Canada's inter-agency wild bird influenza survey

Area of Science:

• Veterinary Virology
• Wildlife Epidemiology
• Public Health Surveillance

Background:

• Avian influenza poses a significant threat to wild bird populations and can have implications for poultry and human health.
• Continuous monitoring of wild birds is crucial for early detection and understanding of influenza virus dynamics.

Purpose of the Study:

• To detail the methodology and findings of Canada's Inter-agency Wild Bird Influenza Survey.
• To assess the prevalence and characteristics of avian influenza viruses in Canadian wild bird populations.

Main Methods:

• The survey employs two components: seasonal sampling of live wild waterfowl and ongoing surveillance of dead birds submitted to diagnostic labs.
• Real-time reverse transcriptase-polymerase chain reaction (RRT-PCR) is used for initial screening targeting the influenza A M1 gene.
• Positive or inconclusive M1 results trigger further RRT-PCR for H5 and H7 subtypes, with positive samples undergoing confirmation and characterization.

Main Results:

• Since 2005, an average of 30% of live ducks, 5% of other live bird species, and 3% of birds found dead tested positive for avian influenza.
• All detected avian influenza viruses were of North American lineage and low pathogenicity.
• Data is managed in a centralized database by the Canadian Cooperative Wildlife Health Centre.

Conclusions:

• Canada's comprehensive wild bird influenza survey effectively monitors avian influenza virus circulation.
• The survey provides valuable data on virus prevalence, lineage, and pathogenicity in wild birds, aiding in risk assessment and management strategies.