An ELISA detecting antibody to conserved pestivirus epitopes.

A monoclonal antibody based competition-ELISA is described for the detection of pestivirus antibodies directed against conserved epitopes on the p80 viral protein. The ELISA detected increases in serum antibody following experimentally induced infections of pigs, cattle and sheep with a wide range of pestiviruses, although the sensitivity of the test was not uniform for the different viruses studied. The ELISA was compared with virus neutralization tests for the assessment of porcine, bovine and ovine field sera. At a cut-off value of 50% inhibition, the ELISA showed a high specificity relative to virus neutralization tests, but appeared less sensitive for the detection of some weakly positive samples from pigs. Sera from both ruminants and pigs could be assessed without any modification of the test.