Comparative diagnostic value of the gel diffusion test and virus isolation in cell culture for detecting equine herpesvirus type 1 (EHV-1)

The gel diffusion test was applied direct to field samples from cases of equine abortion, foal mortality and equine paralysis due to equine herpesvirus type 1 (EHV-1). Following polyethylene glycol concentra­ tion of viral antigen, one line was formed against EHV-1 antiserum after 24 hours incubation at 25°C. Tests carried out simultaneously on 41 field samples showed a high correlation between diagnosis based on this test and virus isolation in primary lamb kidney cell culture. Advantages of gel diffusion over isolation of virus in cell culture were its rapidity and simplicity. The precipitating antigen did not lose activity after heating at 56°C for 30 minutes. A positive reaction was observed with a conta­ minated sample, which failed to yield virus in the cell culture system.