Isolation of influenza A viruses from migratory waterfowls in San-in District, Western Japan in 1979-1980.

From December, 1979 to April, 1980, winter migratory waterfowls of some species staying in San-in District, western Japan were surveyed for influenza virus. A total of 27 influenza A viruses, 11 Hav1 Neq1 and 16 Hav6 Nav3, were isolated from 90 fecal specimens of whistling swans. A total of 13 influenza A viruses, 11 Hav1 Neq1 and one Hav6 Nav3, were isolated from 245 fecal samples of black-tailed gulls. Two viruses (Hav1 Neq1) were isolated from 40 tufted ducks. Sampling date, incidence and the antigenic subtype of the isolates were correlated.