Methods for detection and frequency of contamination of fetal calf serum with bovine viral diarrhea virus and antibodies against bovine viral diarrhea virus.

Methods used by the National Animal Disease Center to test fetal calf serum for contamination with bovine viral diarrhea virus (BVDV) and antibodies against BVDV are described. Using those methods, virus was isolated from 332 of 1,608 (20.6%) lots of raw fetal calf serum obtained specifically for the Center and 93 of 190 (49%) lots of commercially available fetal calf serum. Virus neutralization and immunoperoxidase staining tests were used to detect antibodies against BVDV in 224 of the 1,608 (13.9%) lots of raw fetal calf serum. Both BVDV and antibodies against BVDV were detected in 50 lots of raw serum. The molecular specificity of antibodies against BVDV was determined by radioimmunoprecipitation. Lots of fetal calf serum that contained BVDV-specific antibodies that did not neutralize virus were identified.