Worms & Germs Blog

Piranha Bite Response

Posted in Other animals, Other diseases

Yes, piranha bite response is a pretty niche topic. Nevertheless, it’s interesting (at least to me).

A recent paper in Pediatric Emergency Care (Berkowitz and Goldsmith. An unexpected fish bite. 2017) covers this topic. It starts off this way:

A 22-month-old boy presented to the pediatric emergency department with a missing right fourth distal phalanx [finger tip]. The story, according to his grandparents who were his guardians, was that they had been “fish sitting” for another one of their children and the child had put his hand into the fish tank. The fish, which, as it turned out, was a piranha, bit completely through the distal phalanx of the right fourth finger. The child’s grandfather reached into the tank, pulled out the piranha, gutted it, retrieved the intact piece of finger, and, along with the child, brought it on ice to an outside emergency department.

The question the authors decided to investigate was “Which antibiotics are appropriate?” since recommendations for treatment of animal bites are designed around bites from mammals, not fish. My initial thoughts were that you need to cover against bacteria that are water-associated (e.g. Pseudomonas, Aeromonas, Mycobacterium marinum), as well a those that live on human skin (since your own skin microbiota is a great source of infectious bugs). Not surprisingly, there’s not a lot of information in the literature about the best way to prevent infections after a fish bite (or whether antibiotics are even indicated). The authors came up with similar concerns, and that led to a discussion of the best drug, considering the desire for an oral option, effectiveness of common oral drugs against some of these bacteria, and potential issues using some drugs in young children.

Their overall conclusions included:

  • Standard bite-response antibiotics are not great options because they don’t do a good job against some of the water-borne bugs (mainly Gram negative bacteria). They’re more focused on preventing infection from skin bacteria (mainly Gram positive bacteria).
  • Despite concerns about not using fluoroquinolones when not clearly necessary, they figured ciprofloxacin best fit the bill as an oral option that covers the main risks.
  • The question of whether antibiotics are needed remains a case-by-case assessment, depending in large part on the bite location and severity.

Keeping little fingers away from piranhas wouldn’t hurt either.

Croc Stories, Times Two

Posted in Other animals, Other diseases

When I think about bad things that can happen from interacting with a crocodile, infectious diseases don’t jump to the top of my list (ingestion and amputation being the two first things that come to mind). That leads me to the first crocodile story (thanks Stephen), a rather light-hearted description that everyone but the bitten person might find funny (Fitzpatrick SJ and Thomas AL (2010). “Straight from the crocodile’s mouth.” Med J Aust). I’ll save the commentary and let you read it yourself here.

The other tale is a recent paper that showed wild crocodiles from Mexico had a high rate of antibodies against Leptospira (Perez-Flores et al, Ecohealth 2017). This bacterium is an important cause of disease in people. Infected animals can shed the bacterium in their urine, contaminating water sources and associated environments. Most people don’t have a high risk of being peed on by a crocodile, but it could happen to hunters or people catching crocs for conservation or ecological research. Exposure to urine-contaminated environments could be a concern for people who spend time in the same areas for recreation (including ecotourism) or for other activities (e.g. egg hunting).

The risk to people is probably pretty limited, and crocodiles are just one of many potential sources of Leptospira. So, the results of this paper don’t really change much, but they should remind us of the potential for exposure to this bacterium in wet environments, and they highlight the need for routine infection prevention practices (e.g. hand washing, not drinking untreated water, etc.).

Bordetella Infection in a Transplant Recipient

Posted in Dogs

It’s easy to write a series of posts about oddball infections. I often wonder whether it’s worth highlighting some of these rare disease reports since it’s possible for them to be taken out of context and unnecessarily freak people out. Yet, they often have a couple of useful messages.

A paper in an upcoming edition of Transplant Infectious Diseases (Powers et al 2017) describes Bordetella bronchiseptica infection in a kidney transplant recipient. This bacterium is typically dog-associated, although it can be found in a variety of species. The risk to people is very limited (as evidenced by how common it is in dogs and how rare reports are in people), but infections can occur.

In this case, a person who had a kidney transplant 15 years earlier was being maintained on drugs to suppress his immune response, putting him at increased of infection of any sort. He developed some non-specific signs such as fever and chills, which progressed to signs of respiratory disease, abdominal pain and diarrhea. Blood cultures were taken when he was hospitalized and he was started on antibiotics. Bordetella bronchiseptica was isolated from the blood cultures, and he was then switched to an appropriate drug. Fortunately, he recovered.

A dog source was considered, as is reasonable, and he owned 3 dogs. An interesting aspect of his history was that he had had skin biopsies taken recently, and the dogs had licked the biopsy sites. The combination of inoculation of saliva (a source of this bacterium) into skin wounds and his compromised immune system probably accounts for this rare infection. The dogs weren’t tested and there’s no mention of whether they had been sick or had high-risk contacts for acquiring Bordetella themselves.

In the grand scheme of things, this rare infection isn’t particularly important (unless you’re the person with the infection). But the accompanying message is important. As the authors concluded:

  • Health care providers should ask about animal exposure when taking the history of an SOT patient with a suspected infection. It also serves as a reminder to educate patients on immunosuppressive therapy to maintain good hygiene with pets, especially around open wounds.

It’s a pretty basic message (and one that’s repeated here a lot), but it’s important to keep saying it.

Petland Puppy Campylobacter Update

Posted in Dogs

Here’s some follow up information from the recent (and probably ongoing) outbreak of Campylobacter infections linked to puppies purchased at Petland stores in the US:

  • 55 infected people have been identified now. That’s probably just a fraction of the people who were truly infected, because of the number of steps that need to happen to get on the “identified” list. If someone gets infected, first that person has to be sick enough to go see a physician (many people will just ride it out if it’s not severe). The physician must request a stool sample for testing (not always done, especially if there’s nothing high risk in the patient’s history). The patient must then collect and submit the sample (lots of dropouts on this step). Then, the lab must identify the bacterium, which is perhaps the easiest step in the process. This multi-step pathway is why we assume that reported case numbers are usually dwarfed by the actual number of unidentified cases in an outbreak like this.
  • People from 12 US states have been infected. The greatest number were from Ohio (see map).
  • Of the 55 infected individuals:
    • 14  are Petland employees.
    • 35 recently purchased a puppy from Petland, visited a Petland or visited a home where a puppy from Petland lived.
    • 4 were exposed to puppies in other places.
    • 1 had contact with a person with confirmed Petland-associated illness.
    • One had unknown puppy exposure.

As you can see above, the link to Petland is pretty strong. Additionally, testing of the bacteria showed that Campylobacter from Petland puppies were closely related to those from sick people in multiple states.

Concerningly, Campylobacter from these cases generally appears to be resistant to first line antibiotics, something that presumably hampered initial treatment in infected individuals. This includes resistance to azithromycin, erythromycin, clindamycin and ciprofloxacin.

The ultimate source of the outbreak still hasn’t been found (or at least reported). Hopefully it will be identified both to find out what happened and to implement measures to prevent it from happening again.

Dangerous Dog Designations

Posted in Dogs

Dangerous dogs need to be addressed. Actually, it’s dangerous dog-owner pairs that are the issue, since there’s almost always a major human component to this kind of behaviour.  Unfortunately, we can’t mandate common sense.

Cities have taken a variety of approaches to the issue of dog bites and dangerous dogs, ranging from nothing to breed bans. Dangerous dog designations are another approach. Toronto enacted a bylaw earlier this year that defines a dangerous dog as one that has severely bitten or attacked a person or pet, or that has delivered non-serious bites twice (or more). In the first 6 months, this has resulted in designation of 91 dangerous dogs (with German Shepherds leading the way).

Do bylaws like this have an impact on dog-related injuries? I’m not sure we know.

A concern I have with a designation based on the number of times a dog has inflicted a bite is that it risks driving things underground in terms of reporting. While rabies in dogs is very rare in Canada, we have to think about it with any dog bite. That means that every bite should be reported, so that the proper measures can be taken.  The first option is almost always to observe the dog for 10 days – if it’s normal at the end of that period, then it couldn’t have transmitted rabies virus with the bite at the beginning.

Bringing in penalties for dogs that bite complicates matters, as it makes people less likely to report such incidents. I had a conversation with an owner the other day about a bite. It was a minor bite that occurred during a veterinary procedure (not at our hospital) and we were talking about the need to report it. One of the things I said was “It’s not a big deal. Public Health needs to know but it’s not like the police are gong to be called or anyone’s going to call your dog a dangerous animal.” I can’t necessarily use that line with people from Toronto now, and I suspect it will lead to people who are aware of the new bylaw to be reluctant to report bites. As a veterinarian in Ontario, I’m bound by provincial legislation (as are others) to report bites, but we know that these injuries are massively under-reported, including by vets. In Toronto, this could make it worse.

I’m not against dangerous dog designations, and a clear, objective approach is nice, but if it takes and thought process and wiggle room away, that’s a problem.

A dog that lunges at someone and bites them while on leash as they’re walking dog the street.

  • That’s a problem

A dog that bolts from its yard or owner to attack a kid.

  • Yep, big deal.

With both of these, if the dog only inflicts a “minor” bite, it wouldn’t be captured under the Toronto policy (until the next bite). That’s not ideal.

A dog that has a sore leg that someone grabs and it nips in pain.

  • Not good, but perhaps understandable and not an indication of a lifelong threat. Yet, it’s one strike out of two for the dog, and if it’s deemed a severe bite (no definition provided), it’s an automatic designation as dangerous.

Each bite and each dog are different, and I guess the take home is there’s no perfect approach. A case-by-case approach directed by someone knowledgeable would be the best way to handle this, but it’s unlikely to happen.

Hurricane Harvey Dog Adoptions

Posted in Dogs

Countless people have asked me to comment about the movement of Hurricane Harvey dogs from Texas into Ontario (and other regions). Okay… I’ll bite.

As frequent readers know, risks posed by importation of animals is an interest of mine. A large reason for this is the infectious disease problems that occur, including things I’ve seen here in Ontario (e.g. widespread distemper in rescue dogs from China, heartworm in dogs from the southern US) and broader issues (e.g. importation of H3N2 canine influenza into the US from Asian rescue dogs, importation of rabid dogs). Anytime animals are moved from one region to another, there’s a chance that infectious diseases go with them. The farther apart, both geographically and in terms of the infectious agents that are present in the area, the greater the risk. That doesn’t mean movement is always bad, but it means we need to think about the when, why and how of the process.

I have no doubt about the sincerity and good intentions of most groups that are involved in shipping dogs out of Texas. They see a problem that they want to help address. But do they adequately understand all the issues?  That’s an important question.  Infectious diseases are a big concern because we know they get imported with dogs in situations like this.

Another thing to consider is the potential disruption caused by having even more volunteers in a disaster zone. I’ve talked to emergency responders and disaster relief coordinators in the past, and often the well-intentioned people who come to help end up causing more problems, simply because they add more people to an already chaotic situation and they take up more resources (e.g. food, housing, fuel).

While it shouldn’t always come down to money, the cost benefit needs to be considered. A local rescue agency announced they had raised another ~$30,000 and wanted to go back and get more dogs. The shelter system in Canada isn’t exactly flush with cash (or depleted of animals). How much good could that money do at home, and how many more animals could benefit? As one writer to me stated, the US is the wealthiest country in the world. Do they really need Canadians driving down to help them with a few dozen dogs?

It’s great for the dogs that are adopted, no question. There tend to be massive waiting lists to adopt dogs from high profile rescues like this (with less interest in the “boring” local dogs).

Is it great, in the big picture?

  • Does importation of dogs result in more dogs going into homes, or does every imported dog that finds a home mean that one local dog in a shelter is euthanized because there’s no one to take it? (Or even that more than one dog is euthanized because there aren’t enough funds to care for them?)

At a minimum, there needs to be more attention to how these dogs are obtained, how they are screened prior to importation, and how they are managed after they get here. Unfortunately, odds are good that problems will be imported along with the dogs.

Campylobacter Outbreak From Puppies

Posted in Dogs, Other diseases

Cute. Frustrating. Cuddly. Biohazardous

All of these apply to puppies. It’s well recognized that puppies (and kittens) pose increased infectious disease risks, for a few reasons. These include a higher likelihood of shedding various pathogens, greater environmental contamination when they poop on the floor (or anywhere else) and a tendency to cause minor bites and scratches. That’s not meant to deter people from getting a puppy or a kitten, but it’s important to understand risks to mitigate risks.

Another issue with puppies (and other pets) is the potential for widespread dissemination of certain pathogens when animals are mixed in large breeding operations, warehouses and other mixing points. This allows for more transmission of pathogens and dissemination over wide areas when the animals are sold/dispersed. The way some of these animals are handled and shipped also contributes to stress, which can presumably increase the risk, when compared to low animal density individual breeders with more hygiene, less mixing and less stress.

An ongoing outbreak of (human) Campylobacter infections in the US brings some of these issues to mind. As of September 11th, 39 cases have been identified in 7 US states (see map below). Interestingly, a link to Petland, a national pet store chain, has been made. Twelve affected individuals are Petland employees, and 27 purchased a puppy from Petland, visited a Petland or visited a home where a Petland-origin puppy was present. Whole genome sequencing of Campylobacter isolates from puppies from Petland in Florida indicated that the isolates were closely related to those from a sick person in Ohio, supporting interstate dissemination and a related source.

The link to one pet chain is interesting, since it would suggest that there was some common source, be it a large breeding operation, animal distribution centre or other mixing place. No information about the puppy sources or handling is provided, so it’s hard to say what the sources might be.

Regardless of the specific Petland situation, it’s a useful reminder that any puppy or kitten can be biohazardous. I suspect that puppies from large pet distribution systems, puppy mills and pet stores pose more risk because of the stress and mixing, along with potentially dodgy background, but any puppy will pose some risk. We’re also more likely to identify cases from large operations since a common link can be established, so we shouldn’t focus too much on just reported outbreaks.

That means there’s a need for good hygiene practices, such as hand washing, proper fecal handling, good cleaning and disinfection after fecal accidents in the house, and a concerted effort to house train pets ASAP. Recognizing who is at higher risk (young kids, elderly individuals, immunocompromised persons, pregnant women) and having them take special care around puppies (and kittens) is also important.

More information about Campylobacter can be found on the Worms & Germs Resources – Pet page.

One More for the Oddball List…Infections From Guinea Pigs

Posted in Pocket pets

A series of strange but rare infections or the sign of a new problem? That’s always the question we have to think about when there’s a report of a new disease. Determining that can be a challenge, and often “time will tell” is the true answer.

A paper in the most recent edition of the New England Journal of Medicine (Ramakers et al. 2017) gives us one more for the list, and involves a species we don’t talk about much in terms of zoonotic diseases: guinea pigs.

The report describes 3 people with Chlamydia caviae infection, a bacterium associated with guinea pigs that has been considered pretty harmless to people. However, the case series details 3 cases of infection in otherwise healthy adults in their 30s, a group that’s not high-risk for infections from low-risk bacteria such as C. caviae. All 3 developed severe pneumonia, and two of them ended up in ICU on ventilators. This compounds the surprise and concern, because infections by bacteria that rarely cause disease in people usually manifest as mild disease. That was the situation with the only previous report of C. caviae infection in a person, where mild conjunctivitis was the only clinical problem.

Fortunately, all three patients ultimately recovered.

There was no link between the individuals themselves, and the cases occurred over a three year period. A guinea pig link is assumed because of the association of this bacterium with guinea pigs. One patient’s guinea pig had signs of respiratory tract disease before the person got sick, and (unlike most reports), there was an investigation of the animal. C. caviae was isolated from the guinea pig, and it was identical to the strain found in the person. That’s pretty convincing evidence.

A few questions remain:

  • Were there more people affected? Most people with respiratory tract disease don’t get tested for the presence of bacteria like this. That’s especially true with milder disease. So, are these cases a unique series, or do they represent a small subset of the total number of infections that occurred?
  • Is this a new problem or was it simply found because of better current-day diagnostic testing? Surveillance bias (i.e. the apparent increase in a disease because we are looking more or looking better) is a common issue.
  • What do we do now? Does this change how we approach guinea pigs?

The last question is an important one, and one that doesn’t come with good answers. For me, the take home messages would be:

  • Guinea pig contact poses some infectious disease risk, like contact with any animal.
  • Animals that are sick usually pose more risk.
  • A guinea pig with respiratory disease should be approached with an increased level of hygiene and infection control (e.g. no kissing, good hand washing) in case it’s C. caviae.
  • Veterinarians should be aware of the risk (albeit probably very low) so that they can counsel owners and take necessary precautions themselves when handling guinea pigs.
  • Physicians need to query pet ownership/contact and recent events of pet illness when presented with a sick patient.
  • Contact with a guinea pig with respiratory disease should be reported to the physician if a person develops signs of respiratory disease, and C. caviae infection should be considered.

Small Turtles + Kids = Salmonellosis…No Surprise Here

Posted in Reptiles, Salmonella

It’s not a shocker, but another multistate turtle-associated outbreak of salmonellosis has been ongoing in the US. CDC has reported on an outbreak of Salmonella Agbeni infections involving 37 people in 13 states. As is almost always the case, the number of reported infections is probably a small fraction of the number of people who actually got infected.

Here are some of the highlights:

  • Cases were reported between March 1 and August 3, 2017 (and are probably ongoing).  The map below shows the case distribution by state.
  • Almost half of infected individuals have been hospitalized. That’s a pretty high percentage for an outbreak like this.
  • As is typical, kids bear the brunt of the problem, with 32% of infected individuals being 5 years of age or younger.
  • Contact with turtles or their environments in many of the infected individuals was identified. Those without reported turtle contact probably still had direct or indirect contact somehow that they either didn’t know about or didn’t recall.  This Salmonella strain is rare and the close genetic relatedness of the Salmonella isolates from affected people is consistent with a common source. Furthermore, this Salmonella type was found in turtles from a street vendor in the US in 2015.

Salmonella is not uncommon in reptiles, particularly turtles. Turtles are often implicated in outbreaks because they are common pets (despite a long established and flouted US ban on the sale of turtles with shell lengths less than 4 inches). Small turtles are a major issue because they can be handled easily by small children.

The report concludes:

All turtles, regardless of size, can carry Salmonella bacteria even if they look healthy and clean. These outbreaks are a reminder to follow simple steps to enjoy pet reptiles and keep your family healthy. This outbreak is expected to continue since consumers might be unaware of the risk of Salmonella infection from small turtles. If properly cared for, turtles have a long life expectancy.

More information about turtles and Salmonella can be found on the Worms & Germs Resources – Pets page.

West Nile Virus in Ontario Horses

Posted in Horses

Two Ontario horses have recently been diagnosed with West Nile virus infection, prompting the equine health advisory below from the Ontario Ministry of Agriculture Food and Rural Affairs. That’s not too surprising, as now is the typical time of year that we start seeing this mosquito-borne infection in Ontario. West Nile numbers in both humans and horses tend to vary year-to-year. There’s been some suggestion that this might be a bad year for West Nile virus based on mosquito pool testing, but predicting West Nile infections is far from an exact science, as a multitude of different factors are involved.  Only time will tell whether it’s going to be a bad year or not.

Regardless, West Nile remains a relatively rare disease in Ontario, but one that’s best avoided if possible. That involves mosquito control and mosquito avoidance, for both horses and people.