Isolation of influenza a viruses from migratory waterfowls in San-in District, Western Japan in winters of 1980–1982

Abstract

In the two winters of 1980–1982, we surveyed migratory waterfowl of some species staying in San-in District, Western Japan for influenza virus at a few stations. From November 1980 to April 1981, only two strains of influenza virus, H13N1 and H11N6 subtypes, were isolated from 465 fecal samples from pintails but none from 255 samples from whistling swans nor from 625 black-tailed gulls. From November 1981 to March 1982, 17 viruses were isolated from 1156 fecal samples. Fourteen viruses, 10 H7N3, 2 H1N6 and 2 H3N8, were isolated from 459 feces samples from whistling swans. Two viruses, H13N3 and H13N6 subtypes, were isolated from 425 fecal samples from black-tailed gulls. A strain belonging to H1N3 subtype was isolated from 30 feces samples from mallards but no virus was isolated from 242 samples from pintails.