Tiger smuggler thwarted
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)
Mass rabies exposure from raccoon
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 in Saskatchewan
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.
Photo: Black-tailed Prairie Dogs atop their burrows in Grasslands National Park in Saskatchewan, Canada (source: www.canada-photos.com)
E. cuniculi from rabbit to dog?
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.
Cats and bats and rabies
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.
More animal smuggling
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)
Rabies update
ProMed has a new list of recent rabies incidents. The whole report can be seen by clicking here, but these are some examples of common or important issues they touch on:
- 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.
Rabies, rabies, and more 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.
Stupid, drunk and owner of a venomous exotic pet... Bad combination
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)
Putting "One Medicine" into action
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.
Eliminating E. cuniculi in the household
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.
Cryptosporidiosis from wildlife centre lambs
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.
Distemper outbreak in California
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
Easter chicks and Salmonella
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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.
Distemper in raccoons and dogs
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
Raccoon vaccination in New York
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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.
Tiger troubles in Ontario
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?
Watch out for rabbit pee
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!
More information about E. cuniculi in rabbits can be found in our archives.
Kissing a frog might get you more than a prince
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)!
Antagonzing piranha... Maybe not a good idea
Pet bites are a big p
roblem. 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.
More rabid raccoons in Central Park
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.
Rabid calf at educational centre
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.
Baylisascaris in Winnipeg
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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.
More information about Baylisascaris and raccoon latrines is available in our archives.
Seagulls, beaches and bad bugs
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.
Eye protection urged for people with tarantulas
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)
Beaver attack, Part 2
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.
Internet exotic pet dealer horrors
.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.
Boy attacked by beaver
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.
Salmonella from frogs
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.
How to remove a skunk from a pool
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.
Another ferret flu case
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
Rabies death in Indiana
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.
Pets and H1N1 revisited
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.
Swine flu has gone to the birds
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!
Rabies and roadkill
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.
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Image (top) from www.michiganimaging.com
Image (bottom) from http://users.frii.com/donlight/archive/97arc.htm
Pet bear kills woman
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.
Petting zoo outbreak investigation continues
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.
Petting zoo improvements
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.
Petting zoo zebra bites off finger
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..jpg)
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.
Bat bite in the park
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 bait safety
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.
Image from: http://www.mnr.gov.on.ca/en/Business/Rabies/2ColumnSubPage/275904.html
Raccoon deterrents
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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.
Raccoon latrines in Chicago
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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.
Do not feed the bears
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.
Groundhog day - Not again!
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.
Zebra sidelines football player
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
Transmission of herpesvirus from a person to a rabbit
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.
More on service animals and access
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
Red eared slider turtle rebuttal
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 infected with Campylobacter
...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.
Stupid things done with bats, part II
Last fall, I wrote about rabies exposure in a Montana school. The full story has just been published in CDC's Morbidity and Mortality Weekly Reports. The brief version of the story is:
- 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.
Cooperating on Q Fever
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.
Feeding wildlife: Bad idea
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.
Testing petting zoo animals
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
Verotoxigenic E. coli in petting zoo animals: UK
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.
Google goes green with goats
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.
Garden veggies and poopy parasites
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.
E. coli outbreak at a petting zoo
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.
Swine flu: What about the pigs?
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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 in a rabbit: New Mexico
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.
Raccoon roundworm in New York
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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.
More information about Baylisascaris and preventing transmission of the infection can be found in our archives, as well as information about cleaning up raccoon latrines.
Ban the Easter bunny?
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.
Service monkeys and horses...where do we stop
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 so
meone 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
Sandbox season arrives!
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.
More information on sandbox safety can be found on the Worms&Germs Resources page. More information on larval migrans is also available in our archives.
Lambing season and Q fever
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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.
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- 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.
Testing for ringworm with toothbrushes
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.
More information about ringworm is now available on the Worms&Germs Resources page, and in our archives.
Animal smuggling - Do you know where that pet came from?
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 - The walking dandruff
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)
Neurological bunnies: Encephalitozoon cuniculi
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.
Safe rabbit handling - for you and your rabbit!
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.
Leptospirosis and Pot-Bellied Pigs
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.
Flu problems: people vs pets
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.
Cleaning up raccoon latrines
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.
Rabies in the US in 2007
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.
More information on rabies can be found on the Worms & Germs Resources page, and in the rabies archives.
Nontraditional Pets and Children: Beware
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.
...but pet fish are absolutely safe... aren't they???
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!)
More about Echinococcus tapeworms in dogs
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.
Remember:
- 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
Stupid things done with bats
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.
Your mother was right! Wash your hands
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!
Click here for instructions on how to wash your hands properly.
Updated: Speaking of Baylisascaris...
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.
Updated: Raccoon Roundworms - Baylisascaris procyonis
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.
More information about Baylisascaris is available on the CDC’s Baylisascaris Infection website.
Cows to vultures to dogs to rabies: unintended consequences
"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 - From goats to people (and pets!)
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.
Water Foul - Cryptosporidiosis
- 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.
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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.
Controversy over Crohn's and Cows
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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.
Petting zoos: What's wrong with this picture, Part II
Recently, my family went to an Ontario aviary/animal park. It was possible to touch many of the animals, and contact was encouraged because they sold food for the animals. The kids enjoyed having contact with animals, but this facility was an example of completely inadequate (or negligent) infection control practices. There's actually not much wrong with the picture in this post. The problem is that there was absolutely no means for people to wash or disinfect their hands after touching the animals. This is truly astounding in this day and age, with the increased awareness of the need for hand hygiene in these situations. Even at small, temporary animal exhibits and local fairs, handwashing facilities have become standard. I can't fathom why a large, permanent animal park wouldn't be set up properly. (It was even possible for people to touch aquatic turtles, which are very high risk for Salmonella transmission, but that's another story. More information on turtles can be found on the Resources page). 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.
Petting zoos: What's wrong with this picture?
Petting zoos can be great activities, providing entertainment and education to kids and adults alike. However, contact with animals at these events does come with some degree of risk, and numerous infectious disease outbreaks associated with such contacts have been reported. Because of these risks, most petting zoos are improving their infection control precautions, particularly with respect to handwashing by participants after touching animals. Yet some high risk behaviours continue to occur. The picture at the right was recently published in the York Daily Record. While cute, this picture raises the ire of someone like me (especially since I have young children). My main concern: the goat is licking this baby's bottle. 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.
"Black Death" in South Dakota - Plagued Prairie Dogs
While people often consider plague (aka the 'black death') to be something from history books, it is in fact still alive and well is some areas of the world. In North America, it is most common in the southwestern US but can extend into other regions. 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)
Exposure to animal blood
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.
Keep the 'wild' in 'wildlife'
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.
Hazardous hedgehogs
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.
Sandbox fun...
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.
