[Antigenic characterization of influenza A virus isolated from birds captured in Ontario, Quebec, and the maritime provinces during the 1977 season].

A total of 145 influenza A viruses were isolated from ducks, geese and passerine birds in Ontario, Québec and the Maritimes in July-August 1977. Antigenic characterization of these isolates included five hemagglutinin (Hsw1, Hav4, Hav5, Hav6, Hav7) and five neuraminidase subtypes (N1, N2, Neq1, Neq2, Nav1) in nine different combinations; one combination Hav7 Neq1 had not been previously reported. The majority of these viruses were Hsw1 N1, antigenically related to influenza viruses in pigs and humans. This large reservoir of influenza A viruses circulating in ducks may well be involved in the appearance of new viruses in other species, including humans.