A serological survey of human coronavirus in pigs of the Tohoku District of Japan.

A total of 2496 swine sera from 60 farms in the Tohoku District of Japan was examined for hemagglutination inhibiting (HI) antibodies to human coronavirus (HCV), swine hemagglutinating encephalomyelitis virus (HEV) and bovine coronavirus (BCV). HI antibodies to HCV OC43 strain and HEV 67N strain were highly prevalent with positivity rates of 91.4 and 82.1%, respectively, while the BCV Kakegawa strain was 44.2% positive. Farm D in Miyagi Prefecture showed the highest antibody titers to HCV OC43 strain with geometric mean titers (GMT) of 1:200. These results suggest that pigs might be infected with HCV or an antigenetically related virus as well as HEV.