A SIMPLE, SPECIFIC, AND HIGHLY SENSITIVE BLOCKING ENZYME-LINKED-IMMUNOSORBENT-ASSAY FOR DETECTION OF ANTIBODIES TO BOVINE HERPESVIRUS-1

By using a monoclonal antibody directed against an epitope located on glycoprotein B of bovine herpesvirus 1 (BHV1), a simple, convenient bl ocking enzyme-linked immunosorbent assay (ELISA) which combines a high sensitivity with a low false-positive rate has been developed. The te st can be performed at low variance on undiluted bovine serum samples. The epitope on glycoprotein B appears to be conserved, because it cou ld be detected by immunostaining in all of 160 BHV1 isolates originati ng from 10 countries. In testing 215 anti-BHV1 antibody-negative and 1 79 anti-BHV1 antibody-positive serum samples, specificity and sensitiv ity were 0.96 and 0.99, respectively. This blocking ELISA is superior to a commercially available indirect ELISA and to the 24-h virus neutr alization test in detecting low antibody levels in serum. In addition, this blocking ELISA is able to detect specific antibodies in serum as early as 7 days postinfection. To minimize any risk of introducing la tent BHV1 carriers among noninfected cattle, this blocking ELISA would be, in our opinion, the test of choice.