Seroprevalence of infectious bursal disease virus in free-living wild birds in Japan.

Serum samples collected from 739 free-living wild birds of 44 species from Gifu, Mie and Hyogo Prefectures in Japan during the period 1989 to 1997 were tested for antibodies to infectious bursal disease virus (IBDV) serotypes 1 and 2 by a virus neutralization test. Serological evidence of infection with serotypes 1 and 2 was found in 15 (2%) of the sera of 6 species and 36 (4.9%) of the sera of 11 species, respectively. Antibodies to IBDV were detected from both sedentary and migratory species. These findings suggest that free-living wild birds have an important role in the natural history of IBDV. These findings raise the possibility that the IBDV prevalent in the breeding grounds of these birds in other countries could be imported by the migratory species. This is the first report of an extensive serological survey of IBDV in wild birds.