Evaluation of an antigen-capture ELISA for detection of bovine viral diarrhea virus in cattle blood samples.

From blood samples routinely received for bovine viral diarrhea (BVD) diagnosis, 860 samples without antibodies to BVD virus were examined in both virus isolation and in an antigen-detecting enzyme-linked immunosorbent assay (ELISA) based on monoclonal antibodies (MAbs) against the nonstructural BVD virus protein p125/p80. A total of 843 samples (98%) were positive (n = 170, 20%) or negative (n = 673, 78%) in both tests, corresponding to an agreement of kappa = 0.94. Among 17 samples with diverging results, 3 were from animals transiently infected with BVD virus, and 5 came from clinically affected animals. The reactivity of the MAbs was controlled against 387 field isolates of BVD virus. All were detected by the MAbs, thereby confirming the general view that the p125 virus protein is highly conserved among different BVD viruses.