Despite the stories, Texas woman didn't get rabies from a puppy
Recent reports of a woman in Texas that "contracted rabies" are great examples of less-than-careful reporting. The headlines look dramatic, and a couple of articles state that a woman bitten by a puppy "contracted rabies", but it's far from the truth.
Here's the real story, as far as I can tell:
- A litter of stray puppies was taken to a shelter and then sent to a foster home.
- The woman who took them in was bitten in the leg.
- She received medical care and took the puppy to a vet. The vet euthanized the animal because of the aggression it was displaying and had it tested for rabies.
- The puppy was positive for rabies and the woman is undergoing post-exposure treatment.
It's not a nice situation for the person that was bitten, but it's not exactly a rare event and post-exposure treatment for rabies, when given properly, pretty much has a 100% prevention rate.
Authorities are also trying to track down any people that may have had contact with the puppies before they were taken to the shelter, to determine if more people need post-exposure treatment.
Strangely, the other puppies are being isolated for 45 days, after which time they will be put up for adoption (assuming they don't develop signs of rabies). This doesn't make a lot of sense. Standard recommendations are that unvaccinated animals exposed to a rabid animal should be euthanized or quarantined for 6 months. The 6 month quarantine is in place because rabies can take a long time to develop after exposure. Since these puppies came in with the sick one, and it's almost certain there was no information about their vaccination history, they have to be considered exposed and unvaccinated. This is true even if they were vaccinated at the time of arrival because they could have been exposed before vaccination. Further, animals are not considered protected until 28 days after vaccination, and exposure within 28 days of the first shot is the same as exposure of an unvaccinated animal.
In this case, it was pretty easy to determine that the woman didn't have rabies in some, but not all of the articles. I particularly liked how one of the stories described how rabies "eats away at the brain," a description you wouldn't expect to see from a more mainstream source.
Presumably, the woman who was bitten will be left with nothing more than some bad memories and an increased awareness of rabies. Hopefully the shelter reviews its policies to determine whether this could have been prevented and whether other measures should be in place to reduce the risk to people who foster animals. At a minimum, this would include ensuring foster homes know about the risks, know to get the animal to a veterinarian if it begins to act strangely (as this woman did) and ensure that other pets in the household are properly vaccinated.
Fatal psittacosis in a parrot owner
A 62-yr-old Italian woman has died from psittacosis, an infection caused by the bacterium Chlamydophila psittaci. Sometimes called "parrot fever," psittacosis is an uncommon but important disease linked to contact with birds, particularly psittacines (e.g. parrots, parakeets, cockatiels). In people, C. psittaci usually causes flu-like respiratory disease, but severe pneumonia and encephalitis (inflammation of the brain) can occur in some individuals. With prompt diagnosis and treatment, mortality (death) rates are very low (<1%), however mortality rates are higher when diagnosis and proper treatment are delayed. It's not clear in the this case whether psittacosis was considered early in disease nor when treatment was initiated.
Chlamydophila psittaci can cause illness in birds, but it's also carried by a variable percentage of healthy birds, mainly psittacines. This complicates control of the disease, since you can't tell which birds are carrying the bacterium without testing them all. In this case, the woman's parrot died a few days before she became ill. It's not clear from the brief report whether the bird was diagnosed with C. psittaci infection, however this is a good reminder of the need to consider pet and owner health in parallel. It also indicates why diagnostic testing is important when pets are sick, or even after they've died.
If a pet becomes sick, knowing what caused the disease might be of relevance to human health. Also, if physician's ask about illness of any other individuals in the house, this should include pets, as they might get some relevant information.
In a case like this, if the bird was diagnosed with C. psittaci infection and the owner developed flu-like illness shortly thereafter, it should have been a strong indication that the person might have psittacosis, allowing for early treatment. Alternatively, even without a diagnosis, knowing that the person had a pet parrot (a risk factor for psittacosis), and that the bird had died shortly before the woman got sick, could lead to recognition that both diseases could be linked, and could lead to earlier consideration of psittacosis.
This unfortunate event should be taken as yet another reminder of the need for veterinary personnel and human physicians to communicate more effectively, and that physicians need to know about pet contact and pet health when evaluating their patients.
Image: African Grey Parrot (Psittacus erithacus erithacus). (Photo credit: Eli Duke)
Franklin the potentially biohazardous library turtle
Among the various things I've been called in response to blog posts is "anti-reptile." Actually, I like reptiles. I've owned and treated them, and think many of them are quite fascinating species. They can be reasonable pets in certain situations. The main problem is that they have high rates of Salmonella carriage and are the cause of a large number of infections in people. That's why the CDC, among other groups, recommends that people under the age of 5, the elderly, pregnant women and people with compromised immune systems avoid them.
Why do I bring this up (again)? I read an article today about the Fall River, Massachusetts, library and their resident tortoise, Franklin. Why am I concerned?
- Who goes to a library? Lots of people. Kids and elderly individuals probably go more than average. Those are the high risk groups.
- You could try to make the argument that having a tortoise in a library wouldn't necessarily pose much of a risk if it was kept in a cage or terrarium. That's probably reasonable, as long as good management and hygiene practices were used, but it's not a guarantee. Infections have been reported in households where the reptile never leaves its enclosure and in people who never have direct contact with it.
- Regardless, Franklin doesn't spend his days in a cage of any kind. He gets out and cruises around the library, especially in the carpeted Children's Room. That's a bigger problem. This tortoise is certainly not house trained (my tortoises' repertoire was pretty much limited to eat, poop, wander around, repeat... I don't think there was an extra neuron for something like litterbox training). Tortoises can also easily contaminate their feet and shell with feces. So, we have a potentially poop-contaminated tortoise who may also leave a fecal present at any time wandering around a carpeted (almost impossible to disinfect) surface on which young kids play. Not a good combination.
- See the picture above. The person is described as a "library senior aide" and is presumably in the high-risk group based on age. The tortoise has its leg (which presumably walked over some tortoise poop sometime in the recent past) practically in her mouth. That's not good either.
What should the library do?
1) Ideally find a good home for Franklin. One with no high-risk people.
2) If that's not an option, a protocol should be in place for how to manage Franklin and reduce the risk of Salmonella transmission. This would involve:
- Keeping him in a proper enclosure. Not letting him roam around public areas. Visits outside to walk around on the grass (during the appropriate seasons) are fine, but there should be no walking around general library areas (especially not the Children's Room).
- Not letting the general public handle him. Reptiles are "look but don't touch" pets.
- Emphasizing hand hygiene for anyone that has contact with Franklin or his environment, and facilitating hand hygiene by having convenient access to a properly equipped sink or alcohol-based hand sanitizers.
- Excluding high-risk groups from contact, if people are allowed to have direct contact with Franklin at all. Any public contact should be supervised and there must be immediate washing of hands or use of a hand sanitizer afterwards. Since this is unlikely to be done properly, avoiding all public contact makes the most sense.
- Using Franklin to help teach. Perhaps he could be brought out in a small glass terrarium and people could watch him as part of stories or other events. He (and the way he's handled) could also be used to explain things about infectious diseases and infection control.
Image source: www.wickedlocal.com
Cause of Bahraini horse outbreak identified
A recently reported outbreak affecting horses in Bahrain has been diagnosed as glanders, a very serious bacterial infection caused by the highly contagious bacterium Burkholderia mallei. So far, it has been reported that 8 horses were euthanized over the past 3 weeks because of the infection.
Bahrain's cabinet has allocated BD150 000 to fight the outbreak. Authorities have apparently stated that the outbreak can be "easily" managed, "We have sent samples from nearly 400 horses to a specialist laboratory in the UAE and the 10 results we have got so far give us the all-clear. We now know we can manage this quite easily and are taking appropriate action."
That's a pretty dangerous sentiment to be expressing (and believing) early in an outbreak, but hopefully it's true. "Easily" and "outbreak" aren't often uttered in the same sentence, and it's far from unusual to be fooled by an allegedly contained or controlled outbreak. I'd be very surprised if all of the positive horses have already been identified. Control of glanders involves widespread testing of horses, typically with euthanasia of any infected animals. It sounds like testing is underway and results of this will give a good indication of the extent of the problem. Ten negative samples don't mean that much to me. As more results come in (and if they continue to be negative), more confidence can be had in the assessment that this outbreak is truly contained. Glanders is not solely a concern for horses. It's a zoonotic disease that can cause rare but serious infection in humans, with a high mortality rate (almost 100% if proper treatment is not administered). People can become infected by direct contact with infected horses, with the bacterium gaining entry through skin abrasions, inhalation or contact with tissues of the mouth and nose. Pneumonia, bloodstream infections and other problems can develop. Burkholderia mallei is a Class B bioterrorism agent. Hopefully, people working around infected horses are using appropriate infection control precautions to reduce the risk of infection. Hopefully, more information will be available soon about this outbreak and results of ongoing testing. Image: A horse with glanders (Burkholderia mallei infection), exhibiting the characteristic infectious nasal discharge. Glanders is a reportable disease which has been eradicated from North America, Australia and most of Europe.
This Worms & Germs blog entry was originally posted on equIDblog on 26-Apr-10.
Skin infections in dogs: Stopping the downward spiral
A large percentage of advice calls that I get about methicillin-resistant staph infections in dogs are regarding skin infections. Skin infections (pyoderma) are a common problem, a leading cause of antibiotic use in dogs, and an often frustrating problem for vets and pet owners alike. One problem is that, unlike many other types of infections, skin infections are often recurrent. This frequently leads to an ongoing cycle of infection-treatment-resolution-infection-treatment-resolution... The net result is some dogs get treated very regularly and for long periods of time with antibiotics, and it's not particularly surprising that highly drug-resistant bacteria like MRSA or MRSP eventually become involved.
Normal, healthy, intact skin is an excellent barrier to bacterial infection. Various bacteria normally live on the skin but do not usually cause infection. Skin infections typically (if not always) develop in response to some underlying skin disease, such as flea allergy dermatitis, food allergy, atopy, Cushing's disease or hypothyroidism. Identifying and treating a skin infection is one thing. Identifying and treating the reason for the infection is another, and that is arguably the most critical component. Ignoring the underlying cause may not be the end of the world for a single infection, because proper treatment and a susceptible bacterium can result in a successful outcome, but ultimately ignoring the real problem can lead to a difficult-to-treat, resistant infections.
Any diagnosis of pyoderma should be accompanied by consideration of the underlying cause. If a cause is apparent, this should be treated (if possible). If a cause is not readily apparent, it should be investigated. By investigated, I mean a real search for the problem, not a cursory examination, half-hearted feeding trial and little more. There is almost certainly an underlying cause and, at the end of the day, time, effort and money are better spent on trying to identify the root issue rather than just throwing round after round of antibiotics at the dog. In some cases, the cause (while it's probably there) can't be identified, but it's definitely worth trying anyway.
If your dog has been diagnosed with a skin infection, ask why it happened. If there is not a clear answer, talk to your veterinarian about the best plan to identify the cause. If at all possible, follow through with the plan. It may include certain diagnostic tests (which cost money) or dietary restriction (which takes effort), but it should be thought of as an investment in your pet's health, as well as a potential way to keep multidrug-resistant bacteria (some of which can infect people) out of the house, to save future treatment costs, and to keep your pet much more comfortable.
Eliminating E. cuniculi in the household
A recent question:
"I have two rabbits who just tested positive for E. cuniiculi... Can you please tell me how to disinfect my floors and kill the parasites? I don't think bleach is doing it."
Encephalitozoon cuniculi is a strange little bug. It a member of a unique group of organisms called microsporidia. Originally thought to be parasites like Giardia, they are now classified as a type of fungus. Regardless, E. cuniculi is common in the pet rabbit population, causing neurological disease in some rabbits but living in many others without any signs of illness.
Infected rabbits shed E. cuniculi spores in urine, feces and respiratory secretions. Other individuals are infected by ingesting (and possibly inhaling) these spores. Infected rabbits start to shed spores in urine a month or two after infection, and can continue to shed low levels of spores intermittently. This, along with close housing of pet rabbits and movement of rabbits between breeders, stores and owners, explains why, in some studies, up to 75% of tested rabbits have evidence of current or prior infection.
Disinfecting household environments can be tough because of the surfaces that are involved. Encephalitozoon cuniculi is quite hardy and can live in the environment for prolonged periods of time. It is susceptible to a several types of disinfectant, including bleach, 70% alcohol and 1% hydrogen peroxide. In general, bleach is highly effective and is probably the standard for disinfection of surfaces that can tolerate it. Obviously, bleach isn't a good option for many surfaces like carpets. Steam cleaning might help, as much for the thorough cleaning component as for the steam.
One thing to consider is whether aggressive household disinfection is really required. While humans can be infected, infections are uncommon and predominantly occur in people with compromised immune systems, especially those with HIV/AIDS. If there are no high-risk people in the household, I don't think I'd be too aggressive with disinfection. Good hygiene practices involving handling of the rabbits and their cage are probably much, much more important, and its better to focus efforts there. Household disinfection for protection of the rabbits is probably not too useful at this point. I would suspect that all rabbits in the household have already been exposed, and since infected rabbits can continue to shed intermittently, rabbits are a much greater source of infection than the household environment.
More information about E. cuniculi can be found in our archives.
FDA issues dog bone warning
The US Food and Drug Administration has issued a warning to pet owners to avoid feeding their pets bones. I'm a little surprised the FDA would bother with this topic but I agree with the information. FDA veterinarian Carmela Stamper, states "Bones are unsafe no matter what their size. Giving your dog a bone may make your pet a candidate for a trip to your veterinarian’s office later, possible emergency surgery, or even death.”
The FDA lists 10 reasons why it’s a bad idea to give your dog a bone:
- Broken teeth. This may call for expensive veterinary dentistry.
- Mouth or tongue injuries. These can be very bloody and messy and may require a trip to see your veterinarian.
- Bone gets looped around your dog’s lower jaw. This can be frightening or painful for your dog and potentially costly to you, as it usually means a trip to see your veterinarian.
- Bone gets stuck in esophagus, the tube that food travels through to reach the stomach. Your dog may gag, trying to bring the bone back up, and will need to see your veterinarian.
- Bone gets stuck in windpipe. This may happen if your dog accidentally inhales a small enough piece of bone. This is an emergency because your dog will have trouble breathing. Get your pet to your veterinarian immediately!
- Bone gets stuck in stomach. It went down just fine, but the bone may be too big to pass out of the stomach and into the intestines. Depending on the bone’s size, your dog may need surgery or upper gastrointestinal endoscopy, a procedure in which your veterinarian uses a long tube with a built-in camera and grabbing tools to try to remove the stuck bone from the stomach.
- Bone gets stuck in intestines and causes a blockage. It may be time for surgery.
- Constipation due to bone fragments. Your dog may have a hard time passing the bone fragments because they’re very sharp and they scrape the inside of the large intestine or rectum as they move along. This causes severe pain and may require a visit to your veterinarian.
- Severe bleeding from the rectum. This is very messy and can be dangerous. It’s time for a trip to see your veterinarian.
- Peritonitis. This nasty, difficult-to-treat bacterial infection of the abdomen is caused when bone fragments poke holes in your dog’s stomach or intestines. Your dog needs an emergency visit to your veterinarian because peritonitis can kill your dog.
One point they could have added is that bones can be a source of infectious agents like Salmonella, Campylobacter and E. coli, both for the pet and people, depending on the source of the bones and how they are processed and handled.
I suspect that many people will not like the FDA's statement. Some will express outrage. People that have had to pay for major dental repairs or surgery will (probably silently and vehemently) agree. Most people may never have thought about it, which is why this type of press release is a good thing. It raises awareness about the potential and real problems associated with bones and will hopefully lead to fewer sick and injured dogs. While chewing on bones might be "natural", natural doesn't always mean healthy, and there are much safer alternatives.
Hit by car - How to help and how to be safe
A couple of recent news reports highlight potential issues surrounding good Samaritins helping injured animals:
- A person that tried to help a cat that had been hit by a car was bitten. It turned out the cat had rabies, so the person would have required post-exposure treatment.
- A veterinarian was struck by another vehicle and killed while trying to help a neighbour's dog that had been hit by a car.
These two incidents highlight some of the problems that can occur when people try to help injured animals. Wanting to help an injured animal is an instinctive behaviour for many people. I know, I'm the same way - but you have to look after yourself as well. No matter how much you want to help the animal, you have to make sure you don't put yourself at risk of injury or infection.
The key point is to think before you act.
- Can you actually do anything useful? Are you better off calling animal control or someone else? In most situations, you may be better off getting other help. If you don't actually know how to help the animal, having contact with it just puts you at risk. Injured or frightened animals are more likely to bite. If you are bitten or otherwise exposed to the animal, you need to be concerned about rabies or other infectious diseases.
- Can you do something safely? Despite your best intentions, if the animal is in the middle of a busy highway or in a situation where traffic can't see you (e.g. dark, bad weather, blind corner), don't put yourself at risk. You may think that you can be careful but odds are reasonable once you get to the animal, you are going to focus on it, not traffic.
- Is the animal even alive? This may take a little effort to determine.
- How is the animal acting? Does it look aggressive or fearful? These things might lead to an increased risk of biting. Is it acting normally? The hard part is assessing injured animals. An animal might be acting abnormally because it's injured. It's also possible, however, that it's acting strange because it has rabies. It may have been hit by a car because it has rabies, or it may not have been hit at all and just looks like it's been injured because it has severe neurological disease.
If you are bitten by an injured animal, you need to make sure rabies is considered. If the animal survives, it needs to be observed for 10 days to make sure it doesn't develop signs of rabies. If it dies, it needs to be tested. Once you've made the commitment to get involved, you need to follow through.
I'm not trying to dissuade anyone from helping out. You just need to understand what you can do to help and what risks might be present. In most situations, you're probably better off trying to get proper help and trying to prevent the animal from being injured again. Calling animal control, sending someone to a nearby house to identify the owner and trying to make sure other drivers don't hit the animal again may be the best you can do, for the animal and for you.
Cryptosporidiosis from wildlife centre lambs
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.
Dog bites Maradona
Argentinian soccer star Diego Maradona has had quite a life, including the famous/infamous "hand of God" goal, drug addiction, gastric bypass surgery and a tumultuous coaching career. You can now add "beaten up by a small dog" to that list. Maradona was discharged from a Buenos Aires clinic a couple weeks ago after undergoing recontructive surgery to his upper lip, after being bitten by his pet Shar Pei. It's not clear exactly what precipitated the bite, but apparently he commonly "gets close" to his dogs before bed. Hopefully Maradona figures out what caused the bite.
Dog bites are surprisingly and disappointingly common.
They are not usually random events.
There's usually a cause. It might be related to the dog, the person who was bitten, or both. No bite should be considered acceptable, even though bites are common. Every bite should be investigated. Potential inciting factors should be identified and measures should be taken to reduce the risk of this ever happening again. Sometimes, a cause is clear (for example, if a person threatens a dog and it tries to defend itself). At other times, the reason for the bite may not be as obvious. Sometimes, dogs bite for behavioural reasons (e.g. aggression, fear). Sometimes, dogs bite for medical reasons (e.g. pain, decreasing vision). Sometimes, dogs bite because people act inappropriately around them. Differentiating these, and intervening whenever possible, is important and must be considered after any bite.
Rabies vaccination of adopted cats... Why not?
My parents adopted a cat from their local OSPCA shelter the other day. He's an adult cat (maybe named by now, but not at last report) and he came:
- neutered
- vaccinated against the typical group of feline diseases
- dewormed with fenbendazole
- treated with metronidazole (an antibiotic - it wasn't clear whether this was because he had diarrhea at some point or was diagnosed with something, or whether it was just a routine practice)
- treated with Revolution for flea control
The one thing that's missing from the list is vaccinated against rabies, which I find amazing. Apparently, the cat was given everything they can give at the shelter without the need for a veterinarian. (Presumably the cat came in neutered, because that would hopefully fall under the "need a veterinarian to do it" category. Prescribing an antibiotic would also be something I'd hope would involve a veterinarian.)
Sending cats to new homes without vaccinating them for rabies is bad practice. Rabies is a rare but extremely serious disease. Vaccination is critical, safe and easy. The OSPCA website says that not all shelters vaccinate against rabies. Some shelters have veterinary staff in the facility, so rabies vaccination would be standard there. Other shelters work with local vets to do this, but that's not universal, apparently. I don't see why this isn't a mandatory policy for the OSPCA. Yes, there is a cost to it, but that should be a cost of doing business. Rabies vaccines aren't expensive and many vets would work with groups like this to keep the costs down. Adopting an animal from a shelter isn't cheap, and recovering the small added cost of the vaccine should be possible. I'm not sure whether it really is a question of cost, accessibility or simply not bothering. Getting a veterinarian involved also has benefits beyond just giving the vaccine. Potential health problems can be identified, including diseases that could be transmitted to people that adopt the animals.
It's true that lack of vaccination of adopted pets can be addressed by getting them vaccinated right after adoption. Any pet that has been adopted (or purchased, or otherwise obtained) should be promptly examined by a veterinarian to identify any potential problems, and to make sure the pet is on a proper preventive medicine program. Realistically though, not everyone does this. While you don't like to set policies according to the lowest common denominator, you need to for a deadly disease like rabies when the consequences to people and pets are so high. I find it hard to justify sending any animal out of a shelter without rabies vaccination.
Image source: www.ontariospca.ca
Survival of MRSA in swimming pools
Warm spells in early spring, like the recent warm spell in our area, inevitably lead to (premature) thoughts of summer, and for many people, this includes thoughts of spending time in the swimming pool. I've previously written about the presumably low risk of disease transmission from dogs swimming in pools, and common sense measures that can be taken to reduce any risks. Since more and more people and dogs are carrying resistant bacteria like MRSA, there are increasing questions about the potential for pools to be a source of transmission. A recent paper in the journal Clinical Pediatrics (Gregg & LaCroix, 2010) sheds some light on the issue.
In this study, the researchers obtained different types of swimming pool water (chlorinated water, saltwater, and biguanide (Baquacil) nonchlorinated water) from local pools. No MRSA was identified in any of the samples. They then inoculated the water samples with MRSA. They used a lot of MRSA - roughly similar to the amount that would be released from an MRSA abscess (and much, much greater than the amount that would be released from someone who was just an MRSA carrier). MRSA numbers were greatly diminished after 30 minutes and no MRSA was detected after 1 hour.
This study suggests that pools are likely not a significant source of MRSA exposure. Even with high-level contamination, MRSA died quickly. Presumably, there would be little MRSA shed by a person that was only a carrier, and when you consider the dilutional effect of a small amount of MRSA in a large volume of water, plus the bactericidal effects of treated water, the risks should be extremely low. Common sense would dictate that someone with an MRSA infection shouldn't go in the water because they could shed large numbers of bacteria, but this study suggests that the risks are probably minimal and short-term even then.
Bottom line: Don't worry about pools in terms of MRSA. Pools are a greater risk for certain causes of gastrointestinal disease like norovirus and Cryptosporidium. If you or your dog has an infectious disease, stay out of pools. If not, and you are otherwise healthy, then don't worry. There's always some risk of exposure to infectious disease, but it's very low. Life is full of risks and swimming in a pool is not a big one (at least from an infectious disease standpoint. If you can't swim, that's a different story!).
Image from: http://blog.timesunion.com
Distemper outbreak in California
A canine distemper outbreak has been identified in raccoons, dogs, coyotes, foxes and skunks in Los Angeles County. Local residents are being reminded to vaccinate their dogs against distemper and report any suspected signs of distemper to their veterinarian. (Keeping their pets away from wildlife should also be recommended.)
Distemper is an infection caused by a virus which is related to the virus that causes measles in people. It can cause different types of disease in dogs, raccoons and some other wild mammals, but neurological disease is often present and can appear similar to rabies.
Canine distemper cannot be transmitted to people, but, in a roundabout way, distemper outbreaks can be a public health concern. This is because of the potential for rabies cases to be mistaken for (and dismissed as) distemper cases, leading to increased exposure of people to rabid animals.
Quite a few years ago, there was a cat with neurological problems under my parents front porch. It was a stray cat that had been in the neighbourhood for a while, and which sometimes interacted with people. When the local authorities were contacted, the response was "Don't worry, it probably has distemper." This was probably true, and since there was no known direct contact with people (something that is difficult to really know in a social stray) testing for rabies wasn't done. However, the concern is that rabies cases will be missed, or, more concerningly, human exposure to rabid animals will be missed because of the assumption that it's really distemper.
Understanding disease patterns in an area is important when determining the likelihood of a particular disease and the appropriate response to a sick animal. At the same time, you can't get complacent and assume that trends are absolute. With an almost invariably fatal disease like rabies, you have to be careful not to overlook the rare case amongst large number of other, similarly appearing diseases. If someone has contact with an animal suspected of having distemper, the potential for rabies exposure must not be forgotten.
Image source: http://weblogs.baltimoresun.com
Ongoing rabies problems in Moscow
A large rabies outbreak continues in Moscow. There were 257 rabies cases reported in the area in 2009 - ten times the number from previous years, and well above the very low numbers that occurred for a decade of so after an aggressive control program to control the post-World War II rabies epidemic. Control of that outbreak mainly involved shooting of potential rabies vectors: stray dogs, foxes and raccoon dogs.
Various more humane but still aggressive control measures are being considered to help control the current epidemic, including banning movement of pets to suburban cottages (probably better to just vaccinate the pets first), canceling a dog show (pretty low yield - better to vaccinate), and mass immunization of wild and domestic animals (the key approach).
An aggressive approach makes sense. Rabies is almost invariably fatal and large numbers of people who are exposed require post-exposure treatment every year. Local wildlife population patterns, wildlife rabies hotbeds and rates, pet numbers, pet movement and vaccination must all be considered when determining the best approach to control. Apparently, about 30 000 pet dogs visit cottages in the Moscow area each weekend, and there's concern that they could bring rabies back to the city with them. Authorities have warned about traffic jams that might develop, presumably from police stopping traffic looking for contraband canines. However, instead of banning dog movement, it would likely be more effective to increase vaccination (or even mandate it for dogs in those high risk regions) and control roaming dogs. If a dog doesn't roam freely in the country, it's less likely to encounter a rabid animal. If it's vaccinated, it's unlikely to get infected if it does get exposed. If it's not allowed to roam when it returns to the city, it's less likely to spread rabies to other animals and people in the very rare event that it was exposed and infected. Furthermore, if wildlife are vaccinated through rabies bait drops, the chances that a roaming dog will be exposed get even lower.
Ensuring the highest possible canine vaccination rates is the key measure. Whether that's through mandating vaccination, providing it at low cost, or making it more convenient for owners to get it done, it's a great place to focus efforts and resources. In principle, it's a simple concept. In practice, it can be more difficult, especially when compliance of the general public is required.
For those of you that want to practice your Russian reading skills, here's the original story.
