A first case of avian flu was detected this winter in Quebec. A report in Outaouais caused the death or euthanasia of around 17,000 birds at the start of the year. These infections, although “unusual” during the cold season, confirm that the virus circulates everywhere in wildlife.
The avian flu virus survives frost, and a farm in Saint-André-Avellin learned this the hard way. An entire flock of chickens in the MRC of Papineau had to be slaughtered to avoid further contamination. This virus has caused the death of more than a million farmed birds in Quebec since 2022. Across Canada, the number of affected animals exceeded the 10 million mark this winter.
“It surprises us to have cases in winter,” recognizes Martin Pelletier, coordinator of the Quebec Poultry Disease Control Team (EQCMA). The causes of this latest contamination, however, seem “obvious”.
“The farm was right in front of a lake where a pump ensures that the body of water does not freeze. It attracts wild waterflies. With a surface that is not frozen nearby, there is a greater chance that birds [sauvages] winter near us [et contaminent les oiseaux domestiques], he explains. We think this is probably an obvious risk factor. »
These farm ponds, very common in the agricultural landscape, will prove risky in the future for poultry producers, indicates Jean-Pierre Vaillancourt, a leading specialist in biosecurity on farms and professor at the Faculty of Veterinary Medicine of the ‘Montreal university.
“We did that at the time and there were no consequences,” he notes. However, since the arrival in 2022 of a new “highly pathogenic” strain on Quebec territory, it is now possible for wildlife to contaminate domestic wildlife, and vice versa. “Sick birds will excrete up to 1000 times more of this virus than another low pathogenic virus. »
What’s more, this new virus resists the cold very well and loves humid places, such as lakesides. We might as well say that Quebec is a fertile breeding ground for such a microbe. “A day like Tuesday, with rain and humidity, is exceptional for the virus. Add to that mud and droppings, and it can stay there for weeks, months. »
No transmission to humans… for now
The progression of avian influenza of the H5N1 strain throughout the world is dazzling, to the point where it is now detected in more than 76 countries and in at least 273 species of birds.
From a seasonal disease, avian flu has become endemic year-round in Europe. While the virus once disappeared in a few hours under the Mediterranean sun, it now manages to survive for days, potentially contaminating all fauna, whether avian, aquatic or terrestrial.
“When I speak with my colleagues, they don’t understand,” says Professor Vaillancourt. […] What we know is that in 2022 and 2023, the environment has been very contaminated. »
For the moment, authorities have not recorded any transmission to humans. However, the more the virus replicates in nature, the more likely it is that it will eventually spread to our species. Such a scenario seems catastrophic. Avian flu has the property of turning the immune system against its host, which makes the disease particularly serious for young and healthy individuals, quite the opposite of the flus from which we already suffer. “We are not there at all,” reassures Jean-Pierre Vaillancourt. I sleep well in the evening. But you will have to be careful. »