Is contamination of bovine-sourced material with bovine viral diarrhea virus still a problem in countries with ongoing eradication campaigns?

In this report, we describe the detection of bovine viral diarrhea virus (BVDV) contamination in commercial animal-derived sera and vaccines against animal viral pathogens on the market in Poland. Antibodies against BVDV were detected in 4/45 sera samples (8.9%) using an ELISA test. The presence of BVDV antigen was found using ELISA in 3/45 serum samples (6.6%) and 18/172 vaccine samples (10.5%). An RT -PCR was conducted using primers targeting two genome regions, the five prime untranslated region (5’UTR) and N-terminal protease (N^pro). BVDV RNA was detected in 33/45 (73.3%) of sera, and 11/172 samples (6.4%) of collected vaccines, of which one vaccine did not declare BVDV strain in its composition. A single serum showed the presence of an infectious virus and only one was contaminated with all 3 species of BVDV. The most frequent species in sera was BVDV-3 (75.5%), whereas in vaccines only BVDV-1 was identified. Sequence analysis showed that the tested commercial sera and one vaccine were contaminated by six genotypes of BVDV: -1a, -1b, -1c, -1d, -2a, and -3. Identification of BVDV and its genetic material in animal-derived products is important due to the possibility of pestivirus transmission as well as the chance of falsifying the results of a diagnostic test. It also demonstrates the necessity of rigorous monitoring of the bioproducts used at the laboratory and industry level.