The Canadian Food Inspection Agency has identified a highly infectious form of avian influenza in numerous samples gathered in southern Manitoba following an unusual mass 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 found near the Red River just north of Winnipeg’s Perimeter Highway, the largest concentration was located in a cluster of ponds in Niverville.
Biologist Frank Baldwin from the Canadian Wildlife Service informed CBC News that samples of the birds were forwarded to the Canadian Food Inspection Agency for testing after testing positive for avian influenza, commonly known as bird flu. The federal agency reported that 38 out of 39 wild bird samples sent for testing on December 11 were confirmed to be positive for the highly pathogenic H5N1 strain of avian influenza.
University of Manitoba researcher Hannah Wallace, specializing in viral immunology, expressed relief that the samples tested positive for the H5N1 strain, which is associated with significant disease and mortality in birds. Wallace had concerns about potential mutations of the virus into a more hazardous strain affecting both birds and humans, as previous instances did not exhibit high mortality rates among geese infected with avian influenza.
The H5N1 strain detected in the samples is prevalent among domestic poultry and wild bird populations in North America, as confirmed by the food inspection agency. Wallace noted that most birds in Canada have been exposed to this strain, providing them with a level of pre-existing immunity. Factors such as weakened or undernourished birds being more susceptible to contracting H5N1 were speculated as potential reasons for the bird deaths in southern Manitoba.
According to Wallace, avian influenza can endure in the environment even if birds have migrated, potentially persisting in ponds or river sediment. While the virus may not remain in the exact water locations where deceased birds were found, it could survive in different environmental reservoirs. The behavior of avian influenza varies annually, with some bird populations showing high levels of antibodies to combat the virus, although the duration of this protection remains uncertain.
Poultry farmers in Manitoba have faced challenges due to the contagious and lethal nature of avian influenza. Rod Wiebe, the board chair of Manitoba Chicken Producers, highlighted the difficulty in controlling bird flu transmission from wild birds, particularly during fall and spring migration periods. Candace Lylyk, the owner of Breezy Birds Farm in Morris, emphasized the precautions taken to safeguard her poultry farm against the virus, including restricting farm access and implementing strict biosecurity measures to prevent contact with wild birds.
The detection of the H5N1 strain in the deceased birds in Manitoba serves as a reminder of the ongoing risk posed by avian influenza to both wildlife and poultry populations. With concerns about potential mutations and transmission to humans, continued vigilance and preventative measures are essential to mitigate the impact of the virus on bird and human health.
