a lot more painful than he anticipated. The day after the bite (presumably along with a massive hangover), Mr. Saunders' arm went numb and he was given various antibiotics to help treat a suspected secondary infection.
Unfortunately, the moment of clarity represented by his understanding that it was all his fault passed quickly since "... this incident has not put him off keeping these pets and he is considering buying more exotic creatures in the future." Let's hope he doesn't decide to see what it feels like when an African lion chews on his throat.
Photo: Fort Hall Baboon Tarantula (source: www.lotsalegs.tenczar.net)
People like to talk about the "one medicine" concept. It's a great concept, but my big issue with it is there's a lot of talk but not a lot of action.
One way of thinking about "one medicine" in terms of people and pets is to focus on the health of the entire household as a whole, because:
- People can transmit infections to pets.
- Pets can transmit infections to people.
- People and pets can be infected from the same source.
- Infection in a pet or person may indicate that others in the household are also at risk.
It's a complex dynamic. When I speak about this topic, I use a couple of different ways to make the point. One is the concept that we are not a population of people living with dogs, cats, horses etc. - we are a population of animals. Similarly, I sometimes say "pets are people too, at least microbiologically." What I'm saying is that we can't focus just on humans or just on pets. The household as a whole needs to be considered, and care of the health of the all of its members - human and animal - needs to considered together.
What does that really mean?
Physicians need to be aware of the presence of pets in the household and other animal contacts. This information might be important when considering certain diseases. For example, if someone comes to their physician with flu-like symptoms and their physician knows they have pet birds (especially psittacines), then the physician would hopefully consider psittacosis. This disease is caused by Chlamydophila psittaci, a bacterium that can be carried by healthy birds. Not realizing there is a bird in the household can lead to a missed diagnosis.
Veterinarians need to be aware of the health status of people in the household. People with close contact with the human healthcare system and people with compromised immune systems are more likely to be carrying certain infectious agents. They are also more likely to pass these pathogens on to their pets. Therefore, knowing the health status of the owner might lead the veterinarian to consider different diseases in the pet, thereby improving diagnosis. Conversely, people with compromised immune systems are at increased risk for various infectious diseases from pets. If the veterinarian knows a pet owner is at increased risk, they can provide better advice about disease prevention measures to protect the owner. Veterinarians rarely ask owners about their immune status, including pregnancy (even the "how far along are you?" question is dangerous, because eventually you're going to get the "I'm not pregnant!" response.) Ideally, people should have a positive, comfortable relationship with their veterinarian, realize that their veterinarian is a member of their (and their family's) overall healthcare team, and therefore tell their veterinarian about any relevant health issues. For this to work, they need to understand the value of this communication, trust their veterinarian and know that their personal details will be kept confidential. At the same time, the veterinarian needs to understand the issues and need for such information, and have a plan on how to use it.
Veterinarians and physicians need to communicate better. They need to know who to contact when necessary and be able to do it efficiently. This is also relevant for non-infectious disease issues. For example, there could be a situation where a veterinarian has had to euthanize a pet: the veterinarian may realize that the owner is quite distraught, but can't do much beyond offering condolences and providing contact information for resources to help them out. The physician may not know anything about the situation, but it could be of significant relevance to the person's health. If nothing else, the physician could be notified that there's a potential concern. There are privacy issues that need to be considered and sorted out, but a little conversation can go a long way. The ability of veterinarians and physicians to contact each other about relevant issues can help prevent problems with miscommunication, provide general information about certain topics and help provide optimal patient care.
One medicine needs to be one medicine in action, not just in theory.
A recent question:
"I have two rabbits who just tested positive for E. cuniiculi... Can you please tell me how to disinfect my floors and kill the parasites? I don't think bleach is doing it."
Encephalitozoon cuniculi is a strange little bug. It a member of a unique group of organisms called microsporidia. Originally thought to be parasites like Giardia, they are now classified as a type of fungus. Regardless, E. cuniculi is common in the pet rabbit population, causing neurological disease in some rabbits but living in many others without any signs of illness.
Infected rabbits shed E. cuniculi spores in urine, feces and respiratory secretions. Other individuals are infected by ingesting (and possibly inhaling) these spores. Infected rabbits start to shed spores in urine a month or two after infection, and can continue to shed low levels of spores intermittently. This, along with close housing of pet rabbits and movement of rabbits between breeders, stores and owners, explains why, in some studies, up to 75% of tested rabbits have evidence of current or prior infection.
Disinfecting household environments can be tough because of the surfaces that are involved. Encephalitozoon cuniculi is quite hardy and can live in the environment for prolonged periods of time. It is susceptible to a several types of disinfectant, including bleach, 70% alcohol and 1% hydrogen peroxide. In general, bleach is highly effective and is probably the standard for disinfection of surfaces that can tolerate it. Obviously, bleach isn't a good option for many surfaces like carpets. Steam cleaning might help, as much for the thorough cleaning component as for the steam.
One thing to consider is whether aggressive household disinfection is really required. While humans can be infected, infections are uncommon and predominantly occur in people with compromised immune systems, especially those with HIV/AIDS. If there are no high-risk people in the household, I don't think I'd be too aggressive with disinfection. Good hygiene practices involving handling of the rabbits and their cage are probably much, much more important, and its better to focus efforts there. Household disinfection for protection of the rabbits is probably not too useful at this point. I would suspect that all rabbits in the household have already been exposed, and since infected rabbits can continue to shed intermittently, rabbits are a much greater source of infection than the household environment.
More information about E. cuniculi can be found in our archives.
The May 2010 edition of Emerging Infectious Diseases contains a report about an outbreak of cryptosporidiosis in Scotland (McGuigan et al. 2010). Cryptosporidiosis is a common parasitic disease caused by Cryptosporidium, a protozoal parasite. It causes diarrhea, which is usually annoying (to say the least) but self-limiting in healthy people, but the infection is potentially fatal in people with compromised immune systems.
An investigation was launched after a single case of cyrptosporidiosis was diagnosed by a Scottish laboratory. The reason a single infection caused such concern is that it was suspected to have originated from contact with lambs at a wildlife centre, so there was potential for exposure of many people. The concerns were valid, since a total of 128 cases of cryptosporidosis were uncovered during their investigation, and 117 of the people affected had visited the wildlife centre. Another 252 unconfirmed cases were also identified.
The investigation suggested that direct contact with diarrheic lambs was the source of infection. Lambs (and calves) are high risk for shedding Cryptosporidium, even when they're healthy. Diarrhea increase the risk of transmission from these animals even more, because diarrheic animals are more likely to (1) shed the parasite and (2) have fecal staining of their haircoats, which increases the likelihood of fecal contact for every person and animal around them. That's why young ruminants (e.g. lambs, calves) as well as young poultry are considered inappropriate for petting zoos and other similar public animal contact events. This outbreak is yet another example of why these recommendations are in place.
At the wildlife centre in this study, children were apparently encouraged to pick up the lambs, despite visible diarrhea. No handwashing facilities were near the lamb petting area and it took "considerable effort" to find a location to wash your hands anywhere on site. Alcohol hand sanitizers were available, however Cryptosporidium is resistant to alcohol. Handwashing is a critical component of disease prevention, but unfortunately it is very underused. In general, people are becoming much more aware of the need for handwashing, but even so, if handwashing facilities are not conveniently located, people tend not to go to much effort to find them. That leads to increased risk of infections, as was the case here.
Control measures at the wildlife centre implemented after the investigation included removal of the lambs (who should never have been there anyway), disinfection of the premises with bleach (although disinfecting a farm environment is very difficult, and Cryptosporidium is also resistant to bleach), and stopping direct contact between animals and visitors.
As we enter the season when there are more fairs, petting zoos and other animal contact events, facility managers need to pay attention to important factors like:
- Readily available hand hygiene facilities
- Good design to control the types of human-animal contact and to steer people towards hand hygiene stations
- Appropriate animals: no calves, lambs or chicks
- Proper supervision of people and animals
A little common sense goes a long way. The goal is to set up these events so that there is still a beneficial impact of seeing and interacting with animals while reducing (but never eliminating) the risk of disease transmission. A 100% safe petting zoo is not achievable (there's always some risk in life), but some pretty simple measures can greatly reduce the risks while still providing excellent entertainment and educational opportunities.
A canine distemper outbreak has been identified in raccoons, dogs, coyotes, foxes and skunks in Los Angeles County. Local residents are being reminded to vaccinate their dogs against distemper and report any suspected signs of distemper to their veterinarian. (Keeping their pets away from wildlife should also be recommended.)
Distemper is an infection caused by a virus which is related to the virus that causes measles in people. It can cause different types of disease in dogs, raccoons and some other wild mammals, but neurological disease is often present and can appear similar to rabies.
Canine distemper cannot be transmitted to people, but, in a roundabout way, distemper outbreaks can be a public health concern. This is because of the potential for rabies cases to be mistaken for (and dismissed as) distemper cases, leading to increased exposure of people to rabid animals.
Quite a few years ago, there was a cat with neurological problems under my parents front porch. It was a stray cat that had been in the neighbourhood for a while, and which sometimes interacted with people. When the local authorities were contacted, the response was "Don't worry, it probably has distemper." This was probably true, and since there was no known direct contact with people (something that is difficult to really know in a social stray) testing for rabies wasn't done. However, the concern is that rabies cases will be missed, or, more concerningly, human exposure to rabid animals will be missed because of the assumption that it's really distemper.
Understanding disease patterns in an area is important when determining the likelihood of a particular disease and the appropriate response to a sick animal. At the same time, you can't get complacent and assume that trends are absolute. With an almost invariably fatal disease like rabies, you have to be careful not to overlook the rare case amongst large number of other, similarly appearing diseases. If someone has contact with an animal suspected of having distemper, the potential for rabies exposure must not be forgotten.
Image source: http://weblogs.baltimoresun.com
It's encouraging to see the number of press reports warning people not to bring home baby chicks or ducklings as Easter presents for kids. The warnings are because of the potential risk of salmonellosis associated with contact with poultry and fowl, particularly among children. Young kids (less than five years of age) are at high risk for this type of infection, and are at higher risk of developing more serious illness and complications. They also tend to be at higher risk for exposure because of the close nature of contact that they may have with pets, or in this case Easter chicks. Add close contact and increased susceptibility to the generally low level of hygiene associated with household animal contact, and you have a perfect recipe for sick kids.
Salmonella carriage is an ever-present concern with chicks and duckings. It doesn't matter how they were raised or from where they came - you can never know by looking it it whether a baby bird is shedding Salmonella, and you should assume that they all are to be on the safe side.
The CDC has some basic advice on the topic. The key points are:
- Never buy chicks or ducklings on a whim. If in doubt, buy a stuffed animal.
- Never buy chicks or ducklings for kids under five years of age or people with compromised immune systems. These individuals should not have any contact with chicks or ducklings.
- Don't let these animals roam freely around the house. They're not house trained and can contaminate the household environment.
- Always wash your hands thoroughly after contact with chicks or ducklings.
- Don't eat around chicks and ducklings, since it increases the chance of inadvertently ingesting Salmonella.
Baby chicks and ducklings don't make good pets because of the Salmonella risk. They also grow up, and become larger, messier, and noisier birds for which many people are not prepared to care. Don't buy a baby bird unless you have a low risk household, can properly implement measures to reduce the risk of exposure to Salmonella, and have a plan to properly take care of the bird when it gets older.
The Toronto Star had a front page article today about an ongoing distemper outbreak in raccoons, and the potential effects on dogs. Toronto's not alone, as there are distemper outbreaks underway in many different municipal regions.
Distemper is an infection caused by a virus that is related to human measles virus. It mainly affects dogs, raccoons and ferrets. It can cause intestinal, respiratory and neurological disease, with neurological problems being the most severe. Vaccination of dogs against distemper is highly effective, and has greatly reduced the impact of this virus on the pet dog population.
Distemper cannot be transmitted to people, so the disease itself is only an animal health risk. However, there's an indirect effect of which people need to be aware. Rabies always needs to be considered in dogs and raccoons that have signs of neurological disease. If there is so much distemper in an area that people assume every sick (wild) animal they find has distemper, there is a risk that the odd (but important) case of rabies may be missed, leading to human exposure. It's easy to dismiss a neurological raccoon or unvaccinated dog as having distemper, and it usually is distemper (particular in light of the current outbreak), but the implications of missing a case of rabies can be severe since it can be transmitted to people and is almost invariably fatal.
If distemper is present in your area (or, really, even if it's not currently a problem):
- Make sure your dog is vaccinated.
- Keep your dog away from wild animals, especially ones that are acting strangely.
- Keep yourself away from wild animals, especially ones that are acting strangely.
- Don't do things that will encourage raccoons to move into your yard, like leaving out food.
- If you see a wild animal that is acting strangely, call your local animal control agency.
Photo credit: The Star - Toronto edition 18-Feb-10
In response to ongoing problems with rabies in raccoons in New York's Central Park, a vaccination program is now underway. Raccoons are being trapped, vaccinated, tagged and then released. This is a logical response to the outbreak and one that will hopefully have a significant impact.
Trap, vaccinate and release programs can help in a few different ways. Firstly, they protect the individual raccoons that are vaccinated. However, in the bigger picture, mass vaccination is designed to protect humans and animals beyond those that are vaccinated (this is referred to as "herd immunity" - click here for a good video about this concept from a previous post). As the number of vaccinated (and therefore immune) individuals in a population increases, there's less risk of ongoing transmission of the disease (in this case, rabies), since an infected animal is less likely to encounter a susceptible (unvaccinated) individual. If, on average, an infected individual does not have a chance to infect another individual, the outbreak will eventually die out. The key is getting a high enough percentage of the population vaccinated.
For eradication of dog rabies, the World Health Organization recommends vaccinating at least 70% of dogs in a population. I'm not sure what the critical number is for raccoons, but it's presumably a similar, and reasonably high, number. Since a high vaccination rate is needed, there needs to be a concerted effort to do more than just a token vaccination program. It also helps if there's good information about raccoon numbers and distribution in the area. As long as the Department of Health is serious about this program and puts the required time and resources into it, the odds are very good that it will be successful.
February 14th marks the beginning of the Chinese New Year, and ushers in the year of the tiger. Coincidentally, there's been some publicity surrounding a tiger in Ontario that has nothing to do with a New Year or good fortune. On January 10, a 300 kilogram Siberian tiger killed its owner, 66-year-old Norman Buwalda, when he went into the tiger's cage to feed it. This tiger was one of many owned by private individuals or as part of dodgy roadside zoos in Ontario and across North America.
It is truly amazing how easy it is for people to obtain potentially lethal exotic animals like tigers, and how many (or most) jurisdictions have no rules against it. Tigers are beautiful and fascinating animals, but they shouldn't be pets. Exotic pets carry many risks, including injuries and infections, not to mention animal welfare issues from poor management and feeding practices. This is far from the first exotic cat to have killed its owner, and unfortunately, it's almost certainly not the last.
The latest concerns about this particular tiger involved its whereabouts. When the OSPCA (Ontario Society for Prevention of Cruelty to Animals) went to the property to investigate a complaint about the well-being of other animals, they discovered that the tiger was gone. The town's major was also unaware of the tiger's location.
Provincial police, at least, knew more, and stated that the tiger and two lions were moved to an "undisclosed location" on January 27th. I think people need to realize this isn't the witness protection program, and there's no justification for being secretive about the location of these animals. The fact that they are gone should be a comfort to neighbours in Southwold, Ontario, but what about the people that may now be living next to it? It's pretty unlikely that these animals have been moved to a proper zoo with adequate housing facilities and handlers experienced with big cats. More likely, they're in the same type of situation as before, just is a different locale.
In Ontario, you can be charged if you have a pit bull or even a dog that resembles a pit bull, but you can have a 300 kg carnivorous feline in your backyard. How does that make sense?
Urine from healthy animals is typically considered to be of little to no risk to people. This is generally true, at least for the otherwise healthy human population, but like with most things in infectious diseases, there are exceptions. An interesting one in rabbits is a bug called Encephalitozoon cuniculi. This microorganism (now classified as a fungus, but previously considered a protozoal parasite) is very common in healthy pet rabbits. In fact, the majority of rabbits have antibodies against E. cuniculi and may have it living in their bodies, particularly in the kidneys. It can cause infection of the brain, and is an important cause of neurological disease in rabbits, but more often than not it lives within the rabbit without causing any problems. Rabbits can shed spores of this organism is their urine, although they mainly do this only in the first few weeks after they've become infected, and shedding after that may be intermittent.
E. cuniculi is one of a group of microorganisms that became much more important when the HIV/AIDS epidemic hit. While rarely a cause of disease in people in the pre-HIV era, E. cuniculi is recognized as a potential cause of infection in people with compromised immune systems, particularly people with AIDS. Infections of people with normal immune systems are extremely rare.
It's always a challenge deciding what to do with a microorganism that can be shed by a large number of healthy animals. One reference "strongly advises" routine testing of rabbits, but that makes no sense to me. Here's why:
- Screening always comes down to a question of what you would do with the results. If you get a positive antibody test, it means that the rabbit has been exposed sometime in its life, but that does not mean that it is necessarily still infected or shedding spores - so it's not really convincing.
- Tests can be done to detect spore shedding but they are not particularly reliable. Since infected animals shed spores intermittently, a negative result here isn't convincing either.
- If the animal is positive, what would you do? If the household has no immunocompromised people, I'd say do what you've always done, and pay attention to good hygiene.
- If the animal was "negative," I'd say do what you've always done, and pay attention to good hygiene... same as for a positive rabbit.
- If there is an immunocompromised person in the house, I wouldn't say to get rid of the pet, since there's no evidence that's necessary. There is also no evidence that treatment is useful to eliminate E. cuniculi shedding rabbits. If the animal is positive, immunocompromised persons should avoid contact with urine and feces, and use good personal hygiene... just as they should do if the rabbit is negative!
The Hollywood effect is quite real when it comes to various trends, including pets (remember the glut of Dalmatians after 101 Dalmatians?). I can understand how seeing a cute puppy of some breed might lead to people wanting to get one. However, when Disney's The Princess and the Frog was released, I didn't really think a lot of people who watched this movie were going to start running around kissing frogs. I assumed that some degree of common sense would apply. Apparently, I was wrong.
Various news outlets are reporting that at least 50 children (mainly kids under the age of 10) have become sick in the US after copying the movie's Princess Tiana by kissing frogs. There's not a lot of information regarding what they contracted, whether the illnesses were all clearly linked to frogs, or whether these were truly associated with the movie, but there are certainly disease risks associated with kissing a frog. While we pay more attention to reptiles as a source of Salmonella, the risk is also present with frogs, and the best thing is to do is assume that all frogs are carrying this potentially harmful bacterium. Accordingly, high-risk people (e.g. kids less than 5 years of age, the elderly, people with compromised immune systems) should have no contact with frogs - they shouldn't even be in the same house. Hands should always be washed after touching a frog, and no one should ever kiss a frog. The chances of living happily ever after with a prince are much lower than the chances of a nasty bout of diarrhea (or worse)!
Pet bites are a big problem. Dogs bites in particular are far too common and can result in serious injury or even death in a small percentage of cases. Bites from other pet species also happen, but the extent of the problem is not clear. A good general rule is if it has a mouth, it can bite.
Another good general rule is if it has numerous sharp teeth, is a carnivore and your as upsetting it, you should get your hand out of the way. Pet store owner Dave Brown found this out the hard way, although in this situation he has the dubious distinction of having been bitten by a fish.
It seems that Mr. Brown was trying to catch a piranha that he was selling. I would have thought the standard way of catching a fish, not to mention a six-inch-long carnivorous fish, would be to use a net. Apparently not. Mr. Brown used his bare hands, and after a couple unsuccessful attempts to catch the fish, the piranha fought back, sinking his teeth into the store owner's thumb. The bite was severe enough that stitches were needed. According to Mr. Brown "There was blood everywhere. Every time I had him in a plastic bag the fish would bite through it. He was quite a feisty one." Personally, I think if a carnivorous fish was repeatedly trying to attack me through the bag, I'd probably change my approach to catching it.
According to a local fish expert, "[Mr. Brown] was very unlucky as these fish normally just attack when they're hungry. It may have been a bit peckish."
Fortunately, apart from a sore thumb, it sounds like the biggest problem Mr. Brown will face is the harassment that I assume he's going to take from friends after being bitten by a fish.
Eight more rabid raccoons have been found in New York's Central Park over the past two weeks. These, plus the 12 rabid raccoons reported in the park last year, represent a major increase in disease frequency since only 1 rabid raccoon was identified in Central Park from 2003-2008. That's a concerning development given the number of people that visit this 843 acre park in the heart of New York city every day.
In response, the city's Health Department has started an education campaign to alert people to the risk, and tell people to stay away from wildlife, report any sick animals and to keep their dogs on leashes. Every pet owner also needs to make sure their dog's rabies vaccine status is up-to-date, even if they always keep their dog on a leash, because you never know what a rabid raccoon will do (such as attacking a leashed dog that walks by). There are also plans to vaccinate raccoons in and around the Park, however I couldn't find details about what type of vaccination program will be used.
Rabies has been diagnosed in a 6-week-old Jersey calf at a Maryland educational centre, raising concerns about exposure of farm visitors, particularly groups of school children. At least 70 kids and an unstated number other visitors had recently visited the farm.
Fortunately, the farm in question is not open to the public, so they should have an easier time identifying people who have been there (e.g. school groups). Contact tracing is underway to try to identify people that had contact with the calf. Simply petting the calf or being in the general area does not pose a risk. The main risk would be from contact of open wounds with the calf's saliva, or a bite. We don't typically associate bites and calves, but it can happen when calves are allowed to suck on someone's fingers - if the person sticks their hand in too far he/she may get chomped by the calf's sharp molars. Public health personnel are trying to identify people who had contact with the calf, then they'll determine whether there was a chance of exposure to the virus. People that were potentially exposed to rabies will undergo post-exposure prophylaxis, consisting of a shot of anti-rabies antibodies and four doses of vaccine over the course of a month. Not fun, but much better than getting this almost invariably fatal disease. At least nine students have started treatment so far.
Petting zoos and similar events are a concern in terms of disease transmission because of the large number of people that can be exposed to animals and the high percentage of children that are involved. Rabies is uncommon in petting zoo animals, but it is periodically identified at such a facility/event, often resulting in the need for post-exposure treatment of large numbers of people. Vaccination of petting zoo animals against rabies should be a standard practice. This calf, being only six weeks old, was too young to vaccinate, but if the calf's mother was vaccinated the risk of rabies would be lower (because the calf would get antibodies from the mother). There's no information about the cow's vaccination status or much else about the calf, apart from it being a recent acquisition.
The fact that a recently acquired young calf was allowed to have contact with the public is questionable management, because young calves are a high risk group for certain infectious agents like Cryptosporidium and Salmonella. The CDC recommends that children less than five years of age not have contact with young calves. Since young kids are frequent visitors of places like this, having calves (or at least letting people have direct contact with them) is quite questionable as well. Hopefully there will be a good review of vaccination, animal acquisition and animal contact protocols for this facility to reduce the risk of future exposures to rabies or other infectious diseases.
There was another paper published in the August issue of the Canadian Veterinary Journal about Baylisascaris procyonis (roundworms) in raccoons, this time in Winnipeg, Manitoba (Sexsmith et al 2009). The study was actually undertaken after infection with B. procyonis larvae was identifed as the cause of death of several animals in the collection at the Assiniboine Park Zoo in Winnipeg.
The researchers collected feces from 52 active raccoon latrines around the city and from 114 "nuisance" raccoons that were caught, euthanised and submitted for necropsy to the local lab. Interestingly, the vast majority of latrines and nuissance raccoons were found close to the two major rivers that run through Winnipeg. Half (50%) of all the latrines were positive for roundworm eggs on at least one sample (out of a possible 3). Among the necropsied raccoons, 61/114 (53.5%) were positive for roundworms. Adult raccoons were almost four times as likely to carry roundworms than juveniles (which is in contrast to a previous study that found juveniles more likely to be infected), and bigger raccoons (over 2.75 kg) were more than seven times as likely to carry roundworms compared to smaller animals. Although there are regions where the prevalence of B. procyonis s reported to be very low, Winnipeg, like many other regions of North America, has joined the ranks of those where the prevalence is high and the public needs to be aware of the associated risks.
The most severe zoonotic disease caused by B. procyonis is called neural larval migrans (NLM), which results from migration of parasite larvae through the central nervous system (i.e. brain). Two of the reasons this is much more of a concern with raccoon roundworms (Baylisascaris) compared to dog and cat roundworms (Toxocara) are:
1) A massive number of parasite eggs are passed in the feces of infected raccoons (which typically have a very high burden of adult worms). Coupled with the fact that the eggs are further concentrated in areas where many raccoons defecate (latrines), this can lead to heavy exposure of people (or animals) who come in contact with the soil in these areas, which greatly increases the risk of infection.
2) The larvae of B. procyonis are very active migrators, and they get bigger as they migrate through tissues - much bigger than Toxocara larvae ever get, which means they also tend to cause a lot more damage before they're finally (if ever) trapped or killed by the body's immune response.
Natural infection of dogs living in the same areas as raccoons has been found - it's not common, but it appears to occur frequently enough to warrant noting. Dogs and cats can also be infected by their own species of roundworms, which will also result in parasite eggs being shed in the feces. It's important to have your veterinarian perform a fecal examination for your pet on a regular basis so any parasite infestations (roundworm or other) can be treated.
Dogs and cats may also be susceptible to larval migrans in the same manner as people (and the animals at the zoo in Winnipeg) if they are exposed to high numbers of infectious eggs. Remember that roundworm eggs must be swallowed in order for infection of any kind to occur, so good hand hygiene and avoiding soil contamination of food are key to preventing transmission. Also, do not allow your pet to dig or play in an area where raccoons defecate (preventing direct contact between your dog and raccoons should go without saying!). And of course, feces of any kind (and from any species) should be treated as infectious material, and handled with appropriate precautions.
Just as I'm getting ready to go on vacation (that will hopefully involve some time on the beach), I read an article in the latest edition of Emerging Infectious Diseases about seagulls and beaches as reservoirs of multidrug-resistant E. coli (Simoes et al 2010). In this study, the researchers collected seagull poop from beaches in Porto, Portugal and tested them for the presence of extended spectrum beta-lactamase (ESBL) E. coli, a highly drug resistant form of this common bacterium. Thirty-two percent (32%) of the E. coli they isolated were ESBL, a pretty impressive rate in wild birds that would not be directly exposed to antibiotics. Various E. coli strains were present, including some that can cause severe disease.
In some respects this is pretty concerning, and in other respects not too surprising. We know that birds in various (including remote) regions can carry multidrug-resistant bacteria. The ability of wild birds to carry these bacteria, combined with the wide geographic range that some bird species have, raises concern about the role of birds in the spread of antibiotic-resistant bacteria, as well as the potential for contracting a nasty drug-resistant infection while on the beach. Birds certainly have the ability to help spread certain types of bacteria over wide ranges. However, their overall role is probably very limited compared to the role played by people and (domestic) animals. For birds to become carriers of these bacteria, they have to pick them up from somewhere, which presumably doesn't occur until the bacteria have built up to a good level in people and/or animals. I doubt that birds account for many human infections. Antibiotic exposure through antibiotic residues in water or food sources could also play a role in the presence of these bacteria in birds, but that's an area that's not well understood.
So, how does this influence my time on the beach? Not much. I wasn't really planning on having contact with seagull poop, and this paper just reinforces that basic precaution. Other basic measures such as keeping open sores covered, avoiding cuts by wearing shoes in rough areas or sand that might be contaminated with sharp objects, avoiding contamination of food with sand, avoiding areas with obvious bird poop contamination, and hand washing before eating and after leaving the beach are easy to do.
I've never really understood the appeal of tarantulas as pets. I'm sure there are some people that think they're great pets and I can't really counter with anything beyond "I don't have any desire to have a massive spider in my house." Nevertheless, many people have them. Recently, a rather unusual health concern was reported at medpagetoday.com following publication of a peculiar case report (Norris et al) in the most recent issue of The Lancet.
Hairs on the hind end of the Chilean Rose tarantula, as well as others, have barbed tips. These spiders can release hairs as a defense mechanism. A British tarantula owner was leaning into the spider's terrarium one day when it "doused" his face with a mist of hairs.
When he presented at the ophthalmology clinic three weeks later, his right eye was red, watery, and uncomfortable in bright light. His Snellen visual acuity had degraded to 6/9, versus 6/4 in his unaffected left eye.
Carrim and colleagues reported that initial low-power examination showed diffuse conjunctival injection and multiple corneal subepithelial infiltrates, "visible as scattered white spots."
They initially suspected a viral infection, but higher magnification revealed "fine, hairlike projections" at the center of each spot, with varying depths into the cornea.
At that point, he mentioned the tarantula hair exposure. After 6 months of intensive treatment, his eye problems have greatly improved, and he now wears eye protection around the tarantula.
It's unclear how common this is. There have been other reports of this problem and certainly there must have been other unreported cases. Overall, it's probably rare for tarantula owners to be affected but it seems like a pretty nasty problem and one you'd want to avoid. Pets like tarantulas often come and go in popularity, and any upswing in tarantula numbers could result in more eye injuries. People need to be aware of this problem if they own, or are thinking about acquiring, a tarantula. Animal exhibits that have tarantulas and any other places where tarantulas may be present (e.g. schools) need to think about this as well. Wearing eye protection when handling these spiders in close quarters, keeping your face of the terrarium, avoiding stressful situations that might make the tarantula release hairs, good handling skills and restricting close contact seem like logical and practical measures to reduce the risk.
Image: Chilean Rose tarantula (source: www.wikipedia.org)
Last week, I wrote about the uncommon situation where a child was attacked by a 60 pound beaver. Any bite from a wild mammal, especially one acting different than normal, needs to be considered a possible rabies exposure, and I was impressed that the family pushed for rabies testing. Unfortunately, it turns out that rabies testing was not possible. The beaver was killed with a crowbar and "The skull was crushed to the point where there wasn't enough brain material" for testing.
That creates a difficult situation. The likelihood that the beaver had rabies is probably very slim, but rabies is an almost invariably fatal disease. Post-exposure treatment consists of an injection of anti-rabies antibodies and then a series of 4-5 vaccines. It's not fun, but it's not typically that big of a deal (particularly compared to the old protocol from decades past). It's also expensive, which can be a problem if the government or insurance doesn't cover it. I'd certainly err on the side of caution and get my child vaccinated (been there, done that) but there's no word what was done in this situation.
Inadequate brain material for testing occurs occasionally based on how a potentially rabid animal is killed. If you are in such a situation and you can avoid destroying the head, try to do so. But, while keeping the head intact when beating off an attacking animal is the goal from a rabies diagnosis standpoint, you can see how it wouldn't be high on the priority list when actually confronted with an attacking animal.
More information about rabies can be found on the Worms & Germs Resources page.
.A public health expert has recommended that an exotic animal dealer's facility be demolished or "completely gutted and sterilized" because it is so contaminated with animal feces and vomit, as well as roach infested and swarming with uncaged animals. No evidence of infection control was present in the facility that "reeked of death and decay on a mammoth and overwhelming scale."
26 000 (yes, twenty-six thousand) reptiles, rodents and mammals were removed from US Global Exotic's Texas facility last week, in a raid prompted by an undercover investigation by PETA. An employee working undercover in the facility for PETA documented various abuses. The company now stands accused by the city of inhumanely housing the animals as well as denying them proper food, water and medical care. Hundreds of dead animals were found, and some animals had started eating one another to survive. An SPCA spokesperson said she stopped counting at 200 dead iguanas.
Buying certain things on the internet is fine. Buying live animals over the internet is something that you shouldn't even consider. This is a multi-million dollar industry that feeds off the naivety of people, the willingness of people to ignore serious welfare issues in their desire to get a unique pet, and the suffering of animals. Exotic pets can be good pets in certain situations, but tremendous numbers of them suffer and die from inadequate care at distributors, pet stores and homes, with many (many) more dying during smuggling.
If you want an exotic pet:
- Read a lot about it first. Make sure you can properly manage the animal and that it's legal in your area.
- Learn about any infectious disease risks and whether it's appropriate for your household. In general, exotic pets should not be present in households with children under five years of age, pregnant women, elderly individuals and people with compromised immune systems.
- Find a small, local breeder. Buy the animal from a place where you can see how they are raised so you can have more confidence they are healthy and have been properly cared for.
- If you want to buy an exotic pet from a pet shop, ask clear questions about the origin of the animal and request supporting documentation. Only buy a pet that was bred locally. US Global Exotics apparently sold most of their animals through pet stores.
Don't support illegal and unethical activities by buying exotic pets - if you really want to have such a pet, remember that it requires a lot of forethought and investigation of the source.
A five-year-old Oklahoma boy is recovering after being attacked by a beaver. Beaver and attack aren't two words that you usually put together, but in this case the boy went to pet a 60 lb beaver that he saw outside and it proceeded to attack him, taking a "chunk out of his calf" in the process. The beaver was killed with a crowbar.
This is a pretty unusual situation. Beavers aren't known for attacking people, which should raise some red flags right there. Rabies should be considered in any mammal that acts abnormally. An aggressive act by a species not known for unprovoked attacks would certainly count.
The boy's mother went to "great lengths" to get the beaver tested for rabies. I'm not sure why great lengths were required since this was a bite from an abnormally-behaving wild animal in a rabies endemic area, but it's great that she was aware of the problem and acted accordingly. While the outcome was unfortunate for the beaver, the family is lucky that the beaver was killed and available for testing. If it had gotten away, they would have had to assume that it was rabid, meaning the child would need rabies post-exposure treatment. That's expensive and somewhat unpleasant (two initial shots and 3-4 boosters) but virtually 100% effective at preventing rabies (and since rabies is almost always fatal, it's a necessary procedure).
This report highlights a two key points:
- Leave wildlife alone.
- If you are bitten by a wild animal, make sure rabies is considered. It's very rare but fatal when it occurs, so you don't want to take any chances.
The CDC is investigating an apparent multistate outbreak of salmonellosis associated with contact with frogs. As of December 7, 48 infected people had been identified from 25 states - a pretty remarkable distribution. People got sick between June 24 and November 14, 2009. As is normal for Salmonella outbreaks linked to animals, young children have been more commonly affected, with kids under 10 accounting for 77% of cases. Fortunately, no one has died.
As part of the investigation, contact with animals was investigated and their preliminary analysis indicates contact with water frogs like African Dwarf frogs is the likely source of infection.
Amphibians often get ignored when it comes to zoonotic diseases. The risk of salmonellosis associated with reptiles is fairly well known, but not too many people think about the risk associated with amphibians. The same general guidelines for keeping and handling reptiles should be used for amphibians:
- Children under the age of five should not have contact with amphibians, nor should people with compromised immune systems.
- Hands should be thoroughly washed after handling frogs or having contact with their environment (terrarium/aquarium).
- Frogs should not be allowed to roam freely in the house.
- Aquarium/terrarium water should not be dumped out in the kitchen sink. Ideally, amphibian habitats should be cleaned outside. Care should be taken to prevent contamination of the household environment.
- Amphibians should not be kept in childcare facilities or kindergarten classrooms.
This morning, as my dog Meg and I went out to get the newspaper, she ran towards our pool fence, barking (pretty unusual for a dog that is afraid of chipmunks). I wondered what the issue was until I saw a black and white tail sticking out. The pool has been closed for the season and there was a skunk standing on the cover. The cover's about 1.5 feet below the deck and the skunk couldn't get out.
After going over various options, like putting things in for the skunk to climb out on (unsuccessful), getting a live trap (too lazy to go find one), scooping it up with the pool skimmer net (a matter of how badly I'd be sprayed, not whether I'd be sprayed), getting a wildlife removal person in (too cheap to get someone else to do it) or lacing food with a sedative, I came up with the following plan:
- Find a large garbage pail with a handle. Tie a long rope to one handle.
- Place the garbage pail on its side in the pool, with the handle tied to the rope on top.
- Lure the skunk into the pail (e.g. with food) or, as I did, herd it in using a LONG pole.
- When the skunk is inside, pull on the rope to tip the garbage pail back up.
- Cover the garbage pail. A plastic kiddie pool works well.
- Carefully but quickly lift the covered garbage pail out of the pool.
- RUN... upwind.
It worked for me... no guarantees however.
A second ferret in the US has been diagnosed with H1N1 influenza. The latest case involves a fatal infection in a ferret from Nebraska that was presumably infected by its owner. Three other ferrets in the household were also sick, and it's fair to assume that they had H1N1as well.
It's important to keep things in perspective. We have two confirmed pet cases among thousands and thousands of human cases. Thousands of pets have presumably been exposed to owners infected with H1N1, with few apparent problems. (You can never rule out additional cases completely, because pets tend to get ignored in outbreak investigations, but there's no indication that this is a major problem.)
This is yet another good reminder of the potential for diseases to move between species in households. If you are sick with a potential infectious disease, you should restrict contact with household members - all household members: human and animal. Ferrets are likely the greatest risk when it comes to H1N1, followed by pigs and pet birds. Dogs and cats are presumably low risk, but we can't say there's absolutely no risk.
If you might have H1N1, reduce close contact with your pets. Don't hide from them, but avoid close face-to-face contact and coughing around them. Wash your hands regularly. More details about household infection control precautions are available from the CDC. Take the same precautions around pets as you would around people. If your pet subsequently gets sick, make sure your veterinarian knows about the possible H1N1 exposure.
Image source: www.ferretfriends.org
An Indiana woman has died of rabies. Little information is currently available. Reports state that bat rabies was involved but that the source of exposure was not known. Presumably, they have determined that she was infected by the bat rabies variant (strain), but she didn't report being bitten or otherwise exposed to a bat. Bat rabies is a serious concern because it is easy to get bitten by a bat and not know it. Most cases of rabies in Canada and the US are associated with bat exposure. This is a tragic reminder about why we pay a lot of attention to bats and rabies (and why my family received post-exposure treatment after having a bat in the house a few years ago).
More information about rabies can be found on the Worms & Germs Resources page.
The recent discovery of H1N1 influenza in a pet ferret has led to another round of concern about the potential impact of H1N1 on pets and pets as a source of human infection. Finding H1N1 in a ferret is not particularly surprising, considering ferrets are susceptible to various (including human) influenza viruses. We shouldn't dismiss the potential that certain pets could become infected by this virus or transmit, it but the overall risks are presumed to be very low. There have obviously been many, many cases of H1N1 influenza in pet owners, yet there is just this one report in a pet (although it's certainly possible that other pets have been infected but not diagnosed). Ferrets may be the biggest concern. Pet birds and pot-bellied pigs may also be at higher risk considering this virus can clearly infect pigs and birds. Cats are probably a bigger concern than dogs because of what we know about cats' susceptibility to (and ability to shed) H5N1 (avian) influenza.
The risks are low to pets and pet owners, but there's rarely a no-risk situation with infectious diseases. A few basic measures should be taken to reduce the risks associated with this pandemic virus:
- If you have (or think you may have) influenza, treat you pet like other people in your family. Avoid contact with them, especially their faces, and pay close attention to hygiene (especially handwashing). This should help reduce the risk of exposing your pet to H1N1.
- If you have influenza, or your pet has been exposed to anyone with influenza, and your pet becomes ill (e.g. respiratory disease, fever, lethargy), contact your veterinarian. Avoid close contact with your sick pet (especially the face) and wash your hands after you handle it.
- Relax and enjoy the company of your pet. The risks of influenza are low.
Just when all those turkeys that managed to survive Thanksgiving weekend thought their troubles were over, there's new issue: H1N1 influenza (formerly known as swine flu) has been found in an Ontario turkey flock. The H1N1 virus was first reported in birds in Chile in late August.
This is not a reason to panic. No one can get the flu from eating a properly-cooked Thanksgiving turkey (nor from any other type of properly-cooked turkey). The producer has voluntarily (and very responsibly) quarantined the affected flock, and no birds or eggs have left the facility. There is no risk to the food chain.
Pigs can be infected by human, pig and bird flu viruses, and multiple infections can result in viruses trading genes and producing new viruses that can infect more species. So it's not too surprising that H1N1can infect people, pigs and now birds as well. This incident serves as an important reminder that we need to remain diligent about infection control and hygiene, even around animals. It's highly unlikely that these turkeys had contact with infected pigs - most likely the virus was spread to this flock by a person. Poultry producers may therefore need to consider getting vaccinated for H1N1 flu not only to protect themselves, but also their flocks, and anyone who may have the flu should definitely stay off these farms. Hopefully the virus does not become established in wild bird populations (like H5N1 has in some areas), as this would make it much harder to control.
Recommendations for avoiding the flu (H1N1 or other) remain the same:
- Wash your hands and/or use alcohol-based hand sanitizer
- Sneeze into your elbow
- Disinfect commonly touched surfaces
- Stay home if you are sick
- Get vaccinated!
Here's a recent question: "Can a rabies virus get into the body if you pick up a dead animal the roadway and have a cut on your hand? I understand the animal has to carry the rabies virus but sometimes we don't know what killed the animal. It may be infected and didn't use due diligence or perhaps it just wasn't fast enough. After reading stories here I'm less likely to remove a dead animal. Sometimes they are so juicy, the fluids are flung about and you may get some on your clothes or skin and not know it. How likely is contracting rabies from fluids in a cut? The reason I ask is when I was younger I picked up a dead squirrel with my bare hands and then noticed I had cuts on my hands. I went to a doctor who looked at me like I was crazy but I had that uneasy feeling because I knew rabies is almost always fatal. Of course, I didn't get it but when I watch other people remove dead animals from roadways I cringe. I can't even think about eating roadkill or skinning it for the fur but that's just me."
Good question. You've covered most of the important aspects of risk, which are pretty minimal:
- Animal has to be infected
- Live rabies virus needs to be present
- Rabies virus needs to get into a person's body (not just on it)
Let's look at these individually.
Animal needs to be infected
- You never know whether this is a concern when you find a dead animal. Once it's dead, you can't tell if it's acting strange. In general, it's safest to assume that all such animals are infectious until proven otherwise.
Live rabies virus needs to be present
- I haven't come across good information about how long rabies virus can survive in a dead body outdoors. It probably varies greatly between different situations, particularly depending on the temperature of the body. For very fresh roadkill, there's certainly a possibility that live virus is still present (if the animal had rabies).
Rabies virus needs to get into a person's body (not just on it)
- Rabies cannot be transmitted through intact skin. Rabies infection is transmitted mainly through bites, cuts and scrapes. Saliva or nervous system (e.g. brain) tissue are infectious. Blood, urine and feces are not.
- If you have contact with a dead animal, avoid any direct contact with your skin, and avoid any activities that could result in splashing of fluids. Transmission of rabies from infected fluids is possible if it comes in contact with broken skin or mucous membranes like the eyes or mouth.
- If intact skin has been contaminated with fluid, wash it thoroughly with soap and water, but don't panic - it's really of minimal concern.
- If your clothes have been contaminated with fluid, take them off right away if possible. If that's not practical (or legal), take them off as soon as you get home. Put them in the laundry immediately and wash your hands.
- If open sores or other broken skin has been contaminated, wash the area thoroughly with copious amounts of soap and water under moderate pressure. Disinfectants can be used to help clean the wound, but there's no consensus about whether that's necessary - these chemicals can be painful to use and hard on tissue, and the flushing action of the water probably does the most to remove the virus from the area. You should go to a physician, who will get in touch with public health personnel to determine if there is any reason for post-exposure treatment. If the animal's body is available to test, that's useful. If the brain has decayed too much to be tested properly, it's questionable whether live rabies virus would still be present even if the animal had rabies. Public health personnel will decide whether they think there is any risk.
Bottom line: the risk of contracting rabies from roadkill is very low. Roadkill contact has never, to my knowledge, been identified as a source of infection. Rabies transmission from dead animals has been documented, however, such as a couple cases of rabies from people preparing dead animals for food.
So, if you see a dead animal by the road, leave it alone. If you are going (for some reason) to touch it, first make sure it's really dead. An injured animal might be much more likely to bite. If it's really dead and you are just trying to move it off the road, use a stick, shovel or something else that doesn't involve you having direct contact with the animal. Other than that, I'm not sure why anyone would want to touch roadkill.
In yet another tragic example of why large wild species should not be kept as pets, a 37-year-old Pennsylvania woman was killed by her pet black bear. She entered the 350 pound bear's cage, a 15 by 15 foot steel and concrete enclosure (hardly a good environment for a bear) and was mauled. A neighbour then shot and killed the bear. A Bengal tiger and African lion were also present on the property. No indication was given about what might have triggered the attack.
Large carnivorous mammals don't make good pets. It's also questionable whether people can adequately and humanely care for such animals. I have a hard time believing the bear had a good quality of life living in a small steel and concrete pen. The picture above is not from this case but from another bear enclosure elsewhere in Pennsylvania (see link here).
Every year, there are reports of these types of "pets" severely injuring or killing their owners, yet there is little effort in many regions to control the ownership of these animals. Local officials knew about these animals and the woman had permits for them. Why (and how) someone could actually get a permit to keep these species is beyond me.
Pets are great, but pet ownership has to be logical and safe, and there have to be benefits for both the human and animal. Keeping dangerous animals locked up for curiosity's sake is no longer (or at least should no longer be) socially acceptable. These animals should be in the wild or in a properly managed zoo or wildlife rehabilitation sanctuary.
The investigation into a large E. coli O157 outbreak linked to a UK petting zoo continues, and the number of potentially exposed people is astounding. There are a couple of reasons that I write a fair bit about petting zoos, and they are highlighted here: the potential for exposure of a large number of people and the predominance of children. In this outbreak, it is feared that tens of thousands of people may have been exposed since problems started in August. The exact number of infected people is currently unclear but is in the "dozens," including some with hemolytic uremia, a severe kidney disorder. One report says there are 36 sick people, including 12 children under the age of 10. It's pretty likely that these numbers will increase, and that even more cases will go undiagnosed because they were mild and people didn't get tested.
This week, testing has been performed on animals and environmental areas on the farm to look at sources of E. coli O157. I'm not sure why this wasn't done a while ago. However, at this point, it's mainly going to be useful to confirm that the E. coli strain infecting people is also present in animals on the farm. Finding or not finding the bacterium at various environmental sites at one point in time really doesn't say much about where it was when people were getting infected. If E. coli was in the animals, it's likely to contaminate various environmental areas. If petting zoo design and hygiene were not optimal, this could result in contamination of visitors' areas.
Some parents have complained that the farm was allowed to remain open for more than two weeks after the first cases of E. coli were reported. That's a very valid concern and one that should be clearly addressed. Once there was reasonable suspicion of the farm being involved, measures should have been taken to reduce further exposure. A good synopsis of these events is available here. It certainly depicts a less-than-stellar response to a potential outbreak. Although you don't want to over-react and close a facility that was not actually the source, given the potential severity of disease and massive number of people that could be exposed, public health concerns need to supercede economic concerns in situations like this.
Petting zoos will never be "no risk." There is an inherent risk of infectious disease transmission any time you interact with an animal. That being said, there are standard recommendations that are in place to greatly reduce the risk of disease transmission. I don't know much about the quality of infection control practices on this farm, but it's likely they could be better. One writer to timesonline describes how kids are allowed to climb in with the animals and chase after herds of pigs, which certainly suggests a lack of proper control.
People running petting zoos need to take their role in protecting the public seriously. That includes protection from infectious disease and injuries such as bites. Public health authorities need to take a more proactive role. Instead of the standard approach of just providing documents or signs, these events need to be inspected and any problems need to be identified and addressed. The key is to use basic, practical measures that reduce the risk while maintaining the positive aspects of the petting zoo. It's getting better in many areas, but there's clearly still room for improvement.
The last time I visited the Aberfoyle (Ontario) Fall Fair, the petting zoo was so bad that I ended up writing to the fair organizers and the Wellington-Dufferin-Guelph Public Health Unit. (Neither group replied). It was pretty bad. Young poultry are inappropriate petting zoo animals because of the risk of transmission of bacteria like Salmonella, yet baby chicks were being passed around to young children. One chick was injured by rough handling and the petting zoo supervisor just threw it (still alive) in the garbage. There was a diarrheic calf, poor hand hygiene facilities, and other problems.
We went back to the fair yesterday and I was quite pleasantly surprised: no chicks, no calves, all appropriate and healthy-looking animals, a clean facility and good hand hygiene stations. There were still a couple of suboptimal things, like not having hand sanitizers by one exit, and having a "supervisor" who was staring off into the wilderness and smoking inside the tent filled with kids and straw, but it was night-vs-day compared to the last time. I doubt my letter had much to do with it, but you never know. I think it's important that people not accept inadequacies that put the public (particularly children) at risk. People need to raise a stink when they see a problem. I wrote earlier today about a child who had her finger bitten off by a petting zoo zebra that had bitten other people. The previous bites may not have been reported because they were minor, but we need to report apparently minor problems so they don't escalate into major injuries, disease outbreaks or other bad scenarios.
Anyway, it was great to see an improvement, and people in the petting zoo appeared to be having a good time. Now if they'd just work on "Big Ned's" food concession, where the only sink seems to be a storage area with no soap or paper towels, and which appeared to be in need of a serious cleaning, or on the little midway, where they were hand cranking the questionable kiddie ferris wheel to get kids off when all the rides stopped working. Baby steps, I guess.
A zebra in Buffalo Beal's Animal Park in Maiden, North Carolina, bit the hand of a nine-year-old girl, severing her finger. The girl was feeding the animal when it bit off most of her right pinkie finger. Her father had to hit the zebra a few times to get it to release her hand. The finger was not able to be re-attached. It was also reported that the girl is receiving a series of seven rabies shots. That doesn't make a lot of sense. The animal that bit her is clearly identified and can be monitored to see if it develops rabies. We don't have clear guidelines for duration of monitoring of animals apart from cats and dogs (10 day observation), which may be why they are not simply observing the zebra for signs of rabies. However, it's extremely unlikely that the zebra is rabid, and having the child undergo post-exposure treatment is questionable in the absence of any signs of disease in the animal. Regardless, the zebra should have been vaccinated against rabies beforehand. The owner of the park apparently stated that what happened to the girl is "highly unusual." Severing of extremities shouldn't be a regular event at a petting zoo. It's rather disturbing to hear that this zebra has bitten other children and a volunteer over the past couple of years. A responsible petting zoo operator would not keep a "known biter," or would at least only have the animal on display in an area where no one could touch it. It's irresponsible to put an animal that has been known to cause injuries in close contact with young children. Hopefully local officials will take a close look at this operation, however their ability to act may be limited because often petting zoos can operate with little or no oversight. A lawsuit is probably the most likely way to control such irresponsible behaviour, because the fear of being sued may be the only effective motivation for some people to clean up their operations. I'm pretty opposed to the way society is becoming increasingly prone to suing when anything bad happens, but this is a case where it's not hard to argue that the petting zoo operator's action (or rather, inaction) directly led to a serious and lifelong injury to a child. I'm sure there are some lawyers in North Carolina lining up to talk to the parents. The TV report about this from WCNC can be found here.
The finger was not able to be re-attached. It was also reported that the girl is receiving a series of seven rabies shots. That doesn't make a lot of sense. The animal that bit her is clearly identified and can be monitored to see if it develops rabies. We don't have clear guidelines for duration of monitoring of animals apart from cats and dogs (10 day observation), which may be why they are not simply observing the zebra for signs of rabies. However, it's extremely unlikely that the zebra is rabid, and having the child undergo post-exposure treatment is questionable in the absence of any signs of disease in the animal. Regardless, the zebra should have been vaccinated against rabies beforehand.
The owner of the park apparently stated that what happened to the girl is "highly unusual." Severing of extremities shouldn't be a regular event at a petting zoo. It's rather disturbing to hear that this zebra has bitten other children and a volunteer over the past couple of years. A responsible petting zoo operator would not keep a "known biter," or would at least only have the animal on display in an area where no one could touch it. It's irresponsible to put an animal that has been known to cause injuries in close contact with young children. Hopefully local officials will take a close look at this operation, however their ability to act may be limited because often petting zoos can operate with little or no oversight. A lawsuit is probably the most likely way to control such irresponsible behaviour, because the fear of being sued may be the only effective motivation for some people to clean up their operations. I'm pretty opposed to the way society is becoming increasingly prone to suing when anything bad happens, but this is a case where it's not hard to argue that the petting zoo operator's action (or rather, inaction) directly led to a serious and lifelong injury to a child. I'm sure there are some lawyers in North Carolina lining up to talk to the parents.
The TV report about this from WCNC can be found here.
A Montreal man is undergoing rabies post-exposure treatment after being bitten by a bat in Lachine's Summerlea Park. He found the bat lying on the ground and when he picked it up to take a closer look (surprise, surprise) the bat bit him.
This incident shows yet again the need for better rabies education. While we don't want to create fear and loathing of bats, we should consider them rabies-positive until proven otherwise. That doesn't mean we want to eradicate them. It means we want to educate people to enjoy them from a distance and never have direct contact with them.
Never try to touch a bat. A bat lying on the ground in a park is not a healthy bat. It may be sick for various reasons, but rabies is certainly a possibility. If you come across a sick bat, call animal control. They can safely remove it so that no one has the chance of being bitten. If someone has had contact with the animal, the bat must be tested for rabies, as was done here. Rabies is preventable using proper post-exposure treatment, but it's very expensive, a hassle and a series of vaccine's isnt' exactly fun.
Rabies baiting is a common and effective way of controlling rabies in some wildlife populations, particularly skunks, raccoons and foxes. It involves dropping edible rabies vaccine, by airplane or by hand, into targeted areas. Millions of rabies baits are used across North America and baiting programs have been cited as a key aspect of wildlife rabies control. In one year, 1.3 million baits were dropped in targeted areas of Southern Ontario alone over a two-month period. A good series of pictures of rabies baiting is available here.
Rabies baits are usually a small rectangular block comprised of something that smells or tastes attractive to the targeted wildlife into which a liquid vaccine has been added. Some use fish meal and fish oil to attract wildlife. Others use combinations of fats, icing sugar, vegetable oil and artificial marshmallow flavour (don't ask me why - I'm certain there's a reason but I don't know if they've done taste-testing).
Often, the local public is notified in advance of the drops being made, and it is recommended that kids be closely supervised outdoors for a week or so to ensure they don't come into contact with the baits. It is also often recommended to keep pets indoors or on leash during the same period. (Pets are much more likely to be exposed to and to eat the vaccine than kids). It's also recommended that you wash your hands thoroughly if you have contact with a bait.
Rabies baits are quite safe, and these recommendations shouldn't cause concern. It's a case of being overly cautious. The baits are safe to touch, but it is still recommended that you don't touch them (if nothing else, they may make your hands smell pretty bad). Ingestion of a rabies bait by a person or pet is also unlikely to cause a problem. Any adverse affects are more likely to occur due to the non-vaccine component of the bait, particularly because of the typically high fat content. Ingestion of a lot of baits could certainly cause vomiting or diarrhea in a dog, just like ingestion of large amounts of other inappropriate foods.
Some groups recommend that you contact Poison Control if your pet has been exposed to a bait, but I'm not sure what they'd do in such a case. Other groups ask you to report to them that a pet ingested the bait, likely so they can consider exposure of people and pets when determining target areas for the next year. There's similar variation in recommendations if a person ingests the vaccine. Often it is recommended that public health be notified so they can record it, but it's very unlikely anything would be done.
On a related note, you cannot use rabies baits as a free way to vaccinate your pet. It might work, but there is no way to know, and if your pet is exposed, it would be considered unvaccinated if it was not properly vaccinated by a veterinarian with an appropriate dog/cat vaccine.
We've written various posts about raccoons, raccoon latrines and concerns about the raccoon roundworm (Baylisascaris procyonis). I received a question today about how to keep raccoons from coming back after a latrine has been identified and cleaned. It's a good question, and one without a simple answer. I've looked through various sources and have found a wide range of recommendations. (Whenever I see such a wide-ranging list of recommendations, I wonder whether anything actually works.)
Home remedies include:
- Sprinkling pure soap flakes on the lawn and watering thoroughly
- Mixing bone meal in garden soil
- Sprinkling diluted tabasco sauce over fruits and vegetables (wash before eating, as you should anyway!)
- Lighting up the area where raccoons are a problem
Various commercial deterrent compounds are available, such as one that apparently has the scent of a coyote, or one that's a combination of vinegar, pepper and sulfur.
Another approach is motion-sensitive deterrents. Motion-sensor-based lights can be useful since raccoons often come rooting around in the evening or overnight, and lights that turn on when they approach could be effective. These would require a power source, which could be limiting in some places like sheds. Similarly, motion-sensor based systems that spray water or citronella (sometimes used to keep cats out of certain areas or off countertops) could be useful. Battery-operated units could be used anywhere. (Here's a link to one. I've never used it but it shows you what I'm talking about). There are also motion sensors that hook up to hoses.
One problem with deterring raccoons is their intelligence. They can often find ways around deterrents, or adapt to them. Along with any attempts to actively deter the raccoons, it is also important to try to reduce the desire of the raccoon to come to the location. If there is a good food source or other desirable attraction, the raccoon will probably try harder to stay around. Tightly covering garbage cans and removing other possible food sources (e.g. food for outdoor cats) are important steps. Making sure neighbours (or other family members) aren't feeding the raccoons is also important, because food is a great motivator.
If you live in the suburbs of Chicago (or probably many other cities as well), chances are pretty good that you live close to a raccoon latrine. Raccoons like to defecate in specific areas (raccoon latrines) which can become highly contaminated with eggs of Baylisascaris procyonis, the raccoon roundworm. Human disease caused by this parasite is rare, but when it occurs, it can be devastating. Infected raccoons can shed around 20 000 Baylisacaris eggs per gram of feces (see image right), and the eggs can survive for long periods in the environment, so it's easy to see how biohazardous a raccoon latrine could be.
A study in the upcoming edition of Emerging Infectious Diseases (Page et al) looked at 119 backyards in the Chicago suburbs. Latrines were found in 51% of yards, with up to six latrines per yard! Baylisascaris eggs were found in samples collected from 23% of latrines. The likelihood of having a latrine in the yard was lower in houses farther away from forested areas. No other factors were identified as associated with the presence of a latrine, however there was a trend towards increased likelihood if a food source (e.g. bird feeder) was present.
The fact that raccoon latrines are so common and that a high percentage of raccoons shed Baylisascaris should raise concern, and emphasize the need for good hygiene. At the same time, the rarity of disease despite the widespread presence of infected raccoons should be remembered. You don't get infected by walking by a raccoon latrine, you get infected by ingesting (swallowing) the parasite. Avoiding this is simple, and as the folks at Barfblog (a food safety blog) would say, the key is: "Don't eat poop". Simple measures can reduce the risk, such as avoiding contact with raccoon feces and washing your hands after being in potentially contaminated areas. Young kids are at highest risk because they are more likely to put things in their mouths, so keeping children away from areas potentially contaminated by raccoon feces is important, along with good attention to hand hygiene.
Since raccoon latrines are an obvious source of infection and many (of the limited number of) human cases have been where latrines were close to childrens' play areas, eliminating latrines is also a good idea. Details on cleaning up latrines are available in an earlier Worms & Germs post.
A 74-year-old Colorado woman that had been warned repeatedly not to feed bears was killed by one. The circumstances surrounding the attack are not known, but there was clear evidence of mauling. Wildlife officers had received numerous complaints for at least a decade that the woman was habitually feeding bears. She was warned several times but never ticketed because of difficulty gathering solid evidence of the illegal activity. Wildlife officers and sheriff's deputies killed two bears after the attack. It was reported that a necropsy of the larger 394 lbs animal showed that it appeared to have been feeding on a human, but this has not been officially confirmed yet.
As we've discussed before, people often feed wildlife thinking they are helping the animals, but the opposite is true. Numerous problems are caused by feeding wildlife, including making animals dependent on people for survival, decreasing animals' fear of humans, encouraging animal encroachment into urban areas and generally increasing the chance for both human and animal injury and infection.
If a groundhog sees its shadow, there's more winter on the way. If it doesn't see its shadow, spring is coming soon. So what does it mean when a groundhog attacks a cop?
An aggressive groundhog in New Jersey that tried to attack two police officers and one other person was confirmed to have rabies. Police were called to a house because the groundhog in the garage charged the house owner as he tried to get into his truck. The groundhog was subdued with pepper spray (I wonder if anyone has every used a Taser on a groundhog), caught, euthanized and tested for rabies. Fortunately, none of the people came in direct contact with the animal, therefore there was no exposure and rabies post-exposure prophylaxis was not required.
Groundhogs are not high on the list of animals that tend to get rabies. One-hundred twenty-three rabid groundhogs have been identified in the state since 1989 (I'm actually surprised it's that high), compared to 4 175 raccoons. Like every other mammal, groundhogs are susceptible to rabies virus but they are less likely to carry the virus, because they are rather shy vegetarians and would often not survive attacks from rabid predators. This case is a good reminder that rabies must be considered in any animal acting strangely.
No, I'm not talking about a referee, I'm talking about a real zebra. Pittsburgh State football player Joe Windscheffel will miss the entire upcoming season after being attacked by a zebra on a farm in Kansas. In a related story, Kansas State University Professor Gary West remarked about various problems associated with people owning exotic pets. Some are pretty clear, such as the risks posed by 500 lbs tigers or 20 ft pythons (or unruley zebras). Others are more insidious, such as the risks of transmitting various zoonotic diseases.
Exotic pets are an important source of zoonotic diseases. Some of these diseases, like Salmonella, are very common and well-understood. Others come out of nowhere and can cause major problems, such as the monkeypox outbreak in the US a few years ago that was caused by prairie dogs and African rodents. One problem with exotic pets is that we know little about the disease risks associated with them, and therefore we don't know what precautions should be taken or how to test them for the most important pathogens. While exotic pets can be interesting, they certainly pose an increased risk of disease compared to dogs, cats and other domestic animals for which we have a good idea of the risks involved and how to manage them. That's not to say that all exotic pets will cause disease and no dogs will - that's definitely not true. However, people having contact with exotic pets must accept an increased risk of disease exposure.
The CDC recommends that children under five years of age, elderly individuals, people with compromised immune systems and pregnant women not have contact with exotic pets. While these are the high risk groups, infections can occur in anyone. If you really want an exotic pet:
- Stop, think, and read as much as you can before making the decision. Find out about the animal, how to care for it and what risks might be involved.
- Make sure you can provide appropriate care. Many exotic pets die because of poor management because they're owners can't or don't know how to care for them properly.
- Find a captive bred animal, as these animals likely pose less risk of harbouring exotic diseases. It's also a much more humane way to get a pet than to buy a wild caught animal (especially when you consider that many animals die during capture and transit).
- Make sure there are no high-risk people living in or visiting the household. Saying they will be in the house but won't have contact with the pet is not adequate, because infections from indirect contact can occur.
- Remember that if you do things right, your pet should live for a while (e.g. years). If you think you might want to have kids in a couple of years, do you really want to get an exotic pet that will need to be re-homed at that time?
- Make sure your physician knows you have an exotic pet. Various diseases that would not be an issue for the general population might need to be considered if you get sick.
Image source: University of Bergamo
A paper in the July 1 edition of the Journal of the American Veterinary Medical Association (Muller et al) describes a case of encephalitis (brain inflammation) in a rabbit caused by human herpesvirus type 1. The owner had a severe herpes infection with genital and oral lesions five days before the rabbit got sick, and reported "intensive" nose-to-nose and mouth-to-nose contact with the rabbit. The rabbit started off with a decreased appetite and excessive tear production (epiphora) in one eye. Then other signs of eye and neurological disease developed. Despite aggressive treatment, the rabbit deteriorated and was euthanized after a week of hospitalization. Subsequent testing identified human herpesvirus type 1 in the rabbit's brain.
Human herpesvirus type 1, also called herpes simplex viruses type 1 (HSV-1), is a common sexually transmitted disease (STD) in people. It can cause oral, genital and ocular (eye) lesions. Humans are the primary host of this virus, but it has been found in species such as rabbits, rats, mice and chinchillas. In rabbits, it usually causes encephalitis, and is almost always fatal for these animals.
This case shows how viruses typically associated with one species can sometimes affect others. While we usually focus on microorganisms moving from animals to humans, they can also move in the opposite direction, as was presumably the case here. Close face-to-face contact with the infected owner was probably the source of the virus. This is an example of an uncommon event, but one that should not be ignored.
If you have an active herpesvirus infection:
- Limit close contact with rabbits (and, to be on the safe side, probably restrict contact with other pets as well). In particular, avoid contact with the mouth, nose or eyes.
- Wash your hands or use an alcohol hand sanitizer regularly, particularly after using the washroom or having any contact with infected sites/sores.
- Make sure herpesvirus infection is considered if your rabbit develops eye or neurological disease.
The risk of rabbits transmitting human herpesvirus is completely unclear. Common sense dictates that anyone hanlding a potentially infected rabbit should restrict contact with the eyes/mouth/nose, wear gloves, wash hands after contact (even if gloves were worn) and avoid contamination of clothing.
Recently, I wrote a commentary about the need to better define what service animals are because of potential abuse of regulations regarding service animals and the possibility that illegitimate use of the term could impact true service animals. Here are some good comments from a reader.
As a service dog user and trainer who sometimes lectures at the University of Guelph, I am sorry to see the American-centric slant to this article. In Canada the guideliines are even more vague and there has to be a charter challenge to support the use of a service dog that has been owner trained.
- The article was intended to discuss the American situation since I was talking about American legislation and responding to problems that people have asked me about in the US. Issues are different in various countries and the legal protections in the US certainly don't apply to Canada.
- The last point raises some concerns. What constitutes "owner trained?" Service animals are highly trained to do their specific task and to work safely in public situations. I'm not convinced owner training makes a service animal. There needs to be at least some degree of supervision/review of the training and certification process.
I use a service dog to mitigate the effects of my invisible disability and the vagueness of the laws related to service dogs in Canada has made travelling and working with my dog difficult. I get comments that range from "you don't look disabled" (which I usually reply to with -thank you!
neither do you!) to "that dog doesn't look like he is doing anything and how can he help you if he is asleep (believe it or not, he does get to sleep when I stop to work somewhere, but will wake up and work if needed).
- Those are all legitimate concerns and I empathize with the problems you've had. That's why I think the "spirit" of the US's ADA is excellent. Protection needs to be in place for true service animals. Just as important is the need for education about what service animals are, what they do, and where they should be allowed to go. I also think this reader's concerns support my comments: We need to make sure that service animals are properly scrutinized. If people know that service animals are properly trained and regulated, they are less likely to have a problem with them. On the other hand, if people never know whether a service animal is really a service animal, then they may be less likely to give them the degree of respect and access they deserve.
I strongly feel that if you don't need a dog you won't take a dog with you; why would you? It is too much work! For anyone who would like to take their pet with them to the grocery store, I would be delighted to take them with me to show them what travelling through the meat aisle is like; people stop and stare. You have to plan your route so that the grocery clerk doesn't park their cart under my dog's nose (no...he won't touch it...but why make his day harder than it needs to be). You need to be aware of the two year old who is covered in jam who wants to hug the doggy. And you have to avoid hazards like the display of glass jars that tumbled and broke in front of my dog, surrounding him in glass shards with no way to safely walk out (stand stay! what a useful behaviour).
- Sorry, but I disagree. I think that if a grocery store advertised that it was pet friendly, there would be dogs in there all the time. Some people bring their pets everywhere, no matter how much extra work it is.
- Also, the grocery store example is a great one to highlight concerns. There are public health reasons why we don't want widespread animal access in grocery stores. Check out a previous post about a "service horse" walking through grocery store.
Life with a service dog is enriching for certain, but it is not something you want to do unless you need to. I would advise anyone who is concerned about the illegitimate users to slow down, and think. We are already protected. If your dog is causing a problem, you can be asked to leave.
- In Canada you can. In the US you can't. That was the point of the article. In the US, you can't ask someone to make an animal leave except under very specific circumstances that a true service animal should never create. What we need is more protection in Canada and more clarity in the US.
Image source: http://www.assistancedogsofthewest.org
Following a report on black market turtle sales in Maryland, a letter to the Baltimore Sun by Maryland veterinarian Dr. Jeffery Rhody wanted to "set the record straight".
"All reptiles carry salmonella as part of the normal bacterial population in their body."
- Not really true, however Salmonella can commonly be found in healthy reptiles, so the overall sentiment is valid.
"The risk of getting infected with salmonella from a reptile can be greatly reduced with common sense hygiene practices."
- Absolutely. General infection control practices are critical to reduce (but they do not eliminate) the risk of Salmonella transmission.
"In fact, the incidence of reptile-borne salmonella infections is much less than salmonella infections obtained from improperly handled poultry products."
- Statistics can be manipulated to either support or refute this. The absolute number of Salmonella cases from food is certainly greater than those from turtles. However, I'm not so sure turtles end up looking good when you consider the number of cases compared to the number of people exposed to these factors - a lot more people eat food than own turtles. The number of cases of Salmonella associated with reptile contact every year is stunning, even though only a small percentage of people own reptiles. Fatal infections can occur, so it's not something to take lightly. Statements like the one above can get into some questionable logic, like saying that a machine gun can kill more people than a handgun, so handguns must be safe. Certainly, Salmonella is a risk with handling raw poultry, and efforts are taken to get people to reduce risky behaviours (like contaminating kitchen surfaces with raw meat). The same should apply to reducing risky behaviours with regard to pet contact.
"Of course, if you lick a turtle, the risk of salmonella infection is greatly increased."
- Yep. That's why the focus is on small turtles. But, people get Salmonella from larger turtles too.
"No one who owns a slider should be concerned about breaking the law."
- They should, however, be concerned about getting sick. Turtle owners should learn about risks and preventive measures from sources such as a the information sheet in our Resources page.
As someone who has owned turtles, I understand the appeal of these animals. As someone involved in zoonotic diseases, I understand the risks. People need to have enough information to understand the risks and benefits, to make logical, informed decisions. The risks to healthy adults who handle the animals properly is quite low. That's why the focus is on high risk households like those with young children, the elderly or immunocompromised individuals. There are good reasons for the ban on the sale of small turtles. Banning the sale of small turtles doesn't hurt anyone (except for people wanting to profit from selling them), and may prevent disease. Seems logical to me.
...Macaroni penguins, that is. There is a report in a recent edition of Emerging Infectious Diseases about isolation of Campylobacter jejuni from Macaroni penguins in Antarctica. Campylobacter is a bacterium that can cause diarrhea in people and animals, and which can also be found in the intestinal tracts of a wide variety of animal species, even when they’re healthy. Researchers typed the Campylobacter isolates from a group of penguins in Antarctica and found that many were a strain that commonly affects people. They had a few different ideas about how the penguins became infected. One possibility is contamination from toilet wastes that a nearby research station dumped into the surrounding water. They thought that ships discharging sewage into the ocean near the penguins' feeding grounds could also be a source of the bacteria, as could migratory birds like albatrosses that spend part of the year closer to people. Whatever way it got there, a penguin colony provides an exceptional opportunity for Campylobacter to spread, since huge numbers of penguins live in very close proximity to each other. Fortunately, Campylobacter rarely causes disease in birds, and we hope that's true with this strain in penguins as well.
This report shows how closely linked humans and animals can be, even when we usually live far apart. It also shows why we keep saying that a global ecological approach to infectious diseases is needed - we need to look at the big picture.
More information about Campylobacter can be found on the Worms & Germs Resources page.
- Parent finds a dead bat carried in by the family cat and, for reasons known only to him/her, puts it in a jar.
- The next day, the parent takes the bat to a school, takes it out of the jar, and presents it to 8 classrooms full of children. Many students, teachers and staff touch the bat.
- The school nurse finds out later that day (I assume this finding is accompanied by a large spike in the nurse's blood pressure), and advises the parent to submit the bat for rabies testing.
- The bat tests positive and an investigation is started.
- 107 students and staff are interviewed and all are identified as requiring rabies post-exposure treatment. One student reported that their finger may have been pricked while sticking it in the bat's mouth, which would be a high risk exposure.
- 74 people ended up being treated. There's no word as to why some declined.
This was clearly a completely avoidable situation that resulted in potential widespread exposure to rabies, a large investigation, stress for people and their families, as well as the expense and pain of multiple injections for many individuals - all because one well-meaning but poorly-informed parent brought a dead wild animal to school, and because none of the teachers or staff that witnessed this thought to act.
The school's insurance policy covered the $75 000 in vaccine costs (plus an additional $29 000 for vaccine that was ordered but not used by people who declined vaccination).
- People need to be more informed about diseases such as rabies. This type of information is available on the Worms & Germs Resources page.
- Schools need to develop and enforce policies regarding visitors and pets. Approximately 1/3 of large scale rabies exposures occur in schools.
- Common sense needs to be a little more common.
Another surge in the number of cases of Q fever in people in the Netherlands has been reported. Prior to 2007, the average number of cases of Q fever per year in the country was only 15. In 2007 there were 192 cases, and last year there were 958 cases, making this the largest community outbreak of Q fever ever reported. At the beginning of May 2009, another jump in the number of cases - over 200 - was reported by the dutch newspaper de Volkskrant.
Q fever is caused by a highly infectious organism called Coxiella burnetii. The organism can be carried by many different animals, but particular sheep and goats, and sometimes cattle. Most of the time it does not cause a problem in these species, but it has been linked to abortions and abortion storms (i.e. when many animals in the herd abort in a short period of time). It can be shed in manure, urine and milk, but the largest numbers of organisms are found in birth fluids and tissues (e.g. aborted fetuses, placentae). When the tissues and fluid dry out, the organism can be stirred up into the air over short distances in dust. Humans are highly susceptible to C. burnetii, and inhaling even a single organism can cause infection. Most of the time people who get sick have signs very similar to the flu, but severe pneumonia and liver disease can develop in a small number of cases.
A definitive link between sheep and goats and the Q fever outbreak in people in the Netherlands has not yet been established, but it is highly suspected that many of the cases are associated with infected goats (and some sheep). In the last two years numerous outbreaks of Q fever have been reported on dairy goat farms and one dairy sheep farm in the Netherlands. This has lead to a cooperative arrangement between the Dutch agricultural ministry and the Dutch public health ministry - these two goverment branches have come together to help cover the costs of vaccinating sheep and goat herds in the country, in order to help stem the tide of disease and ultimately prevent more human cases. This is a great example of the "one medicine" concept, whereby groups on both the human health and agricultural/animal health sides are working together on this problem.
Manditory vacciation is now required for sheep and goats on larger farms in the hardest-hit areas, as well as any farms reporting any cases of Q fever since 2005, and any sheep or goats that have a "public function" (e.g. petting zoo animals or occupational therapy farms). It is very important that this last group is included under the manditory vaccination, as these animals have a large amount of contact with people. Steps have also been taken to improve hygiene, restrict spreading manure from sheep and goats, restrict visitors to infected farms, and to make abortion storms on sheep and goat farms reportable, so they can be investigated for Q fever. It will be interesting to see how effective these measures are at controling the outbreak in 2009.
More information on Q fever can be found in our archives.
A recent question from a reader:
"We live adjacent to the Oak Ridges Moraine in Aurora (Ontario) so our property has always been popular to local wildlife. For years, neighbourhood animals have enjoyed dry cat food in our backyard but the town has ordered this practice must stop immediately. Among reasons given, were that this food is harmful to the animals. This should be appropriate food for stray and feral cats but am writing to enquire if there is any information available about the effect of dry cat food on birds, raccoons and other domestic wildlife. Since the Premier declared Ontario free of the raccoon strain of rabies last year and there have been no recorded cases in York region, the main health concern is likely raccoon roundworm. I understand that incidence is quite rare but, coincidentally, the recent articles about roundworm cases in New York led me to you. Can you recommend sources of information to learn if feeding dry cat food is harmful to wildlife (raccoons) and if this food would cause increased risk of raccoon roundworm in the immediate area."
This raises some very interesting points.
What are the bad points about feeding wildlife?
Wildlife is best kept wild. The more we feed wild animals, the more contact there can be with people. That can be dangerous, depending on the animal (e.g. coyotes). It can also bring disease-carrying wildlife in closer proximity to peoples’ living spaces, such as encouraging roundworm-shedding raccoons to live next to houses. If you feed raccoons and they decide to stay, you may end up with a highly contaminated raccoon latrine somewhere on your property. That could pose a particular risk if you have young children or developmentally delayed individuals at home.
The natural food supply is one of nature’s ways of keeping animal populations at appropriate levels. If lots of people feed wild animals, their numbers can increase, resulting in more exposure to people, increasing animal population density (with corresponding risks to the animals from disease transmission) and an unsustainable population should the "free food" source disappear. It can also have a huge impacts on the local ecosystem of which we may not even be aware. Making wild animals dependent on humans is not a good thing.
Cat food is for cats. Dog food is for dogs. Neither of these necessarily provide appropriate nutrition for a raccoon, because dietary needs are different for each species. That being said, eating small amounts of pet food periodically likely doesn't do any harm to the raccoons. However, if raccoons rely on pet food as their main food source, I wonder whether health problems could develop, because the animals may stop eating the foods they need to provide a balanced diet.
What does "raccoon-rabies free" really mean?
Raccoon rabies is a type of rabies virus (example of other types are bat rabies virus and skunk rabies virus). Raccoons can be infected by other rabies viruses, so even though Ontario may be free of raccoon rabies, the province is not necessarily free of raccoons with rabies. Raccoon rabies control efforts have been highly successful in Ontario, but it is important to be aware that raccoons can still carry rabies. Any feeding practices that encourage contact with raccoons (as well as skunks, foxes and other wildlife) are of concern because these animals can carry rabies, of one type or another.
I received the following comment in response to a recent E. coli O157 and petting zoos post, and thought that it merited a post of its own.
"Why doesn't the petting zoo owners have a fecal swab sample taken from each animal in the petting zoo and submitted for STx PCR screen testing. If a positive is found isolate the animal and continue to monitor it. I would assume The University of Guelph's extension service would have some information about this."
That's a great question. When we start talking about infectious disease risks, people often ask about testing. However, testing is not always useful and I think that's the case here. Here's a few reasons why:
- Animals don't shed E. coli O157 all the time. It's been shown in cattle that if you sample animals regularly, you will find the bacterium in the manure some days but not others. Therefore, a single negative result does not mean that the animal is definitely negative.
- No test is 100% accurate. While current tests are quite good, it cannot be stated with absolute certainty that an animal that is negative on a test for E. coli O157 is truly negative.
- Even if the animals are all truly negative for E. coli O157, they may still be shedding other potentially harmful microorganisms (e.g. Salmonella, Campylobacter, Cryptosporidium ) for which people need to take the same kind of precautions as for E. coli.
- If petting zoo operators had to pay hundreds or thousands of dollars a year per animal for diagnostic testing (a reasonable estimate if they had to do multiple tests on each animal, possibly for multiple organisms), there wouldn't be many petting zoos around.
For any test, whether it's being used for screening or to make a diagnosis on a sick animal, it's critical that it be thought of in terms of "what will I do with the results." In this case, negative results would not change recommendations for running or visiting a petting zoo. I'd assume that animals could still be shedding E. coli O157 intermittently, or that they could be shedding various other pathogens, and I'd still recommend use of good infection control practices like hand washing. Efforts are best spent working on petting zoo design and hand hygiene, rather than testing the animals, because these are more likely to have a positive impact by reducing the risk of disease transmission.
Photo source: http://www.microvet.arizona.edu/Faculty/songer/diag.htm
I’ve written several posts about petting zoos, mainly about the potential negative aspects, although I still think they’re valuable if run properly. A major concern with these events is exposure of people to zoonotic infectious diseases, particularly harmful bacteria that can be carried by healthy animals. One of the more common pathogens that causes disease outbreaks associated with petting zoos, including severe or even fatal infections in people, is verotoxigenic E. coli, particularly E. coli O157.
A recent study by Pritchard et al. in the Veterinary Record highlights some of the concerns with this pathogen. Samples were collected from various animals on 31 different farms in the UK. They found verotoxigenic E. coli on 61% of premises. The premises selected were evaluated due to suspicion that they may have been sources of infection for people, so it’s possible that the numbers reported in the study are higher than they would be for all such farms overall, nonetheless the numbers are impressive. Risk factors for finding verotoxigenic E. coli on a given farm were the presence of young cattle and (surprisingly) adult pigs. Verotoxigenic E. coli were most commonly identified in cattle (29%). It wasn’t surprising that cattle, especially young cattle (calves), were the most common carriers based on what we know about the bacterium. However, it was impressive how commonly it was found in other species, including sheep (24%), donkeys (15%), pigs (14%), horses (12%) and goats (10%). On most farms where verotoxigenic E. coli was found, the same strain was identified in multiple animal species, indicating that the bacterium can be wide spread on the property. This may be because different animal species in petting zoos are often mixed together, as opposed to the situation on conventional farms where they are usually housed separately.
Does this mean we should consider petting zoos biohazardous and avoid them? Well, the answer really is "yes" and "no". We should consider petting zoos as potential sources of harmful bacteria. High-risk people (e.g. very young, very old, weakened immune system) should probably avoid them. We should also think about ways to reduce the risks, such as using lower risk species, having good petting zoo design and, most important, encouraging and enforcing hand hygiene on the part of all petting zoo visitors. As the authors of this study stated “It is also necessary to balance this small risk against the undoubted benefits of allowing the public to interact with farm animals. The risk of people acquiring an infection from animals depends more on the degree of contact and the precautions adopted than the prevalence of infection in a particular species. ”
If you get verotoxigenic E. coli on your hands but you promptly and properly disinfect them (before contaminating something or putting your fingers in your mouth), you’ll be fine. The quality of petting zoos varies quite a lot, as we showed in a previous study, and pressure should be put on petting zoo operators to have well-designed and well-run events.
More information about petting zoos can be found on the Worms & Germs Resources page.
The burgeoning green movement has scored another victory at Google's Mountain View headquarters. The facility has fields around it that are cut periodically to control weeds and reduce fire hazards. Google has recently exchanged lawnmowers for a herd of goats. Someone is now paid to bring in a herd of about 200 goats which spends a week or so grazing the area. This provides fossil-fuel-free grass cutting and a source of food for the goats. It's also presumably much nicer to look out at a group of grazing animals than a noisy lawnmower.
This is another interesting example of attempts to "return to nature", at least to some degree. Another example is urban chickens, which are a topic of considerable debate in some cities (more on that in a later post). Any time there is the potential for increased contact with livestock, there is some increased risk of transmission of diseases from these animals, although this risk is likely pretty minimal with lawnmower goats. The main concern is shedding of potentially harmful microorganisms like Salmonella in the animals' manure. Sunlight does a good job killing many of these microorganisms, and the duration and density of grazing would minimize accumulation of manure in the fields. If human contact with the fields is minimal, the risks would be extremely low. It sounds like these fields are not heavily used by people, so it's less likely that Google employees will be exposed to anything harmful, compared to what the situation would be if they used the area for having lunch or lounging in the sun while on break. Q-fever is also a potential concern, but that's mainly a risk around the time of birth (called "kidding" in goats - no joke!), so they just need to make sure they're not using heavily pregnant goats in their lawnmowing team.
There's never a no-risk contact with animals (nor is there such a thing as no-risk contact with people), but slight increases in known or theoretical infectious disease risks are not necessarily a bad thing if the benefits outweigh the risks. There are also no blanket answers to many of the questions about infectious disease risks. For example, while I don't have any real concerns with the Google goats, I wouldn't want to see goats grazing in the yard of a daycare or preschool. In a case like this, however, I think it's a good experiment and it will be interesting to see what happens over time.
Spring appears to have finally sprung in earnest in Southern Ontario (although we may still get one more frost on the weekend, so I hear) and people are getting back out into the garden. An increasingly popular trend in recent years, particularly this year now that the Obama's are doing it too, is vegetable gardening. Lots of people like the idea of growing their own veggies in their own backyard, or perhaps in a community garden plot for city dwellers who still want to get their hands dirty - it's economical, good for the environment, and the plants can be grown "organically" without the use of chemicals or pesticides. However, pesticides and garden bugs aren't always the only things to worry about having on your fresh veggies. We received the following comment from a Worms&Germs reader:
"...What if veggies get infected with raccoon stool[?] Can eggs be killed after [the] veggie is grown and ready to eat?"
Great question. The concern in the case of raccoon stool is the eggs of the roundworm Baylisascaris procyonis, which can be passed in huge numbers by a relatively high percentage of raccoons in many regions. If swallowed, the eggs release larvae which can migrate through the tissues of the body, rarely causing visceral, ocular or neural larval migrans.
The good news:
- Raccoons like to defecate in the same areas most of the time, usually on a relatively flat, elevated surface (e.g. woodpile). These areas become raccoon "latrines", and the soil in the area can become very heavily contaminated with roundworm eggs. The good part is that most raccoons therefore not defecate in your garden.
- Vegetables cannot become "infected" by the parasite - the eggs cannot be absorbed or otherwise get inside a vegetable, they can only contaminate the parts of the plant that are directly in contact with soil.
The bad news:
- Even though raccoons may not poop in your garden, they can still track roundworm eggs into the soil on their fur or paws when they come by to explore your crop, so you should always consider soil outside as potentially contaminated.
- Baylisascaris eggs are highly resistant to disinfectants and chemicals, so they can't be killed this way.
- Raccoon roundworms aren't the only parasites that may be found in garden soil. Dogs and cats can carry other roundworms (Toxocara spp.) which are also capable of causing larval migrans if swallowed (although infection with these worms in dogs and cats is not nearly as common as infection with Baylisascaris in raccoons). Cats in particular, unfortunately, do sometimes like digging in gardens and may sometimes use a garden as a litterbox.
- Soil, particularly if it's contaminated by the stool of any animal, can also contain many different kinds of bacteria such as Salmonella. Even if you can somehow protect your garden plot from animals, purchased garden soil and fertilizers may contain or may have come in contact with animal stool somewhere along the way.
So how do you make your garden veggies safe to eat?
- Wash wash wash: Because Baylisascaris eggs are so difficult to kill, the best thing to do is physically remove them from all surfaces of your vegetables by washing thoroughly to remove all visible dirt before doing anything else. If you cut into a vegetable before washing it, the soil on the outside can contaminate the inside.
- Peel peel: Peeling vegetables ensures that all dirt (including any dirt stuck in tiny crevices on the vegetable's surface, or dirt you may not be able to see with the naked eye) is removed prior to consumption, but it's still crucial to wash the veggie first (and your hands) before peeling.
- Cook: From an infection control perspective, it's best to cook vegetables before eating them. This actually won't do anything to Baylisascaris eggs - these have to be removed by washing and peeling - but it does help kill bacteria that either contaminated the veggies out in the garden or that contaminated the veggies during their preparation in the kitchen. For those of us who like our nice crunchy vegetables, obviously cooking them won't do, therefore washing and peeling become that much more important.
And, of course, always wash your hands thoroughly with soap and water after you've been working in the garden, even if you wear gloves.
In a lot of urban areas, it's hard to prevent raccoons and other animals from getting into yards and gardens. There are things you can do to discourage raccoons from hanging around your house, and if raccoons establish a latrine on your property it must be very carefully cleaned up. For more information on Baylisacsaris, raccoons and cleaning up raccoon latrines, please see our archives.
The latest edition of the CDC's Morbidity and Mortality Weekly Reports describes an E. coli O157:H7 outbreak associated with a petting zoo. The outbreak, which occurred at a day camp in Florida in 2007, involved 7 infected individuals. Two children were hospitalized. The same E. coli strain affecting the people was found in the stool of goats at the petting zoo.
During the investigation of the facility, it was noted that many of the general recommendations for petting zoos were followed, including providing handwashing stations, promoting hand hygiene compliance, prominent signage, and restricting eating and drinking in the zoo area. This shows that outbreaks can occur even at facilities that seem to be doing a reasonably good job of infection control. However, several key issues were identified:
- Campers were not instructed how to wash their hands properly.
- Handwashing was not carefully monitored.
- There was unlimited (and presumably not completely supervised) contact with animals throughout the day.
Numerous outbreaks of disease associated with petting zoos have been reported, often involving E. coli O157, a strain of E. coli that can cause serious or even fatal disease. This E. coli strain can be found in healthy cattle, sheep and goats. Other potentially harmful microorganisms can also be found in healthy animals of these, and other, species (particularly in their manure). Because you never know whether an animal is “potentially infectious,” taking measures to reduce the risk of disease after possible exposure is critical, particularly meticulous hand hygiene. Restricting high-risk animals (e.g. calves, baby chicks, pregnant sheep and goats) from petting zoos is also important.
Petting zoos can be great events, but carry any inherent risk of disease. More information about petting zoos and the diseases associated with them can be found in a new information sheet on the Worms & Germs Resources page. The National Association of State Public Health Veterinarians has also just released its revised Compendium of Measures to Prevent Disease Associated with Animals in Public Settings, a comprehensive document about measures to reduce the risks associated with petting zoos and other animal contact events.
We've been talking a lot about the swine flu outbreak the last few days, but so far all we've really talked about are the human aspects. The reason we're blogging about it on this site is that it's a zoonotic disease - so where do the pigs fit in?
There's a distinct lack of information about where this strain of the influenza virus actually came from. I heard on the news this morning that one person who was interviewed by a CNN reporter was even trying to blame Canada for the outbreak, claiming that it was Canadian tourists that introduced the disease to Mexico in the first place! While I'm sure there will eventually be a great deal of investigation into how the outbreak got started (for the moment I think everyone's more worried about trying to just keep it under control), it's quite possible that we'll never find the "index case" or know exactly from where it came. But one thing's for sure: somewhere along the way, there has to be some pigs involved.
Pigs are the great "mixing pot" of influenza viruses, particularly with regard to avian, human and swine versions of the pathogen. Pigs can be infected by strains of all these different types, and coinfections (infection with more than one influenza virus at the same time) provide the viruses with a prime opportunity to trade RNA and recombine to form new influenza strains with new properties - more infectious, more virulent, or perhaps better able to infect another species, for example. In this case we appear to have a swine influenza virus that is not only capable of being spread to people (as occasionally happens with "regular" swine influenza viruses), but also between people, and hence the developing human outbreak.
But what about the pigs? There isn't a lot of information out there at the moment, with all the focus on the human aspect, but so far Mexican authorities have found no infected pigs in Mexico (at least no where they've looked - so far). Influenza in pigs is really nothing new, and other swine influenza strains are commonly found in pigs around the world. Highly pathogenic strains, like those that cause massive devastation of poultry flocks, don't occur in swine. If an influenza virus gets into a pig barn, however, it's like putting a person with the flu in a crowded room - the virus spreads very quickly through the air over short distances and soon everyone (or every pig) has the flu. Thankfully the virus generally also moves on quite quickly, and after a few days the animals generally start to recover. While such an outbreak certainly affects their growth efficiency, very few (if any) pigs die.
Yesterday the Canadian Veterinary Medical Association (CVMA) distributed a fact sheet on swine flu from the Canadian Food Inspection Agency (CFIA) for all Canadian veterinarians and swine producers. The CFIA is encouraging increased vigilance with regard to monitoring and diagnosing disease in Canadian pigs, to prevent the disease from spreading through the swine population. In addition to emphasizing vaccination, good hygiene practices and biosecurity, particularly around sick pigs, they also point out that it's equally important (especially now) for anyone who may have the flu to avoid contact with pigs (be they Canadian pigs or pigs in any other country), in order to avoid spreading the virus to them. Hopefully people in other countries will take the same precautions.
Another very important point is that swine influenza is NOT a food safety concern. The virus does not survive well in the environment for very long, and therefore cannot survive on pork products, and certainly cannot survive proper cooking (which is always very important for any kind of meat). The fact that some countries are banning pork imports is really not going to do anything to help control the outbreak - the concern should only be about live pigs (and people). So you can still have pork sausages at your next spring barbeque, just ask anyone who's feeling "under the weather" (or a little flu-ish) to please stay home!!
Plague has been diagnosed in a dead rabbit found on a private residence in New Mexico. Plague, also known as the black death, is a highly fatal disease of humans and many animals caused by the bacterium Yersina pestis. While often considered a disease of mainly historical interest - having killed a large percentage of people on the planet during a few pandemics over the centuries - plague is actually still alive and well in some regions. In North America, most cases occur in New Mexico, Arizona, Colorado and California.
Yersinia pestis primarily lives in wild rodents and is transmitted by fleas. Many different animal species, including cats, dogs, rabbits and people, can be infected if bitten by a flea from an infected rodent (hence the historical association of the disease with rats). Predatory species (like dogs and cats) can also become infected by eating infected animals. Dogs are relatively resistant to plague and usually only develop mild disease, while cats and rabbits are as susceptible as people, and can develop bubonic, septicemic or pneumonic plague. Transmission of plague from pets to people can occur, and most often involves cats. People can become infected by close contact with sick pets, or being bitten by a flea from such a pet.
Preventing plague in animals involves flea control and reducing exposure to infected wildlife. In areas where plague is active, all pets should be on a flea control program. Cats should be kept indoors to reduce the risk of exposure (e.g. keeps them from hunting infected rodents). Dogs and cats should not be allowed to have contact with dead animals of any kind. Measures to reduce rodent infestations in and around the house are also important.
More information on plague is available in the Worms & Germs archives.
ProMed mail has a report about 2 cases of Baylisascaris procyonis infection in people in Brooklyn, New York. Baylisascaris is the raccoon roundworm and is very commonly found in the intestinal tract of healthy raccoons. Raccoons shed this parasite in their stool, and after a short period of time, the parasite larvae become infective to other animals and people. Infective larvae can survive for a long time in the environment. People become infected by swallowing the larvae that can be found in dirt or on any object contaminated by raccoon stool. Disease in humans due to this parasite is rare but can be extremely severe.
The first case in this report involved an infant with neural larval migrans, a condition caused by migration of the roundworm larvae through the brain. Despite treatment, the child now has permanent brain damage because of this disease. Unfortunately, this is not uncommon consequence, as the infection is not usually identified until severe and irreversible damage has already occurred. The child had a history of eating soil, and swallowing soil contaminated with raccoon feces is the most likely source of infection.
The second case involved a 17-year-old with ocular larval migrans, which is caused by migration of the parasite larvae through the eye. The parasite was killed using laser therapy, however the patient lost all vision in the affected eye before the infection was identified. There was no mention of where or how the teenager may have been exposed. Infection of someone of this age is very uncommon, as most 17-year-olds are much less likely in ingest (intentionally or accidentally) raccoon stool. It would be useful to know whether this patient had a developmental disability which results in an increased likelihood of swallowing dirt or feces, or whether there may have been some other type of exposure.
Baylisascaris infections in people are extremely rare, despite the fact that a large percentage of raccoons carry this roundworm. This report of two cases occuring in the same area within a few months of each other is surprising. Hopefully it's just a bad coincidence, and not an indication of some change in the incidence of this disease. Avoiding Baylisascaris means avoiding ingestion of raccoon stool. Sounds simple enough, but this is of particular concern with young children and people with developmental delays who are more likely to swallow contaminated dirt or stool, or put dirty/contaminated hands or objects in their mouths.
As Easter approaches, so do the annual commentaries about concerns with people buying "Easter bunnies" (the real variety, not the chocolate version) without knowing what they are getting into. It's a big problem because a lot of spontaneous Easter bunny purchases end up abandoned at humane societies (or worse) after a few months.
In general, rabbits can be great pets. However, they have special management needs, and they can live for a relatively long time (years), so people need to think about whether a rabbit is the right pet for them, and whether they can (or will) look after it properly for the duration of its life.
Rabbits are pretty low risk in terms of zoonotic disease transmission. There are a few concerns but these are typically quite manageable with pretty basic hygiene measures. Knowing how to properly handle a rabbit is very important to prevent scratches (and bites) to the handler, and potentially serious injuries to the rabbit. For more information and a video about safe rabbit handling, see the previous Worms & Germs post entitled "Safe Rabbit Handling - For You And Your Rabbit".
Easter may be as good a time as any to get a rabbit - if it's not a spontaneous decision and you've really put some serious thought into it. Part of that process needs to include finding out about ways to reduce the risk of illness and injury associated with rabbits. This type of information can be found in the rabbit information sheets on the Worms & Germs Resources page.
I was at the annual conference of the Society for Healthcare Epidemiology of America on the weekend. This is a hospital infection control organization, and one of the talks I gave was about animals in healthcare facilities. One question that came up was about unusual service animal species like monkeys. Service animals are specially trained animals that help disabled individuals with specific tasks. The most common examples are seeing-eye dogs. In the US, the American Disabilities Act protects service animals and dictates that they must be allowed to go wherever the person goes. I don't think people have a problem with that in general. However, there are concerns with respect to non-traditional species being used in these roles, and the question at the meeting was about service monkeys. Monkeys can be incredibly strong physically, and they can carry some important infectious zoonotic diseases, so there are concerns about them being allowed in hospitals. Part of the issue is what really makes an animal a service animal. Should all animals that help someone out (in any capacity) be considered service animals?
That same topic came up in a recent ABC News article that described a seeing-eye horse in Texas, including a video of the owner riding the horse while grocery shopping.
I have no doubt that this horse helps out its owner and provides great joy, if not increased freedom. However, I'm not convinced that a horse is necessary to fulfill this person's need for a service animal. Why use a horse when a dog could do as good (or a better) job? How was the horse trained? Was it trained under a formal program so that it is truly helpful? What types of health and behaviour screening have been used? What are the additional risks associated with using such a large farm-animal species?
Horses, even based solely on their size, can easily cause injury to members of the public without meaning to, simply by stepping on a person's foot or bumping into them, for example. Some people might be scared of horses, especially indoors. Horses aren't litter trained, and horse manure can carry potentially infectious agents. I have a big problem with the video of this horse in a grocery store. At end of the day, is a horse really necessary for what this person needs, and has the horse been adequately evaluated to ensure that it is low risk to the public? I don't think the answer is yes to either question, let alone both.
We certainly must do all that we can to allow full access of appropriate service animals, but we also need ensure that novelty "service" animals don't cloud the picture and potentially have a negative impact on true service animals. The article states "...the government has begun rethinking whether the regulations should be changed to exclude some animals." That sounds like a great idea to me. Careful review of this issue, including the benefits to people, risks to the public and the need for new species over traditional options all need to be considered.
Image: captured from video at http://www.abcnews.go.com/GMA/story?id=7157206
We've had some beautiful warm days in southern Ontario lately, and spring - technically - arrives tomorrow (despite the fact that it's been trying to snow in Guelph even this afternoon! But hope springs eternal (pardon the pun)). The picture (right) is Erin, my youngest daughter, enjoying the warmer weather and playing in a sandbox at my parents' house yesterday. Allowing a child to play in the sand carries some degree of infectious disease risk, but the risk is very low and simple measures can reduce the risk even further.
The main diseases of concern with regard to sand in temperate regions (like Ontario) are spread via the fecal-oral route, meaning the diseases are transmitted by swallowing organisms that are passed in the stool. The most important of these diseases - visceral larval migrans and ocular larval migrans - are caused by parasites. These disease are uncommon in most places, and when they do occur they're not typically associated with sand from sandboxes specifically. However, while very rare, larval migrans can be a very serious condition. The risk is greatest in very young children and children with developmental problems who are more likely to eat sand. In warmer (more southern) regions, another parasitic disease called cutaneous larval migrans is much more common. This condition can occur after just skin contact with contaminated sand.
The main points regarding sandbox safety are:
- Keep sandboxes covered so animals don't use them as litter boxes.
- Check the sand regularly to make sure there is no evidence of animal stool or urine.
- Try to prevent children from putting their hands, or other objects, in their mouths while playing in a sandbox (and in general!).
- Don't give children snacks or drinks while they're playing in the sand.
- Wash (or make sure they wash) children's hands after they're done playing in the sand.
For the average child, the risks of infectious diseases from sandboxes are extremely low. I have no problem letting my children play in the sand... I just use these basic infection control precautions.
I have a small flock of Soay sheep and lambing season started today (too early, but better than the -30C weather from a few days ago). For someone like me, lambing season inevitably triggers thoughts about Q fever, a zoonotic disease that is most commonly associated with contact with small ruminants like sheep and goats (especially sheep). The disease is caused by the bacterium Coxiella burnetii. This organism is highly infectious - very few bacteria are required to cause infection - and is considered a potential bioterrorism agent. Coxiella burnetii can be transmitted by direct contact with an infected animal, or by inhalation of organisms in dust or dirt that get blown into the air. It can be carried by healthy animals several species, but the greatest risk of transmission is from sheep and goats around the time of birthing (lambing and kidding, respectively). At that time, large numbers of C. burnetii can be shed with the placenta and fetal fluids, and can also be found on the newborn animals. Close contact with the animal and these tissues during lambing, such as with our first lambing this morning - a stillborn lamb that was stuck at the shoulders and required some manipulation to free it - can result in transmission of C. burnetii.
On a happier note, the second lambing in our flock was unassisted, although I still handled the little guy to make sure he was okay.
Q fever can affect people of any age or health status. Disease can range from mild to life-threatening. More information on Q fever can be found on the websites of the Ontario Ministry of Health and Long-Term Care and the Centers for Disease Control and Prevention (CDC), as well as the previous Worms & Germs post entitled "Q Fever - From Goats to People (and Pets!)". The disease can cause miscarriage in pregnant women. People with heart valve disease or vascular grafts are also at high risk for serious disease from this infection.
- It is prudent to consider all sheep and goats Q fever-positive unless proven otherwise (which is difficult to do).
- Contact with newborn lambs and kids, placentae and fetal fluids of sheep and goats, and any area contaminated by these tissues should be avoided as much as possible. If contact is necessary, it should be done by low-risk people, and careful attention should be paid to hygiene, especially handwashing.
- Pregnant sheep and goats should not be used in petting zoos. Unfortunately, this is actually a common occurence.
- Live birthing exhibits, where sheep or goats give birth in public during fairs or similar events, should not be held. If they are held, they should be in an area where there is no direct or indirect contact with the public, unlike this picture (right).
- While we focus on sheep and goats, many different species can shed Coxiella burnetii, including cattle and cats. It is reasonable to consider all animals a risk around the time of giving birth, and ensure that hygiene practices are optimal.
- At my place, Q fever control consists mainly of careful attention to hygiene around newborn lambs and their ewes, and not allowing my kids to handle newborn lambs.
- Like most zoonotic diseases, hand hygiene is a critical infection control measure.
If your veterinarian suspects your pet may have ringworm, there are several different ways he or she may test for the causative fungus (a dermatophyte) on your animal's fur and skin. Some of these techniques are more useful than others in different situations.
- Wood's lamp: A Wood's lamp is simply a special ultraviolet light. Approximately half of all Microsporum canis strains (the most common species of dermatophyte that causes ringworm in cats and dogs) will fluoresce blue-green under such a light. This type of testing is obviously very easy to perform. However, other debris in an animal’s hair coat may fluoresce as well, and other species of fungus that cause ringworm do not fluoresce, so this test is not useful by itself in most cases.
- Microscopy: Sometimes ringworm fungus can be seen on hair shafts from an infected pet when examined under a microscope. However, it is easy to confuse other debris and structures for dermatophytes. Also, not every hair on an infected animal will carry the fungus, so it's possible to miss the infected hairs altogether with this test.
- Fungal culture: The best way to diagnose ringworm is to culture the fungus from the infected individual (person or animal). In animals, one of the best ways to collect a sample for culture is to comb over all the fur and skin with a new toothbrush, and then try to grow dermatophytes from the toothbrush. This allows the fur from all over the animal to tested, rather than just one little clump of fur plucked from one area. It can also make it easier to get a sample from the face and paws of cats, which is where these animals often carry the fungus. Although fungal culture is the best way to diagnose ringworm, remember that fungal culture takes much longer than bacterial culture – instead of days, it may take up to three weeks to grow some dermatophytes.
It's also important to remember that dogs, and more often cats, may carry dermatophytes on their fur even when they look healthy. A positive fungal culture from an animal with skin disease, particularly a cat, does not necessarily rule out other diagnoses, so your veterinarian may still recommend other tests as well. However, any animal with ringworm should be treated to prevent spreading the infection to other animals and people.
Animal smuggling is a surprisingly big problem. A report in the Canberra Times quotes an Australian customs officer as saying animal smuggling is a $20 billion industry and the third largest criminal activity in the world (after drugs and weapons).
Animal smuggling can range from someone trying to sneak an exotic pet into the country, or large- scale smuggling by certain individuals (like the guy who tried to smuggle 300 poisonous frogs onto a plane). It can also consist of massive organized crime ventures.
There are many concerns associated with animal smuggling:
- Animal welfare: High death rates are not uncommon among animals during illicit transportation. Smuggled animals are often wild-caught, and even if they survive the stress of transportation, they may die soon after arrival. Particularly when you hear about animals being smuggled sewn up in giant teddy bears, or stuffed into pockets and pouches, it's a wonder as many of them survive as they do. The customs office in the Canberra Times article sums it up nicely "'People who smuggle animals don't care about the animals ... They actually see dead animals as an overhead.'"
- Introduction of foreign diseases: Smuggled animals have been blamed for introduction of serious diseases like avian influenza into areas where these diseases don't normally exist. This can be a huge problem, as it creates the potential for large outbreaks amongst indigenous animals or people whose immune systems are completely naive to the diseases.
- Transmission of disease to new owners: Smuggled animals certainly have not undergone good health examinations and quarantines, and can carry a host of potentially harmful microorganisms. This can put buyers and their families at risk.
Despite being a huge industry, there are things that everyone can and should do to reduce animal smuggling:
- Don't buy animals that you know were or may have been illegally imported. Doing so contributes to the death of countless other animals for every animal that survives.
- Don't buy wild-caught animals like birds and reptiles. Wild caught doesn't mean smuggled, but it may be hard to tell the two apart. Some of the disease risks, particularly to individual buyers, are the same with legally and illegally imported wild-caught animals. These days there are good, reputable and ethical breeders of many animal species around that can supply animals. If the species is so rare that there aren't any good breeders around, then don't buy it. It might be rare because the animals don't survive well in captivity, or are hard to find in the wild. You don't want to contribute to either of those situations. In some instances, you can find both wild-caught and captive-bred animals for sale. While the captive-bred version will almost certainly be more expensive, the extra cost is not so great when you consider the overall lifetime costs of the animal. And how much money do you really save if you end up with a sick or dead animal?
- If a deal sounds too good to be true, it probably is. That animal that you're getting for such a "great deal" might have been smuggled or be otherwise unhealthy.
- If, for some reason, you are determined to get a wild-caught animal, make sure that it comes from a reputable source who imported the animal legally. Ask how it was caught, stored and transported. A good supplier should be able to tell you everything that happened from the time of capture to its arrival, or at least be able to find that out. If they don't know or don't care, walk away.
Cheyletiella is a genus of mites that commonly affect dogs (C. yasguri), cats (C. blakei), rabbits (C. parasitovorax), and occasionally people. Unlike Sarcoptes species (the mites that cause sarcoptic mange), these mites live on the surface of the skin and do not burrow into deeper layers. They feed on dead skin cells and occasionally tissue fluid. Infestation with these mites can be very itchy, but not always. Cats in particular can carry the mites without any visible abnormalities of their skin or fur. Typically, however, the affected animal's fur becomes crusty, scaly and inflamed, and sometimes patches of fur may be lost. The mites are usually a little less than a half-millimetre long (so they are visible to the naked eye if you look closely) and grayish-white. They tend to be quite active and crawl around (but they don't jump like fleas), which gives them the appearance of walking dandruff. Diagnosis is easy if the mites are seen strolling around on a table or blanket, otherwise they may be found on a "scotch tape test" or superficial skin scraping.
People can be affected too if they have close contact with a pet carrying Cheyletiella. Lesions, which usually take the form of single or grouped small red bumps on the skin, typically appear on the arms, trunk or thighs, and sometimes can be extremely itchy! It is rare to see the mites themselves on a person - usually they're found on the pet. The good news is these mites can't actually complete their life cycle or survive for long on people, and in the environment even the hardiest forms of the parasite (usually the eggs and adult females) die within about ten days. So once the source of the mites is eliminated (by treating the pet with an appropriate anti-parasitic drug which your vet can prescribe), the signs in any affected people will resolve on their own without specific treatment (but you might want something for the itch!).
Photo: Light micrograph of C. yasguri from a dog (credit: Dr. M. Dryden, College of Veterinary Medicine, Kansas State University)
Encephalitozoon spp. are single-celled microsporidian parasites that can cause infection in the intestinal tract of animals and people, and sometimes infection in other parts of the body (systemic infection). Cases of infection with these parasites (encephalitozoonosis) have been reported in countries all over the world. The species E. bieneusi and E. intestinalis are the most common. A much less common species, E. cuniculi, is thought to be one of the most virulent microsporidia that infects humans (i.e. it causes the most severe infections). Encephalitozoonosis is rare in healthy people, but it is a common complication in patients with weakened immune systems. Encephalitozoon cuniculi can also be found in many animal species, particularly in rabbits. Most infections in rabbits do not cause illness (i.e. subclinical infections), but when disease occurs it typically causes neurological signs. In these cases the parasite tends to attack the brain and kidneys. The primary means of transmission between rabbits is E. cuniculi spores shed in the urine. Organ damage in the few human cases that have been reported have also been primarily in the brain and kidneys.
Direct transmission of this parasite from rabbits to humans has not been reported, but because there is also no evidence that it can't be transmitted from rabbits, the disease is so severe when it does occur, and the parasite is so common in rabbits, it is still prudent to take a few simple precautions. This includes washing your hands after handling rabbits, and keeping rabbits away from food preparation areas and food meant for human consumption. Anyone with a weakened immune system should be particularly careful, and ideally should have someone else clean out their rabbit's enclosure on a regular basis.
In general, the risk of illness in a rabbit and zoonotic transmission can be reduced by proper handling, good management, personal hygiene and routine healthcare. A rabbit that is not stressed and is well cared for is less likely to be susceptible to infection, and therefore less likely to transmit infection to a person. More information about rabbits is available on the Worms & Germs Resources page.
Knowing how to properly handle a rabbit is very important for rabbit owners. If done incorrectly, the handler, the rabbit, or both could be injured. A rabbit's powerful hind legs and flighty nature (being a prey species) are a dangerous combination. Even though rabbits may not do so intentionally, the nails on their hind feet can inflict serious scratches (rivaling those of any cat or dog) if they are trying to get away. Rabbits can break their backs simply by struggling against improper restraint because of the amount of force they can generate with their hind legs.
Knowing the basics about how to handle rabbits safely and correctly can greatly reduce risks to both the handler and the animal. Click on the image below to see a video by Dr. Erin Harrison of the Ontario Veterinary College Avian & Exotics Service about some tips on approaching and handling rabbits safely.
Back in the 1980s, Vietnamese Pot-Bellied Pigs were a popular fad pet. These stout little oinkers are still out there, though they're not quite as popular as they once were. Potbellied pigs are cute (at least to some people... to each their own!), supposedly quite smart, and can even be house trained/litter trained. As with any new pet though, it's very important to do your research before going hog-wild and getting yourself a pot-bellied pig. Talk to your veterinarian about what your pig will need in terms of medical care - vaccines, deworming, spay/neuter, hoof trimming, tusk trimming... Because they are uncommon pets, some veterinarians may not be comfortable treating a pig. Make sure you ask ahead of time so you know to which veterinarian(s) in your area you can (and will!) take your pig.
We recently received a question about vaccination of pot-bellied pigs. Just like dogs, in some areas pigs need to be licensed by the city, and certain vaccines are required in order to obtain a license. In this particular case, pigs are required to be vaccinated against rabies, swine erysipelas and leptospirosis. Regular visitors to this site are no doubt familiar with the issues around rabies and why it's important to vaccinate for this deadly disease. (More information about rabies is available on the Worms & Germs Resources page and in our archives.) Swine erysipelas is a systemic bacterial infection caused by Erysipelothrix rhusiopathia, which can rarely cause a skin infection known as erysipeloid in humans. This is not to be confused with human erysipelas, which is a skin infection caused by various species of Streptococcus (particularly Streptococcus pyogenes).
But the question was about leptospirosis vaccination in pot-bellied pigs. Pigs are susceptible to infection by Leptospira interrogans, just like dogs and people, and if infected a pet pig would be equally capable of shedding the bacterium in its urine and potentially transmitting the disease. The issues around requiring vaccination of pigs for leptospirosis are very similar to those around making leptospirosis a "core" vaccine in dogs. More information about this is available in the Worms & Germs post entitled "Should all dogs in Ontario be vaccinated for leptospirosis?" A pet pig would likely be exposed to the same serovars of Leptospira as a dog kept in the same area, typically by coming in contact with urine from infected wild animals such as raccoons and skunks when they go outside. However, the risk of exposure for a pig that rarely or never leaves the house would be extremely low compared to a pig that has outdoor access. Another important consideration is whether or not the pig vaccine is against the same serovars that a pet pig, instead of a commercial pig, might encounter. This will also vary depending on in what area the pig lives. The Leptospira servoars pomona and bratislava are actually host-adapted to pigs.
It is also important to vaccinate an animal with vaccines that are labeled for use in its own species. Vaccinating a pig with a vaccine meant for dogs could have unpredictable results - it may increase the risk of an adverse reaction, or it may not adequately stimulate an immune response, thereby leaving the pig essentially unvaccinated. Your veterinarian can discuss the pros and cons of vaccination in your pet with the available vaccine products.
More information about leptospirosis is also available on the Worms & Germs Resources page.
It's that time of year again - we're coming up on flu season, and the ads on the radio and the television are out, encouraging everyone to get their "flu shot," (aka influenza vaccination). Influenza isn't just a problem in people - it is a very versatile group of viruses that can infect many different species of animals.
Equine and swine influenza viruses cause serious problems in horses and pigs, respectively. Last year there was a massive outbreak of equine influenza in Australia. Because Australia was previous free of equine influenza, most of the horses there had never been vaccinated against the virus. Therefore the entire population was very susceptible to the disease and it spread very quickly. The outbreak has since been brought under control. A previous Worms & Germs post talked about an outbreak of canine influenza in dogs in Chicago IL this past summer.
Equine and canine influenza (and usually swine influenza) cannot be transmitted to people. However, there are some strains of influenza that can cross species. The most well-recognized one is certainly avian influenza (bird flu), which caused outbreaks in a number of Asian countries in 2004. Although people are much less susceptible to avian influenza than birds, the H5N1strain has caused significant illness and fatalities in people.
A lesser known fact about influenza is that pet ferrets are very susceptible to the virus, including human strains. This is part of the reason ferrets are often used as animal models of the disease in research studies. Signs of the flu in ferrets are similar to what you'd expect to see in people - fever, sneezing, runny nose and lethargy. A pet ferret can both transmit to and catch the flu from a person. Unfortunately for the ferrets, there is no available vaccine for the flu in these animals.
Lucky for us, people can be vaccinated against influenza. Most people are still far more likely to get the flu from another person than from any kind of animal. Getting your flu shot is the best way to help prevent yourself from getting the flu, and spreading it to others. However, it's important to remember that no vaccine is 100% protective, so it's still important to take a few common-sense precautions, like washing your hands frequently, and sneezing/coughing into the crook of your arm, not into your hands. (And watch out for sick ferrets!)
There is lots of information about influenza and flu vaccine available on the web, including some of the links in this post, and also on the CDC Influenza (Flu) website.
Raccoon latrines are a major source of eggs of the raccoon roundworm, Baylisascaris procyonis. Accidental ingestion of large numbers of eggs from these latrines can lead to a disease known as visceral larval migrans. The most severe forms of this condition are known as ocular or neural larval migrans, which are damage to the eyes or brain/spinal cord (respectively) due to the roundworm larvae migrating through the body tissues. The disease is very rare, but the consequences are very severe. Previous Worms & Germs posts have discussed Baylisascaris and larval migrans in more detail.
Raccoons tend to form latrines - areas where they will return to deposit stool repeatedly. In some ways this is handy, because it means you generally don't find raccoon stool all over the place. On the other hand, the latrines themselves contain large amounts of stool, and along with that are large numbers of Baylisascaris eggs, not to mention bacteria and sometimes fungi. So it is important to recognized latrines, particularly when they occur near your house, garden, or anywhere children may play. Raccoons like to used flat, raised areas for latrines, such as roofs, decks, woodpiles, fallen logs or even large rocks, just to name a few.
Cleaning up raccoon latrines warrants some special precautions in order to avoid swallowing the roundworm eggs and to avoid spreading them around. Recommendations include:
- Wear rubber gloves, and always wash your hands thoroughly when you are done.
- Wear disposable overboots, or rubber boots that can be scrubbed and disinfected.
- Wear an N-95 rated particle mask if you are cleaning up a latrine in an enclosed space, such as an attic or crawl space.
- Thoroughly wash your clothes with soap and hot water when you are done, and dry them completely.
Follow this link for detailed information on how to clean up a raccoon latrine. A few of the more important points about dealing with these latrines include the following:
- Avoid stirring up dust. Misting the area with water first can help with this.
- Double-bag and carefully dispose of any garbage/debris you remove from the area.
- Most chemicals will not kill roundworm eggs. Removing the eggs is usually the best option, but extreme heat will also kill eggs instantly. Flaming contaminated areas can be effective, but contact your local fire department about local regulations and safety precautions before attempting to flame a latrine site.
A recent report in the Journal of the American Veterinary Medical Association by Jesse Blanton and colleagues provided a detailed report of rabies infection in the US in 2007. Here are some of the more interesting points:
- Rabies was diagnosed in 7 258 animals and 1 person. That's a 4.6% increase in animals from 2006, but 2 fewer human cases.
- 93% of cases were wildlife: 37% raccoons, 27% bats, 20% skunks, 7% foxes.
- 0.8% of cases were in cattle and 0.6% were in horses.
- 4% of cases were cats, with the largest numbers of feline cases in Virginia, Florida, Pennsylvania, North Carolina, Maryland, New Jersey, New York, Georgia, Texas and Kansas. Cat cases peaked in June and July.
- 1.3% of cases were dogs, with the largest number of canine cases in Texas, Georgia and North Dakota. Dog cases did not appear to have a seasonal pattern.
- Small numbers of a variety of other species were diagnosed, including pigs, wolves, opossums, bobcats, coyotes, otters, bears, deer, mongooses (in Puerto Rico), groundhogs and beavers.
- The largest number of rabies cases occurred in Texas (969).
- The infections that occurred were due to several rabies virus variants in circulation in North America, including raccoon rabies virus, skunk rabies virus, arctic fox rabies virus, bat rabies virus and Texas gray fox rabies virus. In each region of the continent, one or more of these rabies virus variants may be more common.
- No infections with canine rabies virus were identified. Dogs and coyotes were infected by other variants of the rabies virus, but not with the dog variant. It is believed that dog-to-dog transmission of canine rabies virus no longer occurs in the US.
- The one human rabies case in 2007 occurred in Minnesota, and was probably due to exposure to a rabid bat.
A report about the health risks in children associated with nontraditional pets was recently published in Pediatrics, the official journal of the American Academy of Pediatrics. The report also discusses diseases associated with animals in public settings such as petting zoos and pet stores. Although contact with pets and animals can be beneficial to growth and development in children, it is very important to be aware of the risks associated with certain kinds of animals. Physicians, veterinarians and public health personnel can help parents select appropriate pets in order to maximize the benefits while minimizing the risks to children.
One of the most important pathogens discussed in the report is Salmonella. Although Salmonella can be transmitted by many animal species, including traditional pets like dogs and cats, it is a particularly high risk with certain other kinds of pets, including reptiles, amphibians and baby poultry (chicks and ducklings). It has been estimated that direct or indirect contact with reptiles or amphibians is responsible for 6% of all sporadic Salmonella infections in the US, and 11% of cases among people younger than 21 years. There is also a relatively high risk of Salmonella transmission associated with animal-derived pet treats, such as pig ears, and raw meat.
The report makes several recommendations about how to reduce the risk of infection, injury and allergies from nontraditional pets, many of which you may have seen before on the Worms & Germs website. Just a few of these are:
- Always wash your hands after contact with animals, animal products or their environment, and after contact with animal-derived pet treats.
- Supervise hand washing for children less than five years old
Children less than five years of age and individuals with weakened immune systems should avoid contact with reptiles, amphibians, rodents, ferrets and baby poultry. These animals:
- Should not be kept as pets in households where children less than five years of age or individuals with a weakened immune system live.
- Should not be brought to childcare centres.
- Should not be allowed to roam freely in ANY house or living area.
- Should not be permitted in kitchens or anywhere food is prepared.
More information about Salmonella in pets and the risks associated with feeding raw meat and animal-derived treats to pets can now be found on the Worms & Germs Resources page.
Fish are very popular pets. It has been estimated that freshwater fish are owned by over 14 million people in the US, and saltwater fish are owned by approximately 800 000 people. Fish can be interesting, low maintenance pets, and the risks of disease transmission to people are low. However, low does not mean zero, and there are some diseases than can be spread from fish to people.
The most common (but still quite rare) disease that can be transmitted from fish to humans is infection with Mycobacterium marinum. This microorganism can be found in both freshwater and saltwater. It can cause skin infections, usually in areas where the skin is already broken, such as pre-existing scrapes and cuts, or skin that is damaged while cleaning an aquarium. Serious or long-term problems are rare in otherwise healthy people, but infection can be fatal in individuals with a weakened immune system.
Various other bacteria found on fish and in aquariums can cause infection in people as well. These are usually also "opportunistic infections" that tend to occur in people with weakened immune systems or infected wounds.
While fish are low risk pets, you can still minimize the risks that do exist by following a few simple precautions:
- Wash your hands after contact with aquarium water or items in the aquarium. Gloves should be worn to prevent skin damage if you need to touch rough or sharp surfaces.
- Do not clean an aquarium in the kitchen.
- Do not dump aquarium water down the kitchen sink.
- Prevent contact of aquarium water or contents with open wounds on your skin.
- Keep aquariums covered. This helps keep other pets (e.g. cats) from drinking or playing in the water. (It also prevents escape attempts by the fish, which never end well!)
Echinococcus granulosus is a tapeworm of dogs that causes a condition known as hydatid disease or hydatidosis in humans. The parasite is found in many parts of the world, and is very common in some regions of southern South America, the Mediterranean, the Middle East, southwestern Asia, northern Africa and Australia. To the best of our knowledge, E. granulosus does not occur in southern Ontario, but it is present in other parts of Canada including the western provinces and northern Ontario. A related, but much nastier, tapeworm called Echinococcus multilocularis is much less commonly found in North America.
A previous Worms & Germs post described what is known as the sylvatic cycle of Echinococcus granulosus, which is thought to be a common route of infection for dogs in Canada. In the sylvatic cycle, dogs become infected with Echinococcus by eating the internal organs (usually lungs and liver) of wild game such as moose and caribou. The dogs then pass tapeworm eggs in their stool, which can cause infection in other wild animals (thus continuing the cycle) or in people who accidentally swallow the eggs. In humans, Echinococcus forms slow-growing cysts (called hydatid cysts) in different organs of the body which can be very difficult to remove or treat in some cases.
Echinococcus also has a pastoral or domestic cycle. In this cycle, dogs acquire the parasite by eating the internal organs of infected sheep, and sometimes other livestock such as cattle and swine. This cycle is potentially very important in areas where there is a lot of sheep farming. In some areas of Latin America, 20-95% of sheep at slaughter may have evidence of hydatid cysts in their organs.
It is much more difficult to tell when a dog is infected with Echinococcus compared to other tapeworms such as Taenia or Dipylidium. An adult Echinococcus is tiny - only a few milimetres long (see picture right), very unlike the long, stringy white tapeworms that most people picture. Dogs can carry hundreds, even thousands of these tiny tapeworms without showing any signs of illness at all. The eggs can sometimes be difficult to detect on fecal examinations, and when they are seen they cannot be differentiated from Taenia eggs. Nonetheless, this is still the best way to detect infection, so fecal examinations should be performed regularly.
- In areas where Echinococcus is known to exist, it's important to have your veterinarian perform fecal examinations on your dog's stool more frequently than the usual once-a-year, because of the serious zoonotic potential of this parasite.
- Always wash your hands well after handling dog stools.
- Do not let your dog eat uncooked meat, or the organs from farm animals or wild game.
For more information on Echinococcus, see Worms & Germs post entitled Echinococcus and hydatid disease - not your average tapeworm. There is also information available on the Michigan State Department of Natural Resources site.
Lower photo credit: Ontario Veterinary College
I'm constantly amazed at what some people do with bats. Bats are a leading cause of human rabies exposure in North America. Despite extensive efforts to educate people about the importance of avoiding contact with bats, some people still either don't know or don't take these warnings seriously.
The latest bizarre example of stupid things done with bats occurred in Montana, where a parent brought a dead bat to a school and let young children (kindergarten and grade 5 students) touch it. Touching a bat in itself is a bad idea, let alone touching one that has died of unknown causes and encouraging kids to touch it. The teachers apparently had no objections to this activity. The parent who brought the bat had the students use an alcohol hand sanitizer after touching the creature, but it is still very irresponsible for someone to encourage children to touch a high-risk animal, regardless of what is done after. I'm sure the parents of the children didn't know beforehand, and certainly some were no doubt very upset when they found out about the incident (or livid would be a better description, if it was my kids that were involved). School officials did not find out about the dead bat until after its little visit, at which time the local and state public health authorities were contacted. The bat was tested and was positive for rabies.
Overall, the risk of rabies transmission is probably low in this case, but not zero. It has therefore been recommended that the 80 students that may have touched the bat be given post-exposure rabies shots, which may cost up to $800 per child!. Another ten children may have touched the bat at a soccer practice - for a dead bat, it sure covered a lot of ground!
- Never touch a bat, dead or alive. Obviously, if you shouldn't touch a bat, you shouldn't encourage kids to do so either!
- Unstructured and unapproved contact with animals in classrooms should be prevented. Animals can be good educational tools, but only if student and animal health and welfare are properly addressed.
More information on Rabies is available on the Worms & Germs Resources page.
You may notice a recurring theme in many of our posts and on virtually all of the information sheets on the Worms & Germs Resources page: an emphasis on handwashing. There is increasing emphasis on hand hygiene (i.e. hand washing and use of alcohol hand sanitizers) education in hospitals because the hands of healthcare workers are a major (if not the most important) means of disease transmission between patients. Despite hand hygiene being easy, cheap and effective, people rarely wash their hands as often as they should, and they often don't do it properly.
Most of the research about hand hygiene that has been published has focused on its use and impact in human hospitals, but this area is now also being studied more with regard to animals and veterinary medicine. A study published earlier this year in Veterinary Microbiology provided more evidence that hand hygiene is a critical infection control measure when dealing with animals. The study, coordinated by Dr. Maureen Anderson (of Worms&Germs fame) looked at MRSA carriage rate in veterinarians who work with horses. In addition to finding a high rate of MRSA carriage among these veterinarians (which was consistent with other reports indicating that equine vets are at higher than average risk for exposure to MRSA), the study looked at factors associated with MRSA carriage. Vets that reported routinely washing their hands between farms and those that reported washing their hands after contact with potentially infectious cases had a significantly lower rate of MRSA carriage. That should come as absolutely no surprise, but it's one more piece of evidence that we need to pay more attention to this routine infection control measure, in human hospitals, in veterinary environments and in households.
Remember, the 10 most important sources of infection are the fingers on your hands!
This post has been updated with new information as of October 2, 2008.
An article was published on Sunday in a local Guelph newspaper about a 14-month-old child who has been battling infection with Baylisascaris larvae in a Hamilton (Ontario) hospital for the last two weeks. This comes on the heals of a very recent Worms & Germs post about Baylisascaris procyonis - the raccoon roundworm.
The disease caused by migration of Baylisascaris larvae through the body - visceral larval migrans - is uncommonly diagnosed in North America, although it may be more common than we think because it is difficult to diagnose with certainty, and the signs in mild cases may be very non-specific. The most severe form of the disease is called neural larval migrans, which occurs when the larvae migrate through the brain or spinal cord, as in this most recent case.
The parents of the toddler in the article, a toddler who is still blind and cannot sit up on his own as a result of his infection, have a message for parents: keep raccoons out of your yard and away from your house. The disease may be rare, but the effects can be devastating, and the risk can be significantly reduced by a few simple steps:
- Keep garbage in tightly-sealed containers.
- Clear brush and seal openings in buildings where raccoons may nest or form latrines.
- If you find raccoon stool or what appears to be a raccoon latrine on your property, clean it up very carefully. Follow this link for more information on identifying and cleaning up raccoon latrines.
- Always wash your hands well after you've been working outside in soil, dirt or water which could be contaminated with raccoon feces.
For more information, see the last Worms & Germs post about Baylisascaris.
This post has been updated with new information as of October 2, 2008.
Raccoons, just like dogs and cats, can have roundworms in their intestine. Dogs are typically infected by the species Toxocara canis, and cats are infected by Toxocara cati. Raccoons are infected by a type of roundworm from a different genus, called Baylisascaris procyonis. There is one thing that all three of the parasites have in common – the larvae of these worms can infect humans, causing a condition called visceral larval migrans.
Dogs and cats are usually dewormed as puppies and kittens, and often as adults as well, which dramatically decreases the number of pets that are infected with roundworms. Raccoons are not so lucky – in the northern and northeastern parts of North America, over 70% of raccoons may be infected with Baylisascaris. In Ontario, it has been estimated that only about 20-30% of raccoons are infected, but usually with high numbers of worms. In either case, younger raccoons are even more likely to be infected. Infected animals may shed millions of parasite eggs in their stool, and the eggs can survive in the soil for months or even years.
After a few weeks, the eggs in the raccoon stool become infective. If a person swallows the eggs, they hatch in the small intestine and release larvae. These larvae can then burrow through the wall of the intestine and migrate through tissues all over the body, causing tissue damage and inflammation. The signs of illness are often not very specific, and may include things like fever, fatigue and nausea. If the larvae migrate through the brain or spinal cord, a person may develop neurological signs like loss of coordination and muscle control. This is called neural larval migrans, which is the most serious type of disease caused by these larvae. If the larvae migrate through the eye, they can cause blindness. This condition is known as ocular larval migrans.
There have been less than 25 cases of confirmed visceral larval migrans due to Baylisascaris in the USA as of 2003, but the condition is very hard to diagnose with certainty, and it is possible that many cases are mistaken for other illnesses. The disease is also very difficult to treat, and neurological damage from neural larval migrans is usually permanent, so the best thing to do is prevent infection in the first place. Here are some tips on avoiding Baylisascaris:
- Avoid contact with raccoons. Many people think raccoons are cute, but they are wild animals. Raccoons are also a risk for transmission of rabies if a person is scratched or bitten. NEVER keep a raccoon as a pet.
- Discourage raccoons from hanging around your house. Clear brush and seal access to basements and attics where raccoons may try to nest or form latrines. Keep garbage in tightly-closed garbage cans. Eliminate outdoor water sources.
- Always wash your hands well with soap and water after working with soil (e.g. in the garden).
- Clean up raccoon latrines. This must be done very carefully - avoid getting any raccoon stool on your hands or clothes. The stool should be burned, buried or sent to a landfill. Clean the area where the stool was found with boiling water. Wash your hands very carefully when you’re done. Follow this link for more detailed information on how to identify and clean up raccoon latrines.
Baylisascaris procyonis less commonly infects animal species other than raccoons, including skunks, and it has even been found in dogs. It's important to have your dog's stool examined for parasite eggs on a regular basis (typically once or twice a year) and to follow your veterinarian's recommendations for deworming your dog.
"Unintended consequences" are outcomes (usually negative) of a particular action that are unexpected. For example, in some areas, hospitals now receive decreased reimbursement for MRSA infections. This policy was meant to help encourage hospitals to reduce MRSA infection rates. However, there are concerns are that this has actually lead to decreased MRSA testing (and potentially compromised patient care), because if the MRSA infection isn't documented, payment will not be withheld.
Unintended consequences can be found in many diverse areas. An interesting example was recently published in Ecological Economics and reported by the Toronto Star. It described the unintended consequences that linked use of a cattle drug to rabies deaths in India. Here's here story:
- Didofenac is a drug that was routinely used in cattle in India
- The drug is apparently highly toxic to vultures
- Vultures fed on cattle that died of natural causes, but that had didofenac in their bodies
- Millions of vultures died, which led to a larger food supply for feral dogs
- It was estimated that this lead to 5.5 million more feral dogs in India from 1992 to 2006
- These additional dogs would have accounted for at least 38.5 million dog bites
- Rabies is a serious problem in feral dogs in India
- In India, 123 people die of rabies per 100 000 dog bites.
Putting these numbers together, the unintended consequences of didofenac use in cattle may have result in 47 000 human deaths from rabies and $34 billion in health care costs. There are a lot of assumptions in this report, but it is an interesting story and highlights the unpredictable nature of infectious diseases, and the varying effects that seemingly unrelated actions can have.
More information on rabies can be found on the Worms & Germs Resources page.
Q fever is an infection caused by the proteobacterial organism Coxiella burnetii. Although usually not very common, C. burnetii can be carried by sheep, goats, and cattle, as well as birds and even sometimes cats and dogs. Animals often show no signs of illness, although the infection sometimes causes miscarriage, particularly in sheep and goats. Coxiella burnetii is also transmissible to humans. People are much more susceptible than animals to disease from Q fever. Even so, only about 50% of individuals that become infected show signs of illness, which can range from flu-like symptoms to pneumonia and hepatitis (liver infection). About 1-2% of infections in people are fatal.
Infected animals shed C. burnetii in their stool, urine and milk, but the highest number of organisms are shed in birth fluids and placentae. Coxiella is able to survive very well in hot, dry soil, and when dust and dirt from contaminated areas are stirred up into the air, the organism can be inhaled. This is the most common means of transmission, although direct contact with an infected animal or its stool or urine can also transmit the disease. Transmission from drinking milk from an infected animal is very rare, but is more likely if the milk has not been pasteurized. Cats and dogs can be infected by and transmit C. burnetii in all the same ways (especially through birth fluids), but they very rarely get sick. Ticks can also transmit the disease.
Q fever is one of the most infectious diseases in the world. As little as one C. burnetii organism is enough to infect a susceptible person. There are a few things to keep in mind to help reduce the risk of being exposed to this pathogen:
- Only eat/drink pasteurized dairy products.
- The main risk from cats and dogs (especially cats) is when they give birth. If you have a cat or dog that has kittens/puppies, wear gloves if you have to touch the babies or any placentae. Afterwards, cleaning the area very thoroughly to physically remove any tissue or fluid residue is very important, because most disinfectants cannot kill C. burnetii. Always wash your hands thoroughly after handing newborn kittens or puppies.
- On dry, windy days, avoid farms or areas where sheep or goats are kept.
- Avoid sheep and goat farms during the lambing/kidding season.
- Cryptosporidium hominis primarily infects humans. Clearly it can make people sick, whether their immune systems are weakened or not.
- Cryptosporidium parvum primarily infects calves, and clearly makes people (and calves) sick. However, because it is relatively common in people as well, in many cases it is hard to say if a person with C. parvum was infected by contact with calf stool or human sewage.
- Both the dog-associated C. canis and cat-associated C. felis have been found in people, and C. felis can cause diarrhea even in immunocompetent individuals. Infection with these species in humans is very uncommon compared to C. hominis and C. parvum
- The largest outbreak of cryptosporidiosis ever reported in North America occurred in Milwaukee in 1993, when an estimated 1.6 million people were exposed to the parasite and over 400 000 people became sick as a result of the infection.
- In most studies, contact with pets is either not associated with the risk of cryptosporidiosis or may even have a slight protective effect. One study showed no significant association between pet ownership and cryptosporidiosis in HIV patients.
In 1894, HA Johne and L Frothingham discovered a tiny bacterium that was later found to be the cause of a disease in cattle characterized by chronic and severe weight loss and diarrhea. The condition ultimately became known as Johne’s disease, and it has been a thorn in the side of even very well-run dairy farms ever since. The disease is caused by a bacterium called Mycobacterium avium subsp. paratuberculosis (or MAP for short), which is in the same group as the bacterium that causes tuberculosis (TB). These bacteria typically live inside cells (usually white blood cells), and can therefore hide from the body’s immune system, which makes them hard to kill, even with antibiotics. It can also make them hard to detect. In cattle, the bacteria hang out in the lymph nodes and lymph tissue in and around the end of the small intestine (parts of the cow that do not enter the human food chain). The body’s attempts to kill the bacteria over time lead to chronic inflammation, which interferes with the ability of the animal to absorb nutrients from the intestine. This eventually leads to weight loss and diarrhea, even though the cow still eats. The disease also occurs in sheep and goats.
Yes, cows with Johne’s can still produce milk, and even before they’re sick MAP can sometimes be found in the stool and milk. On July 7, 2008, the CBC National ran a story about the possible link between Johne’s disease in cattle and Crohn’s disease in people. This is a very controversial topic, and arguments both for and against a relationship between bovine MAP and Crohn’s disease have been reviewed. There are even cases of Crohn’s that were thought to have been cured by the consumption of raw milk, which is more likely to contain live MAP bacteria (and potentially a lot of other bacteria most people shouldn’t be drinking). It’s also clear that there are genetic and environmental factors that affect whether or not a person will develop Crohn’s disease. It’s a very complicated picture, but I don’t find there’s enough evidence at this point that people need to start boycotting milk and dairy products for fear of Crohn's disease. For now, I’d say cook your meat well, wash your hands, avoid cattle manure whenever possible, and stick to pasteurized dairy products, but don’t be afraid to enjoy a cheeseburger and a glass of milk on a beautiful summer afternoon :)
Cattle (both beef and dairy) are usually infected with Mycobacterium avium subsp. paratuberculosis (or MAP for short) as newborns, but it may take 2 to 10 years to develop any signs of Johne’s disease. The condition is essentially impossible to treat in cattle, so efforts have focused on trying to prevent young animals from becoming infected in the first place.
The Canadian cattle industry is actively addressing the problem of Johne’s disease through the Johne’s Disease Prevention Project. At the moment, Johne’s control programs are still voluntary in Canada, but more and more farms are getting on board. It’s a long, slow process that takes years, but eventually the disease can be eliminated from the herd. Whether or not eliminating Johne’s disease from cattle may have an impact on the occurrence of Crohn’s disease in consumers remains unknown, but it certainly won’t hurt. Regardless, being Johne’s free is better for the farm, and better for the cattle.
For more information on Crohn’s disease, check out the Crohn’s and Colitis Foundation of Canada website.
What do you do if you want to have contact with animals but don't know whether you'll be able to wash your hands? Bring your own alcohol-based hand sanitizer. They're cheap, easy to find and effective, and it never hurts to have them on hand (pardon the pun).
Discussion of other petting zoo issues and links to other resources can be found in our Petting Zoo archives.
Where do you think the goat's mouth just came from? The ground, along with manure from various animals.
What might the bottle have been contaminated with? E. coli O157, Salmonella, Campylobacter, Clostridium difficile...
Where do you think this bottle is going next? The baby's mouth.
What will probably happen to the child?: Nothing.
What might happen to the child?: Disease caused by one of the above-named microorganisms (or others), ranging from mild diarrhea to fatal infection.
While there is good information available about precautions that should be taken for petting zoos, such as from the National Association of State Public Health Veterinarians, not all petting zoos take adequate precautions. A recent study pointed out common deficiencies.
Some important points to consider:
- Petting zoos are safe for the vast majority of the population if common sense measures are used.
- Items that will end up in the mouth of a child should never go into a petting zoo.
- Children should be closely supervised in petting zoos.
- Uncontrolled animal contact should be prevent.
- Hands should be washed after contact with animals or the petting zoo environment.
Plague is caused by the bacterium Yersinia pestis, which is carried primarily by wild rodents. Infection with Yersina pestis can cause bubonic plague (swollen lymph glands), septicemia plague (bloodstream infection) or pneumonic plague (pneumonia/lung infection). An average of 13 human cases are diagnosed in the US every year. In today's modern times, the infection can be effectively treated with antibiotics, but if left untreated the mortality rate is still 50-90%. The Canadian Notifiable Disease Database has never received a report of plague in a human.
Plague has been reported in a variety of animal species, including cats and dogs. However, dogs seem to be relatively resistant to the infection compared to cats. Yersinia pestis gets from rodents to other animals and people mainly by flea bites. Fleas become infected by biting an infected animal, and can then pass on the infection by biting another animal or person. It is also possible for plague to be transmitted by direct contact with infected animals, but this is less common.
A recent report described an outbreak of plague in prairie dogs in western South Dakota. There is concern that the disease could also affect the endangered black-footed ferret in that area. Plague almost always kills prairie dogs, and black-footed ferrets almost exclusively eat prairie dogs.
When plague is present in wild animals in a region, there is always a risk of transmission to people and pets through contact with infected animals or bites from infected fleas. Some basic measures to reduce the risk of plague exposure in areas where the disease exists in wild animals are:
- Keep cats indoors
- Talk to your veterinarian about a flea control program for your pets
- Never touch wild animals, especially sick or dead ones
- Don't keep wild animals as pets
- Try to keep wild animals away from your pets
(Centers for Disease Control and Prevention (CDC) / Janice Carr)
In people, there are detailed protocols for avoiding blood exposure in healthcare situations, and protocols for managing people exposed to human blood in hospitals and in the community. This is mainly driven by concerns about HIV and hepatitis viruses that can be transmitted by contact with blood. But these viruses are not present in animals, and the risks of transmission of disease from pets to people through blood are very low. Even contact with blood from a rabid animal is not considered rabies exposure, because the virus is found in the saliva, not the blood. This has led to a rather cavalier approach towards blood exposure in veterinary medicine, which is understandable but not ideal. New infectious diseases continue to emerge in animals and people, and eventually there is likely to be one that can be transmitted between species by blood. Therefore, it is prudent to try to reduce exposure to animal blood when possible, but without getting overly concerned (or paranoid).
- Direct contact with animal blood should be avoided whenever possible.
- In particular, avoid getting animal blood on any cuts, scrapes or other broken skin, and avoid getting the blood in your mouth, nose or eyes.
- If you do get animal blood on your skin, wash it off as soon as possible.
- While it is extremely unlikely for a person to get sick from touching animal blood, make sure you tell your physician about the incident if you do become ill.
Wildlife should be left in the wild. While some wild animals, especially babies, are hard to resist, little good usually comes from intervention of the general public. This is particularly true when well meaning people ‘rescue’ baby wildlife. Often, ‘orphaned’ wildlife are not orphans; the parents are hiding nearby and would have returned. Few animal facilities are properly equipped or licensed to properly deal with wildlife, and these ‘rescued’ orphans often end up being euthanized. Some people try to nurse these animals themselves but few can do it properly. It’s also illegal in many areas. Add that to the obvious risk of rabies, as highlighted here, and it should be clear that wildlife should be left alone. It’s also a good reminder of the need to vaccinate your pets because rabies exposure can occur in many different ways. The pets in this situation are reportedly under 45 day quarantine, which is certainly not something you want to do, but is much better than what would happen in many jurisdictions in the case of rabies exposure of an unvaccinated pet (long strict quarantine or euthanasia).
Baby raccoons are very cute and hard to resist, but like many other forms of temptation, danger, in this case in the form of infectious diseases, can lurk just around the corner. More information on rabies is available in our Resources section.
No...hedgehogs aren't sneaking out of their cages and attacking people as they sleep. Rather, they can carry a variety of microorganisms that can be transmitted to people. There have been a few reports describing infections associated with hedgehogs, particularly Salmonella and ringworm. An excellent report in the journal Emerging Infectious Diseases highlighted the diseases hedgehogs have been shown to, or could, transmit to people. Hedgehogs don't have to be sick to be a source of infection.
Hedgehogs have been available for years, but they may be a fad pet at the moment. One breeder is quoted as saying “They are going up these last two months we actually have a waiting list about twenty people,” said Sarah Roberts a breeder in Mansfield. “That's never happened in the year’s of breeding we've done.”
While any pet could transmit infections to people, certain pets are higher risk. Overall, species that are rare or 'fad' pets may be of greater concern because we simply don't know much about them (i.e. what diseases they can transmit, how to reduce risks...).
These small creatures can probably be safe pets in some households, but are they really better than other species? You probably should not have a hedgehog if you or someone else in the household has a compromised immune system or if you have small children. If you do have a hedgehog, don't let it roam freely in the house and wash you hands after handling it.
We really have no clue about how common sandbox exposure causes disease. While this skin disease is usually relatively minor, there are some other groups of parasites that can migrate through other parts of the body, including the brain, and cause devastating illness. All of these are very rare in northern climates like Canada, but measures should be taken to reduce the risk of exposure because of the potential severity of disease. Risks are much higher in warmer climates. These are a significant concern in warmer areas. It’s probably pretty uncommon but some of the diseases that can occur are very serious, so attention should be paid to these risks. The main things that can be done to reduce the risk are keeping animals out of sandboxes and handwashing after contact with sand. Check out our “Sandbox” information sheet for more details.
2012 International Clostridium difficile Symposium
2012 International Conference on Equine Infectious Diseases IX
2011 ASM-ESCMID Conference on Methicillin-resistant staphylococci in animals
- Miconazole susceptibility of MRSA and MRSP
- Livestock associated MRSA in community hospitals in Ontario
- Equine hospital MRSA surveillance
- Biofilm production by S. pseudintermedius
- Methicillin-resistant staphylococcal pyoderma in dogs, and impact of treatment on colonization rates
- Surgical site infections in a small animal hospital
2011 University of Guelph Centre for Public Health and Zoonoses Symposium
- Pet ownership, interactions and animal-associated disease risks in Canadian households
- Metagenomic investigation of the oral microflora in healthy dogs
2011 Canadian Animal Health Laboratorians Conference
2011 Canadian Association of Clinical Microbiology and Infectious Diseases
- 2011 American College of Veterinary Internal Medicine Forum, June
- 2011 ASM-ESCMID conference on methicillin-resistant staphylococci in animals, Sept