Analysis of polymorphism of pestivirus-positive cattle samples from the UK. Bovine Viral Diarrhoea Virus Biobank sequence

The livestock pestivirus bovine viral diarrhoea virus (BVDV) is a major pathogen of cattle that causes important economic losses for cattle industries around the world. BVDV is closely related to classical swine fever virus (CSFV) of pigs and border disease virus (BDV) of sheep, forming the genus pestivirus. Pestiviruses share genetic similarity with Hepatitis C virus (HCV) and BVDV has often been used as a model for HCV. Cattle herds with BVDV generally have reduced reproductive performance and a higher rate of diseases such as diarrhoea and pneumonia due to the immunosuppressive and abortifacient nature of the infection. Infection of pregnant cattle with BVDV can lead to the generation of persistently infected (PI) calves that are tolerant of the virus and which are the major source of infection within and between herds. BVDV exists in two major types, of which only type 1 is normally found in the UK. BVDV type 1 has at least 15 recognized sub-types (named 1a to 1o) that are defined by sequence similarity, particularly in the 5’ untranslated region (5’-UTR) and in the adjacent Npro gene. In order to facilitate molecular epidemiology during the ongoing Scottish national BVDV eradication we are developing a comprehensive collection of Scottish and UK BVDV sequences for comparison with ‘new’ virus samples. To date we have sequenced the 5'UTR from over 5000 pestivirus-positive samples representing eight different BVDV type 1 (Pestivirus A) subtypes.