Worms and Germs Blog : Animal Health & Diseases : University of Guelph : Ontario Veterinary College : Zoonotic Diseases : Guelph, Hamilton, Ontario

The Redlands Animal Shelter in California is looking into bird control measures after blaming Giardia infections in dogs on exposure to wild bird poop. On Facebook, Redlands Friends of Shelter Animals have declared "We have a serious problem with birds at the shelter. They land on the kennels and poop goes into the water bowls and give the dogs giardia - which is a parasite that gives them explosive diarrhea."

Giardia is a protozoal parasite that can cause diarrhea in dogs and other species. It can also be carried by healthy dogs, at relatively high rates in some groups. The scope of the problem at the Redlands shelter isn't clear since the news article only talks about one case. Whatever the scope, shelter management is blaming the birds.

Apparently, discussions are underway with different companies about a solution to the bird problem, something that is anticipated to be expensive. However, it's all too common for people to jump the gun on expensive interventions when there's an outbreak and overlook the root causes. While news reports don't always give the whole story, I'd be wary about blaming birds without much more evidence.

Can wild birds carry Giardia? Yes. However, there's more to the Giardia story than that. It doesn't sound like they've actually tested the bird feces to determine whether Giardia is there. Additionally (and critically) it doesn't sound like they've determined the type of Giardia that's infecting the dogs. There are different types (assemblages) of Giardia and most have a limited range of species they can infect. The vast majority of dogs with Giardia in most regions are infected by Assemblage D, a dog-specific strain that comes from other dogs and poses no risk to people. I'm not aware of Assemblage D being found in birds. Dogs can also be infected by Assemblage A, a type that infects people, and also can infect birds.

So, if Assemblage D is involved, they need to look at transmission between dogs within the shelter. If Assemblage A is involved, they still need to focus on dogs but could investigate birds as a potential source.

Overall, Giardia transmission is much more likely due to breakdowns in cleaning, disinfection, hand hygiene and general shelter practices rather than birds pooping in water bowls. It's a lot cheaper to address these shelter management practices (which will also help control various other infectious diseases) rather than dumping a lot of money into controlling bird exposure when in fact that may not be causing the problem. Trying to reduce exposure to bird poop is a good thing as a general practice, but it's important to focus efforts and resources on finding and addressing the true root problems during an outbreak. 

More information about Giardia can be found on the Worms & Germs Resources page.

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A parvovirus outbreak has been identified at the Occupy San Francisco camp, with at least three dogs affected by the highly contagious and potentially very serious viral disease. The San Francisco SPCA has visited the camp and their temporary clinic was attended by "dozens" of dog owners (indicating lots of dogs at the camp). This is a nice proactive step to help contain the parvo outbreak and hopefully reduce the risk of transmission of various other infectious diseases amongst the animals. Some people appreciated the help. Others (probably the subset that complains about everything) accused the SPCA of spreading bad publicity to help shut down the camp. (I guess they'd rather have good press than healthy dogs.)

In many ways, it's not too surprising. "Occupy" camps are just asking for infectious disease outbreaks, more so in people, but the same risk factors are there for dogs. Whenever you mix together lots of different individuals from different sources, put them in close and prolonged contact and have hygiene challenges, you set the scene for infectious diseases. From a canine parvovirus aspect, heavy fecal contamination from dogs defecating in a small, concentrated area and unvaccinated dogs feed the fire even more. (I don't know for sure that the affected dogs were un- or incompletely-vaccinated, however given the excellent effectiveness of parvovirus vaccines, it's highly likely that sick dogs were not adequately vaccinated.)

Parvo isn't the only infectious disease problem at the camp. Kennel cough (now known as canine infectious respiratory disease complex, CIRDC) has also been identified. This syndrome, caused by a mix of bacteria, viruses and Mycoplasma, has greater potential to spread widely because some of these bugs are highly contagious and vaccination coverage in the population will be lower than for parvo. A large-scale kennel cough outbreak is quite likely if there is kennel cough activity at the camp.

What can you do to reduce the risk, whether it's while "occupying" or during your daily activities?

• Have your puppy vaccinated as per your veterinarian's recommendations.
• Don't take unvaccinated puppies to areas where there will be lots of other dogs. "Unvaccinated" includes puppies who have not had their full initial series of vaccines.
• If your dog is sick, don't take it out in the public, especially to places where other dogs will be present.
• If your dog gets sick during a public event, take it away promptly to reduce the risk of it infecting other dogs.
• Don't let healthy skepticism grow to paranoia, and don't let political squabbles interfere with proper healthcare... both human and veterinary.

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A Kitchener, Ontario family is dealing with a household outbreak of ringworm, likely contracted from a new pet guinea pig. Ringworm is a fungal infection cause by a few different types of fungi. Some ringworm fungi are able to infect both people and animals, and those can be spread in households from direct contact with an infected person or pet. In this case, the Gross family purchased a new guinea pig from a local pet store, and unfortunately, ended up bringing ringworm home as a bonus.

As is common, the new pet was the centre of attention when it got home, and the Gross' three children, ages 8, 5, and 2, had very close and frequent contact with it. The next day, the family noticed an area of hair loss on the guinea pig, at which point they took it back to the store. Ringworm was subsequently diagnosed, though there's no mention of how this was done, nor is there any mention of what actually happened to the little critter afterward.

The big problems started a week later, when a red lesion was seen on their youngest child's back. This was also diagnosed as ringworm, though again there's no mention of how, or whether it was definitively confirmed as ringworm. The newspaper report goes on to say "More spots kept appearing on Matthew’s skin as Gross was given different steroid creams to try and contain the infection." You always need to take media descriptions of medical issues with a grain of salt.  Hopefully, the child was treated with anti-fungal cream, not steroid cream, as the latter not only won't treat ringworm, they may make it worse if used alone. Steroid creams are often prescribed for non-specific skin issues (particularly if the skin is very itchy, which can certainly happen with ringworm), but in a case like this where there was known contact with an animal with ringworm, I have to hope that the physician was treating with an antifungal cream instead of, or in addition to, a steroid cream. 

Anyway, whether despite or because of the treatment, more skin lesions kept appearing on the child. Then skin lesions were found on the family dog, and both the dog and cat ended up being treated for ringworm.  The treatment for dogs and cats is relatively straightforward, but it's still a hassle and can be somewhat expensive, and often takes several weeks.

The family has contacted the pet store about paying for cleaning supplies, air purifiers and veterinary bills, but the company did not respond to the newspaper reporter's inquiries, citing an ongoing investigation. It's hard to say whether the company should be held responsible. It largely depends on the measures they take to reduce the risk that they are selling pets at increased risk of transmitting infectious diseases. There's always a chance of picking up something from a pet, so an infection does not necessarily indicate incompetence or liability. If a store had reasonable practices in place, it's probably the purchaser's responsibility to take proper precautions when they take the pet home, and it's an example of why prompt veterinary examination of new pets is always a good idea. It's rarely done, particularly for species that cost less than the price of a veterinary exam, and you never know whether it would have helped prevent anything in this case, but in many instances it can help identify potential issues and address them before problems occur.

Preventing outbreaks like this can be difficult. Ringworm can be found on animals in the absence of any skin disease, so you can't always tell an animal is infected by looking at it. (However, in this case if a large patch of hair loss was noticed by the owners the day after the guinea pig came home, it's likely that something was evident the day before). Ringworm is spread by direct contact, which is common between pets and kids, especially new pets that often get smothered with attention in the first few days. Good hygiene practices, particularly attention to handwashing, can certainly help, but some degree of risk will remain.

Overall, guinea pigs are relatively low risk for zoonotic diseases, but this report shows that even "low risk" pets can be sources of infection. Fortunately, while controlling ringworm outbreaks can take time and be frustrating, it's not a serious disease and it is controllable.

More information about ringworm can be found on the Worms & Germs Resources page.

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There have been a few large outbreaks of dead birds around Ontario lately, with botulism being the main suspect. In one area alone, up to 6000 dead birds have washed up on Georgian Bay beaches. While dramatic, it's not a rare situation at this time of year, and typically relates to birds ingesting fish that died of botulism. When birds eat enough fish with enough botulinum toxin inside them, they can develop botulism themselves and die. This pattern can continue if dead birds are eaten by other animals.

In response to these events, I often get calls about risks to dogs and people. When thinking about it, it's important to consider how botulism occurs. There are two main forms of botulism:

1. Toxicoinfectious botulism involves growth of the Clostridium botulinum bacterium in the intestinal tract, and as the bacterium multiplies it produces toxin which can be absorbed  into the body through the intestinal wall. This type of botulism is rare in adults (both people and animals), since the mature intestinal bacterial population usually prevents C. botulinum from overgrowing. It's mainly a risk in young individuals.  )This is why you're not supposed to give honey to babies, since C. botulinum spores that can be present in honey can pose a risk to them.)
2. The other form of botulism in from ingestion of botulinum toxin that's already been produced. This is the most common form. When birds eat fish that have died of botulism, they ingest both the bacterium and its toxins, but it's the toxins that make them ill and ultimately lead to death. Dead birds will probably have some C. botulinum in their intestinal tracts, but the main concern is the botulinum toxin in the rest of their tissues.

Dogs (and cats) are quite resistant to botulinum toxin, and reports of botulism in these species are rare. It would take a pretty large amount of toxin to cause disease (at least compared to many other species) but it's not impossible. Casual contact with areas where birds have died is of basically no risk. Eating dead birds could pose some risk to the dog, depending on the amount eaten and how much toxin was present in the bodies. Ingestion of some C. botulinum bacteria in the birds is of limited concern.

So, walking in an area where birds have died is very low risk. People should ensure that their dogs don't have uncontrolled access to areas where birds have died, so that they can't eat lots of dead birds.

I also get questions about whether dogs that get exposed to beaches where birds have died pose any risk:

• Even if a dog ate a lot of dead birds and got botulism, a person could only be exposed to that toxin by eating the dog - an unlikely event. The dog could ingest some C. botulinum bacterium, but this also poses minimal risk since the bacterium is pretty widespread and people can be exposed to it from many different sources. Even if a dog had some C. botulinum in its intestinal tract, avoiding contact with feces will reduce the risk of exposure. Even if there was some ingestion of C. botulinum from the feces, there's little risk, especially to adults. Perhaps the main public health concern (which is still very low) would be exposure of infants to C. botulinum from dog feces or perhaps from a dog's contaminated haircoat.

Bottom line: Keeping dogs and cats away from dead birds is a good idea, for several reasons, including botulism exposure, but there's limited public health concern.

Image: Dead birds washed up on the shore of Georgian Bay, on the eastern side of Lake Huron (click for source)

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An outbreak of canine influenza is occurring in San Antonio, TX, as this virus continues its strange and unpredictable movement through the North American dog population. In an article published on a local San Antonio news website, Dr. Michele Wright, a San Antonio veterinarian, reports 20 confirmed and 70 suspected cases over the past month. It's not clear whether these are all from her clinic, nor is there any information about possible sources of the virus or the severity of disease. Dr. Wright also states that the virus has been identified in Austin and Dallas.

It's not particularly surprising that canine flu has been found in Texas. It's now been identified in at least 38 US states, as well as one Canadian province. An outbreak is not particularly surprising either in this case, because when a virus reaches a new area, it can easily cause widespread disease since it encounters a population of animals that don't have any pre-existing immunity (i.e. antibodies) against it.

What's strange about canine flu is how it has spread across North America. When it was first identified in Florida greyhounds in 2004, it seemed like it was going to spread widely across the dog population. It spread quickly at greyhound tracks and in clusters in Florida and in other states, but it's subsequent spread across the continent was quite patchy - it caused only localized outbreaks in different states, instead of the catastrophic continent-wide epidemic that was anticipated. Whether this relates to the amount and type of direct contact between dogs (e.g. dogs are only infectious for a short period of time and an infected dog has to meet a susceptible dog during that time to continue transmission of the virus, otherwise it dies out), specific aspects of the virus in dogs (e.g. how long it is shed) or lack of recognition of disease in some areas (e.g. mild disease that doesn't get diagnosed) is unclear.

We've been looking for canine flu in Ontario for a few years now, with no "success" (that is, we haven't found it yet).

Are we flu-free at the moment? Probably not. I suspect it's lurking out there, but it's possible that it really hasn't made it to Ontario - yet.

If it's not here now, will it make it here eventually? Almost certainly. It's taking longer than I expected but all it takes is one infected dog entering the country. With the amount of cross-border dog movement, it's probably inevitable.

What about vaccination for canine flu? It comes down to risk of exposure and risk aversion. If flu is in the area, vaccination is a good idea. If flu is in adjacent areas, it's also a good idea. If flu isn't recognized in the area, it's a matter of how much risk people are willing to take and thinking about higher risk situations, as described below.

What about vaccination in Ontario, or other places where the virus doesn't seem to be present? It's hard to say when to recommend canine flu vaccination. Certainly, vaccination of dogs traveling to areas where canine flu is or has been present is a good idea. Vaccination of dogs that engage in high risk activities such as going to shows or kennels is also prudent, since these are the places where we may see the firsts outbreaks if/when canine flu makes it here. Vaccination of low-risk dogs in the province is probably not necessary at the moment (unless people are very risk averse and don't want to take any chances).

Why vaccinate?  It's just "the flu"... This is an attitude that the human public health field battles all the time. Most people who get human influenza (humans can't get the dog version of the virus) feel crappy for a few days and get over it. The perception that it's only and always a mild disease keeps some people from getting vaccinated. However, thousands of people die from flu complications, particularly the very young and elderly individuals. Vaccinating everyone helps reduce the chance that these high-risk people will get sick. Also, while rare, serious (including fatal) infections can occur in otherwise healthy people. In dogs, there's probably actually more indication to vaccinate if there is a realistic risk of exposure. Canine flu can cause classical flu-like disease, akin to the typical human case. However, severe (often fatal) pneumonia can also occur in otherwise healthy dogs. High rates of severe disease were reported initially when canine flu was first identified. It seems like severe disease rates have dropped, but it's still a concern. I wouldn't be surprised if severe disease is more common in dogs with canine flu than in people with human flu.

Whether or not to vaccinate is a discussion dog owners should have with their veterinarian, considering the risk of exposure, risk of severe illness and risk aversion. At the same time, people in areas where flu has not been identified need to be on the lookout for it, to ensure that it gets diagnosed promptly if it emerges, and that information gets communicated to veterinarians and the dog-owning public so that appropriate responses can be made.

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The US CDC is investigating yet another multistate outbreak of salmonellosis associated with contact with chicks and ducklings. As of June 18, 39 people have been diagnosed with Salmonella Altona infection (with a large number of others presumably infected, since only a minority of cases tend to be diagnosed). People in at least 15 states have been affected, as indicated by the map on the right.

Reported cases so far occurred between February and the end of May, but the outbreak could still be ongoing. Of all the affected individuals, 28% have been hospitalized but there have been no deaths.

Outbreaks like this lead to investigation of possible sources, starting with the usual suspects of high-risk foods and animal contact. In interviewing people that became sick, 81% of them reported having contact with live poultry before getting sick. In people that identified the type of poultry, all reported contact with chicks, ducklings or both. All 19 people that provided information about the source of chicks or ducklings reported getting them from different locations of a nationwide agriculture feed store (which is not being identified). The same strain of Salmonella was isolated from ill people and chick/duckling displays in two store locations. A single mail-order hatchery was then identified as the source of the animals.

Large distributors of animals, especially high-risk animals like chicks and ducklings, can be the sources of large outbreaks since they can supply large numbers of infected animals to a large region. While cute, chicks and ducklings are high risk for carrying Salmonella and they can shed large numbers of Salmonella in their feces without showing any signs of disease. That's why standard recommendations are that high risk persons (e.g. children less than 5 years of age, immunocompromised or elderly individuals) should avoid contact with baby poultry.

In the context of this outbreak, since the store is not being named (and since it's possible the hatchery sent chicks to other sources), anyone who has had contact with chicks and ducklings needs to be aware of the potential for Salmonella exposure. In reality, this is also true outside of the context of this outbreak, since Salmonella exposure needs to be considered after any contact with chicks and ducklings. It doesn't mean that people who have had contact with baby poultry should go to the doctor, get tested, or do anything different. However, it is important that people notify their physician about poultry contact should they get sick. For more information about reducing the risk of Salmonella exposure from poultry, click here.

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As I mentioned in an earlier post, there's been a large and ongoing outbreak of salmonellosis in people across the US associated with pet aquatic frogs (such as African dwarf frogs). A recent edition of Morbidity and Mortality Weekly Reports provides an update on this large and concerning outbreak. Here are the highlights regarding infections reported between April 1, 2009 and May 10, 2011.

• 224 infections with the unique outbreak strain of Salmonella Typhimurium have been identified in 42 US states. Since it is estimated that only ~3% of Salmonella infections are laboratory confirmed, this means that the number of true cases is probably much higher (e.g. >8000, if the 3% estimate is accurate).
• The median age of affected people was 5 years, with a range of <1-67 years. The young age bias may be because of increased susceptibility to infection, increased likelihood of severe infection (which would more likely result in testing) or more common exposure.
• 30% of affected individuals were hospitalized. There were no deaths.
• 65% of affected people reported contact with frogs in the week before illness. 18% of those occurred outside the home (which is why we need to make sure that even non-pet-owners are educated about zoonotic disease risks associated with pets).
• The median time from acquiring a frog to onset of disease was 15 days. This means people often got sick fairly soon after acquiring their new pet.
• One breeder in California has been implicated as a common source of infected African dwarf frogs. As with many kinds of small pets (e.g. rodents, reptiles), this is a large breeder that sells to distributors who then sell to pet stores and elsewhere. This type of mass production and distribution system means that a problem with a single breeder can result in widespread disease. This has been clearly shown previously in various other outbreaks, especially with pet rodents.

What should the average pet owner know?

• High-risk households - those including kids under the age of five, elderly individuals, pregnant women or individuals with a compromised immune system - should not have pet aquatic frogs.
• High-risk people (as describe above) should not have contact with aquatic frogs in other places.
• People with aquatic frogs should consider the frogs to be infected with Salmonella until proven otherwise. Since we don't know how to prove otherwise, that means treat all pet aquatic frogs as infectious.
• Frog owners should avoid direct contact with the frogs and their water. Hands should be washed thoroughly after contact with frogs or their environment.
• Frog owners should never dump aquarium water into kitchen or bathroom sinks.
• Any spills of water during aquarium cleaning should be promptly and thoroughly cleaned up.
• Other pets should be kept away from aquaria (I remember when I used to have aquatic turtles and a cat. The cat used to drink from the aquarium and occasionally bat at the turtles. Not something I'd endorse now, but that was in my pre-DVM era).

This outbreak doesn't mean that aquatic frogs can't be good pets. It means that they shouldn't be pets for certain people, that good routine infection control practices need to be used by frog owners and that consideration needs to be given to whether mass production of pet frogs (and other species) is appropriate.

Photo: An African dwarf frog (Hymenochirus boettgeri) (photo credit: James Gathany, CDC Public Health Image LIbrary #11831).

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A paper in Epidemiology and Infection (Belchior et al 2011) describes an outbreak of psittacosis (Chlamydophila psittaci infection) in people who attended a bird fair in western France in 2008.

The investigation started off with the identification of the bird-associated disease in three people at a local hospital. All three were hospitalized with respiratory disease, and all had attended the bird fair.

• A critical step in diagnosis of psittacosis and recognition of outbreaks is knowing about bird contact. If bird contact isn't questioned, psittacosis is unlikely to be considered. Too often, physicians don't inquire about animal contact, which limits their ability to detect zoonotic diseases. In this case, a survey on psittacosis was underway, which may have helped.

This finding led to an investigation of the fair to determine what happened and make sure there were no other unidentified cases.

The fair lasted one day, and had 83 exhibitors, 1500 birds and around 600 visitors. The investigators ultimately identified two confirmed cases of psittacosis in people who attended the fair, along with two probable and 44 possible cases. (Possible cases were people who developed respiratory disease and were exposed at the event, but did not necessarily have any diagnostic testing done to confirm the cause).

The reported disease characteristics were pretty typical:

• Fever in 96%
• Pneumonia and cough in 63%
• 98% visited a doctor
• 23% were hospitalized
• No one died (psittacosis can be fatal, but is quite treatable if identified in a reasonable time)

Thirty-eight percent (38%) of exhibitors and organizers got sick. That's a very high attack rate for people casually interacting with a group of (presumably) healthy birds. Poor ventilation may have played a role. The fair was held inside, windows were closed and there was no mechanical ventilation. This might have helped the bacterium build up in the air in the building and result in wider, heavier exposure.

The source of infection wasn't determined. They were only able to obtain samples from birds from six of the 83 exhibitors, and all 64 tested birds were negative. Chlamydophila psittaci can be shed by healthy birds, and identification of the source isn't always easy.

It's not guaranteed that everyone who got sick after the fair had psittacosis. You can't rule out the possibility that there were only a couple people with psittacosis and a large number with the flu or another disease, but the incidence of disease, type of disease and timing of disease are all quite suggestive.

How do we prevent outbreaks like this in the future? It's tough to prevent them completely, because you can't tell that a bird is shedding the bug just by looking at it, and testing every bird before a show is  impractical. Risks can probably be reduced by ensuring proper ventilation, limiting crowding of areas, limiting unnecessary direct contact between birds and people, and improving general hygiene practices.

Thanks to Dr. Doug Powell of BarfBlog for sending the article.

More information about psittacosis is available in our archives.

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You can probably tell from various posts that I'm a fan of the CDC's journal Emerging Infectious Diseases. It's a great journal containing interesting infectious disease reports about people and animals (it's free too, which is a nice bonus). In addition to the ferret infection I wrote about, the last edition also has a very interesting report about tuberculosis (TB) in people associated with an elephant sanctuary.

Tuberculosis is a big problem in elephants. It is relatively common in captive elephants in North America (2-12% are thought to be infected), and it It can be a tricky infection to diagnose, so it's very hard to know who's infected an who isn't.

Beyond being a problem for the elephants (because infection can be fatal), elephants with TB pose a risk to people, and there have been reports of human infections associated with elephant contact. Close and prolonged contact is most often associated with transmission of TB from elephants to people, but this recent report shows that indirect transmission may also be a concern.

The report in question deals with an elephant sanctuary in Tennessee. Problems were identified in July 2009 when routine TB skin testing of some workers at the facility indicated exposure to TB. Further investigation revealed that a quarantined elephant had tested positive in December of 2008. The elephant was diagnosed by culture of a trunk wash - to do this, the elephant is trained to suck water into its trunk and then "exhale" it into a plastic bag. The sample is then cultured for Mycobacterium tuberculosis. Animals with positive trunk washes are considered infectious, just like people with positive sputum (spit) cultures.

The TB history at this facility goes back further. In 2004, they took in two elephants that were known to be infected with TB. They were handled as per USDA Guidelines for the Control of Tuberculosis in Elephants (yes, such a document exists). One died of TB and the other was later released from isolation after treatment, according to the guidelines. In 2006, they took in eight more elephants from the same facility. All were considered high-risk for TB and were tested annually. All samples between 2006 and 2009 were negative, except for that one December 2008 sample. There's concern that since the elephants tested negative, people might have become lax with infection control practices. It's a problem beyond elephant facilities, where compliance slips over time since people may not see the need to continue to do what's required. 

After being notified of the the 2009 human TB test results, Public Health personnel launched an investigation. They eventually determined that 9/46 people whom they were able to contact had positive TB skin tests during the 2006-2009 period, despite having negative tests before then (confirming that they were truly exposed during this period). The strange thing was that it wasn't only the people with prolonged, close contact who were infected. People who worked in the quarantined area in 2009 were significantly more likely to be positive, but of the 13 people that worked in the quarantine area, only one had close contact with any elephant. Furthermore, three of the people who were infected were administrators.

This is where is gets interesting. Normal cleaning practices included the use of high-pressure washing to clean the barn. We know that this increases the risk of spreading bacteria in the air over long distances, and it's generally frowned upon from an infection control standpoint. People in the quarantine area wore respirators to reduce the risk. However, the administrative area was attached to the quarantine area and investigators subsequently determined that there was airflow from the quarantine area into the administrative area. So, when people were cleaning the quarantine area with high pressure washing, they were creating infectious aerosols that spread into the administrative building. That presumably accounted for infection of the people who had no contact with elephants. Furthermore, one of the investigators was also exposed during time spent in the administrative area before the risk was identified.

This highlights a few issues:

• Infectious diseases continue to surprise us. We may know what they tend to do, but new transmission patterns and new concerns can develop.
• Power washing can contribute to the spread of infectious diseases. This is a concern in many types of facilities.
• Infection control compliance needs to be maintained over time, even if it seems like the risks have dropped.
• Captive elephants continue to pose a risk to people around them, and careful precautions are needed to reduce the risk of exposure to TB.

(click photo for source)

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Glanders, a very serious disease of horses, donkeys and mules caused by infection with the bacterium Burkholderia mallei, has made the news again in a rather unusual manner – it has been reported as the cause of an outbreak in lions and a tiger at an Iranian zoo in Tehran.

The story goes that two Amur tigers arrived at the Tehran zoo from Eastern Russia in April 2010 as part of an exchange program between the two countries. The tigers were supposed to be used to help restore the tiger population in northern Iran on the Miankaleh nature reserve, but their living quarters there were apparently still not ready, and thus they were being kept at the zoo. One of the tigers died in December 2010.

And that’s were the story starts to get a little dicey. The Iranians claim the tigers were imported already carrying the disease, and that the last case of glanders at the zoo was 50 years ago. The tigers had already been at the zoo for eight months - although the incubation period for glanders can be months in some cases, it is normally only weeks. The Russians of course insist that the tigers were completely healthy when they were transferred – they’d been thoroughly examined and quarantined prior to being moved. (This makes the most sense to me, since transporting an animal such a long distance is a major stress and increases the risk of illness, and transporting an animal that is already sick would be even more risky. Not a chance I would take with two members of a species of which there are fewer than 900 individuals left in the world.) They also pointed out that a sick tiger from the cold regions of Russia would be much more likely to succumb to illness during the very hot Iranian summer, not during the winter.

Another report said that three lions at the zoo also died from glanders in the last two months, and subsequently another 14 lions were diagnosed with the disease, all of which were put down by the authorities. The main concern seemed to be the spread of the disease from the big cats to the feral cat population, and then to the human population. This second report states that “the tiger died after being fed contaminated meat, though it is possible it could also be related to the glanders.”  Yet another report said that the tiger was infected with feline immunodeficiency virus (FIV - the feline equivalent of HIV).

Facts to keep in mind:

• Glanders is an highly contagious disease, and highly fatal (B. mallei is even classified as a Class B bioterrorism agent).
• Animals that do recover from the disease can become long-term carriers of B. mallei, and are a risk to other animals (and people). Prompt euthanasia of affected animals is therefore often the primary means of controlling outbreaks (but the bacterium is susceptible to antibiotics).
• The infection can be transmitted to other animals (and people), usually through close direct contact or contact with oral and nasal secretions and discharge from skin ulcers. It can also be transmitted by eating tissues from infected animals.
• The bacterium is killed by most disinfectants, and UV radiation (sunlight).

Glanders can affect species other than equids, including people and cats, however there is very little information available about glanders in any felids, let alone lions and tigers. Theoretically it might be possible for the disease to spread from the zoo animals to feral cats and then to people, but I don’t know how many feral cats are brave (or stupid) enough to wander into a lion enclosure. There’s also a possibility that a glanders-positive feral cat may have infected the zoo cats (but again, it would have to be very brave, or very stupid). It is also unclear what tests were used to confirm that the big cats were infected with glanders, and it is unknown if other animals at the zoo have been tested. Since this is typically a disease of equids (and has also been found in goats and camels), I would certainly be checking these animals first.

The big question is, where did the glanders come from in the first place? It seems unlikely that the tigers brought it from Russia, when the disease is actually endemic in Iran (even though they’d had no diagnosed cases at the zoo for many years). Is there a carrier animal in the zoo? Were the animals infected by eating contaminated meat? Was it brought in by feral cats?  The source needs to be identified and addressed or animals will continue to be infected, which is particularly bad news for the kinds of rare species that may be found in a zoological collection. Some more details about the testing would also be appreciated – given the severity of this disease, and the severity of the consequences for positive animals (euthanasia), one needs to be as sure as possible that these animals are infected with B. mallei and not something else.

Photo: Amur Tiger (Panthera tigris ssp. altaica) (click image for source)

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Recently, I wrote about a potential outbreak of respiratory disease in dogs in Ottawa, Ontario. That "outbreak" seems to have died down (as is common, since outbreaks typically burn out over a period of time). However, I had a call today about a similar situation that might be occurring in the Whitby (Ontario) area. A few veterinarians are reporting a spike in "kennel cough" cases, including some dogs with severe disease. Whether this is truly an outbreak, and whether it's related to the Ottawa situation are both unclear, but it's concerning to get two similar reports over a relatively short period of time.

Situations like this can be caused by a variety of factors, including

• Movement of a known pathogen into a new area. Emergence of canine influenza in Ontario is my main concern in this category.
• Increased disease caused by typical pathogens that are present in the area.
• Hyper-awareness (and increased reporting), as opposed to a true outbreak.

Veterinarians and dog owners should be aware that something different may be going on in different Ontario regions, and consider more thorough diagnostic testing should respiratory disease be encountered. Including testing for canine flu would be a good idea. The two most common and effective ways to test for this disease are:

• Seroconversion: Detection of an increase in antibody levels against canine influenza virus in blood samples taken 10-14 days apart.
• Detection of virus by PCR: This molecular test looks for viral RNA. Testing can be done by certain labs on deep nasal swabs.

Testing does cost money (not much, but free testing isn't available) and it's sometimes hard to convince people that testing is useful, since it may not change the treatment for an individual dog. However, it is important to find out what caused the disease in order to explain why disease happened, to help prevent further disease in the individual dog, to determine optimal vaccination programs, and to provide important information for protection of other dogs in the community.

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A somewhat strange report from MSN News India describes measures that are being considered following an outbreak of salmonellosis that killed 3 tigers at Bannerghatta Biological Park.  The zoo authority is investigating whether tests used by the Indian army to detect Salmonella in milk and milk products could be used to detect Salmonella in meat.

Testing of meat for Salmonella is a reasonable consideration, but it really depends on how often meat samples are contaminated.

• If most meat samples have Salmonella, what will be done with the results and the meat? The cats have to eat, and unless they have a plan to throw out all positive food or do something to it eliminate Salmonella (like cooking it), testing might be of limited use.
• Also, if Salmonella is usually there at low levels and problems only occur with sporadic high level contamination, or contamination with particularly virulent strains, then using a test that just says "Salmonella yes" or "Salmonella no" may not help much.

It is also reported that "the authority is also in talks with some firms to come up with a microwave which has the capacity to kill microbes in 300-400 kg of meat at a time."

• This is questionable since it's probably a lot of expense to develop a large microwave, and particularly since microwaving is not a reliable method of killing Salmonella. If there is a need to treat the meat to kill Salmonella, there are more reliable measures, such as cooking in a conventional oven, irradiation or high pressure pasteurization.

Another bizarre aspect is someone from the zoo authority stated "In Canada, when 7,000 pet dogs died on being fed infected beef last year, some firms there came up with a microwave with the capacity to kill microbes in 500 kg of beef in three to four minutes. We are exploring the possibility of similar technological innovation being implemented here, for which we are in talks with some technicians".

• I have no idea what this guy is talking about. I am not aware of any outbreak killing 7000 dogs in Canada (and if it really happened, I'm pretty sure I'd be well aware, if not in the middle of it).

On the positive side, all of the tigers that survived have now completely recovered and no new cases have been identified.

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The UK's Health Protection Agency is warning families who own reptiles about the risks of Salmonella, following the diagnosis of salmonellosis in 9 Merseyside children in the past 6 months. All the affected kids had direct or indirect contact with reptiles. Three of them (all less than three years of age) were hospitalized. One of them, an infant who was infected at four weeks of age, is still sick five months later.

Salmonella is commonly found in or on healthy reptiles. All reptiles should be considered Salmonella carriers, and handled accordingly. Standard guidelines are that children under the age of five, along with immunocompromised individuals, the elderly and pregnant women, should avoid contact with reptiles. The reason for this is clearly evident here, with the bacterium having caused serious illness in these young children.

Thinking that you can eliminate the risk in a high-risk household by making sure the high-risk person  never handles the reptile isn't adequate. There are numerous reports of Salmonella infections in people who never had direct contact with the reptile.  Salmonella can be spread from the reptile's enclosure to other parts of the house, resulting in indirect infections. 

Reptiles can make great pets (I used to have tortoises and turtles). However, reptiles are responsible for a large and disproportionate number of Salmonella infections in people, and high-risk households should not have reptiles. People with reptiles need to take basic infection control measures seriously, including:

• Washing hands after contact with reptiles.
• Never cleaning aquaria or terrariums in kitchen or bathroom sinks.
• Never bathing or soaking reptiles in the bathtub, or kitchen or bathroom sinks.
• Keeping reptiles confined to their enclosures and not allowing them to roam the house.

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

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A Salmonella outbreak at the Bannerghatta Biological Park in Bangalore, India, has resulted in the death of three tigers. The latest victim, a four-year-old female tiger named Minchu, had been critically ill for the past two weeks and died of kidney failure. (Kidney failure is a potential complication of severe intestinal bacterial infections like salmonellosis.) This followed on the deaths of Minchu's older sister Divya and a 45-day-old tiger cub. Fifteen of the remaining 41 tigers are sick, and more deaths would not be surprising.

The source of the outbreak at the Bannerghatta Biological Park hasn't been reported. Likely, it originated from Salmonella in raw meat. Whether the large outbreak indicates a highly contaminated batch of meat, a particularly virulent strain of Salmonella or widespread transmission of Salmonella from an initial case or two is not clear. Regardless, good infection control practices are going to be critical, since the animals' environment is certainly highly contaminated. This poses a risk to all animals and people exposed to the environment. Good infection control is also needed to prevent Salmonella from spreading to other parts of the park.  Spread is most likely to occur via peoples' hands or clothing, or through contaminated equipment.

Large Salmonella outbreaks can be very hard to contain. Aggressive infection control, including testing of animals, isolation, thorough cleaning and disinfection, restriction of movement, and re-assessment of various management practices are key aspects of any outbreak control program. Hopefully this outbreak is now under control and Salmonella doesn't "escape" and affect other animals or people at the park.

(click image for source)

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An article released today in the journal Pediatrics (Behravesh et al, 2010) provides more information about a salmonellosis outbreak linked to pet food. The outbreak itself is old news - I commented about it almost two years ago. What is new is the detailed epidemiological analysis of the outbreak, and there is some interesting information in the paper that is worth reporting. Here are the highlights:

Almost 50% of people who were infected were kids two years of age or younger.

• That's not too surprising considering kids less than five years of age are a high-risk group for getting sick after being exposed to Salmonella.

Households with sick people were almost 7 times as likely to have recently purchased the affected food.

• This provides good evidence of the link between the contaminated food and disease.

The Salmonella strain that was found in people was also found in bags of pet food at the manufacturing plant, samples from the manufacturing plant environment, and fecal samples from dogs that had eaten the food.

• This is pretty convincing evidence that the food was the source. Because they were able to type the Salmonella strain in people and it was an uncommon strain, and they then found the same uncommon strain in food, animals and people, it paints a pretty clear picture of what happened.

Illnesses occurred over a 3 year period.

• This is pretty concerning. This was more than a little lapse at a plant that led to contamination of a single batch of food or a short term event. This was a major failure in quality control that was undetected for a long period of time, resulting in at least 79 human infections in 21 US states.

A cluster of infections caused by the strain involved here, S. Schwarzengrund, was identified early in the outbreak. However, a link with pet food was not considered until the following year.

• That's unfortunate but maybe not surprising. There are a lot of other more likely sources of infection that were probably focused on initially. "What kind of pet food do you feed your dog?" was unlikely to be a routine question asked of people with infections. Identification of outbreaks caused by uncommon events is difficult and typically takes more time.

People that fed their dog in the kitchen were 4 times as likely to have an infection.

• Feeding a pet in the kitchen presumably increased the chance of cross-contamination with human food or contamination of the food preparation environment.

The cause of contamination was never identified. The authors of the paper suspected that contamination occurred after extrusion (the process during which the kibble is formed), which makes the most sense. The extrusion process results in high enough temperatures to kill bacteria like Salmonella. Possible causes of contamination include contaminated equipment used after extrusion, cross-contamination of pre- and post-extrusion food and contamination of substances (e.g. flavour enhancers) sprayed on kibble after extrusion. The fact that Salmonella was found in the room where materials were sprayed on the kibble supports this further.

In general, dry pet food is quite low-risk in terms of Salmonella contamination, but just like with other non-raw-animal products such as lettuce, tomatoes and sprouts, contamination can occur and human infections can result. The best way to reduce the risk is to use good general hygiene practices, particularly washing hands after handling food, keeping pet food and pet food bowls out of kitchens and limiting contact of young children and other high-risk individuals with pet foods.

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A study we just published in the journal Veterinary Record (Floras et al 2010) described an MRSA outbreak in a dog breeding kennel. That's a little unusual in itself, but considering how MRSA is spreading amongst the dog population, it's not really astounding. What was unique about this outbreak was the strain of MRSA that was involved, sequence type 398 (ST398).

ST398 MRSA is commonly referred to as livestock-associated MRSA, since this strain seems to have originated in pigs, and is commonly found in pigs and calves in some regions of the world. It can also infect people, and high rates of carriage of this MRSA strain can be found in pig farmers, pig vets and other people with close contact with livestock. In some areas of Europe, this strain is a big problem, accounting for a large percentage of human MRSA infections. Interestingly, it seems to be a rare cause of illness in people in North America (at least at the moment).

Dogs seem to be innocent bystanders when it comes to MRSA. The vast majority of MRSA strains found in dogs are common human strains, indicating that, ultimately, MRSA in dogs originated in people. There are only two other reports of dogs with ST398, both from Europe. One was a dog with a skin infection. The other was a healthy dog (a carrier) who was owned by a pig vet. 

This kennel outbreak involved a larger number of dogs, including both healthy carriers and sick dogs. Overall, MRSA was isolated on at least one occasion from 23/42 (55%) dogs in the kennel. In a couple of litters, most of the puppies were identified as carriers, but fortunately most stayed healthy. MRSA caused skin infection in one puppy and mastitis in a mother dog, and was also found in the respiratory tract of a puppy that died (although it may or may not have been the cause of death).

The source of the ST398 was not identified. One of the owners worked on a pig farm, but MRSA was not isolated from either owner. It's most likely that the owner did bring MRSA home from the farm, either as a transient carrier (in their nose) or as a contaminant on their skin. Regardless, once it got into the kennel, it was able to move between dogs, either from dog-dog contact or with the help of human hands. Fortunately, ST398 MRSA carriage by dogs seemed to be transient in this situation, which is consistent with what we know about carriage of other strains. MRSA is not really adapted for long-term survival in dogs, so they only carry it for short periods of time. That's a big advantage when it comes to trying to control this pathogen.

While we have to be careful to not over-interpret data from only a few studies, this report indicates that ST398 can cause disease in dogs and it can be present in apparently healthy dogs. It can also be spread relatively easily amongst dogs in a breeding kennel situation. While a pig-link was not confirmed, it's reasonable to suspect that dogs with contact with pigs (and perhaps other livestock) might be at higher risk of developing ST398 infections, as is the case with people.

This is a perfect example of the one medicine concept, and why we need to think about infectious diseases in broad terms, not just focusing on specific populations or species. This situation involved a pig Staphylococcus aureus that somehow acquired methicillin-resistance, spread widely around the world (most likely in pigs, initially), spread to people, and then likely spread to another species, in this case dogs.

(click image for source)

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The OSPCA has changed their plans for management of the ringworm outbreak that is ongoing in a Newmarket, Ontario shelter. Now, some (hopefully all) remaining animals will be fostered out to local veterinarians while the situation is being brought under control.

One question that has been asked widely in the press and by the public is why these animals haven't simply been sent to foster homes. Particularly now, with all the attention, there would presumably be many people willing to take in these pets. However, putting animals infected or potentially infected with ringworm into foster homes is a controversial and potentially problematic situation, because ringworm can be spread easily to people and other animals in the household. Sending out an animal that is or may be shedding a zoonotic disease is a tricky situation, and one that can't be taken lightly. Additionally, proper management of these animals can take significant time and effort.

A better approach is to send the animals to places where they can be properly, safely and humanely isolated and treated. Veterinary clinics are a logical option, and a request has been sent to clinics in the area to take animals for quarantine and treatment. The reason veterinary clinics are being solicited is that many clinics have the ability to properly house these animals in isolation units and have the expertise and commitment to properly treat them.

Nonetheless, this is no small favour to ask of these veterinary clinics.  Just as taking an infected pet into a household carries some risk, taking these animals into a clinic is also associated with some risk of transmission to people and other animals. However, with proper facilities and protocols, and the donation of sufficient personnel hours to implement those protocols, the risks should be minimal. To facilitate this, we have developed an information sheet with infection control and treatment recommendations for veterinary clinics. For anyone else who is interested, the document can be found here and on the Worms & Germs Resources page under Information Sheets For Veterinarians.

Image: Ringworm lesions on the paws of a dog. Although this is how "classic" lesions tend to appear, clinical signs of ringworm in pets can be highly variable.  (click image for source)

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Never a dull moment...

This morning the Toronto Star published an article about the intended euthanasia of 350 animals at a humane society in Newmarket due to an ongoing ringworm outbreak.  This was quickly followed by another article about the same event that gave a few more details, including some comments from the OSPCA chief executive officer Kate MacDonald, who confirmed that the euthanasias had begun.  A "very aggressive strain" of ringworm and "human error" (related to a breakdown in protocols) are currently being blamed for this morning's actions.  A lot of people are (understandably) very upset.  No one ever wants to see an infectious disease outbreak come to something like this.

I’m hesitant to comment too much at this stage, because we still don’t have all the facts - apparently even the duration of the outbreak is unknown.  No one has said if all 350 animals are infected (or what percentage of them are), nor how many other animals are present at the shelter. We also don’t know what’s already been tried in terms of controlling the outbreak.

A few facts about ringworm (dermatophytosis) that people need to remember:

• Ringworm is a skin infection that can be caused by several species of fungi.  It is not a "worm" at all.  It is also very easily transmitted by direct or indirect contact with infected animals - their fur, their cages, their blankets, or anything else that may be contaminated with infected skin cells or hair.  Such infectious material can even be spread over short distances (e.g. room to room) in dust that is stirred up into the air.
• Ringworm is transmissible to people, so with a large outbreak there are also issues with staff safety, and concerns with adopting out infected animals.  For most people ringworm infection may cause itchy, uncomfortable skin lesions, but for higher-risk people (e.g. very young children, the elderly or immunosuppressed individuals) the infection can be much more serious.
• There are also a lot of animals (particularly cats) that carry ringworm without showing any signs of infection. If the Newmarket shelter has 350 animals with clinical signs of ringworm (a detail about which we have no information right now), that’s pretty bad, but even the animals who don't appear to be infected may be carrying the fungus and could spread it to others.
• Crowding, close contact and warm, humid environments are all factors that increase the risk of ringworm transmission. These are also all factors that are very hard to control in a crowded animal shelter.
• Ringworm is treatable, but it is not cheap or easy. Animals typically require systemic therapy (usually oral medication, which can be very expensive particularly in large dogs) as well as whole-body topical therapy (e.g. dips, shampoos, sprays), and they need to be treated for several weeks. Decontamination of the environment at the same time is critical to prevent reinfection.

Cleaning up a ringworm outbreak at a shelter with at least 350 animals is no small undertaking.  The second article in the Star also describes personnel at the shelter this morning wearing "white hazardous material suits, latex gloves and plastic covers over their shoes", which would be considered reasonable precautions for entering a highly contaminated environment.

I'm sure we'll hear more about this in the days to come, and hopefully that will include more details about why the mass euthanasia was deemed necessary by the OSPCA.

For more more information about ringworm, download the information sheet from the Worms & Germs Resources page, or check out our archives.

Photo source: yorkregion.ontariospca.ca via www.thestar.com

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The May 2010 edition of Emerging Infectious Diseases contains a report about an outbreak of cryptosporidiosis in Scotland (McGuigan et al. 2010). Cryptosporidiosis is a common parasitic disease caused by Cryptosporidium, a protozoal parasite. It causes diarrhea, which is usually annoying (to say the least) but self-limiting in healthy people, but the infection is potentially fatal in people with compromised immune systems.

An investigation was launched after a single case of cyrptosporidiosis was diagnosed by a Scottish laboratory. The reason a single infection caused such concern is that it was suspected to have originated from contact with lambs at a wildlife centre, so there was potential for exposure of many people. The concerns were valid, since a total of 128 cases of cryptosporidosis were uncovered during their investigation, and 117 of the people affected had visited the wildlife centre. Another 252 unconfirmed cases were also identified.

The investigation suggested that direct contact with diarrheic lambs was the source of infection. Lambs (and calves) are high risk for shedding Cryptosporidium, even when they're healthy.  Diarrhea increase the risk of transmission from these animals even more, because diarrheic animals are more likely to (1) shed the parasite and (2) have fecal staining of their haircoats, which increases the likelihood of fecal contact for every person and animal around them. That's why young ruminants (e.g. lambs, calves) as well as young poultry are considered inappropriate for petting zoos and other similar public animal contact events. This outbreak is yet another example of why these recommendations are in place.

At the wildlife centre in this study, children were apparently encouraged to pick up the lambs, despite visible diarrhea. No handwashing facilities were near the lamb petting area and it took "considerable effort" to find a location to wash your hands anywhere on site. Alcohol hand sanitizers were available, however Cryptosporidium is resistant to alcohol. Handwashing is a critical component of disease prevention, but unfortunately it is very underused. In general, people are becoming much more aware of the need for handwashing, but even so, if handwashing facilities are not conveniently located, people tend not to go to much effort to find them. That leads to increased risk of infections, as was the case here.

Control measures at the wildlife centre implemented after the investigation included removal of the lambs (who should never have been there anyway), disinfection of the premises with bleach (although disinfecting a farm environment is very difficult, and Cryptosporidium is also resistant to bleach), and stopping direct contact between animals and visitors.

As we enter the season when there are more fairs, petting zoos and other animal contact events, facility managers need to pay attention to important factors like:

• Readily available hand hygiene facilities
• Good design to control the types of human-animal contact and to steer people towards hand hygiene stations
• Appropriate animals: no calves, lambs or chicks
• Proper supervision of people and animals

A little common sense goes a long way. The goal is to set up these events so that there is still a beneficial impact of seeing and interacting with animals while reducing (but never eliminating) the risk of disease transmission. A 100% safe petting zoo is not achievable (there's always some risk in life), but some pretty simple measures can greatly reduce the risks while still providing excellent entertainment and educational opportunities.

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The latest edition of the journal Emerging Infectious Diseases contains a paper describing the 2008  Australian Hendra virus outbreak in horses and people.

In this outbreak, there were five horses infected and two humans infected. The horses predominantly had signs of neurological disease, not respiratory disease like some other reports describing this disease. Four horses died. One recovered but was euthanized for public health reasons.

Two people became infected after working with the sick horses, which represents 10% of the total veterinary staff that were exposed to the infected horses.  Both people started off with influenza-like illness, which seemed to improve initially, but then signs of severe neurological disease developed. They were treated with ribavirin, an antiviral drug, as part of an experimental treatment. One of them died after 40 days of illness, the other person survived.

The authors stressed that the effectiveness of ribavirin could not be determined, but they recommend it nonetheless because of the severity of Hendra virus infection and lack of other options. Ribavirin was also used in the 2009 outbreak, but it is clearly not 100% effective since one person died there also.

A number of concerning activities occurred that put people at risk of infection, including a "percutaneous blood exposure while euthanizing an infected horses" (they didn't explain exactly what this was, but it could have been a needlestick), low use of personal protective equipment, and contact with potentially infectious body fluids. This is unfortunately not surprising since the approach to infection control (particularly in terms of zoonotic infections) is often lax in equine medicine. That certainly has to change, particularly in areas where Hendra virus may be present.

Much more information about how to control this potentially devastating virus is needed. Fortunately, infections are uncommon and it is restricted to a fairly small geographic range in Queensland, Australia.

Image source: http://animalphotos.info/

This Worms & Germs blog entry was originally posted on equIDblog on 27-Jan-10.

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A very poorly-written and confusing report suggests that another Streptococcus zooepidemicus outbreak is underway in dogs in a shelter in Ohio. Five of 175 dogs on the premises died suddenly of hemorrhagic pneumonia. The report variably mentioned a "virus that mutated from horses," that it's thought to be "not contagious" despite multiple dogs being affected, and that it's a "rare form of streptococcus" (a bacterium). Presumably, they are dealing with a group of dogs with Streptococcus zooepidemicus pneumonia (technically, Streptococcus equi var. zooepidemicus). This bacterium predominantly lives in horses but periodically causes infections in other species. Outbreaks in dogs are uncommon but have been reported in other shelters. I assume that cultures from the dead dogs identified the bacterium, otherwise other possible causes such as canine influenza would also have to be considered.

The statement about it not being contagious is bizzare. Obviously, it is contagious between dogs. It may have been referring to dog-to-human transmission, but while that's rare it has been reported.

The shelter is apparently treating all dogs with penicillin prophylactically (i.e. to prevent any more dogs from getting sick). There's no clear guidelines regarding management of S. zooepidemicus outbreaks in kennels. It's now known whether mass antibiotic treatment does anything helpful, but it has been used in other outbreaks. I think it's likely that these outbreaks stop on their own, rather than penicillin having a major impact, and that there's probably another underlying cause such as a viral infection to account for outbreaks of this rare disease. However, that's just speculation for now. Hopefully this outbreak will cease with whatever treatment and infection control measures they put in place (or on it's own). Hopefully a good review of routine infection control practices will be performed at the same time, as routine practices (or lack thereof) are often a major problem in shelters.

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You'd think, after countless outbreak of salmonellosis associated with pet turtles, that people would learn and things would start to improve. I guess not. A paper published this week in Pediatrics (Harris et al) described a large outbreak of Salmonella Java associated with pet turtles. Between May 2007 and January 2008, 107 infections were identified. The median age (the age in the middle of the range of affected people) was seven years old. Sixty percent of infected people reported exposure to turtles during the week before they got sick; 87% were small (<4 inch) turtles, and 34% were purchased at a retail store (despite the fact that the sale of turtles less than 4 inches long is banned in the US). Five infected people, all less than 10 years of age, reported kissing the turtle or putting it in their mouths.

When they compared people with Salmonella Java infection to people without the infection, 72% of people with Salmonella reported contact with turtles versus only 4% of controls.

Salmonella is far from rare but it's nothing to ignore. Thirty-three percent of infected people were hospitalized. Fortunately, no one died.

The link between turtles and Salmonella has been known for a long time. Healthy turtles can carry the Salmonella bacterium and be a source of infection, particularly for children. The sale of small turtles is banned in the US to reduce the likelihood of close contact between turtles and kids, but this law is widely flouted. An understanding of the link between turtles and Salmonella is surprisingly uncommon - only 32% of Salmonella patients in this study (and 28% of controls) reporting knowledge of this link. Clearly, there are a lot of areas which could be improved.

• If banning the sale of small turtles is truly an effective measure, then it should be enforced. "Black market' turtles are far too easy to find.
• More public education is needed, among the general population and particularly people buying turtles. You shouldn't be able to take a turtle home from a store without an information sheet about the risk of Salmonella and how to avoid it.
• People with turtles (or any reptile) need to recognize the risk and act appropriately. Good general infection control and hygiene measures are needed to reduce the risk of Salmonella exposure.
• Households with children under five years of age, or with immunocompromised individuals should not have pet turtles.
• Antibiotics are not the solution. Attempts to create Salmonella-free turtles with drugs have just led to the production of turtles carrying antibiotic-resistant Salmonella.
• Common sense needs to be a little more common. The picture above (from http://www.familylovezone.com/js_DeepAndWide.htm) was proudly posted by a parent.

More information about infectious disease risks associated with turtles can be found on the Worms & Germs Resources page.

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Tuttle Animal Medical Center in Florida has reported six dogs with severe bloody diarrhea, vomiting and fever, over the past month. The affected dogs were from the same general area in Sarasota County, and all but one died within 24 hours. However, care must be taken when interpreting information such as this. Apparently, most dogs were owned by people with limited finances, so it's hard to say whether they would have died if aggressive (and expensive) treatment could have been provided. A disease like parvovirus is highly fatal without treatment, but survival rates are excellent if proper treatment is provided.

Initial testing of these dogs to identify the causative agent has been unsuccessful, including a rapid in-clinic test for parvovirus. Because of limited finances, complete diagnostic testing has not been performed, and it's likely that only a very limited range of possible causes have been investigated. That's a problem with a user-pay system such as this. There's no incentive for owners of dead pets to pay for further testing that could help understand the problem and/or help other peoples' pets.

Various experts have been consulted, but it sounds like there is minimal material (e.g. saved fecal samples) to use for further testing.  Trying to make a diagnosis based on clinical signs and basic laboratory data collected by the clinic during standard work-up and treatment is essentially impossible. Veterinary infectious disease expert Dr. Cynda Crawford told VIN News Service by e-mail last Wednesday "There is very little case material to work with, so am struggling with meaningful diagnostic approaches,...Everything is basically speculation at this point."

Florida's Division of Animal Industry is apparently "monitoring the situation." At this point, there's nothing that can really be done, but hopefully assistance with testing will be provided should further cases be identified. One official from this agency speculated that E. coli O157 could be the cause. That seems pretty unlikely. This bacterium can cause disease in dogs but it's quite rare. Six apparently unrelated cases due to such a rare cause seems pretty unlikely, although it shouldn't be dismissed.

A general tenet of medicine is "common things occur commonly." Situations like this are most often unusual presentations of a common disease (e.g. parvovirus) rather than a new disease. More aggressive diagnostic testing for known causes of disease, along with additional testing to try to identify new pathogens is needed if further cases are identified. Sometimes apparent outbreaks like this go away on their own without any intervention or diagnosis. Only time will tell whether this is a small local event or the "tip of the iceberg."

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Quarantining animals that have potentially been exposed to rabies is a standard practice, but quarantining a whole town is new to me. Because of a large increase in rabies cases in the Flagstaff, Arizona area, a rabies quarantine was established on April 8th by the Coconino County Board of Supervisors. The quarantine requires all dogs and cats to be enclosed or secured on their owner's property. When off the property, animals must be on a leash that is no longer than six feet in length. All dogs and cats must be vaccinated, and low-cost rabies vaccine clinics have been held to help increase compliance with this requirement. Vaccination of wildlife using baits containing an oral form of rabies vaccine will also be performed. The quarantine also restricts feeding and interacting with wildlife. Also, people cannot leave pet food outside after sunset and all compost piles must be completely enclosed.

This is an aggressive approach to rabies control in an area experiencing a wildlife outbreak of the disease. They've implemented comprehensive but still quite practical measures that should help reduce the risk of exposure of domestic animals (and people) without a significant negative impact on pet owners. I've mentioned my concerns about rabies vaccine clinics in the past, but this is a situation where I think it's a good idea.

It's always hard to evaluate the effectiveness of outbreak measures, because you never know what would have happened if nothing had been done. Regardless, it will be interesting to see how well this quarantine works, both in terms of the number of new rabies cases they see and the response of citizens to these restrictions. It would be very useful if Coconino County personnel provide information about how things went when the quarantine is over - the information might be useful for management of future rabies outbreaks.

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A large outbreak of rabies continues to have devastating effects in Angola, Africa. While rabies outbreaks are not uncommon in some parts of the world, the number of people affected in this outbreak is remarkable. A hospital in Luanda, the nation's capital, has diagnosed rabies in at least 93 children in the past 3 months. All have died. The main source of the disease in this case is Angola's large stray dog population. Stray dogs can transmit rabies to other dogs and people through bites. The poor socioeconomic status of the country increases the risk of outbreaks like this because:

• Vaccines are not readily available (for dogs or people)
• It is difficult to organize and fund vaccination programs for stray dogs
• It is difficult to educate the general population about how to avoid and manage rabies exposure
• The healthcare system is relatively limited

These problems, all related to a poor economy, create a "perfect storm" for a rabies outbreak. The shortage of human rabies vaccine and the high cost of post-exposure prophylaxis (PEP) makes it much more likely that people will actually develop signs of rabies after being exposed. The cost of PEP is more than the average Luanda family makes in a month.

Fortunately, the outbreak seems to be waning. However, without improvements in stray dog management (including vaccination) and access to adequate PEP, future outbreaks and problems are inevitable. It was reported that "adequate" supplies of canine rabies vaccine are now available. Hopefully, a concerted effort to vaccinate as many dogs as possible will reduce the rabies load in the canine population, thereby helping to decrease the risk to the people living in the area as well.

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