Bovine pestiviruses as contaminants of biological preparations (review)

Bovine pestiviruses are causative agents of bovine viral diarrhea-mucosal disease, a widespread and economically significant infection (J.F. Ridpath, 2010; C.A. Evans et al., 2019). These viruses include the prototype species Pestivirus A (bovine viral diarrhea virus type 1; BVDV-1), Pestivirus B (bovine viral diarrhea virus type 2; BVDV-2) and Pestivirus H (Hobi-like pestivirus, HoBiPeV; bovine viral diarrhea virus type 3; BVDV-3) (P. Simmonds et al., 2017; ICTV, 2019). All agents are represented by cytopathogenic (CP) and non-cytopathogenic (NCP) biotypes. The NCP biotype, unlike CP, does not cause visible morphological destruction of cell cultures and represents more 90 % of virus population (P.H. Walz et al., 2020). The number of known subtypes of BVDV-1 is 22 (a to v), BVDV-2 4 (a-d) and BVDV-3 4 (a-d) (N. Su et al., 2023). In Russia, circulation of 12 subtypes of BVDV-1, three subtypes of BVDV-2 and one subtype of BVDV-3 has been established (A.G. Glotov et al., 2022). One of the ways of spreading pathogens in cattle populations may be biological products produced using contaminated fetal sera (L.V. Uryvaev et al., 2012; A.G. Glotov et al., 2018), cell cultures and trypsin (O . Lung et al., 2021), namely veterinary vaccines and interferons. Agents can be distributed through embryos and sires’ semen (J.A. Gard et al., 2007; K. Gregg et al., 2010). Contaminated medical vaccines (M. Giangaspero et al., 2004), as well as biotechnological materials (L. Djemal et al., 2021), and stem cells (S. Viau et al., 2019) can pose a significant problem. Contamination of vaccines occurs during their production with NCP strains of all types of pestiviruses which are randomly introduced into cell cultures from untested fetal serum (B. Makoschey et al., 2003; P.P. Pastoret, 2010). Existing decontamination methods cannot always ensure complete inactivation of agents (W.P. Paim et al., 2021). An additional challenge is the increasing number of virus species and subtypes (C. Luzzago et al., 2021). Contamination of mammalian cell cultures can lead to false diagnostic test results, contamination of biological products and their transfer to recipients. Antibodies to bovine pestiviruses were found in 40 % of serum samples from twins with schizophrenia (M. Giangaspero, 2013), and their antigens were found in 23.6 % of fecal samples from children with gastroenteritis (R. Yolken et al., 1989). Only careful routine monitoring and culling animals used to obtain fetal serum or organs for cell cultures, all batches of serum, cell cultures and biological products based on these components, can prevent potentially dangerous contamination with pestiviruses. It is necessary to take into account the plasticity of viruses and the emergence of new species and subtypes.