Atypical pestiviruses: Risk for cattle breeding and importance for the control of bovine viral diarrhea virus (BVDV)

The paper presents the current state of knowledge on the prevalence and risk of a new type of bovine viral diarrhea virus known as type 3 (BVDV-3). The first discovered atypical pestivirus was the isolate D32/00_'HOBI', detected in fetal calf serum (FCS) originating from Brazil. The isolates CH-KaHO/cont, SVA/cont-08 and IZSPLV_To are further examples confirming the presence of BVDV type 3 in the FCS. This new species of pestiviruses (BVDV-3) is a problem not only for research laboratories using bovine serum, but also for cattle breeders. Natural infections with this virus have been reported in Brazil, Thailand and Italy, which may suggest that the new species of pestivirus is also present in European cattle. The methods used for routine diagnosis of BVDV infection are ineffective in detecting atypical pestiviruses, which may pose a risk of false negative results. It may also influence the safety of vaccines and biological products produced on the basis of contaminated batches of fetal bovine serum.