Bovine respiratory syncytial virus strains currently circulating in the Czech Republic are most closely related to Danish strains from 1995.

In this study we showed a high degree of genetic homogeneity among recently (2002-2003) circulating Bovine respiratory syncytial virus (BRSV) strains in cattle population in the Czech Republic. These strains are in a phylogenetic tree more closely related to the Danish strains from 1995 than to the Czech strain VS97 from 1997 that shares the highest similarity with the French strain F1 and the Belgian strain P10. From the sequence analysis we deduce that the revealed high diversity between BRSV strains from 2002-2003 and those from 1997, at both nucleotide (0-11.4%) and amino acid (0-21%) level, is more likely due to distinct sources of the virus strains than to the sequence evolution.