More H1N1 cat cases
Perhaps not too surprisingly, more cats have been diagnosed with H1N1. Following the first reported case in Iowa, two more cases have been reported; one in Utah and one is Oregon. The Utah case apparently had typical flu-like disease. The cat from Oregon died of severe respiratory disease.
This doesn't really change anything. We know cats are susceptible, although not highly so considering the small number of cases despite large numbers of cats being exposed by their owners. H1N1 in cat is a human-associated disease, with cats getting infected from infected people. We still have no evidence that pets are a source of human infection. Despite that good general hygiene practices should be used around infected pets and people to reduce the risk of transmission in both directions.
Stray cats and H1N1 influenza
The topic of the potential for feral (stray) animals, particularly cats, to be sources of human influenza infection came up today. For feral animals to be a public health problem, the following sequence has to happen:
Feral animals need to be exposed to H1N1
- This is pretty unlikely. Influenza is spread through close contact, mainly through aerosols generated by an infectious person coughing, sneezing or breathing. Influenza only travels short distances in this manner. The likelihood of a feral animal being exposed to the H1N1 influenza virus is very low because it is rare for a feral animal to get that close to people. If there is close contact, it's probably very short term, and not high risk for exposure.
They need to become infected AND shed appreciable levels of virus
- Considering the number of infected people, how common pet cats are, and the fact that only one cat has been diagnosed with H1N1, the risk of actually transmitting the virus to a cat is very low even with close contact with an infected person. If tens of thousands of household pet cats have had close and prolonged exposure and only one infection has been diagnosed, this virus is pretty poorly transmissible to cats.
They need to be exposed to susceptible people
- As discussed above, there's not too much contact between stray cats and people. Close and prolonged contact is extremely rare. Influenza is only shed by infected individuals for a short period of time, unlike some other infections. So, the chance of an infected cat having close contact with a person during the relatively short infectious period is very low.
Each one of these events independently is very unlikely. When you combine them, it should be clear that the risks posed by feral cats are extremely low (probably about as close to zero as we get with infectious diseases).
A bigger concern might be someone infecting their indoor/outdoor cat, who would then infect a stray cat, which would then infect another indoor/outdoor cat, which could infect a family member. That's still a VERY unlikely situation - really it's nothing to worry about.
There are certainly public health issues with feral cats. H1N1 is not one of them.
H1N1, cats and the potential for mutation
I've spent a lot of time talking to the press this week about H1N1 and pets. One question that has come up repeatedly involves concern about the potential for this virus to mutate because of its presence in pets. This largely relates to the general knowledge that pigs are potentially important "mixing vessels" for influenza viruses.
H1N1 infection of cats carries almost no risk of a significant mutation. For this to happen, the animal must be infected with two different influenza viruses, and those viruses must recombine so that a new virus containing parts of each of the parent viruses is produced. This virus must then be able to infect a new host and be transmitted. Pigs are a concern because they can be infected by various influenza viruses (from humans and birds, as well as swine-origin viruses), and they tend to live with many other pigs so that the transmission cycle can be started. This isn't the case with cats.
Cats don't have their own influenza virus that is in circulation. Therefore, it's very unlikely that a cat exposed to H1N1 already has a different influenza virus in its system. Even if a cat was infected with a different flu virus (which is exceedingly unlikely) and this virus recombined with H1N1 (which is unlikely even if the two viruses were present), your average cat doesn't have much contact with different individuals, human or animal, and it's quite possible that the virus would just die-out in that animal.
While we don't want to ignore some of the issues regarding H1N1 in pets, such as the potential for pet illness and the unproven possibility that they could transmit H1N1 to other people, we need to keep the concerns in perspective. The risk that pets pose to people is much lower than the already very low risk that people pose to pets, in terms of H1N1 influenza.
How to diagnosis influenza in pets
One of the common questions accompanying the onslaught of calls I've taken today is "How do you diagnose influenza in pets?"
Clinical signs, such as sneezing, coughing, fever and lethargy, are not useful for diagnosis. Influenza can produce highly variable disease, ranging from almost none to very severe - so you can't look at an animal and say it has influenza just based on the clinical signs. We don't know much about H1N1 influenza in different animal species (including pets), but this type of influenza can probably cause a wide range of disease in animals as well (at least in those it can infect).
The presence of someone in the household with influenza should get you thinking about flu in a sick pet, but it is far from diagnostic. Many, many people have influenza, but very few pets do. There are many other diseases that can produce signs similar to influenza in pets. The health of people in the household is an important thing to know, but we can't jump to conclusions based on the household history alone.
Laboratory testing is required for the diagnosis of influenza, and there are a few options:
- PCR testing of nasopharyngeal (throat) or nasal swabs, or fluid collected from the trachea: This molecular test detects influenza virus RNA. This is the fastest test and it is most sensitive when samples are taken early in disease. This is the main option for diagnosis at this time.
- Serology: This involves testing blood for antibodies against influenza. Two samples are taken 10-14 days apart. If the antibody level rises 4-fold or greater, that is indicative of influenza infection. This is considered the most reliable method of diagnosis of influenza in many species but takes time. It is not currently a viable option for pets because tests for pets are not available.
- Virus isolation from nasopharyngeal or nasal swabs, or tracheal fluid: Samples are inoculated into eggs to try to grow the virus. This can take quite a while and isolation of the virus can be difficult. This is a method used by specialized labs with laboratory containment conditions appropriate for this virus and may not be readily available.
H1N1 in a cat
H1N1 influenza has been confirmed in a cat in Iowa. The cat had "influenza-like illness" and was tested, with H1N1 being confirmed today. Two of three people in the house were also sick, but they became ill before the cat, and were presumably the source of infection for the cat. There's no evidence that the cat has infected anyone.
This doesn't really change anything that we've been recommending regarding H1N1 and pets. H1N1 infection is pets is rare but has been diagnosed in ferrets, and now in a cat. Considering the large number of infected people and the presumably large number of exposed pets, the risk of transmission to pets appears to be extremely low. Low doesn't mean no, however, and taking basic precautions is still wise.
Basically, remember that your pets are part of the household - microbiologically as well as socially. If you are doing something to reduce the risk of transmission of infection to people in the household, act the same way around your pets. Reduce contact with pets if you are sick. Avoid being around them when you are coughing. Wash your hands frequently. Avoid contact with their faces. If your pet gets sick after you've had H1N1 (or any other infection) make sure your veterinarian is aware of it.
Image source: icanhascheezburger.com
Another ferret flu case
A second ferret in the US has been diagnosed with H1N1 influenza. The latest case involves a fatal infection in a ferret from Nebraska that was presumably infected by its owner. Three other ferrets in the household were also sick, and it's fair to assume that they had H1N1as well.
It's important to keep things in perspective. We have two confirmed pet cases among thousands and thousands of human cases. Thousands of pets have presumably been exposed to owners infected with H1N1, with few apparent problems. (You can never rule out additional cases completely, because pets tend to get ignored in outbreak investigations, but there's no indication that this is a major problem.)
This is yet another good reminder of the potential for diseases to move between species in households. If you are sick with a potential infectious disease, you should restrict contact with household members - all household members: human and animal. Ferrets are likely the greatest risk when it comes to H1N1, followed by pigs and pet birds. Dogs and cats are presumably low risk, but we can't say there's absolutely no risk.
If you might have H1N1, reduce close contact with your pets. Don't hide from them, but avoid close face-to-face contact and coughing around them. Wash your hands regularly. More details about household infection control precautions are available from the CDC. Take the same precautions around pets as you would around people. If your pet subsequently gets sick, make sure your veterinarian knows about the possible H1N1 exposure.
Image source: www.ferretfriends.org
Pets and H1N1 revisited
The recent discovery of H1N1 influenza in a pet ferret has led to another round of concern about the potential impact of H1N1 on pets and pets as a source of human infection. Finding H1N1 in a ferret is not particularly surprising, considering ferrets are susceptible to various (including human) influenza viruses. We shouldn't dismiss the potential that certain pets could become infected by this virus or transmit, it but the overall risks are presumed to be very low. There have obviously been many, many cases of H1N1 influenza in pet owners, yet there is just this one report in a pet (although it's certainly possible that other pets have been infected but not diagnosed). Ferrets may be the biggest concern. Pet birds and pot-bellied pigs may also be at higher risk considering this virus can clearly infect pigs and birds. Cats are probably a bigger concern than dogs because of what we know about cats' susceptibility to (and ability to shed) H5N1 (avian) influenza.
The risks are low to pets and pet owners, but there's rarely a no-risk situation with infectious diseases. A few basic measures should be taken to reduce the risks associated with this pandemic virus:
- If you have (or think you may have) influenza, treat you pet like other people in your family. Avoid contact with them, especially their faces, and pay close attention to hygiene (especially handwashing). This should help reduce the risk of exposing your pet to H1N1.
- If you have influenza, or your pet has been exposed to anyone with influenza, and your pet becomes ill (e.g. respiratory disease, fever, lethargy), contact your veterinarian. Avoid close contact with your sick pet (especially the face) and wash your hands after you handle it.
- Relax and enjoy the company of your pet. The risks of influenza are low.
Swine flu has gone to the birds
Just when all those turkeys that managed to survive Thanksgiving weekend thought their troubles were over, there's new issue: H1N1 influenza (formerly known as swine flu) has been found in an Ontario turkey flock. The H1N1 virus was first reported in birds in Chile in late August.
This is not a reason to panic. No one can get the flu from eating a properly-cooked Thanksgiving turkey (nor from any other type of properly-cooked turkey). The producer has voluntarily (and very responsibly) quarantined the affected flock, and no birds or eggs have left the facility. There is no risk to the food chain.
Pigs can be infected by human, pig and bird flu viruses, and multiple infections can result in viruses trading genes and producing new viruses that can infect more species. So it's not too surprising that H1N1can infect people, pigs and now birds as well. This incident serves as an important reminder that we need to remain diligent about infection control and hygiene, even around animals. It's highly unlikely that these turkeys had contact with infected pigs - most likely the virus was spread to this flock by a person. Poultry producers may therefore need to consider getting vaccinated for H1N1 flu not only to protect themselves, but also their flocks, and anyone who may have the flu should definitely stay off these farms. Hopefully the virus does not become established in wild bird populations (like H5N1 has in some areas), as this would make it much harder to control.
Recommendations for avoiding the flu (H1N1 or other) remain the same:
- Wash your hands and/or use alcohol-based hand sanitizer
- Sneeze into your elbow
- Disinfect commonly touched surfaces
- Stay home if you are sick
- Get vaccinated!
Internet drug buyers beware
The US Food and Drug Administration (FDA) has warned consumers about buying antiviral flu treatments over the internet. The FDA issued this warning after it tested "Tamiflu" purchased over the internet. Most of the products contained oseltamivir, the active ingredient in the original Tamiflu, but at varying concentrations. Some were pretty obviously a problem, such as one of the orders that arrived in an unmarked envelope with a postmark from India, and consisted of unlabeled, white tablets taped between two pieces of paper. These tablets contained talc and acetaminophen (the active ingredient in Tylenol), but no oseltamivir.
The commissioner of Food and Drugs, Margaret A. Hamburg, M.D, stated in the FDA press release that “Medicines purchased from Web sites operating outside the law put consumers at increased risk due to a higher potential that the products will be counterfeit, impure, contaminated, or have too little or too much of the active ingredient.”
Another issue is that a drug like Tamiflu needs to be given very early in disease to have any effect. If you think you're getting the flu and order Tamiflu over the internet, it's pretty unlikely to have any chance of working by the time it actually arrives (if they send you the appropriate drug in the first place). Then there's the concern that few people actually need to use Tamiflu compared to the number that do, and that viral resistance to Tamiflu may develop with unnecessary use.
Bottom line: if you really need medication, you should get it from a reputable source on the recommendation of a physician. If your pet needs mediciation, you should take the same approach. It's hard to be certain about what you're getting if you order it through the internet, especially from companies that are illegally selling prescription drugs. It might seem cheaper to buy drugs over the internet, but if it's not needed or it's fake, it's going to cost you more in the long run.
Canine influenza vaccination
A canine influenza virus vaccine has recently been released. Canine influenzais a virus that originated from a horse influenza strain and is now circulating in some dog populations. (To my knowledge, we have yet to find it in Ontario. We didn't find any evidence of it in an earlier surveillance study). It typically causes mild disease, as with influenza in people, but can also cause serious (including fatal) infections. These cases are most common in densely-populated, stressful environments like shelters and racing greyhound facilities.
Like most vaccines, this canine influenza vaccine does not claim to provide 100% protection. Veterinary vaccines can get conditional licensing and be marketed with little evidence of effectiveness. The manufacturers have produced data "supporting product purity, product safety under normal conditions of use in field safety trials and demonstration that the product has a reasonable expectation of efficacy." That means they have shown the vaccine is produced with good practices, had no obvious adverse effects in a safety study, and there is a possibility that it could be effective (presumably from showing vaccinated dogs produce antibodies against canine influenza virus). During the conditional licensing period, the manufacturers "will continue to submit data obtained in support of the product’s performance, which will be evaluated by government regulators to determine whether a regular product license may be issued."
There's a good likelihood the vaccine will be effective at reducing the incidence and severity of disease, as with influenza vaccines in other species. Basically, if a vaccinated dog gets exposed to the virus, it should be less likely to get sick, and if it gets sick, it should be less likely to have severe signs. Reducing the incidence and severity of influenza also has the benefit of reducing the chances of developing a secondary bacterial infection, which can cause very serious disease.
Deciding whether to vaccinate your dog largely comes down to the risk of exposure and the implications of your dog becoming ill. In an otherwise healthy dog that is not in a high risk environment (e.g. kennel, shelter, greyhound racetrack), it's questionable whether vaccination is needed. If canine influenza virus is in the area, it's something to consider, but the virus seems to be rare (or at least rarely identified) in pets in most regions. Discussing the risks and benefits with your veterinarian is the key.
Canine influenza is NOT considered a zoonotic disease. There is no evidence that it can infect humans. Therefore, there is no public health argument for vaccination.
Image source: www.petinsurance.com/healthzone/pet-articles/pet-health/Canine-Influenza.aspx
Influenza found in Canadian pigs: human source suspected
The new H1N1 influenza virus has been found in pigs in Alberta, Canada. This marks the first time this virus has been found in pigs, or any other non-human species. It's not surprising - genetically speaking, the virus is most closely related to other swine influenza viruses (which is why it was originally referred to as "swine flu"), so it should be able to infect pigs. However, this is still a disappointing development because if the virus becomes established in the pig population, the pigs could become a potential reservoir for human infection.
In this case, the source of the pig infections is presumed to be a person - a farmhand that contracted the infection in Mexico. He became ill upon returning to Canada, and the pigs started showing flu-like signs about ten days after he returned to work. Various swine industry and health organizations sent out reminders to pig producers that sick people and/or people returning from Mexico should avoid contact with pigs, however the farmhand in question here returned from Mexico before much of this information became available.
I assume that much more information about this situation will soon become available. A close review of biosecurity practices on this farm is needed to determine if transmission occurred because of defiicient infection control protocols, or whether transmission occurred despite the use of standard practices. The farm is under quarantine and the pigs are being closely monitored to determine what effects this virus will have on them and how long is will stay in the herd. Undoubtedly, close monitoring of other pigs farms (both in Canada and many parts of the world) will continue, with particular emphasis on farms where individuals potentially exposed to the H1N1 virus may have had contact with pigs.
Updated H1N1 (swine) influenza outbreak numbers from WHO
The World Health Organization (WHO) has provided the latest update about H1N1 influenza numbers internationally. (People are still often calling this "swine flu", but it has yet to be found in pigs and is clearly being transmitted human-human now, therefore some have recommended it be called "Mexican flu" or "North American flu" instead. This also decreases the negative associations with pork products, which are totally unfounded because the virus is NOT a food safety concern). Regardless of the name, this pathogen continues to move across the planet. The WHO is reporting 148 laboratory confirmed cases. Ninety-one have been confirmed in the US with 26 confirmed in Mexico.
It's important to remember that confirmed cases are very much the "tip of the iceberg". It's likely that there are thousands of cases in Mexico, despite only 26 having been confirmed by laboratory testing. For a case to make this list, the sick person has to go to a doctor AND samples have to be collected for testing AND the testing has to be appropriate for identification of swine flu versus other types of influenza. Areas with more diagnostic testing capacity and public health infrastructure (like some places in the US) will end up reporting more cases, even if they actually have fewer sick people. So, we shouldn't become complacent when reading about relatively small numbers of confirmed cases, and we must take care when comparing regional rates.
Confirmed cases have also been reported in Austria (1), Canada (13), Germany (3), Israel (2), New Zealand (3), Spain (4) and the United Kingdom (5). Deaths have only been reported in Mexico and the US, with the single (to date) US death being a child that was visiting from Mexico.
Swine flu: What about the pigs?
.jpg)
We've been talking a lot about the swine flu outbreak the last few days, but so far all we've really talked about are the human aspects. The reason we're blogging about it on this site is that it's a zoonotic disease - so where do the pigs fit in?
There's a distinct lack of information about where this strain of the influenza virus actually came from. I heard on the news this morning that one person who was interviewed by a CNN reporter was even trying to blame Canada for the outbreak, claiming that it was Canadian tourists that introduced the disease to Mexico in the first place! While I'm sure there will eventually be a great deal of investigation into how the outbreak got started (for the moment I think everyone's more worried about trying to just keep it under control), it's quite possible that we'll never find the "index case" or know exactly from where it came. But one thing's for sure: somewhere along the way, there has to be some pigs involved.
Pigs are the great "mixing pot" of influenza viruses, particularly with regard to avian, human and swine versions of the pathogen. Pigs can be infected by strains of all these different types, and coinfections (infection with more than one influenza virus at the same time) provide the viruses with a prime opportunity to trade RNA and recombine to form new influenza strains with new properties - more infectious, more virulent, or perhaps better able to infect another species, for example. In this case we appear to have a swine influenza virus that is not only capable of being spread to people (as occasionally happens with "regular" swine influenza viruses), but also between people, and hence the developing human outbreak.
But what about the pigs? There isn't a lot of information out there at the moment, with all the focus on the human aspect, but so far Mexican authorities have found no infected pigs in Mexico (at least no where they've looked - so far). Influenza in pigs is really nothing new, and other swine influenza strains are commonly found in pigs around the world. Highly pathogenic strains, like those that cause massive devastation of poultry flocks, don't occur in swine. If an influenza virus gets into a pig barn, however, it's like putting a person with the flu in a crowded room - the virus spreads very quickly through the air over short distances and soon everyone (or every pig) has the flu. Thankfully the virus generally also moves on quite quickly, and after a few days the animals generally start to recover. While such an outbreak certainly affects their growth efficiency, very few (if any) pigs die.
Yesterday the Canadian Veterinary Medical Association (CVMA) distributed a fact sheet on swine flu from the Canadian Food Inspection Agency (CFIA) for all Canadian veterinarians and swine producers. The CFIA is encouraging increased vigilance with regard to monitoring and diagnosing disease in Canadian pigs, to prevent the disease from spreading through the swine population. In addition to emphasizing vaccination, good hygiene practices and biosecurity, particularly around sick pigs, they also point out that it's equally important (especially now) for anyone who may have the flu to avoid contact with pigs (be they Canadian pigs or pigs in any other country), in order to avoid spreading the virus to them. Hopefully people in other countries will take the same precautions.
Another very important point is that swine influenza is NOT a food safety concern. The virus does not survive well in the environment for very long, and therefore cannot survive on pork products, and certainly cannot survive proper cooking (which is always very important for any kind of meat). The fact that some countries are banning pork imports is really not going to do anything to help control the outbreak - the concern should only be about live pigs (and people). So you can still have pork sausages at your next spring barbeque, just ask anyone who's feeling "under the weather" (or a little flu-ish) to please stay home!!
Interactive swine flu map
GoogleMaps has an interactive swine flu map that is quite interesting. The map indicates where cases of the disease have been diagnosed or are suspected, and it's updated frequently. Clicking on a marker gives you more information about what is happening in that particular location. Many of the pink "suspected" markers will probably turn out to be negative, but I fear the map's going to get a lot more crowded over the next couple of days. The picture below is a captured image of the map, but click here for the live interactive version.
.jpg)
Pets and household quarantine
A few years ago, I wrote a commentary in the journal Emerging Infectious Diseases about pets and household quarantine. It was written after SARS (severe acute respiratory syndrome) had caused tremendous problems in many areas, including Toronto. The point I was trying get across was that while there was a strict household quarantine implemented for exposed people, there was no consideration of pets. We now know that cats can become infected with the SARS coronavirus, and can transmit it to other cats. However, when people were quarantined, there were no recommendations for pets - pets could interact with quarantined people, then visit non-quarantined family members, or interact with other animals or people outside. From my standpoint, this was a significant concern. If cats had become infected with SARS, they could have been a source of transmission in households and potentially beyond. If SARS had infected the feral cat population in Toronto, it might have been very difficult to eliminate. I encouraged groups to ensure that pets are included in household quarantine guidelines.
The topic is front and centre again with swine flu. We don't know whether dogs and cats can be infected with this particular swine flu virus, but we DO know that cats can become infected with H5N1 avian flu and shed the virus. In my mind, that means that we should consider pets susceptible until proven otherwise.
So what should we do if people are being quarantined?
- If you are quarantining the family, quarantine the WHOLE family, including pets.
- Quarantined cats must be kept in the house. Quarantined dogs must be kept in the house as much as possible. They should only be taken outside to urinate/defecate, and this should be in a "remote" area where they can't have contact with other people or animals. They should always be under physical control (e.g. on a leash) when outside.
- If a quarantined pet gets sick, a veterinarian should be called first. That way, it can be determined if the pet needs to be examined, and if so, the clinic can know when it's coming and have protocols set up to handle it with infection control precautions.
EU recommends avoiding US/Mexico travel
The European Union's Health Commissioner has recommended that Europeans avoid all non-essential travel to the US and Mexico (Canada's apparently under the radar so far) as a measure to contain the spread of the emerging swine influenza virus. This has been met with some disdain by US officials, who emphasize the small number of cases (so far) in the US, and the much, much larger numbers of people that die in various countries every year from classical human influenza.
It's hard to say what type of restrictions are appropriate at this point in the outbreak. In general, it's better to be prudent and excessive (within limits) when dealing with a developing problem. The lack of information about the true scope of the problem, and the delays from transmission to definitive diagnosis of new cases, complicate assessments about whether the problem is truly contained, or containable.
Swine flu was most recently confirmed in Spain, and it has probably reached many different countries. It is also suspected in a group of students in New Zealand that recently visited Mexico. Considering the massive volume of travel between North America and much of the world, and the wide geographic range of cases in North America, it's hard to envision keeping this localized.
The fact that this outbreak is going to be difficult to contain, however, should not be taken as an excuse to not try to contain it. Even if this virus spreads to many different countries, good infection control and surveillance measures can help limit the impact of the disease.
Photo: Chichen Itza, one of the major tourist attractions on the Yucutan Peninsula in Mexico (credit M. Anderson)
Swine flu confirmed in Canada
Not surprisingly, swine influenza has been confirmed in Canada: 4 cases in Nova Scotia and 2 cases in British Columbia. More cases are certain to follow. As in the cases reported from the US so far, all Canadian cases have been mild.
The 4 cases from Nova Scotia were from the same high school. One of the affected students had been on a school trip to the Yucatan Peninsula in Mexico recently. Presumably, he or she picked up swine flu in Mexico and other students were infected by that student or others that went on the field trip. This is similar to a cluster of cases from a high school in New York. Eight students from that school were diagnosed with swine flu while more than 100 students had flu-like disease (it's unclear how many of these were tested). The two cases from BC were both in people who recently returned from Mexico themselves.
I imagine that we're going to see almost hourly reports over the next few days describing swine flu cases in people in various regions. Lets hope the pattern of mild disease that has characterized the Canadian and US cases persists.
US government declares public health emergency over swine flu
In response to increasing numbers of confirmed or suspected cases of swine flu in the US, plus a still relatively unknown number of cases and at least 81 deaths in Mexico, the US government has declared a public health emergency.
This H1N1 swine influenza virus has many of the hallmarks of a virus with pandemic potential. It is of animal origin but has a unique combination of gene sequences that has not been found previously in swine or human influenza strains. People don't have pre-existing antibodies because they have not been exposed to it before, which leads to the chance for widespre
ad disease. A big concern is that it seems to spread at least somewhat efficiently between people (unlike the H5N1 avian flu virus which is not efficiently transmitted between people). Fortunately, while it can cause death, this swine flu virus does not seem to be as deadly as avian flu, which kills approximately 50% of the people it infects. Therefore, while swine flu appears to be much more transmissible, it's probably not as fatal. (However, the large number of reported deaths in Mexico and early stage of the outbreak at this point means we need to be cautious making such statements).
It is clear that this swine flu strain is spreading in the US. It's been found in multiple US states and it is probably going to be found throughout the country. Mild cases have already been confirmed in Canada, and there are suspected cases in other countries. The number of cases in different regions and the amount of international travel makes containment of a reasonably-transmissible virus very difficult.
Some tips to reduce the risk of catching (or spreading) swine flu:
- Wash your hands regularly, particularly after contact with other people or common-contact sites (e.g. public door handles, public transit).
- If you are sick, STAY AT HOME. The era of "sucking it up" and going to work when you are sick should be over. All you're doing is putting others at risk.
More information about swine influenza can be found on the CDC's swine influenza website.
Image from http://www.nydailynews.com
Bird Flu and the Singing Roosters of Java
The following is a post by guest-blogger, Dr. David Waltner-Toews.
For North American veterinarians, the term “companion animals” covers a wide territory, from dogs, cats, and caged birds, to a variety of rodent and porcine escapees from barnyards and burrows. But when does a companion become something else? In my work with Veterinarians without Borders/ Vétérinaires sans Frontières – Canada, I find that I sometimes have to change my ideas of what companion animals are.
We have all heard about bird flu, and the fear that it might become a global pandemic. We know that wild water birds are the main reservoir for all the different kinds of influenza viruses that emerge every year from Southeast Asia and circle the world. The viruses are unstable, and historically haven’t caused many problems in birds. The disease in people can be serious, especially in older people, but large scale vaccination programs have helped. The big concern is that a new variation of the virus has evolved and has spilled from water birds into domestic poultry. A virus that not only kills birds, but also kills a high percentage of people – and other animals such as cats. Fortunately, it is difficult to contract – you pretty much have to be the one killing and cleaning the bird.
To some people, the way to stop a global pandemic is easy. If you suspect bird flu on a premise, kill all the birds and disinfect the area. Easy, isn’t it? They are, after all, “just chickens”. Or are they?
When my wife and I recently visited a part of the island of Java, Indonesia, where this new virus is thought to be endemic, that is, a lot of birds are carrying it, I already knew it was more complicated than just killing chickens. Often, poor people will “salvage” sick, dying or even already-dead birds by cooking them up and eating them before the authorities discover them. If you are hungry, it seems such a waste not to. As a result of such situations, about 120 people in Indonesia have died of bird flu since 2003.
But, we discovered, poverty is not the only “complication”. We held a town hall meeting in one village, in the middle of this endemic area, to explore how they were coping with the disease. They told us that they didn’t have any bird flu. Certainly, sometimes, they had some sick birds, which they threw into the river, but no bird flu. They attributed their disease-free status to the fact that they fed their birds a warm porridge made from snails and papaya leaves.
After our town hall meeting, we trundled through the rain to one of the nearby chicken-owners. When we entered the well-kept concrete-walled yard, a young boy proudly showed us his pet pigeon. His father, however, did him one better. It turns out that this family raised singing roosters, so-called Ayam Pelung, beautiful birds, about a metre high. I knew that wild jungle fowl had first been domesticated in Southeast Asia tens of thousands of years ago as fighting birds, now referred to in Indonesia as Ayam Bangkok.
I had heard about the singing birds, and had seen them in their cages at a competition at the veterinary college in Yogyakarta when I worked there in the mid 1980s, but this was my first close-up view. The men who owned them proudly crouched next to them for pictures. Periodically, one of the roosters would stand still and give a long, drawn out, low, throaty call, an avian version of some sultry lounge singer. These birds, if they win competitions throughout the country and region, apparently bring in up to 500 to 1000 U.S. dollars each. In a country where the average annual income is between $3000 and $4000, a few birds can represent a huge investment. Are these birds companion animals? Are they friends, workers, threats… or just chickens?
When is a dog or a cat or a bird more than a companion? When they sing? Race? Fight? When they are worth lots of money? In Thailand, where fighting cocks are common, and are valuable, the authorities have issued “vaccination passports”, with pictures of the roosters, indicating vaccination with a reputable influenza vaccine. When, in trying to control a disease, do we cross the line from “culling” economically important “units” to killing companions? When do we hand out passports?
If you had an amazing purebred dog worth tens of thousands of dollars, and the public health authorities threatened to kill it if it was found to be harbouring some virus which might or might not make you sick, what would you do? What if that dog was not only your companion, but your retirement investment?
Suddenly controlling a bird flu pandemic is a lot more complicated than killing “just chickens”. Welcome to the real world.
David Waltner-Toews is the founding President of Veterinarians without Borders/ Vétérinaires sans Frontières – Canada (www.vwb-vsf.ca) and a Professor in the Department of Population Medicine at the Ontario Veterinary College.
More on Avian Influenza
.jpg)
Wild birds are the natural hosts of all influenza type A viruses, of which there are numerous subtypes distinguished by their hemagglutinin (HA – 16 types) and neuraminidase (NA – 9 types) surface proteins. Subtypes H5, H7 and H9 can infect both birds and humans, but H7 and H9 infections in humans are uncommon. Within subtypes H5 and H7 there are both low pathogenic and highly pathogenic strains. Highly pathogenic strains can cause severe illness in both domestic birds and people, and death rates are high, although many wild birds (particularly water fowl) seem to be resistant to disease even from these more virulent viruses. Both sick and seemingly healthy birds can shed the virus in their respiratory secretions and droppings, and contact with this contaminated material can spread the virus to other birds. Transmission of the currently circulating avian influenza viruses from birds to people is uncommon. Fortunately, person-to-person transmission of avian influenza is uncommon.
The big worry with influenza viruses is that they have a high propensity to "mutate" - sometimes they change slowly (i.e. antigenic drift), and sometimes they change quickly (i.e. antigenic shift). When two different influenza viruses infect the same animal or person, the different components of each virus can recombine to make a new virus that will share some characteristics of both the original viruses. For example, if a highly pathogenic avian influenza virus (like the H5N1 virus from Asia) were to recombine with a human influenza virus, it could create a virus that causes severe disease like the avian virus, but which can be readily transmitted between people. This would create the potential for a serious outbreak of severe, even fatal illness in people.
Highly pathogenic avian influenza of either the H5 of H7 subtype is reportable in many areas of the world (including Canada), due to the potential for massive mortality in domestic bird flocks, as well as the risk of severe illness in people should such a virus start to circulate in the human population. Since 2004, avian influenza has been detected in Canada four times - highly pathogenic H7 types were found in British Columbia (2004) and Saskatchewan (2007), and low pathogenic H5N2 viruses were found twice, also in British Columbia (2005, 2009). The latest outbreak in January 2009 resulted in the destruction of 60 000 birds on the BC premises where the virus was originally detected, as well as all the birds on a second premises where the virus was found just over two weeks later. This disease is taken very seriously, and the response to these outbreaks by the Canadian Food Inspection Agency (CFIA) must always be swift and definitive.
The risk of highly pathogenic avian influenza to the general public in countries such as Canada that are (usually, though not at the moment) considered free of the disease is very low. The virus cannot survive in poultry products (i.e. meat, eggs) that are properly cooked. Contact with wild birds (dead or alive), particularly migratory birds that could potentially be from other continents, is likely the highest risk. Pet birds are also susceptible to these viruses, so its important to prevent them from coming in conatct with wild birds as well, especially because owners have such close contact with their feathered friends.
More information on influenza in animals and people is available in our archives.
Flu problems: people vs pets
It's that time of year again - we're coming up on flu season, and the ads on the radio and the television are out, encouraging everyone to get their "flu shot," (aka influenza vaccination). Influenza isn't just a problem in people - it is a very versatile group of viruses that can infect many different species of animals.
Equine and swine influenza viruses cause serious problems in horses and pigs, respectively. Last year there was a massive outbreak of equine influenza in Australia. Because Australia was previous free of equine influenza, most of the horses there had never been vaccinated against the virus. Therefore the entire population was very susceptible to the disease and it spread very quickly. The outbreak has since been brought under control. A previous Worms & Germs post talked about an outbreak of canine influenza in dogs in Chicago IL this past summer.
Equine and canine influenza (and usually swine influenza) cannot be transmitted to people. However, there are some strains of influenza that can cross species. The most well-recognized one is certainly avian influenza (bird flu), which caused outbreaks in a number of Asian countries in 2004. Although people are much less susceptible to avian influenza than birds, the H5N1strain has caused significant illness and fatalities in people.
A lesser known fact about influenza is that pet ferrets are very susceptible to the virus, including human strains. This is part of the reason ferrets are often used as animal models of the disease in research studies. Signs of the flu in ferrets are similar to what you'd expect to see in people - fever, sneezing, runny nose and lethargy. A pet ferret can both transmit to and catch the flu from a person. Unfortunately for the ferrets, there is no available vaccine for the flu in these animals.
Lucky for us, people can be vaccinated against influenza. Most people are still far more likely to get the flu from another person than from any kind of animal. Getting your flu shot is the best way to help prevent yourself from getting the flu, and spreading it to others. However, it's important to remember that no vaccine is 100% protective, so it's still important to take a few common-sense precautions, like washing your hands frequently, and sneezing/coughing into the crook of your arm, not into your hands. (And watch out for sick ferrets!)
There is lots of information about influenza and flu vaccine available on the web, including some of the links in this post, and also on the CDC Influenza (Flu) website.
Dog flu in Chicago
The Chicago Tribune is reporting canine influenza in dogs in the Chicago area. These are the first reported cases oin Illinois. Canine influenza has now been reported in 27 American states. It has also been previously identified in the UK.
Here are some canine flu facts:
- Canine influenza originated from an equine influenza virus.
- Canine influenza can cause a wide range of clinical signs, ranging from mild illness (cough, fever, decreased appetite and activity) to very severe (and potentially fatal) pneumonia.
- Dogs that have frequent contact with other dogs (e.g. in kennels or parks) or dogs in shelters are at higher risk of catching the virus.
- About 80% of dogs that are exposed to this virus will get sick.
- Most affected dogs recover fully.
- Canine influenza cannot be diagnosed just by looking at the dog. Various other bacteria and viruses can cause similar disease.
- Because the disease is caused by a virus, it can NOT be treated directly with antibiotics (just like influenza in people!)
- There is no vaccine for canine influenza.
- Canine influenza is not transmissible to people.
- Try to keep your dog away from any dogs that looks ill, particularly those that are coughing.
- If your dog starts coughing or looks otherwise sick, you should take your dog to the vet, especially if your dog has been in a kennel, shelter or in contact with another sick dog.
More information about control of canine influenza can be found on the American Veterinary Medical Association Public Health Information website.
To our knowledge, there are still no reported cases of canine influenza in Canada. However, it seems inevitable that the virus will eventually make its way north of the US border, considering the number of US states that are now affected.
Cats and avian influenza
Avian flu is a tremendous concern at the moment. While it is not (currently) easily transmitted between people, bird-to-human infections have been reported in various countries. Mortality rates are very high, and the concern is that this strain could change to become easily transmitted between people, and lead to a pandemic (worldwide outbreak) not seen since the Spanish flu pandemic in the early 20th century. While birds and people are the focus, some attention has been paid to other species, such as cats.
Fatal avian flu developed in leopards and tigers in a zoo in Thailand during an avian flu outbreak. It was suspected that they ate infected chickens. Similarly, avian influenza in a pet cat was thought to have resulted from eating a dead pigeon (the pigeon presumably having died of avian flu). The potential role of cats in transmitting disease was highlighted by a study that reported that cats can become infected by eating infected birds, and can transmit avian flu to other cats.
While unproven, cats could theoretically play a role in transmitting this virus from birds to people. It's unlikely cats would be a major factor in a flu pandemic, but if such a situation were to arise, any possible source of transmission would need to be considered.
Should we worry about cats and avian flu right now? Worry....no. Be aware....yes. H5N1 avian influenza is not currently present in North America and it's hard to say if/when it will appear.
Should we think about cats when making plans for management of avian influenza if/when if reaches us? Absolutely. It's issues like this that get overlooked in outbreak planning.
Should I keep my cat inside? Yes. Outdoor cats are exposed to a large number of different infectious agents, including parasites and bacteria that can infect people. Outdoor cats can also get into fights, during which animals can transmit important diseases or cause nasty wounds. Also (obviously), an indoor cat isn't like to get hit by a cat...an important cause of premature death in cats.
Avian flu is just one more indication that our relationship with infectious diseases is much more complex than we've thought, and that broad (ecological) approaches to infectious disease control are required. We need to think about household pets when considering emerging infectious diseases because of the close and prolonged contact that millions of people have with their pets.
