As expected, rabies continues to be an issue in Ontario following the emergence of raccoon rabies in the Hamilton area in late 2015, and a separate emergence of fox rabies northwest of there around the same time. Hopefully raccoon rabies will be eradicated, as it was the first time it entered the province (1999-2005), but it’s a multi-year (and expensive) process.
We don’t know how common rabies is in the bat population, since most testing of bats is sporadic and focused on bats with which people have been in contact (a group that doesn’t likely represent the overall bat population). However, we know it’s there and we know it’s widespread. We know that people get exposed to rabid bats. Most importantly, while bat-associated rabies in people is rare overall (especially compared in dog-associated rabies in Asia and Africa where canine rabies is endemic), exposure to rabid bats is still an important cause of human rabies in Canada and the US.
The risk of bat rabies was highlighted by the recent death of person in Florida. I haven’t seen many details but it’s been reported in the news that a person from Highlands County, FL, died of rabies, most likely transmitted by a bite from a bat.
Bats are an important reservoir. Any bite (or potential bite) from a bat must be considered a potential rabies exposure unless the bat is tested and shown to be negative. Because bat bites don’t cause much trauma, they’re easy for people to ignore. If anything, increased awareness is needed. On the flip side, paranoia is also bad, and exterminating normal healthy bats also makes no sense as they play an important role in natural ecosystems, and it’s not an effective way to control the risk of rabies. People need to know that there is a risk of rabies from bat encounters, and who to contact (i.e. public health) should contact occur. The same risk applies to domestic animals – if your dog or cat has come into contact with a bat, contact your veterinarian for advice on booster vaccination for the pet and potential testing if the bat is available.
Hardly a week goes by that I don’t get a question (or a dozen) about backyard poultry. As more cities consider or enact laws allowing urban poultry, the debates about and around this issue increase. It’s also becoming a big business, with ample options for people to buy chicken coops (or high end chicken condos), birds and other accessories. (I won’t even get into chicken diapers).
There are arguments for and against keeping backyard poultry. As the CDC states, “Owning backyard chickens and other poultry can be a great experience. However, children and other groups of people have a greater chance of illness from handling live poultry or anything in the area where they live and roam. Even handling baby birds displayed at stores can cause a Salmonella infection.”
Infectious disease risks often get dismissed, but they are very real, as US data show. Here are the final results from CDC’s investigation of multistate outbreaks of salmonellosis from backyard poultry.
- Perhaps not surprisingly, as backyard chickens become increasingly popular, 2017 saw the largest number of infections linked to backyard poultry.
- 1120 infected people were identified. That probably represents only a small fraction of true cases, since most infections are not identified and reported. Even if that’s not the case, it’s still an impressive number.
- Cases were identified in 48 states and the District of Columbia. California led the way with 61 cases.
- 249 people were hospitalized. 1 died.
- Several different Salmonella types were involved, as would be expected.
This doesn’t mean that backyard poultry are necessarily all bad; however, it reminds us that there is some degree of risk that comes with keeping them. That risk is higher in certain populations (e.g. young children, elderly individuals, pregnant women, immunocompromised individuals). If those people have contact with backyard poultry or their environment, they are at greater risk of getting sick.
People considering getting backyard poultry need to consider the risks, and whether anyone in the household or anyone who visits is at increased risk. Basic precautions / measures can help reduce the risk, but some degree of risk will always remain. CDC’s recommendations are along these lines… basic practices that can be easily implemented (but which are often ignored):
- Always wash hands thoroughly with soap and water right after touching live poultry or anything in the area where the birds live and roam.
- Adults should supervise handwashing for children.
- Do not let live poultry inside the house.
- Do not let children younger than 5 years handle or touch chicks, ducklings, or other live poultry without adult supervision.
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.
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.).
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.
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 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.
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.
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.