Army vs parents in soldier rabies case
The parents of a US soldier who died of rabies after being bitten by a dog while deployed in Afghanistan want their son's superiors to be held accountable. Specialist Kevin Shumaker died last August, eight months after being bitten by a dog. An Army investigation concluded that he died because members of his unit ignored rules prohibiting keeping pets (they were befriending feral dogs) and that he didn't seek treatment or notify the chain of command after being bitten. His parents feel that their son is being falsely blamed and that people who should have known better didn't do their jobs. It's a complex issue with some interesting questions.
What should the average soldier know about rabies?
It should be assumed they know absolutely nothing to start off, and a risk assessment should be performed for each deployment to determine what they need to know. When they are being deployed to a rabies-endemic area, they need to learn to stay away from dogs and report dog bites promptly, and why.
Whose job is it to report a bite?
At the end of the day, everyone has to be their own advocate and make sure they report any possible rabies exposure. People up the chain of command don't see everything and individuals need to protect themselves. However, once the bite is reported, others have to act. That might be the breakdown here.
Was anyone actually notified?
The Army's investigation actually documents the fact that Spc. Shumaker notified other personnel at least twice. One was a veterinary corps officer and the other was the person doing his post-deployment health screening. Here's where the ball was probably dropped. Every veterinarian knows about rabies. A veterinarian working in a rabies endemic region is certainly aware of the risks and has a responsibility to act on a reported bite. I find it astounding that a veterinarian in this situation wouldn't initiate a response, particularly given the fact that (at least in my limited experience) the US Army Veterinary Corps has some excellent veterinarians, so this seems rather strange. Further, what's the purpose of a post-deployment health screening if health issues that arise are ignored? If the person doing the health screening didn't understand the concerns about rabies, he or she was inadequately trained and shouldn't have been doing the job. If the screener was properly trained and didn't report it, he or she was incompetent, plain and simple.
Would anything have changed the outcome here?
Absolutely. Rabies is almost 100% fatal, but it's almost 100% preventable when post-exposure treatment is given before the onset of disease. There was lots of time in this case between the bite and when the soldier became ill, and if he had been treated following one of these reports, you can almost guarantee he would not have developed rabies.
Whose fault is this?
Well, everyone plays a role here. The soldier ignored the animal contact rules. Superior officers on base presumably ignored the fact that they were ignoring the rules, probably not thinking about the possibility of rabies, and seeing the positive effect on morale of interacting with the dogs. If the veterinary officer and post-deployment health screener were told about the bite and did nothing, they played a huge role since they, of all the people in this chain, should have known better.
What should happen here?
Rather than fighting over who's to blame (the usual response), an investigation should figure out why this happened and how to prevent it from happening again, largely via better training and clear expectations of personnel.
Hopefully that's happening, since Deputy Commanding General Maj. Gen. William Rapp recently approved a series of recommendations, including:
• Further investigation to see if any members of the unit should be disciplined for their actions or omissions during the unit’s deployment to Afghanistan
• Institute an animal-borne disease surveillance program, standardize rabies vaccine requirements and improve dog bite reporting requirements (I'm surprised that wasn't already the case)
• Reinforce animal bite and rabies training for veterinarians and post-deployment health screening staff
Rabid horses in Tennessee
Rabies is pretty rare in horses in North America, with only 37 reported cases in the US in 2010 and 1 in Canada in 2011 (the latest years for which data are available). So, finding two apparently unrelated cases of rabies in horses in the same area in the same month is pretty unusual and concerning. Yet, that's what's happened in Tennessee, where rabid horses were identified in both Rutherford and Marshall counties in January.
Little information is available about the cases, but both were identified as having the skunk rabies virus variant. That doesn't necessarily mean they were infected by skunks (since other species can be infected by this virus variant) but it is suggestive, and indicates that rabies must be active in the skunk population in that region.
Regardless of the source, these cases are a reminder of why rabies vaccination of horses is important, and why rabies vaccination is considered a "core" equine vaccine by the American Association of Equine Practitioners. Rabies is invariably fatal in horses and it's also a major public health risk. While I've been unable to find confirmed cases of horse-to-human rabies transmission, it's a possibility, and additionally, rabid horses have killed people because of their unpredictable and aggressive behaviour.
Vaccination is cheap insurance against rabies - it's never a 100% guarantee, but it's a whole lot better than without vaccination.
Toxoplasma risk factors for cats
There's been a lot of publicity (aka hype bordering on paranoia, including a recent article in the Toronto Star) about the cat-associated parasite Toxoplasma gondii lately. Cats are the definitive host of this parasite and it can cause serious disease in certain people: in pregnant women who have not been previously exposed to the parasite it can infect the unborn fetus, and it can cause severe illness (including neurological disease) in people with severely compromised immune systems. It's also been very loosely implicated in various other conditions, but much of the information gets overblown, as there is lack of solid evidence of a role of Toxoplasma in most of these cases. Unfortunately, cats end up getting a bum rap in the process, even though most Toxoplasma infections don't come directly from cats.
Nonetheless, toxoplasmosis is a potentially devastating disease in some circumstances. and taking measures to reduce exposure to the parasite makes sense. To do this you need to know what makes cats more likely to be infected, so that these factors can be modified. A recent paper in Preventive Veterinary Medicine (Opsteegh et al. 2012) investigated risk factors for cats having antibodies against Toxoplasma. It's important to note that the presence of antibodies means the cat was exposed at some point and mounted an immune response, not that it's currently shedding the parasite in its feces. Most cats only shed Toxoplasma in their feces for a very short window of time (a week or two) after initial exposure, and that usually occurs early in life. Therefore, it's rare for older cats in households to be shedding the parasite.
The research group found 18% of cats they tested had antibodies against Toxoplasma, and they identified a few factors associated with previous Toxoplasma infection:
- Age: Younger cats were less likely to have antibodies. The likelihood of having Toxoplasma antibodies increased steadily from 1-4 years of age.
- Hunting
- Presence of a dog in the house
- Being a former stray
- Feeding raw meat
Most of these make perfect sense and are consistent with other studies. Cats typically get infected by ingesting Toxoplasma cysts found in the muscle of other animals. So, cats that are outside (indoor/outdoor cats, former strays) and hunt, or cats that are fed raw meat are more likely to be exposed. Analysis of the data indicated that hunting contributed the most.
So, while the risk of Toxoplasma infection for the average person is pretty low, some basic management practices can further reduce any risk:
- Keep cats indoors: This greatly reduces the chance they will be exposed to the parasite. It is also good idea for several other reasons.
- Don't feed cats raw meat: Cooking meat to the recommended temperature and time will kill any encysted parasites - this also helps prevent exposure of people eating the meat (to Toxoplasma and lots of other bacteria).
- Control rodents in the house (not by getting a cat!): Indoor cats can still be exposed to various infectious agents through catching mice. I know it's not always easy or even possible (my cat still catches the odd indoor critter) but taking measures to reduce the likelihood of this is wise.
Other important preventive measures include:
- Changing the litterbox regularly, especially if a high-risk person has to do it. Toxoplasma oocysts need at least 24-48h in the environment to become infective. If feces are removed daily, they don't get that chance.
- Clean up any fecal accidents and remove any fecal staining of the haircoat (e.g. poop stuck around the rear end of long-haired cats) promptly, before that 24-48h window expires.
- Wash you hands regularly, especially after contact with the litterbox or any potentially contaminated areas.
- Wash vegetables and cook meat properly. You're more likely to get Toxoplasma from food than from your cat.
More information about Toxoplasma can be found on the Worms & Germs Resources page.
Tropical Rhodococcus equi outbreak?
TheHorse.com has reported on an outbreak of Rhodococcus equi that has claimed the lives of seven ponies at an equestrian facility on the island on Mayotte (a French protectorate off the coast of Madagascar). Local agriculture officials report that two other horses are also affected, but recovering, and the facility has been quarantined
There are a few strange aspects of this report. Rhodococcus equi is an important cause of respiratory disease in foals, in which it can cause serious abscesses in the lungs. However, it's extremely rare in mature horses, and it seems that the horses affected in Mayotte were adults. It's not impossible, but an outbreak of Rhodococcus in adults would be incredibly surprising, indicating either something that made these horses remarkably susceptible to the bacterium, or the presence of a strain of Rhodococcus more able to cause disease in adults. A more likely explanation is that it's not actually Rhodococcus. There's no mention of what type of disease the horses had or for what other infectious agents tests were done. A Department of Agriculture official stated that the diagnosis was made by blood tests, but blood testing is pretty useless for diagnosis of Rhodococcus. So, I'd consider the diagnosis highly questionable without further information.
Whatever the cause, something that kills seven horses on a farm is remarkable and thorough testing is needed to determine exactly what's happening. In the unlikely event that this was caused by Rhodococcus, more work needs to be done to explain why the outbreak occurred and why it was so severe. If (as is likely) it wasn't Rodococcus, knowing the actual cause is important for controlling further spread and preventing problems in the future.
Fortunately, the remote nature of this location makes it rather unlikely that whatever's happening there will spread to another region soon.
Image: Location of Mayotte (click image for source)
Ontario equine biosecurity seminars
Equine Guelph has announced a series of equine biosecurity workshops across Ontario which will take place during the month of March 2012. The sessions are free to attend and will focus on how to apply basic and practical concepts of infection control to reduce the risk of disease exposure and outbreaks in horses of all types. The workshops are part of a broader Beat the Bugs biosecurity program being organized by Equine Guelph, which also includes a two-week e-session being offered in April 2012.
More information about the workshops (including dates and locations, and to register), e-session and the Beat the Bugs program can be found on the Equine Guelph website.
Kennel cough and vets
An article from NBCMontana.com describes a kennel cough outbreak in dogs in Bozeman, Montana. It's a pretty basic article that outlines a rather typical presentation of kennel cough (now largely referred to as canine infectious respiratory disease complex - a respiratory infection that can be caused by a range of viruses, bacteria and Mycoplasma).
As part of the story, they state that if you have a sick dog, the "best course of action is to call your local veterinarian and get medication." I realize it's a quick statement, perhaps tossed in without much consideration, but there are some important issues to consider.
Should someone call a veterinarian and get medication, or should a veterinarian actually see the dog?
- Sometimes dogs just need to be given time and rest. Viruses are often the cause of this condition, and it just takes time for the infection to resolve (just like person with a cold virus). If that's the case, a little over-the-phone veterinary advice might be fine. If drugs are needed, then the dog needs to go to a veterinarian. Affected dogs might need something to control cough, which need to be given by prescription, and occasionally antibiotics are needed, but in either case a veterinarian needs to see the dog first. If the dog is sick enough that it needs additional treatment above and beyond this, then of course it needs to be seen by a veterinarian.
Are there any problems with a dog like this going to the veterinarian?
- Here's where the ball often gets dropped. The last thing we want to see is someone walking through the from door with a hacking, biohazardous dog who goes nose-to-nose with other dogs in the waiting room, breathes on half of the surfaces in the room, sits there for ten minutes while waiting for the appointment, and gets handled by every staff member before they realize the dog might be infectious. A situation like that can turn a veterinary clinic into a source of infection for many other dogs, and help an outbreak spread.
A very basic but well coordinated approach can greatly reduce the risk of dogs infecting other dogs in the clinic. These would include:
- Not taking a biohazardous dog into the waiting room. The owner can call from the car upon arrival or come in without the dog to let the clinic know they're there.
- The dog can be admitted directly into isolation or an exam room, thereby avoiding contact with other animals in the waiting room or elsewhere in the clinic.
- Veterinarians and techs that are going to work with the dog can know in advance and come in prepared, wearing appropriate protective outerwear (e.g. gloves and a labcoat or gown that they use for only that appointment) to prevent contamination of their clothing or body.
Very easy to do. Probably very effective too, but often not done.
Another rat bite fever warning
A case report in the Medical Journal of Australia (Pananicolas et al 2012) describes a case of rat bite fever and comes with the typical warning about this uncommon but concerning disease.
Rat bite fever is an infection caused by the bacterium Streptobacillus moniliformis (the main cause in most countries) or Spirillum minus (the main cause in Asia). The condition is, not surprisingly, associated with being bitten by a rat, although it can be transmitted by other routes such as dog bites. The bacteria live in the mouths of most rats (and a less-well-understood percentage of other animals). Disease occurs when these bacteria make it into the body via a bite, or other high-risk contact such as kissing the animal or letting it lick an open wound.
The Australian case report describes a 26-year-old woman who had a fever and sore throat, which progressed to a severe unrelenting headache with nausea, vomiting, sensitivity to light, neck stiffness and pneumonia. Streptobacillus moniliformis was isolated from a blood sample. The strain was fortunately susceptible to the antibiotics that had been started earlier. It wasn't until a couple of days later that a rash (a classic sign of rat bite fever) developed. Fortunately at that point the diagnosis had already been made and the woman was responding to treatment.
After "further history taking" it was revealed that the patient owned two rats and, while she had not been bitten, she had close contact with them, including kissing. It's not clear when the "further history taking" occurred, but it probably happened after they found the S. moniliformis and made diagnosis, which rounds out the case report nicely but doesn't speed up the diagnosis or improve case care. The animal contact question needs to be asked at the start. One of the Lessons from Practice that the article highlights is "A thorough history, including history of animal exposure and pet ownership, should be taken for all febrile patients." Remove "febrile" and I agree completely.
Anyway, the woman responded to treatment and went home after 17 days in hospital. Most people that are properly diagnosed and treated survive, but rat bite fever can be fatal.
Most rats carry at least one of the two bacteria that cause this disease. There's no indication to test pet rats (since we assume they all have the bug until proven otherwise, and we can't confidently prove otherwise) or treat them (since we have no evidence we can eliminate the bug from the mouth of a healthy rat). It's a limited but ever-present risk of rat ownership, and one that can be greatly reduce by avoiding kissing rats, preventing bites, proper wound care should bites occur, and ensuring that physicians know about potential rat contact if illness develops.
Methicillin-resistant staph...What's in a name?
I've written about this topic before, but it's an important (and increasingly common) issue to understand, so bear with me while I address the subject again.
I typically get multiple case consults in person, by phone or by email about methicillin-resistant (MR) staphylococci every day. A lot of these start with "I have a case with an MRSA infection..." While trying not to be rude, I tend to interrupt the conversation at that point with "Is this actually Staph aureus or another staph?"
I do this for a few reasons:
- A few years ago, the vast majority of "MRSA" infections in dogs, cats, horses and other companion animals were actually MRSA - that is methicillin-resistant Staphylococcus aureus. However, in the past few years, there's been a tremendous upsurge in other MR-staph, particularly booming numbers of MR-Staphylococcus pseudintermedius (MRSP) infections in dogs. These days, if it's a dog or cat, when I ask the "What staph is it?" question it's usually not actually MRSA. We're starting to see more MRSP in horses too, complicating things in that species as well.
- Staph are divided into two groups, coagulase positive species (which include S. aureus and S. pseudintermedius) and coagulase negative species. The coagulase negative species are commonly found in or on healthy animals and are often methicillin-resistant, but they are not very virulent and don't usually cause disease outside of very high risk populations (e.g. very sick animals in a veterinary hospital). If a MR coag-negative staph is isolated, I am far from convinced it's the culprit, and typically the real cause of the problem still needs to be found.
- MRSA is much more of a concern from a public health standpoint, as it can move between animals and people. While MRSP can cause human infections, these are extremely rare.
- MRSA is not really adapted to live in dogs, cats, horses and many other animals. It can, for a while, but doesn't do so longterm, and the vast majority of MRSA carriers will get rid of it on their own. In contrast, it appears that MRSP (at least in dogs) can stay with the animal for a very long period of time. Therefore, an animal that has had an MRSP infection has a reasonable chance of shedding the bacterium for a long period of time, which might be of relevance for its health in the future.
- The two main MR-staph of concern in companion animals are MRSA and MRSP. Some diagnostic labs still don't try to differentiate the two, despite the fact that there are different guidelines for determining whether they are methicillin-resistant. If someone has a result that doesn't differentiate MRSA from other staph, I tell them their lab isn't doing things right and they need to talk to them so they can have confidence in the results.
More information about MRSA and MRSP can be found on the Worms & Germs Resources page.
Obscure bug, obscure journal...but infection from feces in the eye not surprising
The latest edition of the journal Orbit (a journal dealing with eyes, not planets) describes an uncommon infection linked to a pet dog. The article (Zuberbuhler et al 2012) outlines 'acute unilateral dacryocystitis' in a 23-month-old girl (translation: .acute=sudden, unilateral=one side, dacryocystitis=inflammation of the nasolacrimal system, which is made up of a small sac and duct that runs from the eye to the nose).
In this case, the child had been playing in a gated children's area in a city park. At one point, she rubbed her eye after touching the ground, and shortly after the parent noted that the area around her eye had dog feces on it (not sure how they confirmed it was dog feces, but it's a logical guess). Two days later, she was taken to an emergency room because of severe swelling around the eye. A culture from the eye detected Pantoea, a bacterium that can be found in the intestinal tract of many different animal species (including people). It is a rare cause of disease but can cause infections when given the chance (such as being rubbed into an eye, or a wound, or other compromised sites).
While the bug and the infection may be a bit unusual, it's far from surprising to find an infection caused by fecal contamination. It reemphasizes the importance of basic hygiene measures such as hand washing (especially when feces are involved) and supervision of children, along with responsible pet ownership to prevent fecal contamination (i.e. picking up after your dog), particularly in enclosed children's playgrounds.
Salmonella from turtles...again
Yet another outbreak of salmonellosis traced back to pet turtles has been investigated by CDC and Pennsylvania's State Health Department. Pet turtles are notorious Salmonella vectors, for several reasons, including the fact that small aquatic turtles very commonly carry the bacterium, they are marketed towards young kids (who are increased risk of infection), and people tend to use poor (or no) hygiene practices when handling turtles or having contact with their environments. Efforts to restrict the sale of small (less than 4-inch long) turtles have greatly reduced Salmonella infection rates in people in the US, but have come under continual pressure from the turtle breeding industry, and the regulation is often flaunted by pet stores and road-side turtle sellers.
From August 5 to September 26, 2011, 132 cases of Salmonella Paratyphi B infection were identified in 18 US states.
- The median age of infected individuals was 6 years, and 2/3 were less than 10 years of age. This is consistent with a pet-associated outbreak.
- 56 patients (and their families, presumably) were interviewed, and 64% of them reported turtle exposure. That's a lot higher than one would expect if a random sample of the general US population was surveyed, and suggests that turtles were an important source.
- Of the 15 people who could provide details about the turtle, 14 of them described turtles that would have been too small to be legally sold in the US. This isn't surprising, and shows both the risk associated with these small turtles and the fact that this law is being widely ignored.
- The same strain of Salmonella was isolated from turtle tank water in five homes (it's not clear if only five were tested or if there were some negative tanks too). That's further evidence implicating the turtles.
This is yet another reminder of the risks posed by small turtles, particularly to young kids. Small turtles have high Salmonella shedding rates, are easy to handle and are even small enough for kids to put in their mouths (yuck!). That's a bad combination.
In 2007, Louisiana turtle breeders sued to reverse the FDA's small turtle ban. Fortunately they weren't successful, however it's clear that the turtle ban needs to be enforced, but that's hard to do. Perhaps more important, then, is increasing public awareness of the risks. If people are better informed of the issues, they can make better decisions about acquiring pets and how to properly manage them. One such resource for the public is the Turtles fact sheet that we have freely available on the Worms & Germs Resources page.
Norovirus from dogs?
Norovirus sucks. It's been a while since I had it, but it doesn't conjure up fond memories. A bunch of Canadian tourists returning from Cuba (and presumably all of the other people on their planes) can also attest to the unpleasant nature of this viral infection.
Norovirus in people is (logically) caused by human norovirus. There are some other types of norovirus that infect other species, but the human version predominantly infects people. Predominantly doesn't mean always, though, and other hosts of the virus need to be considered. A recent study published in the Journal of Clinical Virology (Summa et al 2012) looked at whether human norovirus could be found in dogs. Researchers collected fecal samples from 92 indoor pet dogs in Finnish households where people had vomiting and diarrhea or where the dog owner had had close contact with someone with norovirus. Fecal samples were tested for the presence of the virus using molecular tests.
Norovirus was detected in feces of 4 of the 92 (4.3%) canine fecal samples. All positive dogs were from households that had more than two sick people. Additionally, kids were present in all households with positive dogs. Two of the dogs had been sick, with nausea and loss of appetite. Illness in the dogs was pretty mild and only present for one day, and it's not clear whether norovirus was responsible. Fecal samples from owners were only available from one of the positive households, and there the same norovirus strain was found in the owner and the dog.
These results are interesting and indicate that a small percentage of dogs in contact with people with norovirus can shed the virus. The big question is, "what does this mean?" That's not so clear. Finding norovirus in the dogs' feces is one thing. Determining that it's relevant to human (or animal) health is another, and it's important not to over-interpret the results, because...
- The testing that was used detects norovirus RNA, i.e. genetic material from the virus. That means that the virus passed through the intestinal tract. It does not necessarily mean that live virus was present, since this type of testing detects both live and dead virus. Dead virus obviously poses no risk to anyone.
- Even if live virus was being passed in the dogs' feces, the amount of virus coming out the rear end of the dogs isn't known. It might be pretty low and therefore of less concern.
- The relative risk posed by the household dog is a big thing to consider. All dogs that were shedding the virus were from households with multiple sick people, therefore they were already in pretty biohazardous environments with lots of virus being tossed around (in many different ways). This suggests that it may take a lot of exposure for dogs to shed (potentially only a little) virus. Also, it minimizes the relative risk posed by the dog, since if only dogs from severely affected households shed the virus, the dog is only one of many possible sources and probably of lesser risk than exposure to sick people and environmental surfaces they contaminated. Dogs from households with active disease are probably not very likely to encounter lots of other people or dogs (probably less so than the people in the house), therefore limiting their potential role in transmission. There's no evidence that dogs are long-term carriers of norovirus.
Does this change what you should do if you have norovirus? Not really. It means you should try to limit contamination of the environment, wash your hands frequently, stay away from others as much as possible and avoid puking on your pets. Maybe we should add "keep your dog isolated along with you," just in case.
Another interesting finding was the association between sick kids and norovirus-shedding dogs. It's further evidence of the "kids are biohazardous" theory. We know that kids are at increased risk of various infectious diseases. At the same time, we have previously shown that contact with kids is a risk factor for dogs shedding Clostridium difficile and MRSA. Whether that's because kids are more likely to be shedding these bugs, they have closer contact with pets, they pay less attention to hygiene or a combination of these isn't clear, but this result isn't particularly surprising. (No, I'm not recommending banning kids from pet-owning households. As parents, we know our kids are effective disease vectors... that's just part of having kids.)
This study doesn't tell us whether pets are sources of human norovirus, and we really shouldn't expect it to. A single study rarely answers all the questions, and good studies sometimes raise more questions than they answer. This is an interesting study and it shows that more work is indicated to clarify the answers to the questions raised above, and to determine whether there is any real concern about dogs and this nasty virus.
