Recent isolates of bovine respiratory syncytial virus from Britain are more closely related to isolates from USA than to earlier British and current mainland European isolates.

Eight isolates of Bovine respiratory syncytial virus (BRSV) were made from calves with severe respiratory disease on seven farms in one region of Britain. Genetic analysis of the viruses showed that seven, which were isolated between 1997 and 1999 were almost identical and were distinguishable from an earlier 1991 isolate. When compared with the available sequences of BRSVs from other countries, the recent British isolates were more closely related to US isolates than to earlier British and current mainland European isolates.