A couple of months BC (before COVID-19), I was planning a live simulation exercise for our hospital. The goal was to see how well we could identify and handle a nasty, reportable zoonotic disease, and to look at our personal protective equipment training and needs (COVID-19 helped with that last one, at least).

Here’s the test scenario we were going to use:  A cat is presented with fever, lethargy and cough, with rapid progression to severe pneumonia. If travel history was queried (another test for the staff, as this step is commonly missed), the “owners” would say they just moved with the cat from Colorado. From there, some good questions would hopefully raise concerns about plague, although it’d be easy to miss initially as plague is a disease we don’t see around here, and most veterinarians have never seen a case. The primary goal of the exercise was to be to look at when and how we identified the concern, and our response to it. Those aspects are themselves educational, but the big-picture goal was to see how we can improve our ability to identify, respond and communicate around such a case.

Once the COVID-19 pandemic hit, it didn’t seem like a good time to do an exercise like this, given the changes and stressors in the clinic.  However, while unlikely, the scenario wasn’t unreasonable. Plague, caused by the bacterium Yersinia pestis, is still present in some regions of North America and other parts of the world.  Pets can be infected and the can occasionally pass the infection on to their human contacts. Veterinarians are at particularly high-risk for this kind of transmission because of our close contact with infected animals during examination and treatment.

A recent case of plague in a cat in Colorado highlights the zoonotic risks. There’s not any detail in the report, beyond saying a person got plague from a cat, but cat-associated plague is well documented.

Plague is now rare (thank goodness), but it can still be found in certain wildlife. People can be exposed from contact with infected wildlife (or their fleas), or via contact with domestic animals that were exposed to infected wildlife (or their fleas). People living in or traveling to areas where plague is present need to be aware of the risk and take some basic precautions:

  • Avoid contact with wildlife (especially species like prairie dogs, squirrels and other rodents) and places where they live.
  • Keep pets away from wildlife and their burrows/nests. In particular, keep pets away from dead wildlife.
  • Keep pets indoors or under control when outdoors.
  • Keep pets on a good flea prevention program.

I frequently harp about the need to query travel history in pets, since a lot of animals move around and knowing an animal came from somewhere else can be a key part of making a diagnosis. Pet owners need to play a role in that too, by making sure they mention places their pet has visited, or if it came from another region. Also (another factor that is often overlooked),  travel doesn’t just mean long distances. From a disease standpoint, it simply means going to a place that is somewhat different microbiologically. The classic example is a dog that lives in the city but visits a cottage that may only be a few hours away by car.  Since we have some regional differences in certain diseases (e.g. blastomycosis) and vectors (e.g. ticks), you don’t always have to go far to be exposed to new risks.

A few basic questions, like “where did you get your pet” and “have you gone anywhere with your pet recently” are easy, free and can make a big difference.

The amount of money being spent developing a COVID-19 vaccine is astounding. (The amount being spent on ensuring people will actually get such a vaccine, not so much – but that’s a different story.)

Beyond vaccine hesitancy, one potentially major issue with vaccination is inequity. Rich countries have greater ability to produce and/or buy vaccine. We’ve already seen how nationalism can impact COVID-19 control, such as US efforts to restrict companies from selling critically important personal protective equipment abroad. That may play well to a certain political base, but it’s globally unethical.

The message that really needs to be pounded into some peoples’ heads is control of a pandemic requires control of the whole pandemic, everywhere. Controlling it in one country is great, but it’s only effective if you are willing and able to completely isolate your country from the rest of the world. That’s simply not practical in the modern era. So, if we really want to get this pandemic under control, we need to think and act globally.

Vaccine nationalism is a barrier to that. Countries buying up hoards of vaccine, cornering the market on vaccine production capacity, and not thinking about the global needs will cause problems. It’s obvious why some countries do it – we all want to take care of ourselves and our own. However, we need to think and act globally to protect locally.

I remember talking to a colleague in the medical field a few years ago. She was just back from working on the Ebola outbreak in West Africa.  Someone asked why she’d go there, putting in substantial time and risk, when she has a lot of important infectious disease issues here to handle. Her response was  (and I’m probably paraphrasing poorly) “to me, the best way to prevent problems with Ebola in Canada is to help control it in Africa.” It’s not a direct analogy to the current situation with COVID-19, as we still need to work on local control efforts here too of course, but we need to remember that there’s a whole world outside our borders, and viruses don’t care about geopolitical boundries.

That’s my long winded introduction into the Joint CCGHR-CSIH statement and call to action: Defeating COVID-19 calls for global solidarity, not a vaccine power playThis topic is well outside of my traditional area, but it’s very important, and I’m one of a big and broad list of signatories on this document.

The statement is a call for Canada to:

(a) increase its COVAX contributions commensurate to its advance purchase agreements;

(b) lobby other countries entering into such agreements to do the same; and

(c) urge all WHO member states to join the COVAX initiative.

It’s short and worth a read.

We all know that backyard chickens are becoming increasingly popular – despite some of their associated infectious disease hazards, which we’ve discussed many times before.  The latest “pandemic pastime” takes the trend to a whole new level, with scores of people fostering chicks or ducklings as a family activity, aka something to keep the kids engaged at home while so many other activities are still on hold.  While such an activity can certainly be a valuable learning opportunity for all involved, we really don’t want kids learning first-hand about diarrhea and other nasty infections caused by bacteria like Salmonella and Campylobacter that are often carried by poultry.  While many (but not all) backyard chicken enthusiasts keep their chickens in (as the the name suggests) their backyard, which helps to reduce poop and other contamination in the house (please don’t mention chicken diapers to me here), many families that are fostering young poultry as part of this new trend live in cities like Toronto, where many may not even have a backyard (and where it is may not be legal to keep poultry even if you do have a backyard – check with your municipality).  So the baby birds are sharing the same living space as the people (uh-oh), including the kids (uh-oh!), and sometimes very young kids, or other high-risk individuals (really uh-oh!).

Baby birds that are fostered or adopted may or may not come with some “instructions,” or at least some tips on how to care for them and how to feed them, but it’s unclear how often they also come with appropriate warnings about the infectious disease risks associated with live poultry, and how to reduce these risks.  (Even when they do come with the warnings, it’s hard to know how often people actually pay any attention to them.) It’s really important to ensure families are looking out for the health and safety of the birds, as well as the health of the people living in the house (or those who may visit).

The Ontario government has recently released a factsheet “Keeping your family healthy with backyard poultry, including chicks and ducklings” to help provide those who have decided to try out this new trend with some additional guidance that they may not receive directly from other sources (the factsheet is also available in French).  None of the recommendations are rocket science, and we’ve certainly mentioned them all before at one time or another, but in the excitement of the arrival of some cute new fluffy feathery friends, it’s good to have all of these reminders in one easy-to-find place.  Just to name a few:

  • Wash your hands after handling birds, or items or surfaces they contact
  • Supervise children around birds (also see rule #1 above)
  • Don’t kiss or snuggle the birds (also see rule #2 above)
  • Don’t eat around the birds
  • Don’t let the birds into places where there are things that you eat (i.e. kitchen)
  • If anyone in your family gets sick, be sure to tell your doctor about the birds

As with anything, especially anything to do with animals, make sure you know what you’re getting yourself into before you sign up (and also be aware of what the fate of your feathery friend may ultimately be, depending on the program).

As things continue to gradually open up (more gradually in some areas than others), myriad questions of “can we do…” or “how do we do…” come up. One that I’m getting increasingly is about pet visitation or pet therapy programs. These programs can be very valuable to patients in hospitals and residents in long-term care homes and other settings; however, they always come with some degree of risk from interaction with the animal, and the handler.

Currently, most places have these kinds of visits on hold, which is reasonable in this phase of the COVID-19 pandemic. Fewer people coming in means fewer potential sources of infection. However, some programs are restarting, so thought needs to go into doing this safely.

What are the risks?

While we often try to get people to think about the various pathogens that pets (particular dogs in this case) can leave behind or pick up in these settings, right now the main risk with pet visitation programs is SARS-CoV-2 from the human handlers. This virus likes people a lot better than dogs – the COVID-19 pandemic is being propagated almost exclusively through human-to-human transmission. While there is some potential for dogs to be infected or for them to act as fomites (i.e. tracking virus around on their haircoats), the far greater susceptibility of people means that dogs are probably the lower-risk component of visitation teams.

Routine prevention measures:

  • Standard pet therapy program measures, as outlined in the 2015 SHEA guidelines on animals in healthcare facilities, are still key, with particular emphasis on making sure:
  • Handlers self-screen and are healthy before entering a facility.
  • Everyone involved pays close attention to hand hygiene. Patients should use hand sanitizer before and after animal contact. Handlers should use hand sanitizer before and after every visitation, regardless of whether they touched the person or any part of the person’s environment.

Added COVID-19 measures:

  • Ensure the patient has no signs of COVID-19 and is not being isolated. (Yes, that sounds like common sense, but you’d be amazed how often things like that get missed.)
  • Ensure the handler and animal have not had exposure to an infected person in the past 14 days.
  • Have everyone involved (that is to say the people, not the dogs) wear a mask.
  • Remember the 3 C’s to avoid: closed spaces, crowded spaces, close contact. (I also talk about a fourth C, “continuous,” with regard to time.)
  • Limit person-to-person contact. Handlers should stay as far back from patients as possible.
  • Have the visit outside in an open space, when possible.
  • Keep the visits relatively short – 15 minutes is typically used as the time when risk goes up.
  • Have handlers use a tracking app, like Canada’s COVID Alert app. Anyone involved with pet therapy in a region with an app like this should use it. It might help pick up exposure in a facility, but more importantly, it helps identify other community exposures, so exposed people know when they’ve been exposed and can suspend their visitation activities.
  • Stick to one facility. Some visitation teams typically visit multiple facilities. That’s probably best avoided, especially now. Teams should focus on one facility, to reduce the risk of cross-transmission.
  • Consider limiting visits to one person per team per day, especially as programs restart and while there’s less risk tolerance. Limiting a visit to a single patient each time reduces the risk of encountering or spreading the virus between patients.

How to respond to an outbreak or exposure

  • The key here is being able to identify exposed individuals quickly and easily. One recommendation we’ve had since our very first guidelines on pet therapy is keeping track of who gets visited when, and by whom. This has been very hard to get implemented, but it’s especially critical now. Tracking can be as simple as having handlers write down the date and the rooms/patients they visited, and leave the log with the facility as they depart.
  • An additional component of this tracking should be recording the duration of the visit, since the time spent with the infected person plays a role in determining whether exposure was likely.  With basic practices like hand hygiene, mask use, and distancing, it’s unlikely a handler would be considered exposed if they visited an infected patient for a short time. However, some visits could end up stretching beyond that typical 15 minute limit, and some could end up involving direct contact between the handler and patient. If the handler fits the criteria for exposure, the response would depend on the local public health directives for exposed people (e.g. self-monitoring vs isolation). However, given the severe implications of COVID-19 in most populations where pet therapy is used, handlers with any plausible degree of exposure should suspend visitation for 14 days. If a dog had direct contact with an infected person, then I’d isolate the dog for 14 days as well, to be safe.
  • Handlers also need to have an established means of communication with the facility and must be able to report illness. If a handler develops COVID-19 (probably acquired in the community, not during visitation), the person needs to be able to contact the facility as soon as possible, so they can then determine if any of the patients/residents might have been exposed, based on the timing of illness and visitation.

None of this is rocket science, or expensive. It’s use of basic infection control practices and good communication. Unfortunately, those are often lacking.

The risk from a well-run pet visitation program following these precautions is low, but not zero. There’s never going to be risk-free pet visitation. The key is limiting the risk as much as possible, while maximizing the benefits. The implications of tracking SARS-CoV-2 to, within or between facilities (especially long-term care homes) can be huge, so serious thought needs to go into when and how to restart these programs.

Rat bite fever (RBF) is an uncommon disease in people, but one that I nonetheless spend a lot of time talking about with owners, veterinarians, and physicians (and sometimes lawyers). It’s a bacterial infection spread by (you guessed it) rats. The causative agent of RBF is an obscure bacterium called Streptobacillus moniliformis, which lives in the mouth of most healthy rats.  It’s typically introduced into a person’s body via a bite from a rat. Usually people don’t get an infection after such a bite, but sometimes they do, and the consequences can range from mild to fatal. Most cases aren’t too bad and respond to treatment, even though treatment is often started later than it should have been (because many physicians don’t ask about animal contact and many patients don’t mention if they’ve been exposed to a rat).

It’s not clear how common RBF really is, especially because it’s not reportable (so no one formally tracks it) and it’s probably under-diagnosed anyway.

A recent study in Open Forum Infectious Diseases provides a bit more information about RBF, but it’s still pretty limited. The paper, “Rat bite fever in the United States: an analysis using multiple national data sources, 2001-2015” (Kache et al. 2020), concludes that it’s a rare disease. That’s presumably true; however, what they looked at were hospitalizations and emergency room visits. So, they can conclude that it’s a rare cause of hospitalizations, but that’s not necessarily the same as telling us how often it causes milder disease. Regardless, the study still provides useful information about the more serious cases of RBF.

Here are a few highlights:

Rat bite injury visits were 10.5 per million people. Hospitalization for rat bite injury was 0.27 per million.

  • That’s rare, but not unexpected.  Visits to an ER after a rat bite would be unusual since they don’t cause the same degree of trauma as for example, a dog bite.

Rat bite injury hospitalization rates were highest in females, people over 60 years of age and Blacks, as well as people from the Northeast.

  • It’s maybe easiest to explain the higher rate for older individuals, as they may be more likely to seek care after an injury. The others are tougher to explain. Knowing more about the type of rat bites would help. Pet rat vs wild rat exposures weren’t differentiated, and it’s certainly plausible that someone bitten by a wild rat would be more likely to go to an ER than someone bitten by their pet. There could be socioeconomic-related reasons for racial disparities in exposure to wild rats in urban areas.

The ER visit rate for RBF was 0.33 per million.

  • Again, that will be an underestimate of RBF, since it only includes people with RBF that go to the ER and are diagnosed and properly documented in the medical record (both potential issues).

RBF hospitalization was most common in people 19 years of age or younger.

  • That’s fully expected and consistent with the cases with which I get involved. One reason is that kids are presumably more likely to be bitten, based on how and how often they interact with animals. Young kids are more likely to get sick after exposure. Put those together, and an age predisposition is expected, as with many other pet-associated diseases.

Outcomes weren’t reported. Rat bite fever is typically easily treatable, but serious disease can occur. Sometimes that’s because the diagnosis is missed, but it can also cause rapidly progressive severe disease in rare cases, and even death.

For anyone interested, the paper has a lot more data about hospitalization rates, duration of hospitalization and costs, but I won’t get into those here.

The conclusion states: “For the medical community, clinical recognition involves enhancing awareness of RBF and the implications of this disease among pediatrics.” That’s a critical point, since RBF is a niche disease that can be overlooked by physicians (and veterinarians counseling owners about zoonotic disease risks). One of my typical talking points is about the need for physicians to query animal exposure ALL the time. This disease gets missed time and again because rat bites and rat contact get missed. Rat bite fever won’t jump to mind for most physicians examining a kid with a fever and rash, but if they ask about animal contact or the parent mentions it, there’s a good chance the diagnosis will be made. If not, it’s very unlikely. Asking a question about animal contact is free and takes a few seconds – there’s no reason not to do it.

As things change, both in the epidemiology of COVID-19 and our approach to containment, re-assessment of how we practice veterinary medicine and COVID-19 protection is important. The latest iteration of our guidance document has been released: COVID-19: A Guide to Reopening Veterinary Medicine in Ontario, Stage 3. As for the previous versions, this is a guide, not a standard – meaning it’s a document of recommendations and considerations, not a “standard of care.”

The guidance is designed for Ontario veterinary clinics, but much of it applies more broadly as well. Balancing the need to reduce SARS-CoV-2 transmission risk and the need to deliver practical, effective and efficient veterinary care is a challenge (I assume, as always, that I will get an earful of complaints from both sides of the spectrum).  A lot of factors need to be considered when deciding what to do in a particular clinic, including the epidemiology of COVID-19 in the region, clinic layout, clinic size, presence of high-risk individuals in the clinic, and risk aversion just to name a few. This document outlines the issues and some of the possible approaches, and hopefully will help clinics tailor their practices to find the right balance for them.

Previous versions of the guidance and other related documents can be found on the Worms & Germs COVID-19 Veterinary Resources page.

I’ve been away and need to catch up on some posts.  I was planning a nice non-COVID post, until a few seconds ago when I saw the CNN headline “Chinese officials say chicken wings imported from Brazil tested positive for COVID-19.”

My response… oh crap.

Not because I fear a wave of foodborne COVID-19. Rather, I fear a wave a paranoia about foodborne COVID-19 (and an overstuffed email inbox today).

According to the report, testing identified SARS-CoV-2 in a sample of chicken wings from Brazil. We have to realize that it’s most likely the testing was done by PCR, which is a very sensitive method that detects the nucleic acid building blocks of the virus (the RNA). That means it can detect live OR dead virus.  This virus does not live long outside its host, so it’s almost certain the virus (or more specifically pieces of virus) detected in the chicken wings wasn’t infectious.

How did the virus get there?

  • Likely from people handling the food. While research is still limited, this virus has not been identified in poultry, so a human origin is almost certain. That would fit with other recent reports from China of detection of SARS-CoV-2 on packaging of imported food. Infected people contaminate surfaces they touch.

Is there any risk?

  • Presumably no. Small amounts of this virus are probably common of surfaces in areas where the virus is circulating. The more infected people, the more contamination is likely. Yet, transmission risk still seems to be mainly from droplets and direct contact. The presence of viral “bits” on surfaces does not mean the presence of risk.
  • The risk from handling chicken wings is mainly from our run-of-the-mill foodborne bugs like Salmonella.

What should people do?

  • Pay attention to measures that we use to reduce the risk from our run-of-the-mill foodborne bugs like Salmonella, such as handwashing after handling raw meat, and cooking meat properly, and avoiding cross-contamination of food and surfaces in the kitchen. (If you want an extra level of protection, avoid sticking raw chicken wings up your nose.)”

There are a lot of things regarding SARS-CoV-2 to be concerned about. This isn’t one of them.

Around here, infection in dogs caused by Leishmania infantum typically comes up in the context of imported dogs, particularly those from countries around the Mediterranean (e.g. Greece, Israel, Spain).  This parasite is usually transmitted between a variety of mammalian species, including dogs and humans, by certain species of sandflies.  We’re quite lucky here in Ontario because the kinds of sandflies that transmit Leishmania don’t live here (yet), and we have yet to identify any local insect vectors that can do the same job.  There is still some risk of transmission from an infected dog to others, but it’s much more limited (e.g. direct handling of infected tissues by veterinary staff).  The other really concerning aspect of this disease is that it is very hard to completely clear the infection – so while acute episodes can often be treated, infected dogs are prone to recurrent bouts of illness throughout their lives, and remain a potential reservoir of infection for others (including people), even when infection is subclinical.

Despite the blood-borne parasite’s typical reliance on its favorite insect vectors, there have been instances of transmission within groups of dogs, possibly from breeding or fighting or other very close contact.  One outbreak in foxhounds in the early 2000s affected dogs in 18 states in the eastern US and even spilled over into dogs in Ontario and Nova Scotia, but fortunately there was no evidence found of infection in people in contact with the dogs.  Another report described a rather convoluted web of contacts between five dogs in Finland, two of which were infected with Leishmania while abroad, and resulting in infection of the other three.

Most recently, a case of leishmaniasis was described in a young Boxer dog born in California that had never been overseas (de Almeida et al. 2020).  There are a few notables from the case report:

  • The dog was 1.3 years old when it first presented, and while it had never been overseas, its dam had been imported from Spain, where canine leishmaniasis is endemic. (The dam reportedly died of an “unknown cause” the following year.)
  • It took a year and a half to finally determine that the dog’s illness was being caused by Leishmania (in part, no doubt, because it wasn’t on the radar for a dog that had never been to a high-risk area).
  • Despite multiple courses of antibiotics and other treatments, the dog’s condition gradually deteriorated and it eventually developed neurological signs as well. It was euthanized just over a year later, a little less than three years after it initially presented.

The authors concluded that the dog was likely infected through vertical transmission from its dam, since California is not currently considered an endemic region for this disease.  There are now several studies that have examined the ability for various species of sandflies that are found in certain states to transmit this parasite, which makes it all the more important to avoid creating a canine reservoir in the US through increased scrutiny and testing of imported dogs (and in this case their puppies as well).

I get a lot of emails about vet clinic access from a wide spectrum of individuals. This includes:

  • Owners who are upset they aren’t allowed in the clinic with their pet
  • Owners who are worried that their vet clinic isn’t doing enough to prevent transmission of COVID-19
  • Vets who want to know how to increase owner access to clinics safely
  • Vets who want to keep people out of the clinic as much as possible for safety
  • (And still some that just yell at me regardless what I say)

There’s no “one-size-fits-all” approach to veterinary medicine in the COVID-19 era. I‘ve written about different approaches before but since I get so many questions, here are some more thoughts.

Why can’t someone just say “here’s what all vet clinics should do”?

There’s too much variation between clinics. This includes things like the degree of COVID-19 activity in the region, local rules, staff and management risk tolerance, clinic size, waiting room and overall clinic layout, exam room numbers and size, and ventilation, among others.

What are the basic concepts of COVID-19 prevention in a clinic?

  1. Restrict access as much as possible
  2. Choreograph movements in the clinic
  3. Restrict close contact situations, especially in small rooms
  4. Use appropriate PPE

1. Restrict access

I’ve said to keep owners out “as much as possible” in the past. This has led to issues since “as much as possible” is very subjective, but I can’t really say more. There’s a cost-benefit consideration. Every time someone new comes into a clinic, there’s some risk. The more that happens, the more the risk. The better our other control measures are, the lower the risk (i.e. we can get away with more people in the clinic by doing everything else right).

We can limit access but still allow some people into clinics, with some preventive measures. There may be logistical reasons to let people in (e.g. owner walks to the clinic and would have to wait outside in -20C weather) or patient care reasons (e.g. something needs to be shown to the owner that can’t be done well remotely, euthanasia, patient for which curbside transfer might be risky) that are worth the limited increase in risk. There are many other situations where it’s not worth the risk. We can still do a lot with telemedicine, curbside drop offs and hybrid appointments (e.g. telemedicine appointment followed by a drop off for a quick in-clinic procedure like vaccination or blood sampling) where the owner doesn’t need to be present.

2. Choreograph movements

I was in a clinic the other day looking at traffic flow, and it’s a good exercise to try. It’s not usually too hard to come up with a logical flow system that creates one way traffic and avoids mixing of people… if numbers are limited. Minimizing the number of people who come into the clinic helps us optimize other preventive measures in the clinic. In combination with some floor markings, furniture re-arranging, designated direction of movement and designated entry/exit points, we can significantly limit contacts and decrease the risk of virus transmission.

3. Restrict close contact situations

Close contact. Closed spaces with poor ventilation. Droplet generating procedures like talking. Those are the high-risk situations for COVID-19 transmission, and they also happen to describe a vet clinic exam room. Time plays a big role in the amount of risk. Fifteen minutes isn’t a magical number, but it’s the one typically used to indicate the time that risk goes up. The smaller the space and the worse the ventilation, the higher the risk and the less time you should spend in it.

All those factors together show how the normal exam room visit needs to be rethought. To me, exam rooms are now “owner waiting spaces.” If the owner needs to accompany the animal into the clinic, they check in and are admitted directly to an exam room (again, the number of people in the clinic needs to be limited to some degree for this to work). Vet personnel come in and retrieve the animal, keeping chatting to a minimum, distance to a maximum, and everyone’s masked. A little conversation is fine and is good for patient care and the vet/owner relationship, but it should be distanced and short. The pet is then taken to a treatment area for examination and whatever needs to be done. Vet personnel can pop into the exam room or connect electronically to ask more questions or talk about things. The owner and pet are re-united in the exam room, and a short conversation can be had to explain or demonstrate things. If a demo is needed that requires restraint of the animal, someone from the clinic joins in so the owner does not have to help out, and can maintain distance from staff. (That’s still a potential issue because of the reflexive nature of owners jumping in to help hold, but that just needs some communication to head it off.)

4. Use appropriate PPE

As much as they are annoying, masks are critical. Masks need to be worn for any close contact situation, by owners and clinic personnel alike.


Lots of questions remain, I know. I’ll touch on a couple of them here but I’m sure there will be more to follow.

What do we do with the exam room after the owner leaves?

The room is ideally minimally stocked with easy to disinfect surfaces. Routine disinfection, focusing on owner contact surfaces (vs our previous focus on things like the examination table) is straightforward. A sign on the door indicating the room has been disinfected is useful and is good for clients to see.

What about the airspace in the exam room? Can the next person go right in?

That’s a tough one. We focus on droplet transmission and direct contact when it comes to SARS-CoV-2, but there is likely some risk from accumulated aerosols in closed spaces with poor ventilation (like an exam room). It’s probably limited in time and degree of risk, but we just don’t know. Most aerosols settle quickly out of the air so they’ll be taken care of with surface disinfection. However, should we leave 1 minute, 2 minutes, 5 minutes, or more between owners? Who knows. There are no recommendations for this kind of precaution in similar human healthcare situations, and I haven’t seen any real evidence of risk. A few minutes between occupancies, with disinfection performed after this brief waiting period, is probably reasonable, based on what we know (especially with good mask compliance, as masks reduce aerosol release).

How important is ventilation in the exam room?

More is better. Looking at how much airflow can be achieved in the clinic is useful, as better ventilation disperses and dilutes any aerosols that may be present. Ventilation rates of less than 3 L/s per person have been suggested as being high risk, and 8-10 L/s per person as being low risk. If you don’t know what your ventilation rate is and can’t figure it out, go with the “more is better'” approach.

Just some quick thoughts that I’m sure I’ll add to soon (and get more questions about).

Last spring, we posted about a report of alveolar echinococcosis (AE) in a child in Quebec from 2018.  This very serious parasitic infection is caused by the intermediate stage of the fox tapeworm, Echinococcus multilocularis (EM), which despite its common name is often also found in coyotes (including right here in southern Ontario), and it can infect dogs as well.  Canids typically become infected by eating small mammals like rodents that carry the intermediate form of the parasite in their organs, and then the infected canids pass the tapeworm eggs in their feces, which then infect more small mammals when they’re ingested.  The big problem is people can also become infected by accidentally ingesting these tapeworm eggs and go on to develop AE. In most cases of AE, parasitic cysts start to develop in the liver, and the cysts grow and spread like a malignant tumour.  The cysts can also appear in other parts of the body, but in any case it often takes years for a person to start showing any signs of illness.  By the time AE is diagnosed, treatment can be very difficult, and it may be impossible to remove the cysts.  Occasionally dogs can also develop the AE form of infection.

Now a new report has been released about an unusual case of AE in a child from northern Manitoba (Joyce at al. 2020).  There are several noteworthy points about this case:

  • The patient was only 12 years old. Cases of AE in children are uncommonly reported – only 4 of 559 patients in a European registry from 1982-2000 were children. Although children are generally more likely to have fecal-oral exposure due to poorer hand hygiene, because of the long incubation period for AE (5-15 years) people exposed as children might not be diagnosed until they are adults.
  • The patient did not have any parasitic cysts in the liver. In the same European registry, only 13 of 559 patients lacked liver involvement. The authors speculate that this could be due to the fact that the patient also had a large portosystemic shunt (an aberrant vein that allows blood coming from the intestine to bypass the liver).  However, the patient did have lesions in the kidney, lungs and brain, all of which were presumed to be parasitic cysts once the diagnosis was made.  It’s an important reminder that what usually happens doesn’t always happen.
  • The boy had a history of latent tuberculosis which was treated 10 years earlier, so initially the masses seen on CT and MRI were thought to be due to tuberculosis, until more tests were completed. You can see how this would be a challenging diagnosis to make.
  • The authors also report that two years later the child does not have any clinical signs of disease from the cysts, and/but regular imaging shows that the lesions have not changed for better or worse.

The paper also provided a very brief summary of recent epidemiological findings regarding EM in Ontario and western Canada.

Since January 1, 2018, EM infection in animals in Ontario is reportable to public health.  In 2019 there were three cases of fecal shedding of EM in dogs reported in Ontario, in Niagara, Durham and Kawartha Lakes regions (though one dog was recently imported and was likely infected before coming to Ontario).  No cases of AE in people in Ontario were reported in 2019.  Nonetheless, this is definitely a parasite for veterinarians and dog owners to keep on the radar.  Dogs that hunt and may consume small mammals, or that have a lot of contact with coyote feces, may be at increased risk of exposure.  The best way for people to avoid infection is (dare I say it again) don’t eat poop (in other words, wash your hands and practice good hygiene around food and drink), and try to reduce the risk of infection in dogs in the household.

More information about Echinococcus multilocularis can be found on the Worms & Germs Resources – Pets page, or check out the EM infographic from the Ontario Animal Health Network.