The Canadian Food Inspection Agency has identified a highly transmittable form of avian flu in multiple samples gathered in southern Manitoba following an unprecedented bird mortality event. Approximately 500 bird carcasses, predominantly Canada geese, were discovered near waterways in southern Manitoba in early December. While separate groupings of deceased birds were located near the Red River north of Winnipeg’s Perimeter Highway, the largest concentration was found in a set of ponds in Niverville.
Biologist Frank Baldwin of the Canadian Wildlife Service informed CBC News that samples from the birds, which tested positive for avian influenza, commonly known as bird flu, were forwarded to the Canadian Food Inspection Agency to ascertain the strain of the infection. The federal agency revealed that 38 out of 39 wild bird samples submitted for testing on December 11 were confirmed to be positive for the highly pathogenic H5N1 strain of avian flu.
University of Manitoba researcher Hannah Wallace, specializing in viral immunology, expressed relief that the samples tested positive for the H5N1 strain, which is known to cause significant illness and mortality in birds. Wallace had concerns that the virus might have mutated into a more dangerous form for both birds and humans. Although previous instances of high mortality rates in geese due to bird flu were uncommon, Wallace highlighted the potential risks associated with the virus mutating into a more severe variant.
The detected H5N1 strain is the predominant strain circulating among domestic poultry and wild bird populations in North America, as confirmed by the food inspection agency. Wallace emphasized that the detection of H5N1 in southern Manitoba was not unexpected and aligned with previous experiences in dealing with the virus.
H5N1 was initially identified in Canada in late 2021, with most Canadian birds having already developed some level of immunity due to prior exposure. Vulnerable or malnourished birds may be at a higher risk of contracting H5N1, especially if they remain in the region for an extended period, facing adverse weather conditions and food scarcity.
Research indicates that avian influenza can persist in the environment even after birds have migrated. While Wallace believes the virus may not remain in the water where the deceased birds were located, it could potentially survive in ponds or river sediment, posing a risk until spring despite cold temperatures.
Avian influenza has been a longstanding concern for both scientists and poultry farmers in the region. The highly contagious and deadly nature of the virus presents challenges for farmers, particularly during peak migration seasons when wild birds can serve as vectors for transmission. Farmers like Rod Wiebe from Manitoba Chicken Producers have emphasized the importance of biosecurity measures to prevent the spread of bird flu from wild birds to domestic poultry.
Candace Lylyk, owner of Breezy Birds Farm in Morris, Manitoba, shared her efforts to safeguard her poultry farm from wild birds carrying avian influenza. She highlighted the changes made to farm operations to minimize the risk of exposure, including restricting visitor access and implementing strict biosecurity protocols.
The detection of the H5N1 strain in deceased birds in southern Manitoba underscores the ongoing vigilance required to monitor and mitigate the spread of avian flu in both wild bird and poultry populations.