Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: May 2, 2008
Publication Date: May 2, 2008
Repository URL: http://www.vin.com/abvp/2008/
Citation: Ridpath, J.F. 2008. Bovine Viral Diarrhea Viruses. In: Proceedings of the American Board of Veterinary Practitioners 13th Annual Symposium, May 2-4, 2008, Savannah, Georgia. Available: http://www.vin.com/abvp/2008/. Technical Abstract: Infections with bovine viral diarrhea viruses (BVDV) result in significant economic losses for beef and dairy producers worldwide. BVDV is actually an umbrella term for two species of viruses, BVDV1 and BVDV2, within the Pestivirus genus of the Flavivirus family. While denoted as a bovine pathogen, they will also infect many species of domestic and wild ruminants and pigs. Acute infections may result in enteric, respiratory, and/or reproductive disease of varying severity, depending on the viral strain, the immune and reproductive status of the host and the presence of secondary pathogens. BVDV are further subclassified into cytopathic and noncytopathic biotypes based on their activity in cultured epithelial cells. Noncytopathic BVDV predominate in nature. Acute infections with BVDV are always accompanied by immune suppression due, at least in part, to the death of immune cells within lymph nodes and gut associated lymphoid tissue and reduction of numbers of circulating white blood cells. The suppression of the immune system leaves infected animals vulnerable to secondary infections. In addition to acute infections, noncytopathic BVDV strains may establish life long persistent infections. These persistent infections are the result of fetal exposure to BVDV before the development of the immune system. Persistently infected (PI) animals that become superinfected with cytopathic BVDV may develop mucosal disease (MD). The PI animal is thought to be the major vector for introduction of BVDV into herds. Thus most control programs in the U.S. are focus on the detection and removal of PI animals. The other goals of control programs are to increase herd resistance via vaccination and improve biosecurity to lessen the risk of exposure to BVDV.