Respiratory syncytial virus infections in children in Montreal: a retrospective study.

Seventy-seven hospitalized children from whom respiratory syncytial virus was subsequently isolated were studied in retrospect. This demonstrated the association of host invasion by this agent with an acute respiratory disease requiring hospitalization for approximately one week.Boys considerably outnumbered girls, the average age was 7.5 months, and in 56% the admission diagnosis was "bronchiolitis". Cough and difficulty in breathing were the most common presenting complaints and "pneumonia" the most common radiological diagnosis. Nearly half the patients also harboured accepted disease-causing bacterial pathogens. All the patients recovered and have remained well.The appearance of the virus in Montreal was seasonal, beginning in late autumn and terminating in early spring.