Bovine respiratory syncytial virus in Quebec: antibody prevalence and disease outbreak

The prevalence of antibody to bovine respiratory syncytial virus in Quebec and the role of the virus in a respiratory disease outbreak was investigated. The indirect immunofluorescent, neutralization and haemagglutination inhibition techniques were used to carry out this study. Of the 1,444 adult animals examined 519 (35.9%) had antibody to bovine respiratory syncytial virus. These positive reactors were found in each agricultural region of Quebec. The highest (53.0%) and the lowest (21.8%) prevalence was observed in the sera collected by the laboratories of St. Hyacinthe and Sherbrooke. During a respiratory disease outbreak affecting 77 calves on a farm, bovine respiratory syncytial virus was shown to be associated with infectious bovine rhinotracheitis, bovine parainfluenza type 3, bovine viral diarrhea viruses and bovine adenovirus type 3 as detected by seroconversion. Of the 38 seroconverted animals 14 were seropositive to bovine respiratory syncytial virus.