Isolation and serological characterization of influenza A virus from a pig in Thailand.

A hemagglutinating agent was isolated from a pig in Thailand in 1978 during the early febrile stage of an influenza-like illness and identified as influenza A virus. The isolate contained hemagglutinin and neuraminidase antigens that were antigenically indistinguishable from those of A/Tokyo/6/73 (H3N2), a Port Chalmers-like strain isolated in Japan. Serological tests also indicated that prevalence of H3N2 virus in the swine population in Thailand.