1993 Volume 46 Issue 6 Pages 459-462
Outbreaks of swine Influenza occurred on 2 pig-farms in Nagasaki Prefecture during the 1989-1990 period. Two hemagglutinating viruses were isolated from nasal swabs of affected pigs and identified antigenically as reassortants of the influenza virus having the hemagglutinin subtype 1 (H1) and neuraminidase type 2 (N2). Serological tests indicated significant increases in hemagglutination inhibition (HI) and neuraminidase inhibition (NI) antibody titers in convalescent sera against the isolates of the influenza virus. A serological survey was conducted using 1, 512 sera from pigs raised on other farms in the prefecture; 31.6% of the swine had the HI antibody to subtype H1 and 29.1%, the HI antibody to subtype H3 of the influenza virus. Antibodies against H1 and N2 antigens of the reassortant viruses were shown present in 12% of the swine.
The present results suggest that H1N2 type influenza virus may possibly be spreading among pigs in Nagasaki Prefecture.
