Why is Quebec spared more from AI?
While cases of avian influenza are increasing on poultry farms in Western Canada with 64 active cases, Quebec has only three and Ontario, one. Why? This is the question that epidemiological veterinarian Dr. Manon Racicot from the Canadian Food Inspection Agency (CFIA) wanted to answer during the most recent AQINAC Poultry Meeting in November 2023.
In 23 months until Manon Dr. Racicot’s conference on November 15, 2023, there had been 374 infected farms, including 15 reinfected and 9 infected by two viruses. In total, 215 control zones were established and 900 calls were made for sick birds.
According to Dr. Racicot, three reasons explain why Quebec differs: the seasonality of cases, the mutation of the virus and the distribution of the industry. In Canada, there have been two gateways for the current H5N1 avian influenza event: Newfoundland in November 2021 in the East, and British Columbia in February 2022 in the West.
After the virus entered, it recombined with the North American virus present on our territory. The virus has been detected in migratory aquatic birds. The cases recorded in 2022 were very numerous, but fewer this year. But beware! That doesn’t mean there are much fewer viruses. “We think the virus is still present,” explains Dr. Racicot. We have fewer cases detected, but we also have fewer reports. » In an interview, Manon Racicot explains that the large number of cases to date in wild birds in Eastern Canada could have provided a certain immunity.
To date, four waves have occurred in Canada: spring 2022, fall 2022, spring 2023 and fall 2023. These are bird migration seasons, but also periods during which the temperature is favorable for the transmission of virus. “The virus lives very well when the temperature is cold and humid,” explains Dr. Racicot. The contaminated environment can then remain contaminated for a long time.
One of the concerns with avian influenza is that a mutation in the virus allows the virus to adapt in mammals, especially skunks. This causes public health concerns. This is why Manon Racicot recommends that people in the poultry industry get vaccinated against seasonal flu. This will reduce the risk of recombination between the two viruses in the event of infection.
The greater presence of ducks in Quebec could partly explain the difference with Western Canada. Ducks become infected, but very few die, unlike turkeys, which all die. However, in Quebec, there seems to be a correlation between infected duck farms and turkey farms.