Worms & Germs Blog

Raccoon Roundworm Infection

Posted in Other animals, Parasites

Backyard raccoonThe August edition of Emerging Infectious Diseases has an interesting case report of Baylisascaris procyonis infection in a California man (Langelier et al. 2016). Baylisascaris procyonis, commonly known as the raccoon roundworm, is a parasite that is very commonly found in the intestinal tracts of raccoons. Massive numbers of parasite eggs can be found in areas where raccoons congregate to defecate (raccoon latrines). When a person ingests these eggs and they hatch, the parasite larvae can migrate throughout the body, particularly the brain, and cause significant damage.

This report details infection of a previously healthy 63-year-old man. His course of disease included 2 weeks of progressive fatigue and neurological abnormalities (e.g. confusion, headache, trouble moving his arm and head). He was hospitalized and continued to deteriorate. A sample of CSF (the fluid that surrounds the spinal cord and brain) had a few abnormalities, including an increase in eosinophils, a cell type that is often found in allergic and parasitic diseases. This led the physicians to consider an additional range of possible causes, and to ask some important questions. This questioning led them to discover that, among other things, the patient had recently undertaken a project under his house, where raccoons had been observed. As a result, they considered the potential for B. procyonis and started treatment while awaiting test results. Results were ultimately positive for the parasite.

A few noteworthy points:

  • It’s impressive that they considered B. procyonis. It took until eosinophilia was identified in the CSF to ask the critical questions about exposure, but at least they were asked fairly early in the process. This is a rare infection that wouldn’t normally jump to mind. A good history that included potential direct and indirect animal contact was the key. If they hadn’t gotten information about potential exposure to raccoon feces, they probably wouldn’t have tested. A good history goes a long way, but history-taking sometimes seems like a lost art.
  • Disease from this parasite in an otherwise healthy adult is very rare. Most of the small number of infections of which I am aware have been in young kids or kids with behavioural issues that made them higher risk for ingesting strange things like raccoon feces. Inadvertent exposure of a relatively healthy adult is unusual.
  • The patient responded reasonably well to treatment, particularly when compared to the usual (devastating) outcome. Whether this was because he was an adult, the infective dose was low, treatment was started early or he was lucky is unknown. It’s encouraging though, and another reason that getting a good history early in disease is so important. Early diagnosis (or even early consideration of infection) can lead to early treatment and better outcome.

Eastern Equine Encephalitis Season in Full Swing

Posted in Horses, Other diseases, Vaccination

‘Tis the season for mosquitoes, so ‘tis the season for some nasty vector-borne diseases. Few are worse that Eastern Equine Encephalitis (EEE), a viral infection that causes typically fatal disease in horses, and less commonly other species, including people. Cases tend to start mid-summer and peak late summer to fall, depending on the mosquito dynamics in the particular area.

This series of maps from WormsAndGermsMap (below) shows the progression of this disease in horses along the east coast of the US so far this year. Note that some flags represent multiple cases that occurred in the same area, so just counting flags doesn’t tell you the whole story.

I haven’t seen any reports of EEE in Canada in 2016 – yet. It’s a rare disease here but we often see a handful of equine cases each year.

Prevention

For horses, there is an effective vaccine. Vaccination is recommended in horses that live in (or travel to) typically affected areas. In areas where occurrence of EEE is rare but still plausible, it’s a good insurance policy, considering the safety of the vaccine and serious nature of disease, but it’s not considered a “core” vaccine.

The other important part of prevention is mosquito avoidance. That’s easier said than done, to some degree, but there are a number of things that can be done to reduce mosquito exposure, thereby reducing the risk of EEE as well as other mosquito-borne diseases (e.g. West Nile).

For people, the key is mosquito avoidance. A human vaccine is not available.

We haven’t heard the last of EEE this season, and we probably haven’t even neared the peak, unfortunately. The map is updated as cases come in so check WormsAndGermsMap for updates at any time.

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Move Over mcr-1. You’re Old News.

Posted in Other animals, Other diseases

Recent identification of mcr-1, a gene that makes bacteria resistant to colistin (an antibiotic of last resort) raised a lot of concern. Now, there’s another one to be worried about, as a related gene, mcr-2 has been identified (Xavier et al, Eurosurveillance, July 2016).

In this study, 105 colistin-resistant E. coli from calves and piglets in Belgium were studied. mcr-1 was found in 12% of these. They then looked at 10 of the bacterial isolates that were colistin-resistant but negative for mcr-1. They found a new resistance gene related to mcr-1 (and not surprisingly named it mcr-2) in 3 of the isolates.

That’s bad enough.

Of additional concern is that the gene was found on plasmids, which are  smaller pieces of DNA (separate from the bacteria’s chromosomal DNA) that can be transferred readily between bacteria. They found that mcr-2 had a 1200-fold higher transfer frequency compared to mcr-1 on its plasmid, meaning (under lab conditions, at least), that it’s much more adept at moving between bacteria. If it truly can more readily hop to other bacterial species (and therefore potentially more disease-causing bacteria), that’s even more concerning.

Does this mean that we’re seeing a rapid rise in colistin resistance genes?

Probably not. The bacteria from which mcr-2 was isolated were collected in 2011-2012. The increase in recent reports is most likely a factor of an exponential increase in people looking for colistin resistance in bacteria from animals and people. mcr-3 and 4 are probably lurking in the gut of a person or animal somewhere, they just haven’t been described yet.

Is this really a concern?

Yes. While the number of people that will be infected with bacteria possessing these genes will hopefully remain low, these raise the spectre of the “untreatable infections.” When your drug of last resort is gone, you’re in big trouble.

What do we need to do?

There’s no simple answer. A lot involves common sense, good infection control, infection prevention and prudent antibiotic use. These will help reduce the number of infections of any sort, and with fewer infections, along with less (and better) antibiotic use, the spread of resistance genes like this can likely be reduced. They’re not going to be eradicated, but if we can keep them contained, their impact can be lessened.

The authors’ conclusion: Taken together, these data call for immediate inclusion of mcr-2 screening in ongoing molecular epidemiological surveillance to gauge the worldwide dissemination of mcr-2 in both human and animal colistin-resistant Gram-negative bacteria of medical importance.

mcr range

Figure from Xavier et al, Eurosurveillance 2016

Capnocytophaga Back in the News

Posted in Dogs

Dog tongueCapnocytophaga canimorsus is a bit of an obscure bacterium. When I talk about it to veterinary or physician audiences, I’m usually met with blank stares – not surprising, since it’s not really mentioned in veterinary or medical school, from what I can tell. It’s a rare cause of infection, but a nasty one. The fact that it’s present in almost all dogs’ mouths and can cause fatal infections in people (especially people that are lacking a spleen or have a compromised immune system) makes the approach to managing it challenging. Virtually every dog poses some risk of a fatal infection, but the overall risk is very low.

The latest report about this particular bug is entitled “Lick of death: Capnocytophaga canimorsus is an important cause of sepsis in the elderly” (Wilson et al. BMJ Case Reports 2016).

The title is pretty misleading.

  • First, it should be noted that the patient survived the infection (but sepsis is very serious).
  • “important cause of sepsis” hardly applies to something that’s so rare that a single case warrants a publication.
  • There also wasn’t any proof that a lick was the source; however, it’s a reasonable assumption.

Regardless, the report describes the case of a 70-year-old woman that developed C. canimorsus sepsis (overwhelming bloodstream infection). She owned an Italian greyhound, and while no bites or scratches were reported (which doesn’t necessarily mean they didn’t occur), the dog licked her frequently. It was assumed that the source of exposure was a lick from the dog.  The bacterium would have had to enter the body through some broken skin, or through a mucous membrane (e.g. if the dog licked her face a lot and saliva got in the woman’s eyes, nose or mouth – not unheard of, unfortunately).

This report has lead to a variety of news articles (some straightforward and some very much over-the-top) about the risks associated with licking from pets.

Yes, licking is associated with some risk, but so are many other things in life that we do on a daily basis. I get asked about licking all the time. My standard response is that I don’t like my dog licking me, but that’s not a germaphobic thing, I just don’t particularly like it. For most people, the risk from being licked by a dog is low, but in some situations it’s higher, including:

Typical high risk groups: young children, elderly individuals, people with compromised immune systems and pregnant women. The highest risk groups for this bug in particular are people without a functional spleen and alcoholics. More care (or complete avoidance) should be taken by them.

Licking around the eyes, nose, moouth, ears and open wounds: this is riskier than licking intact skin.

Also remember that a little washing goes a long way. If there’s concern about saliva exposure, washing the site after an inadvertent lick probably helps a lot.

The “learning points” from the article are good:

  • Capnocytophaga canimorsus is a rare but significant cause of fulminant sepsis in pet owners.
  • Identification of C. canimorsus is facilitated by clinical suspicion and requires close collaboration with microbiology colleagues.
  • Infection may occur following close contact with a dog and does not require overt scratch or bite injuries.
  • Increased pet ownership and age-related immune dysfunction are thought to confer higher risk in the elderly.
  • Bacterial zoonoses from common household pets are frequently missed diagnoses.

For more information about this potentially nasty bug (and many others), check out the information sheets on the Worms & Germs Resources – Pets page.

Classroom Pets Going Home for the Holidays

Posted in Other animals, Pocket pets, Reptiles

My kids come home from school with lots of consent forms. Last week, one came home asking permission to enter Erin into the draw to see who gets to take home their Grade 3 class fish (Lord Bubbles). She didn’t win the draw, but it fit with a recent article in the Toronto Star entitled “Classroom pets head home for the holidays”.

Classroom pets are an area that has been minimally studied from animal welfare and zoonotic disease standpoints. Problems such as infectious diseases (mainly Salmonella from reptiles), bites and scratches definitely occur, but there can also be positive impacts, particularly when pets are brought into learning activities or when kids have no pet exposure at home. As with most things, it’s a balancing act, managing the risks and maximizing the benefits. How to actually do that (and whether any thought goes into it in most classrooms) isn’t clear.

Adopting out classroom pets is usually necessary. If the teacher won’t take the animal home, someone else has to. I suspect there’s often little prior communication with parents – “look what I brought home Dad!” is probably a common way this happens. Ideally, there’s some advanced planning and education of the prospective adopters before the animal goes home. The gecko shown in the picture with the Star article highlights a high-risk species (a reptile), so hopefully there was some consideration of whether the household to which it was going included any high-risk individual (e.g. pre-school age kids) and some information was provided about animal care, including zoonotic disease risks and how to mitigate them. Unfortunately, those thought processes aren’t particularly common. That’s one reason we have info sheets for various species on the Worms & Germs Resources – Pets page.

Most classroom pets are low-risk and adopting them can be beneficial all around. A little education and some common sense go a long way.

Photo: Jennifer Pyz, thestar.com

Clean Hands Save Lives: Horsey-Style

Posted in Horses

Infection control isn’t rocket science. Wash your hands, don’t eat that, keep your finger out of your nose… things you learned in kindergarten go a long way to preventing infections. The basic nature of the core infection control concepts is also a barrier – hand washing isn’t fancy, new or associated with some fancy machine. (There is actually “an app for that,” but it can’t get people to wash their hands, it’s only used for recording whether or not they do.)

Clean hands save lives” is more than a slogan, it’s a fact. Whether it’s a human, horse, dog or any other species, hands are important sources of bugs that cause infections. That’s why a lot of effort is put into getting people in human and veterinary hospitals to improve hand hygiene compliance; something we know (in large part from Maureen’ s work) isn’t great in veterinary medicine.

On the equine side, here are a couple of new hand hygiene posters – perfect for posting in equine clinics, but also excellent reminders in any barn, boarding facility or competition venue where horses are brought together.  More information and resources will be coming soon to the veterinary hand hygiene website.  Remember, “Clean hands – Safe Animals“.

Worms and Germs Map Update

Posted in Cats, Dogs, Horses, Parasites, Rabies

A few years ago, we launched WormsAndGermsMap to help track certain emerging and endemic diseases. Data are entered by participating veterinary clinics, surveillance programs and the WormsAndGerms team. While we certainly can’t capture every case, we do collect some interesting information about the presence of certain diseases.

Using the “Report Filter” bar on the left, you can filter by disease, animal species and date.

For those who haven’t visited the Map (yet!), here are some screen shots from a few selected diseases – check out the website for lots more!  Clinics interested in participating by submitting cases for the map can register using the link at the top of the page.

Rabies

Equine herpesvirus myeloencephalopthy (EHM)

Canine lungworm in Ontario

Equine influenza in the UK

Canine Importation Working Group Recommendations, and Rio2016 Adoptions

Posted in Cats, Dogs

Last year, a Working Group was established to review the issue of importation of dogs into Canada and to come up with options and recommendations to:

  • Mitigate the risks to animal health (domestic and wildlife) and public health posed by the current system through which dogs are imported from abroad.
  • Mitigate the same risks posed by unmonitored movement of animals within Canada (particularly from remote northern regions)
  • Address animal welfare issues with regard to transportation of companion animals exhibiting clinical signs of illness within and at Canadian borders.

Stray puppyThe report of the working group has now been released; to view it, click here.

The time might be right to be thinking about this topic again. We saw large numbers of “Sochi” dogs shipped out of Russia after the 2014 Sochi Olympics. Already, people are talking about “Rio 2016” dogs. The Rio 2016 Olympic Committee is actually running a program to adopt stray dogs from Olympic venues and find homes for them – in Brazil.  That’s great. “Rio 2016” becoming the next fad pet in other countries wouldn’t be so great.

The report doesn’t say importation shouldn’t be allowed. However, there’s a need to make sure it’s done better to minimize the risks to the imported dogs, to local dogs and to people.

Will anything come from this report? Only time will tell, but hopefully it will lead to more discussion and ideally some changes in regulations to reduce the inherent risks of importation.

Worms & Germs is now on Facebook too! Find us there @wormsandgermsblog.

Raccoon Road Trips and Raccoon Rabies

Posted in Rabies

When raccoon rabies re-emerged in Ontario last fall, one of the big questions was “where did it come from?” It had been eradicated from the province and control measures were in place at the borders to reduce the risk of re-introduction. It was assumed that a rabid raccoon hitched a ride across the border from northwestern New York state and made it into the Hamilton region (outside the border area where rabies prevention measures were greatest).

Further genetic analysis of the raccoon-variant rabies virus that was found in Hamilton has essentially confirmed that it did indeed come from New York state, but it doesn’t seem to be from the closest border area as expected. As reported by the Canadian Press, Susan Nadin-Davis, a researcher with the Canadian Food Inspection Agency, compared the genetic sequence of the Hamilton virus with strains from different parts of the northeastern US. Surprisingly, “the virus is closely related to a strain from southeastern New York state, and quite distinct from the strains found closer to the border.”

Rather than a (still impressive) hitch-hike of 100 km or so from northwestern New York, past the rabies control zone in the Niagara Region and into Hamilton (where it infected other raccoons and and then spread into the skunk population as well), the index animal’s road trip was likely more like 500 km.

That road trip has caused a big problem in Ontario, with ongoing transmission in the raccoon and skunk populations (128 cases detected at last report) and a widening control zone (that now includes where I live).

For more information on rabies in Ontario and a full series of maps showing to the progression of detected cases to date, visit the OMAFRA rabies website.

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