Isolation of a recombinant influenza virus (Hsw1N2) from swine in Japan

Abstract

Outbreaks of swine influenza were first observed in Japan in 1978. A number of influenza viruses were isolated from diseased swine. Almost all viruses isolated were swine influenza virus (Hsw1N1) but two viruses isolated from the nasal swabs of swine showing clinical signs of influenza in the Kanagawa prefecture were characterized antigenically as Hsw1N2. Analysis of swine sera showed that influenza virus Hsw1N2 was epidemic in the farm from which the virus had been isolated. The new virus (Hsw1N2) seems to have been produced by recombination between swine influenza virus (Hsw1N1) and Hong Kong influenza virus (H3N2). © 1980 Springer-Verlag.