Pestiviruses

This chapter presents relevance, etiology, public health, epidemiology, pathogenesis, clinical signs, lesions, diagnosis, immunity, and prevention and control of pestiviruses. Pestivirus includes four formally recognized species: classical swine fever virus (CSFV), bovine viral diarrhea viruses 1 and 2 (BVDV-1 and BVDV-2), and border disease virus. In addition, seven new species are proposed: Pestivirus E (pronghorn pestivirus), Pestivirus F (Bungowannah virus), Pestivirus G (giraffe pestivirus), Pestivirus H (Hobi-like pestivirus), Pestivirus I (Aydin-like pestivirus), Pestivirus J (rat pestivirus), and Pestivirus K (atypical porcine pestivirus). The majority of pestiviruses are non-cytopathogenic in cell culture, but some CSFV strains and some BVDV isolates from cases of mucosal disease are cytopathogenic in vitro. A protein-rich medium usually enhances the stability of pestiviruses. Transmission of CSFV is most commonly oronasal, with primary virus replication in the tonsils. CSF lesions vary in severity and distribution, depending on the course of the disease.