Worms & Germs Blog

Rabies from a mongoose bite

Posted in Other animals, Rabies, Vaccination

Yellow mongooseEvery few days, it seems, I get an email or call that goes something like “I was just bitten by [insert various mammals here]. Do I need to worry about rabies or do anything?”

The answer’s pretty similar every time. While the relative risk posed by different animal species in different geographic regions varies, you have to think about rabies anytime you’ve been bitten by a mammal. Knowing what to do can save a lot of hassles, and maybe your life. While the likelihood of rabies exposure from a bite in most countries is very low, ignoring or not being aware of this low risk leads to deaths.

CDC’s Morbidity and Mortality Weekly Report Recently published an article about a rabies death in Puerto Rico from 2015 (Styczynski et al 2016). The affected person was a 54-year-old man who initially presented to the ER with fever, difficulty swallowing, tingling in a hand, cough and chest tightness. He died the next day. Upon further investigation, his wife reported that he had been bitten by a mongoose approximately 2 months earlier. However, he did not seek care for the bite. Rabies was confirmed on autopsy. After an investigation of his contacts, seven family members and two healthcare personnel received rabies post-exposure prophylaxis (PEP).

Mongooses are a rabies reservoir species in certain areas, and rabies is very common in mongooses in Puerto Rico. An astounding 97% of mongooses that were tested after biting a person between 2005-2008 were positive for rabies. Not surprisingly, rabies PEP is recommended after mongoose bites, as it is for bites from other rabies reservoir species (e.g. raccoons, skunks, foxes, bats) in other regions.

If this bite had been reported, it’s virtually guaranteed that the man would have received PEP, and with that, it’s virtually guaranteed that he would not have developed rabies. There are a number of reasons why people don’t get appropriate care following a bite from a potentially rabid animal. In some regions, it’s because of poor access to medical care, or little to no supply of the rabies vaccine and rabies antibodies required. That’s not the case in Puerto Rico, where failure to obtain treatment is much more likely due to lack of the victim knowing it’s needed.

As the authors conclude, “Public health measures to reduce the risk for human rabies should include increased resources for primary prevention, including routine pet vaccination (canine rabies in Puerto Rico results from transmission from mongooses) and pre-exposure prophylaxis for persons at highest risk. Community education should highlight measures to avoid bites from pets and wildlife. Effective oral rabies vaccine baits targeting mongooses might also be considered as they become commercially available. Interventions should focus on areas with known human-mongoose contacts, as determined by overlaying bite surveillance data and population density. Secondary prevention measures should be aimed at increasing awareness of the need for medical evaluation and PEP after any mongoose bite.”

More avian flu in cats…H5N6 in South Korea

Posted in Birds, Cats

Cat washingFollowing on the heels of an H7N2 influenza outbreak in cats (and one person) in New York, H5N6 avian influenza has been found in two dead cats in Pocheon, Gyeonggi province, South Korea. This highly pathogenic avian influenza strain has been active in South Korea since November 2016, resulting in the death or euthanasia of more than 28 million chickens and ducks from 606 farms. The affected cats weren’t on a farm, but were found only about 2 km away, so may have visited the farm or potentially be exposed to the virus through wild birds in the area.

These infected cats are less surprising than the New York flu outbreak that has affected a large number of shelter cats. Rare spillover infections of avian flu in other species occur, particularly when large outbreaks are present and there are many opportunities for exposure. Cats are susceptible to a variety of flu viruses and can be exposed by eating infected birds (and sick or dead birds are easier to catch of course). The potential for avian flu to spread to other species, and in the worst case scenario to mutate or recombine with another flu virus to become more transmissible in people (while still causing severe disease), is why there’s such an aggressive response to avian flu outbreaks.

The risk infected cats pose to people is hard to determine. Usually, avian flu is not readily transmissible from aberrant hosts (including people), and close, prolonged contact is required for subsequent cases to develop. That’s like the New York outbreak where only one person has (so far) been identified as infected, and that person had very close contact with large numbers of infected cats.

To some degree, these infected cats should just be considered unsurprising but unfortunate collateral damage of the avian flu outbreak, and nothing to get too concerned about. However, roaming cats in areas where avian flu is present cause concern because they are a potential bridge between the bird population and humans. People who are working or living closely with birds are at highest risk of avian flu. If local cats become infected and roam to other areas, they could expose other people outside of these high-risk groups, and outside of standard outbreak containment and surveillance efforts. The two dead cats in this case may have been feral cats, but the potential for cats to act as a bridge is another reason that pet cats should be kept inside in areas where avian flu is actively circulating.

Biohazardous hedgehogs…multistate salmonellosis outbreak

Posted in Pocket pets, Salmonella

HedgehogWhen I talk about hospital visitation animals, I often use hedgehogs as an example of a novelty critter that we want to keep out of high risk situations. They’re interesting, but is there any advantage f seeing a hedgehog vs interacting with a properly trained visitation dog? Probably not. When you add in the greater potential for hedgehogs to be carrying things like Salmonella, it’s pretty clear they shouldn’t be in high risk situations.

Along those lines, a recent paper in Zoonoses and Public Health (Anderson et al 2016) describes a multistate outbreak of salmonellosis associated with pet hedgehogs.

Twenty-six (26) people infected with the outbreak strain of Salmonella Typhimurium were identified in 12 states. Most of those people reported contact with hedgehogs. As ever, the real number of cases was probably much higher, since a large percentage of people who get infected with Salmonella don’t get diagnosed.

  • Not surprisingly, kids were over-represented. The ages ranged from <1 to 91 years of age, with a median of 15 years of age.
  • 35% of cases were hospitalized. That’s probably a bit higher than the average outbreak report. More concerning, there was one death attributed to the infection.
  • When information about hedgehog purchase was available, 8/11 people had purchased the pet in the past 1-5 weeks. That’s pretty consistent with other outbreaks, where recently obtained pets are highest risk. Whether that’s because hedgehogs are more likely to shed Salmonella during that initial period, people have closer contact with them when they are new pets, or other factors isn’t known.
  • Limited hedgehog health information was available, but 3/6 had diarrhea before the person’s illness.
  • Various high-risk behaviours were identified, such as bathing hedgehogs in the family bathtub.
  • Traceback of where the hedgehogs came from didn’t identify any consistent source.  If a point source can be identified, the problem can potentially be controlled (e.g. closing down or eradicating Salmonella from a central facility or source breeder).  In an outbreak like this with no identifiable source, control is much more difficult, so that’s a concern.

This report doesn’t mean that people shouldn’t own hedgehogs. However, hedgehogs should be considered high risk pets, like reptiles, and kept away from high risk people (e.g. kids under 5 years of age). Like reptiles, good basic hygiene practices should be used to reduce the risk of Salmonella exposure. That’s probably particularly true with new pets. While it hasn’t been well-studied, it is likely that most pet species carry more infectious agents when they are purchased/adopted, because they typically come from higher risk facilities (e.g. more animals, more stress, lots of mixing) and can naturally eliminate many pathogens over time when they get into a lower risk household. The initial new pet period is also the time when people tend to have the most contact with pets, especially pocket pets, before the novelty factor starts to wear off.

Another thing to consider with this report is the fact that diarrhea occurred in the hedgehog before the person in some situations. For any pet owner, diarrhea or other illness should be a flag that the pet poses a greater risk, and more precautions should be taken with any diarrheic animal.

A lot of common sense goes a long way… and handwashing can prevent a lot of problems!

Backyard poultry…knowledge, attitudes and practices

Posted in Salmonella

Backyard chickensThe backyard poultry debate continues in many areas. It raised is head again in Guelph recently, with more city government debate about how far you have to keep your backyard chickens from your neighbours. There are a number of issues to consider, like potential for spread of zoonotic bacteria (e.g. Salmonella), avian flu, noise, smell and attracting other critters (e.g. coyotes).

A recent study in Zoonoses and Public Health (Kauber et al 2016) engaged owners of backyard chickens in Seattle to look at their level of knowledge of Salmonella, and practices that might influence Salmonella exposure risk.

Here are some highlights from the study:

  • Owners of the 50 studied backyard flocks were predominantly white (94%), female (74%) and well educated. 36% had a 4-year college degree and 54% had a graduate degree.
  • 90% of flocks were comprised of 8 or fewer birds.
  • Only one person had chicks on the premises at the time of the study. Those were kept inside.
  • 80% of people knew Salmonella was a bacterium, all but one knew people can get salmonellosis.

They also asked people about their infection control practices. You always have to take results like this with a grain of salt because if people know what they should be doing, there’s a chance they’ll give you that answer rather than what they actually do. They also collected video footage of people caring for their birds. This would likely provide more accurate information but still with some potential for people changing their behaviour because they knew they were being watched (the Hawthorne effect).

  • Two thirds of people said they don’t wash poultry-related items in the house or in areas where food is prepared. (The flip side is that 1/3 of people do this, and that is considered a high risk practice).
  • Three quarters rarely (10%) or never (66%) let their birds inside the house (a more obvious way to track bacteria and other bugs into the house).
  • One quarter had close contact with the birds, such as kissing them (to each their own, I guess).
  • Over one half allowed children less than 5 years of age to have contact with chickens, especially chicks. (This is getting into higher risk territory too, since contact with chicks is recurrently associated with salmonellosis outbreaks, particularly in kids).
  • In the videos, young kids were seen petting chickens, playing barefoot in the chicken area and entering the house with shoes worn in the chicken area. (I’m not a germaphobe and think environmental exposures are good for kids. This is to the extreme of that, given the known Salmonella risk. Outside and dirty… good. Outside and dirty with chickens… not so much).
  • People often touched their mouth or face while caring for the birds.
  • When comparing the video and survey results, over 50% of people who said they don’t have close contact with birds were observed snuggling with birds or touching their face.

What does this mean?

It’s hard to say. We really don’t know what the Salmonella risk is to owners of these small backyard flocks. The risk is probably greatest when people buy chicks, since lots of outbreaks have occurred from newborn chicks (both because they often carry Salmonella and because there is often closer contact with them). The risk to neighbours is also unclear, and presumably varies a lot with things like climate, rainfall and the contour of the land (e.g. a sloping lawn that sends chicken-poop-tea into the neighbouring lawn every time it rains).

There are some good aspects of having backyard chickens and some concerns, including disease and other issues. This study helps with one piece of the puzzle, and points out some potential areas to address.

The paper’s conclusions aren’t surprising but are logical: The data from this survey reveal that backyard poultry owners are aware of the association between Salmonella and poultry, but that they do not consistently perform risk-reducing husbandry and hygiene practices as recommended by CDC and the State department of health to help prevent infection with Salmonella. There is a need for better education to effectively communicate the risk of potential for zoonotic disease transmission and provide recommendations for husbandry and hygiene practices.

Bats, rabies and a hospital NICU

Posted in Rabies

SinkWhen a bat is found in a household, the response can be quite variable.  Many public health units may consider it a potential rabies exposure if the bat was in the house overnight, on the assumption that a bite could have occurred without being noticed (I have personal experience with that).  Based on the large number of people that are given rabies post-exposure prophylaxis (PEP) for this type of exposure (and the large cost associated with PEP), along with an estimate that changing this policy would only result in an extra rabies case every few hundred years, many jurisdictions don’t automatically consider sleeping in a room with a bat to be exposure.

But, what about a situation where you have people who can’t reliably report whether they were bitten, who are immunocompromised, and for whom there is no information about whether rabies PEP is safe or effective?

That situation occurred in a neonatal intensive care unit (NICU) in Austin, Texas, as reported in Infection Control and Hospital Epidemiology (Bailey et al 2016).

Two bats were found in a sink in the NICU… a strange place for them to be, and any time bats are in a strange place or acting abnormally, it’s a big red flag that they could be rabid. The bats were released outside, so they could not be tested. That means you have to err on the side of caution and assume they were rabid, then determine whether there might have been any human exposure.

While there was no evidence of them having contact with any patient, there’s no way to rule that out since bat bites can be very small and hard to detect, and the patients in a NICU obviously can’t report a bite.

After considering various factors, such as the nearly 100% fatal nature of rabies infection, the lack of evidence of vaccine effectiveness or safety in premature infants, and the known potential for poor response to rabies vaccination in people with compromised immune systems, it was decided that at least some of the infants should receive PEP (the paper doesn’t describe how those were selected). Rabies vaccination was recommended for 6 and offered for the 13 other infants in the NICU. Families of 5/6 of the high risk and 2/13 of the lower risk group consented to the PEP.  None of the patients developed rabies.

The paper provides some information about response to rabies vaccination. None of the infants developed any identifiable complications. Three infants were tested 6 moths after treatment, and all had developed an adequate immune response (circulating rabies antibodies). It’s a small number of patients, but provides at least some indication that premature infants can mount an effective response to rabies vaccination.

There’s no mention of what they did to figure out how the bats got into the NICU or hanging around in the hospital, nor if they provided any subsequent training to make sure people don’t just release bats that are found inside.

More on H7H2 influenza in cats (and now a person)

Posted in Cats

Cat nose pawA press release by the New York Department of Health and Mental Hygiene has provided some interesting new information about the recent H7N2 influenza outbreak in cats. This avian influenza strain is causing an ongoing outbreak in cats in shelters in New York, and human surveillance has been underway.

Three-hundred fifty (350) people have been screened for the virus and one person was positive. This person is a veterinarian who had “prolonged close exposure to respiratory secretions of section cats” at one shelter, including collection of respiratory specimens from sick cats. There’s no mention of the infection control practices that were used when samples were collected from the animals, but it’s possible they were limited, particularly if influenza had not yet been diagnosed in the shelter at that point. The individual had mild illness and has recovered.

One of 350 is obviously a low number, but it’s one nonetheless. It’s not too surprising since humans are susceptible to various flu strains, and there was close contact between people and infected cats. Disease was mild, as is common with low pathogenicity avian influenza strain infections in people. However, any time flu moves between species and new strains are encountered, there’s concern. Surveillance of cats and people in New York is ongoing.

Below is updated information on the cat situation from the press release:

Since last week, more than 100 cats have tested positive for H7N2 across all NYC shelters. This was expected because the virus is highly contagious among cats and cats are sometimes moved between shelters. All of the newly infected cats are experiencing mild illness and have been separated from other animals in the shelters. They are expected to recover. One cat admitted to the shelter with H7N2 infection died. ACC suspended adoptions of cats once the virus was discovered. The Health Department, working with ACC, the ASPCA and New York City Emergency Management, has identified a location where the cats will be quarantined soon, which will allow ACC to resume full intake and adoption of cats. The ASPCA will assume operational costs and manage the care of the cats.

More information will continue to become available as this outbreak is tracked both in cats and people.

H7N2 influenza in cats, New York

Posted in Cats

Cat on bedEmerging problem, newly recognized issue or oddball infection? Recent identification of H7N2 in cats at a Manhattan animal shelter has raised recurring concerns about animal health, human health and the movement of influenza viruses.

As a quick recap, flu viruses are named (in part) based on the genes coding for two important viral proteins, hemagglutinin and neuraminidase. There are several variations of each each gene, and a number is given to each variation. The flu virus strain is then named accordingly: H5N1, H3N2 or, in this case, H7N2.

It’s interesting but not particularly surprising for a flu outbreak to occur at an animal shelter. We know that cats are susceptible to various human and avian influenza viruses. They don’t tend to spread very far since they’re not really designed to live in cats. The fact that this outbreak is caused by an H7N2 virus is interesting. H7N2 influenza is a rarely diagnosed strain, being of avian origin with only a handful of cases diagnosed in people.

Whatever the original source was, at least 45 cats became infected (unclear whether these were all confirmed or only suspected cases), with no cases in dogs or other species at the shelter. Fortunately, as is often the case, the cats didn’t get particularly sick.

People who have been in close contact with the affected cats are being tested. This is an unusual (but interesting) response, since in my experience most often the “wait and see” approach is used, whereby people are only tested if they developed signs consistent with flu. This isn’t often done because of the cost, effort and relatively low likelihood of an action in response to the results. It can provide some useful information, though, and is probably particularly important with a rare strain like this.

The facility is currently quarantined and is being disinfected. Disinfection isn’t a huge component of flu control since the virus doesn’t live too long on surfaces outside the body, and transmission directly from infected individuals (animal or humans) is the main risk. However, it’s an easy(-ish) thing to do, might be of some use in highly contaminated environments, and it also buys time to watch for further cases.

It’s assumed that November 12th was the earliest potential infection date, and health officials are contacting people who adopted cats after that time. The risk posed by a cat adopted a while ago is low to non-existent, since flu virus shedding tends to be very short term. Evaluation of whether people who adopted cats during this time were more likely to report flu-like illness compared to a control group (people who didn’t adopt cats or people who adopted cats outside of this period) would help determine if there was likely any subsequent transmission to household members.

As with most flu outbreaks, with reasonable containment, this should burn itself out. There is no longterm carrier state for influenza, so infected cats (and people) have to encounter a susceptible individual during their relatively short virus shedding period in order to pass on the infection. If that can be stopped, or when all susceptible individuals get infected (and therefore become no longer susceptible), flu should disappear from a closed population like this.

Not all bugs must die…subclinical bacteriuria in cats

Posted in Cats

Tabby catSince we developed the first version of the ISCAID guidelines for diagnosis and management of urinary tract infections in dogs and cats in 2011 (revision currently underway), most discussion about them has probably revolved around our recommendations for animals with subclinical bacteriuria. In this condition, an animal has bacteria in the urine, but no signs of disease. Traditionally, these cases were classified as urinary tract “infections”, and treated with antibiotics. Yet, we know that a reasonable number of dogs and cats (and people) have bacteria in their bladder at any time, and it doesn’t cause any problems. The condition occurs at higher rates in certain groups (e.g. diabetics, elderly females). While bacteria can cause true urinary tract infections (UTIs), we don’t have evidence that subclinical bacteriuria is actually an issue for the animal (or person), either by itself or as a risk factor for development of UTI or other complications. However, a lot of antibiotics are used to treat this “problem” that probably really isn’t one. In people, a lot of time and effort has gone into reducing unnecessary treatment of asymptomatic bacteriuria (the human equivalent of subclinical bacteriuria in animals). In veterinary medicine, it’s been a tougher battle.

A lot of animals with subclinical bacteriuria still get treated, for a few reasons. One is difficulty accepting that the bladder isn’t always sterile (since that’s what most people have been taught), and that having bacteria there isn’t rare. There’s also the fear that it could lead to the development of other problems, even though evidence indicating a health risk is lacking.

The situation is definitely improving though. While I still get a lot a comments about people not being willing or able to withhold treatment, more and more veterinarians are no longer prescribing antibiotics for these cases. It can be scary at the start, but once they start holding off on treatment, they realize it doesn’t cause any harm, and that usually converts them. I probably get more comments now about how our guidelines should be stricter, as opposed to complaints about the recommendation that treatment isn’t needed.

It’s a small research field, but more supporting information continues to trickle in, including an article in the most recent edition of the Journal of Veterinary Internal Medicine (White et al 2016).  Here’s a brief summary of the highlights:

  • Researchers looked at 67 cats at five time points over 3 years.
  • Urine was collected, along with various health and laboratory data.
  • Overall, bacteria were present in the urine of 9.8-12.7% of cats over the 5 timepoints. In some, bacterial counts were very high, and 6 female cats were repeatedly positive.
  • Female cats over 7 years of age were at highest risk of bacteriuria. However, signs consistent with a urinary tract infection were only identified in 0-2 cats at each timepoint.
  • The presence of bacteriuria was not associated with death during the study period (i.e. it did not affect the cats’ survival).

The report ends with a nice conclusion: “…[Subclinical bacteriuria, SB] is common in older, nonazotemic cats at a similar prevalence to previous studies of cats with hyperthyroidism and diabetes mellitus. Cats in our study were nonazotemic, and some cats were euthanized for progressive weight loss associated with chronic conditions often treated in private practice. Among this cohort of cats, SB was not associated with body weight, azotemia, the development of CKD [chronic kidney disease] at necropsy, or overall survival. These findings are consistent with large studies in people and suggest that treatment of SB in the absence of risk factors for urosepsis or urogenital disease may be unnecessary.”

Raccoon Rabies – 1 Year Later

Posted in Rabies

Rabies_Surveillance_and_Control_11_30_2016It has been just over 1 year since the discovery of the first rabid raccoon in Ontario in over a decade, and the first rabid wildlife in the Hamilton area in over two decades.  Since then well over 4500 abnormal or “found dead” wildlife have been tested, and 253 animals carrying raccoon-variant rabies have been found in Hamilton and the surrounding areas (see map).  To see more maps of how the outbreak has progressed, visit the OMAFRA rabies website and click the first link “OMNRF Wildlife Rabies Control Zone“.  The raccoon variant has been found in 175 raccoons, 76 skunks, 1 red fox and 1 stray cat.  There have been no human cases and no confirmed domestic animal cases (not counting the stray cat) associated with the outbreak, but there has been lots of effort on the part of the local public health units to provide post-exposure prophylaxis to potentially exposed people, and local veterinarians have been working with owners to ensure pets are vaccinated, and with OMAFRA when needed to arrange testing of suspect animals and confinement of exposed animals that were not properly vaccinated.  The MNRF has also dropped over 1.6 million oral rabies vaccine (ORV) baits in southern Ontario to help contain the spread of the virus.

In addition, almost 30 rabid bats have been detected from all over southern Ontario, and one rabid skunk was found to be carrying bat-variant rabies as well.

Two weeks ago a rabid cow was found in Perth County, but the cow had fox-variant rabies, similar to another cow in December 2015 and a skunk in March 2016 from the same region.  Based on these cases we know that fox-variant rabies is still circulating in the area (at a very low level), even though no cases were detected for 3 years prior to December 2015.  These cases are not related to the raccoon-variant cases in the Hamilton area.

The take-home message is that rabies is still alive and well in Ontario, but veterinarians, public health, OMAFRA and the MNRF are all working hard to protect people and domestic animals from this deadly zoonotic virus.  It is critical for members of the public and animals owners to do their part as well, including:

  • Avoid direct contact with wildlife (including bats) or animals that are behaving abnormally.
  • Vaccinate pets and livestock that may be at high risk of exposure (or that may travel or have contact with a lot of different people, such as show or competition animals).
  • Report any human exposure to saliva of a potentially rabid animal to the local public health unit, or a physician.
  • Report exposure of any pet or livestock to a potentially rabid animal to your veterinarian so a risk assessment can be performed.
  • Live wild animals that are in distress or acting in a threatening manner should be reported to local animal control, if available, or the local police as a last resort.

Ontario lungworm update

Posted in Dogs, Parasites

The fox lungworm, Crenosoma vulpis, continues to be identified in dogs in Ontario. The attached map from WormsAndGermsMap shows the cases we know about. There aren’t many, but the issue of “rare vs rarely diagnosed” is important. As a relatively new (or newly identified) problem that requires specific testing, it’s easy for it to be overlooked. The distribution on the map shows how widely lungworm cases have been spread across the province.

Lungworm is a possible cause of chronic cough dogs in areas where the parasite is present. That now includes much of Ontario. Readily treatable, it’s important that lungworm testing is considered in cases of chronic respiratory disease, particularly those that have not been recently or routinely treated with antiparasitics that are effective against lungworms.