15 novembre 2016

Myths and facts about the H5N1 avian influenza virus

Santé et nutrition

Am I at risk of contracting the H5N1 avian influenza virus? This has to be a concern of any resident of Alberta who has heard about the fatal case of H5N1. Canadians across the country are certainly looking for information and answers.

To get a better understanding of where this type of virus is coming from, we have to go back to 1997 when this virus started circulating in East Asia. We do not know exactly where it originally came from, but it probably originated in wild birds and then jumped to other animals, including domestic poultry, and eventually in rare cases to humans. Avian influenza virus H5N1 fell off the radar screen for some time, then came back in 2003. Subsequently, it again took a low key profile, but for some unknown reasons, it seems to be resurfacing. Although this virus is highly contagious in poultry, thankfully it has much less ability to infect humans. More importantly, when this virus infects humans, there is no evidence that it can be transmitted from infected patients to other people. This means that there is an extremely low risk (or virtually no risk) for those passengers who took the same flight as the infected woman from Beijing to Vancouver. But could this virus jump from humans to poultry? This is very unlikely, so chances are Canadian poultry flocks will never become infected with the exact same virus that sadly killed the Albertan woman.

Biosecurity Measures to Protect Poultry Flocks

As I mentioned above, this virus originated in East Asia, but why that region of the world? There are several theories around this observation, one of them being the presence of live poultry markets in countries like China, which increases the chance of human exposure to the viruses that poultry carry, such as avian influenza virus. Over the last few decades in Canada, we have implemented strict biosecurity measures for our poultry flocks. According to the Canadian Food Inspection Agency, biosecurity is the collection of “measures needed to protect against the introduction and spread of diseases”. Today, in modern poultry production, biosecurity measures implemented include housing the chickens inside and ensuring handlers wear clean clothing and footwear that have not been outside the barn. Diseases can be spread very simply, for example, by stepping in the excrement of wild birds including ducks and pigeons and then entering the poultry barn. According to Dr. Helen Anne Hudson, Burnbrae Farms is one of the leaders in Canada in this area and its management has designed and implemented several successful biosecurity plans to minimize the risk of introduction of infectious diseases, including avian influenza, into their flocks.

Is there a vaccine?

Now given all the media attention, you probably wonder if you can somehow protect yourself and your loved ones, for example by vaccination. Unfortunately there is no vaccine against this virus for humans, at least not in Canada! Also, the seasonal flu vaccines, which are now available in Ontario in local pharmacies, do not protect against this particular type of influenza.

Is it safe to eat poultry eggs and meat?

As a consumer you are probably asking yourself if it is safe to eat poultry eggs and meat in the unlikely event of an outbreak. The answer is yes! There is virtually no evidence to link consumption of meat or eggs from infected birds to occurrence of disease in humans. For those who want to err on the side of caution, one should properly cook meat and eggs because this virus is susceptible to high temperatures and will not survive these harsh conditions.

Research into new Poultry Vaccines

Finally, we have some good news to share with you! At the University of Guelph as well as a few other institutions in Canada and the rest of the world, poultry researchers are hard at work to develop new vaccines against this virus. These researchers have made a lot of progress and we are hoping that one day these vaccines will be available to veterinarians for protecting animals against the avian influenza virus.

Thanks to our Guest Blogger:

Dr. Shayan Sharif is a professor of poultry immunology at the Ontario Veterinary College, University of Guelph. His research is focused on understanding how the chicken immune system sees avian influenza viruses and how it responds to these viruses. The ultimate goal of this research is to develop efficacious vaccines to control avian influenza viruses. Dr. Sharif is also the leader of the Poultry Health Research Network ( www.uoguelph.ca/phrn ).