Worms & Germs Blog

Rabies in a 3 Month Old Puppy with Human Exposure

Posted in Dogs, Rabies, Vaccination

In many countries, rabies is a disease we’re concerned about but one that is rarely seen in domestic animals and is exceptionally rare in people. It’s easy to forget that people in other areas are confronted with a risk of rabies on a regular basis. Canine rabies is a major problem in Africa, leading to major challenges for veterinarians, public health personnel and the general population. Dr. Philip Mshelbwala is a veterinarian in Nigeria, with special interest on rabies research. He holds a certificate in Rabies Surveillance and Control of the University of Lausanne, Switzerland and currently works with the University of Abuja, Nigeria. Philip will be providing some front-line information about the challenges of rabies in Nigeria.

P.P. Mshelbwala: On February 23, 2017 a para-veterinarian brought a 3 month old puppy to the attention of a veterinarian in Gwagwalada, Federal Capital Territory, Abuja, Nigeria following unsuccessful empirical treatment of babesiosis. Further history from the owner revealed that 3 of his puppies were attacked 2 weeks earlier by a stray dog. One of the puppies died instantly from trauma, while the other two survived with bite wound injuries. Veterinary care was not sought until 2 weeks later, at which time unusual behaviour was observed. The para-veterinarian treated the dogs for babesiosis; however, one died during the course of treatment, which prompted him to call the attention of a private veterinarian. On presentation the puppy was recumbent, with clear spasms and muscle tremors . There was marked salivation, unusual violent biting behaviour and vocalization. The puppy was quarantined and died the following day.

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The brain was removed and rabies was diagnosed by Fluorescent Antibody Test at the National Veterinary Research Institute Vom, Nigeria. A visit was then made to the house for contact tracing. Following questioning, it was determined that five people, including the para-veterinarian, private veterinarian, an owner, the owner’s security guard and a cousin, were exposed to the puppy. They were all advised to go for full post exposure prophylaxis (PEP), with each dose costing $10. Despite public education to those exposed, the security guard and para-veterinarian refused to undergo PEP.

IMG_20170304_123749An outbreak response vaccination campaign was also organized. Notices of vaccination and educational materials were prepared and distributed in all the households in a 50 km radius from the index case by team of 2 veterinarians and 10 veterinary students from the University of Abuja and VET Ville. A total of 220 dogs were immunized using house-to-house strategy. This required the support of many people, including the director Veterinary Teaching Hospital who provided a vehicle and vaccination supplies and the Federal Ministry of Agriculture and Rural Development, who provided the vaccines, as well as the people that did the investigation.

IMG_20170304_155227J.S. Weese: This report highlights the challenges of rabies. The cost and time commitments required here were major and it’s impressive that this degree of response was coordinated in such a short time. However, it’s much more cost-effective to vaccinate dogs than to do emergency response. The typical target for canine vaccination to control rabies in a region is 70%… with 70% of dogs vaccinated, eradication is possible. That’s a hard number to reach, especially in areas with large feral dog populations. While emergency response vaccination campaigns are important, more structured, large scale vaccination is needed to reach that goal. Campaigns such as Mission Rabies (something we’ll be reporting on later) are needed for both vaccination and education, with education being a critical and often overlooked aspect. Despite timely intervention, the vaccine couldn’t go around the whole community, as a case was reported in a community nearing that of the index case, three weeks after. Despite the history of dog bite, the para-veterinarian didn’t consider checking for rabies, showing knowledge gap.  There is therefore the need to organize a large scale vaccination campaign to target 70% dogs.  Also there is the need for large scale public education on rabies, both on radio and television as it is done for other diseases of public health significance. Veterinarians need to be stationed at each local government area to help in surveillance.

Rodent Importation…Booming Business, Booming Risks?

Posted in Pocket pets

HamstersThe recent (ongoing) Seoul virus outbreak associated with pet rats and recurrent Salmonella outbreaks linked to feeder rats have focused more attention on the national and international movement of rodents. Most people probably don’t realize the massive number of rodents that are shipped internationally, and we don’t really understand the risks. Anytime animals are moved from one population to another, they can bring infectious diseases with them. In general, the more movement (both in terms of occurrences and distance), the more risk.

A recent paper in the journal Transboundary Emerging Diseases (Lankau et al, Public Health Implications of Changing Rodent Importation Patterns – United States, 1999-2013) describes data about rodents (legally) imported into the US over more than a decade, acquired using a Freedom of Information Act request.

Here are some highlights:

  • 4435 rodent shipments were identified. The number of shipment increased significantly between 1999 and 2013.
  • The total number of rodents imported was 1,490,383, with a peak of 246,040 in 2007.
  • Rodents came from 68 countries, including countries from all continents except Antarctica.
  • Shipments from Africa plummeted in 2004, associated with a change in regulations that followed the rodent-associated monkeypox outbreak in people in the US.
  • Only 34 (0.8%) of shipments were denied entry. Four were abandoned (I’m not sure what happened to those), 12 were sent back and 18 were seized (I don’t imagine that ended well for the rodents).
  • 80 different species were imported, although some shipment records did not have clear species information, so it was stated that up to 100 different species might have been involved.
  • As time passed, hamsters, chinchillas, guinea pigs and gerbils became an increasing majority of the imported rodents. Presumably most of these were destined for the pet trade. Hamsters, in particular, were common, accounting for close to 85% of all imports.

Where the animals went and if they brought any problems (e.g. infectious diseases) with them cannot be tracked. It’s assumed that the bulk of imports went to the pet trade.

There are valid reasons for animal importation, and some reasons that are hard to justify. One thing to consider is whether importation is really needed, at least on this scale. It’s not exactly difficult to breed those most commonly imported species in captivity, so I have to assume that cost is a motivator. It’s simply cheaper and easier to import massive numbers of pet rodents from large scale breeding operations in certain countries. Large commercial breeding operations may pose increased risk because of the potential for widespread dissemination of infectious agents, something that has been seen with a variety of pathogens. It also raises welfare questions, with large scale breeding and long-distance shipping, versus local smaller scale breeding and shorter distance transportation. What percentage of animals born in those operations are alive in households a year later? I have not idea, but fear the number is low. Another thing to consider is behavioural issues. Bites are among the biggest problems associated with pet rodents. Is an animal bred in a warehouse in Europe and shipped to North America, passed through a large central warehouse, distributed to a local pet store then sold into a household going to be a well-adjusted pet? Maybe, maybe not. Local breeding doesn’t mean it’s guaranteed to be well-adjusted either; however, I have to assume that a small scale breeding operation and less stress of shipping would only help.

Cost drives a lot of this. So does lack of public awareness. Would people pay a premium for a locally raised hamster? Maybe, since the cost is pretty low already. Locally-sourced animals aren’t necessarily safer and they can still pose various risks (as the Seoul virus outbreak showed), but there’s probably an added degree of risk from imported animals. People simply don’t think about from where that animal in the pet store comes, and they usually don’t think about disease risks and what they need to do to reduce those risks either. More public education could go a long way.

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Petting Zoos, Outbreaks and Denial

Posted in Other animals, Parasites

baby-goatI think petting zoos can be great. I’ve taken my kids to many and think they’re a great way for people to see and interact with animals they would not normally encounter.

However, there’s always some risk, and petting zoos range from exceptionally well run to horrible. It seems like there’s been steady improvement over the past 10 years or so in how petting zoos are managed, but problems persist. Some risks are the inevitable consequences of contact with animals. However, in most, if not all, there are obvious things that could be done to reduce the risk to people. Unfortunately, young kids bear the brunt of petting zoo infections, and serious disease can occur.

It’s early for the start of petting zoo outbreak season, but an animal rescue farm in Pennsylvania has been closed for investigation of a cryptosporidiosis outbreak.

Cryptosporidiosis is caused by the microscopic parasite Cryptosporidium, which is commonly found in some animals, particularly young calves, kids (as in baby goats) and lambs. It can cause nasty, although usually short-lived intestinal disease in people, but severe disease is possible in the very young, very old and people with compromised immune systems. One problem with “crypto” is that it’s hard to kill. The parasite is resistant to most disinfectants and alcohol-based hand sanitizers, so when someone gets it on their hands after contact with manure or manure-contaminated surface, thorough hand washing is needed. Unfortunately we know that’s something that doesn’t get done well enough at petting zoos, for various reasons. It’s also why avoiding contact with calves and other young ruminants is a standard (and often ignored) petting zoo guideline recommendation.

The recent outbreak at Heaven On Earth in Bethlehem Township, PA, involves at least 5 confirmed cases. Hundreds of people were potentially exposed so presumably there are other currently unidentified cases.

A crypto outbreak investigation is usually going to focus on a few key things, such as:

  • Was there contact with high risk species such as calves?
  • Were adequate handwashing stations present?
  • Was there adequate signage to encourage handwashing?
  • Were people eating and drinking in the petting area?

The farm recently took in 30 kid goats and had asked for volunteers to help hand feed them. That’s a group of high risk animals and potentially a group of high risk people (if they don’t have any training on how to avoid crypto). It appears that young kids were involved in this, and the Facebook page for the facility has a post from the parent of a 3-year-old that had helped feed the kids and got crypto.

It’s reported that the farm is now closed to the public, which is a sensible response during a outbreak (although their Facebook page has comments from people who visited yesterday, so it’s not clear to me what’s happening). There seems to be the typical level of denial, as reported by local media: [“The farm owner] said he is working with the Health Department to determine the origin of the reported sicknesses. He said he isn’t sure anyone was infected at the farm, but it is possible. “People come every day with their kids and we never had a problem,” Melhem said. “I’m fine.  I’m here every day.  Three or four women are here every day and none of them are sick.”

It’s never happened here before (that they know of) and I’ve worked here for years and have never had a problem are typical refrains, but it’s pretty much guaranteed the farm was the source.  Their Facebook page shows evidence of even more denial.

Outbreaks aren’t always someone’s fault, but there’s almost always something that can be done to improve and decrease the risk of the same thing happening again. Given the lack of understanding or acceptance, let’s hope this place stays closed to the public and focuses on their rescuing, not public visitation.

Colistin Resistance in Pets

Posted in Cats, Dogs

DNA helix2I’ve had a lot of emails over the past few months from colleagues from other countries, asking if we’re finding much mcr-1 in Canada. mcr-1 is a gene that makes bacteria resistant to colistin, a “drug of last resort” in people with some highly resistant infections.  The gene has emerged in bacteria from both animals and humans. It’s also been found a few times in a couple of different types of bacteria from food animals and food products in Canada.

This gene probably originated in food animals and is likely distributed in farm animals internationally, although only recently have researchers starting testing for it. I’ve been interested in the pet side, particularly following a report last year of mcr-1 in multiple dogs and cats in a Chinese pet store (after infection of a pet store employee was identified). When there was a large shipment of rescue dogs from China to Canada late last year, I would have loved to have tested some of the animals for mcr-1 in the bacteria they were shedding, along with various other things (for example, we know that multiple cases of distemper were associated with that particular group of dogs).

A recent paper in Emerging Infectious Diseases entitled mcr-1in Enterobacteriaceae from companion animals, Beijing, China, 2012-2016 highlights these concerns.

In that study (Lei et al, 2017) they tested Enterobacteriaceae from healthy and sick dogs and cats from Beijing’s Veterinary Teaching Hospital of the China Agricultural University. Enterobacteriaceae is a group of Gram negative bacteria, including most notably E. coli, Enterobacter, Salmonella and Klebsiella. The results were a bit scary:

  • 14% of the 566 isolates tested were resistant to colistin. This was mainly in E coli and Klebsiella.
  • 62% of the colistin-resistant isolates harboured mcr-1.
  • Bacteria that possessed mcr-1 were typically resistant to many other antibiotics, but were susceptible to some drugs.
  • Many different strains were involved, showing that this gene has moved to lots of different bacteria that have dispersed in the population.
  • 7/35 pet food samples (primarily chicken-based) were positive for mcr-1. What this means is unclear. Testing was done by PCR, which detects DNA, not necessarily live bacteria. So the bacteria containing mcr-1 could have been killed in cooking. But wow – that’s a concern, and further suggests that this gene may be highly prevalent in food animals.

Why was the colistin resistance rate so high? That’s an interesting question, since colistin is not used to treat dogs and cats (as opposed to food animals in some regions). It could reflect widespread exposure from food and the environment. It could also reflect use of other antibiotics in pets, since use of any drug to which the bacterium is resistant can select for that bug, and all its genes (e.g. if a bacterium is resistant to ampicillin and colistin, use of either drug will select for it).

What’s the threat to pets? Pretty minimal, since we don’t use colistin in pets.

What’s the threat to people? That’s the big question, since sharing of mcr-1 ­containing bacteria can definitely occur. The main concern is that pets might be a reservoir of mcr-1-carrying bacteria in households and the community. More work needs to be done to assess this risk, and look at mcr-1 in various species in other countries.

Immunocompromised People and Their Pets

Posted in Birds, Cats, Dogs, Other animals, Pocket pets, Reptiles

Cat on bed2This month’s edition of the Internal Medicine Journal contains an article entitled High rates of potentially infectious exposures between immunocompromised patients and their companion animals: an unmet need for education (Gurry et al. 2017). The study is fairly superficial and there’s nothing particularly surprising in the paper, with results similar to what has been reported in the past (including one of our earlier studies on high risk children (Stull et al. 2014)). The sad part, perhaps, is the conclusion that there is a need for increased education of patients – something that’s been said many times before but with little resulting action.

Here are some highlights from the study, which surveyed 265 adults with a few types of disorders that would increase their risk of infection.

  • 52% owned an animal. That’s pretty consistent with other studies and what we know about pet ownership in general. High risk people tend to have the same ownership patterns as the general public.
  • Dogs and cats were the most common pets, but other species were also reported. 3% owned reptiles, which are  very high risk pets for immunocompromised individuals.
  • 30% of individuals reported having been bitten or scratched by their animal at some point. This probably poses the greatest risk for most pet owners (beyond reptile owners, where Salmonella is the main concern).
  • Close to half allowed their pet to sleep on/in the bed. That’s gotten a lot of attention in the past and I really don’t get too concerned about it in most situations. (On the bed is also different than in the bed, or sleeping right against your face.)
  • Only 17% recalled getting some information from healthcare workers about safe practices around their pets. If anything, that’s probably higher than average, showing a major gap that needs to be filled.

I think most people would agree that we need better education for high risk people about pets and zoonoses. How to actually get that done is the challenge.

Seoul Virus in Ontario

Posted in Pocket pets

RatsIt’s not particularly surprising, I guess, but a few cases of Seoul virus infection have been identified in Ontario residents who breed or have contact with rats.  Fortunately, like most infections with this type of hantavirus, disease was mild. Equally not surprising is that infected rats have been found in Ontario rat-breeding facilities.  The Ministry of Health and Long-Term Care is investigating the source of the virus, including any possible connections to the ongoing outbreak of Seoul virus in the US, which has resulted in 16 confirmed human infections to date.  It’s another reminder of the ever-present risk of emerging or unusual diseases, and that risks increase when animals are moved around the country or planet.  Seoul virus can be transmitted from rats to people via contact with urine, feces or saliva (so wash your hands after handling rats and avoid kissing them!), but there is no evidence that it can be transmitted from person to person.  More information for Ontario veterinarians is available in the OMAFRA Veterinary Update posted on OAHN.ca.

Flesh Eating Disease with a Pony Link

Posted in Horses

Shetland ponyThe bacterium Streptococcus equi subsp. zooepidemicus (often simply called Streptococcus zooepidemicus) is one that I think I understand less and less, including the risks this predominantly equine-associated bug poses to humans. It’s a well-known and common bacterium in horses, both healthy and sick, and can also be found in dogs and cats (where it can cause serious disease). Despite what has to be very common and sometimes abundant exposure in equine personnel in particular, human disease is rare. Yet, disease can occur. It seems like it’s being reported more often in the medical literature, but whether that’s because human infections are becoming more common or just more commonly identified and written about is a big question.

A recent case report entitled “Zoonotic necrotizing myositis caused by Streptococcus equi subsp. zooepidemicus in a farmer” (Kittang et al, BMC Infect Diseases 2017) once again shows the potential for nasty human infection.

The affected person was an otherwise healthy 73-year-old farmer who owned two healthy Shetland ponies. He was admitted to hospital with pain in his groin. His condition deteriorated and a CT scan identified suspected necrotizing myositis (flesh-eating disease). Emergency surgery was performed to remove the infected tissue in this case, as this type of bacterial infection is so severe and rapidly progressive that the best chance of survival is for the infected tissue to be removed ASAP – antibiotics alone are unlikely to to be effective. Culture of the affected tissue yielded S. zooepidemicus. Thirty days, two surgeries and lots of very intensive care later, the patient was discharged from the hospital. Rapid diagnosis, initial administration of antibiotics that were effective against the bacterium and most importantly, rapid surgery, were probably the most important factors in this successful outcome.

The link to horses is through the nature of the bacterium and not any specific investigation. Since S. zooepidemicus is a horse-associated bacterium and the man had contact with ponies, the potential link is obvious. However, the bacterium can also be found in other animal species, so it’s still only a presumptive link. As is typically (and unfortunately) the case, swabs of the ponies were not taken to see if the same bacterial strain could be identified.

How the man was infected isn’t clear. He reportedly had some minor abrasions and blisters on his fingers at a time when he was handling the ponies. So, it’s possible the bacterium from respiratory secretions of a pony got into the wounds and spread to the muscles in his thigh. That’s a pretty oddball occurrence for minor skin wounds and healthy horses. Considering the number of horse personnel that have skin wounds at any time, this highlights the potential but presumably exceptionally low overall risk. The man’s age probably increased his risk of infection, but other reasons why he (and not the large number of other people similarly exposed to horses on a daily basis) got sick are not obvious.

Does this change anything?

  • Not really. We’ve known that S. zooepidemicus can cause disease in people for a long time. This type of infection is different but not overly surprising. It’s another reminder of the ever-present potential of exposure to zoonotic pathogens from healthy animals.

What should be done?

  • A little hygiene goes a long way. Keeping wounds covered and washing potentially exposed sites are probably the best preventive measures when working around apparently healthy animals. That’s particularly true for people at increased risk of disease, such as people over 65 year of age, young children, pregnant women and people who have a compromised immune system.

So, don’t run screaming next time you get horse slobber on your hands, but don’t forget to wash your hands.

Canine and Feline Respiratory Infection Treatment Guidelines

Posted in Cats, Dogs, Other diseases

Dog cough SSThe latest set of clinical treatment guidelines from the International Society for Companion Animal Infectious Diseases have been published in the Journal of Veterinary Internal Medicine (Lappin et al 2017): Antimicrobial Use Guidelines for Treatment of Respiratory Tract Disease in Dogs and Cats: Antimicrobial Guidelines Working Group of the International Society for Companion Animal Infectious Diseases.

It’s available via the link above or through the JVIM website.

Rabies and Bite Responses

Posted in Dogs, Rabies, Vaccination

There tends to be confusion about what happens when an animal bites or is bitten, and rabies is being considered. Most of the confusion revolves around how long an animal is quarantined or observed. Yet, it’s actually pretty straightforward if you think about why quarantine/observation is being performed and some basics about the virus and the disease itself.

Scenario 1: A dog bites a person

This one’s easy.

  • The response: 10 day quarantine or observation. Basically, we need to ensure that the dog is normal 10 days after the bite.

Why?

  • To see if it develops signs of rabies. Based on the nature of rabies virus infection, by the time a dog is infectious (shedding rabies virus in saliva) the infection is well advanced. If the dog is neurologically normal 10 days after the bite, it could not have had rabies virus in its saliva at the time of the bite

What if the dog was vaccinated against rabies?

  • That doesn’t have any impact. Vaccination is highly effective but not 100% protective. Since you can’t guarantee a vaccinated dog doesn’t have rabies, even vaccinated dogs may be placed under a 10-day observation period.

Raccoon doubleScenario 2: A dog is bitten by a raccoon (or other potentially rabid animal)

One variable here is whether the offending animal is available for testing. If it is killed/euthanized and tested, and shown not to have rabies virus in its brain, the bitten dog is in the clear (same applies if a person is bitten by a wild animal).  In a large proportion of cases the offending animal is not available for testing, and the rabies status of the animal is never known at the time of the bite.

Why is there a response?

  • Unlike scenario 1, the goal here isn’t to see if the dog was incubating rabies virus when it was bitten. The goal is to determine if there is a reasonable risk that the dog will develop rabies, and to keep it contained during the period when rabies is most likely to develop so it can’t infect someone else. The incubation period for rabies in dogs can be long (months) so the quarantine/observation period has to be longer.

What is the response?

  • The first step is to perform a risk assessment to determine the likelihood that the offending animal transmitted rabies to the dog.  Although the risk from a bite from another mammal is never zero, if the risk is deemed to be very low then no specific action is taken other than to ensure the dog’s vaccination status is up-to-date.  Pet owners must always be vigilant for neurologic signs in their animals that may be consistent with rabies.  Even indoor animals can have contact with potential rabies vectors such as bats.
  • If the risk assessment is that there is a significant risk of rabies transmission, unlike scenario 1, the dog’s vaccination status then plays a role in determining the subsequent response. (Note: These rules are for Ontario. There’s some variation between jurisdictions).

If the dog was full vaccinated, according to the intervals specified by the vaccine manufacturer, and is not overdue for a booster:

  • The dog still requires a rabies booster is given within 7 days of the bite.  If this is done, there is no confinement period, although an informal observation period (45 days) is recommended out of an abundance of caution.
  • If a booster isn’t given within 7 days, then the dog gets a 3 month precautionary confinement period (PCP). During this time, they have to stay on the owner’s property (except for medical care), have contact only with one caregiver, have no contact with other animals, can only go outside on a leash and in a fenced area and must be cordoned off when inside with a double barrier (e.g. kept in a room with a closed door in a house with a closed door).

If the dog received an initial rabies vaccine but is not yet due for its first booster (i.e. within 12 months but no less than 14 days after initial vaccination):

  • Same as for fully vaccinated dogs. The key is getting to booster done within 7 days.

If the dog has been vaccinated in the past but is overdue for a booster:

  • This is handled on a case-by-case basis, thinking about the time since vaccination, the number of vaccines the dog has had in the past and other things that might influence protection. Usually, the response is a booster within 7 days and a 3 month PCP. Without a booster, a 6 month PCP is used.

If the dog has never been vaccinated against rabies or rabies vaccination history is unknown:

  • If the dog gets a rabies shot within 7 days of the bite, it gets a 3 month PCP. If not, it’s 6 months. Euthanasia is the other option and is sometimes chosen because of the issues with long quarantines. That’s particularly true with puppies (who are more likely to be unvaccinated), where long confinement periods can be very difficult and impact socialization.

Incidentally, the same rules apply to cats in Ontario. Don’t forget, all dogs, cats and ferrets over 3 months of age in Southern Ontario are legally required to be fully vaccinated for rabies at all times.  Failure to do so can result in a fine (which usually costs more than the vaccination!)

2016 Rabies Compendium

Posted in Cats, Dogs, Horses, Other animals, Rabies, Vaccination

Vampire smileyThe 2016 Compendium of Animal Rabies Prevention and Control has been released by the US’s National Association of State Public Health Veterinarians (NASPHV). This version has updates in a few different areas, such as some changes to recommendations for dogs, cats and ferrets that have potentially been exposed to rabies. It can be downloaded directly here or be found with other documents at the NASPHV Compendium site.