Detection of equine herpesvirus-1 antigen and the specific antibody by enzyme-linked immunosorbent assay.

Enzyme-linked immunosorbent assays (ELISA) were developed to detect equine herpesvirus-1 (EHV-1) antigens and specific antibodies. Detection of EHV-1 antigens was done by a 4-layer ELISA. In inoculated cell cultures, EHV-1 cell antigen was detected after postinoculation (PI) hour 4, reached approximately twice the value of EHV-1 viral antigen (extra-cellular virus) in PI hour 18, and peaked in PI hour 24, whereas EHV-1 viral antigen appeared after PI hour 12, increased steadily, and peaked higher than EHV-1 cell antigen in 24 hours. The ELISA titer and infectivity titer of 24-hour PI cultures were 200 and 9.2 X 10(5) plaque-forming units/0.1 ml, respectively. Equine anti-EHV-1 antibody (EAEHV-1) from experimentally inoculated pony foals and rabbit anti-EHV-1 antibody (RAEHV-1) were detected by indirect ELISA and direct ELISA, respectively. The RAEHV-1 had ELISA titers of 665,000 and 102,000 when rabbits were immunized with EHV-1 infected cell culture lysate and with sucrose-purified virus, respectively. The corresponding plaque-reduction virus-neutralization titers were 270 and 150 in the absence of complement and were 6,200 and 3,200 in the presence of complement. The EAEHV-1 had a mean ELISA titer of 60,000, and the corresponding mean virus-neutralization titer in the absence of complement was 34 and that in the presence of complement was 2,142.