Understanding and Managing the Hazard

Recently, a new approach of upstream detection of BVD virus in raw, unprocessed FBS has been described. This is a sandwich enzyme-linked immunosorbent assay (S-ELISA) designed to detect presence of BVD virus in the serum, using a commercially available diagnostic kit (Syracuse Bioanalytical, Syracuse, NY). In this study, the S-ELISA kit that uses raw (unprocessed) FBS as the testing sample was evaluated for upstream BVDV testing. Pooled FBS samples were tested: (n = 84), each representing a 3-L FBS sublot. Thirty serum samples originating from persistently infected (PI) calves that had been confirmed by virus isolation (VI) as BVDV positive and another 30 samples previously confirmed by VI as BVDV negative were also evaluated. Of the 84 field samples, the S-ELISA detected 13 (15.5%) BVDV-positive specimens. When these 13 positive samples were tested by VI and immunofluorescent assay, 11 (84.6%) were positive and 2 (15.4%) were negative. The S-ELISA was positive for all 30 PI samples (100%) and negative for all 30 negative samples (100%). These data indicate that the new kit is a relatively reliable diagnostic tool and can be considered for upstream detection of BVDV-contaminated raw FBS pools. Although the S-ELISA cannot replace 9 CFR virus testing, it can be efficiently implemented at early manufacturing steps to identify and segregate positive sublots. This approach would considerably reduce the chance of virus entering the manufacturing plant, as well as minimize the percentage of contaminated final FBS products in