A capture-enzyme immunoassay for rapid diagnosis of transmissible gastroenteritis virus.

Two enzyme immunoassays (EIA) were developed for the detection of swine transmissible gastroenteritis virus (TGEV) antigens. The 2 EIAs used the same detecting system, a monoclonal antibody conjugated to horseradish peroxidase, but used different capture systems including a monoclonal antibody (m-EIA) or a polyclonal antibody (p-EIA). The EIAs were compared with the fluorescent antibody test (FAT) and electron microscopy (EM) for the detection of TGEV in intestinal samples of experimentally inoculated gnotobiotic piglets and of conventional diarrheic pigs submitted for diagnosis. In the gnotobiotic piglets experimentally inoculated with TGEV, 81.8% (9/11) were positive for TGEV by p-EIA, and 72.7% (8/11) were positive by m-EIA. In comparison, 81.8% (9/11) were positive by FAT and 27.2% (3/11) were positive by EM. Three noninfected controls were negative by all tests. In the diagnostic samples, 86.0% (43/50) were positive by p-EIA, 68.2% (30/44) were positive by m-EIA, 28.6% (14/49) were positive by IFA, and 38.0% (19/50) were positive by EM. The m-EIA had a higher agreement with FAT and EM than did p-EIA.