Data from: Occurrence and phylogenetic analysis of bovine respiratory syncytial virus in outbreaks of respiratory disease in Norway

Background: Bovine respiratory syncytial virus (BRSV) is one of the major
pathogens involved in the bovine respiratory disease (BRD) complex. The
seroprevalence to BRSV in Norwegian cattle herds is high, but its role in
epidemics of respiratory disease is unclear. The aims of the study were to
investigate the etiological role of BRSV and other respiratory viruses in
epidemics of BRD and to perform phylogenetic analysis of Norwegian BRSV
strains. Results: BRSV infection was detected either serologically and/or
virologically in 18 (86%) of 21 outbreaks and in most cases as a single
viral agent. When serology indicated that bovine coronavirus and/or bovine
parainfluenza virus 3 were present, the number of BRSV positive animals in
the herd was always higher, supporting the view of BRSV as the main
pathogen. Sequencing of the G gene of BRSV positive samples showed that
the current circulating Norwegian BRSVs belong to genetic subgroup II,
along with other North European isolates. One isolate from an outbreak in
Norway in 1976 was also investigated. This strain formed a separate branch
in subgroup II, clearly different from the current Scandinavian sequences.
The currently circulating BRSV could be divided into two different strains
that were present in the same geographical area at the same time. The
sequence variations between the two strains were in an antigenic important
part of the G protein. Conclusion: The results demonstrated that BRSV is
the most important etiological agent of epidemics of BRD in Norway and
that it often acts as the only viral agent. The phylogenetic analysis of
the Norwegian strains of BRSV and several previously published isolates
supported the theory of geographical and temporal clustering of BRSV.