Canada's inter-agency wild bird influenza survey.

Canada's Inter-agency Wild Bird Influenza Survey, which started in 2005, and is a collaborative effort among federal, provincial and territorial government agencies as well as non-governmental organizations and academic institutions, has two components: (i) a seasonal survey of live wild waterfowl species from selected geographic regions across Canada (to expand our understanding of the avian influenza viruses circulating in wild bird populations); and (ii) an ongoing survey of birds found dead that are submitted to a regional diagnostic laboratory (to enhance detection of highly pathogenic avian influenza strains). Combined swabs from the cloaca and oropharynx collected from each bird are screened using a real-time reverse transcriptase-polymerase chain reaction (RRT-PCR) that targets a unique segment of the influenza A M1 gene. If the M1 result is positive or inconclusive, RRT-PCR for gene segments of the H5 and H7 hemagglutinin subtypes are performed. All samples that are RRT-PCR positive for H5 or H7 are sent immediately for test confirmation and further characterization. All field and laboratory data are entered into a database developed and maintained by the Canadian Cooperative Wildlife Health Centre. Since the survey commenced in 2005, on average, 30% of all live ducks sampled, 5% of other species of live birds and 3% of birds found dead have tested positive for avian influenza, all of North American lineage and of low pathogenicity.