title: Prevalence of human (H1N1) influenza virus-antibody in Japanese swine.
abstract: A total of 571 swine sera collected at an abattoir in the city of Obihiro, Hokkaido during the period February-November 1984 were tested for antibody against human (H1N1) influenza virus strains. A high prevalence of antibody was observed for only 3 months from April to June in that year, in 81/180 sera (45.0%) to A/USSR/92/77 strain and in 50/180 sera (27.8%) to a current epidemic strain (A/Hokkaido/1/84). Some cross-reactions were observed between the A/USSR/92/77 and A/Hokkaido/1/84 antibodies (r = 0.75). Only minor relationships were noted between the A/New Jersey/8/76 (swine type H1N1) and A/USSR/92/77 (r = 0.35) or A/Hokkaido/1/84 (r = 0.51) antibodies. Absorption of sera positive for antibody to the A/Hokkaido/1/84 strain with the homologous virus strain removed all detectable antibodies, while the absorption of the sera with the A/New Jersey/8/76 strain produced incomplete absorption in one half of the sera tested. These results strongly suggest that the swine became infected with a human H1N1 virus as piglets during an epidemic of influenza which occurred in the human population during January and February 1984.
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis*; D003429:Cross Reactions; D006385:Hemagglutination Inhibition Tests; D053118:Influenza A Virus, H1N1 Subtype; D009980:Influenza A virus / Q000276:immunology*; D007564:Japan; D009976:Orthomyxoviridae Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D013552:Swine / Q000276:immunology*; D013553:Swine Diseases / Q000453:epidemiology / Q000382:microbiology*
chemical_list: D000914:Antibodies, Viral