Bovine Viral Diarrhoea Virus (BVDV) is an RNA virus of the Pestivirus species within the family Flaviviridae, which also incorporates other pestiviruses, such as the Classical Swine Fever Virus (porcine) and Border disease virus (ovine). Its clinical manifestations were first described in 1946 (Olafson and others 1946)although phylogenetic analysis suggests that the divergence of the aforementioned species occurred as long ago as 1483 (Liu and others 2009). BVDV is classified into two genotypes; Type 1 (BVDV-1) and Type 2 (BVDV-2). Type 1 predominates in both Europe and Australasia, and is subdivided into sub-groups entitled 1a to1k; however some occasional outbreaks of BVDV-2 do occur in Europe. In the UK it is BVDV-1a that is most commonly reported, and in a study by Booth and others (2013) 85% of isolates were classed as BVDV-1a;although BVDV-1b, 1d, 1e and 1i were also identified. The most common subgenotype in Australia is BVDV-1c, with BVDV-1a also found (Ridpath and others 2010). On the North American continent both BVDV-1 andBVDV-2 prevail. In the USA it is BVDV-1b that is most frequently isolated, and in Canada BVDV-2 (Ridpath and others 2010). BVDV-2 was estimated to have diverged from BVDV around 1783 in North America; hence it is on that continent that most of the worldwide cases of BVDV-2 occur.
|Number of pages||8|
|Issue number||Part 2|
|Publication status||Published - 2014|