Submitted to: Virus International
Publication Type: Review Article
Publication Acceptance Date: May 16, 2001
Publication Date: N/A
Technical Abstract: While reports of BVDV2 in European cattle are rare, isolation of BVDV2 from European sheep is common as reported herein. BVDV2 have been isolated from European sheep since the mid 1980s, although it is only recently that these isolates were identified as BVDV2 rather than border disease virus (BDV). Earlier studies divided ruminant pestiviruses, isolated between 1985 and 1987 in Great Britain, into two groups. One group showed high reactivity with monoclonal antibodies prepared against classic BVDV1 isolates and were identified as BVDV. The second group had limited reactivity and was identified as BDV. Subsequent phylogenetic analysis demonstrated that this group contained both BDV and BVDV2. A second study characterizing European ovine pestiviruses, isolated in the mid 1980s, divided these isolates into two 'genogroups'. One contained isolates that amplified well with primers based on BVDV1 sequences. The second, thought to represent BDV, consisted of pestiviruses that did not. Once again, subsequent phylogenetic analysis of this group showed that it contained both BVDV2 and BDV. BVDV2 viruses characterized in the present study were also initially identified as BDV. It is possible that BVDV2 isolated from sheep prior to the mid 1980s were frequently misidentified as BDV. It appears that BVDV2 were circulating in European sheep herds concurrent with the isolation of BVDV2 from outbreaks of clinically severe disease in North American cattle. It is intriguing that BVDV2 are not more frequently isolated from European cattle when they are commonly found in European sheep. It would be interesting to compare the host tropism of European sheep BVDV2 to North American cattle BVDV2.