Abstract
A total of 2,703 pig sera from 171 farms in six regions in Japan were screened for virus neutralizing (VN) antibody against transmissible gastroenteritis virus (TGEV). Although none of the farms had clinical signs of transmissible gastroenteritis (TGE) or vaccination against TGEV, VN antibody was detected in 14.4% of sera at 30 farms (17.5%) across all six regions. On testing of 263 VN antibody-positive sera from 27 farms with a commercial blocking ELISA to distinguish TGEV and porcine respiratory coronavirus (PRCV) antibodies, 78.3% of sera were positive for PRCV antibody only, while 12.5% of sera were positive for TGEV antibody only or both TGEV and PRCV antibodies. Seven of the eight TGEV antibody-positive farms were also positive for PRCV antibody. Five months after the antibody examination, a TGE outbreak occurred at one of the seven farms. These results suggest that most of the detected VN antibody were to PRCV, and that TGEV infection might be present at some PRCV-positive farms in Japan.
