Respiratory syncytial virus infections in Oslo 1972--1978. I. Virological and epidemiological studies.

Respiratory syncytial virus (RSV) infection was diagnosed in 464 children admitted to hospital with acute respiratory disease from autumn 1972 to spring 1978. The virological surveillance was approximately 70%. As a rule, RSV infections occurred in distinct outbreaks in late autumn and winter together with a marked increase in the number of children admitted to hospital with acute lower respiratory tract disease. The incidence in children less than 1 year of age was about 10/1000 children/year. Spread of the infection from one end of the city to the other was discernible in 2 outbreaks. More children than expected with siblings were admitted to hospital because of RSV infection, but no correlation could be observed with some other socioeconomic factors. A negative correlation was observed between RSV disease and mean air temperature and hours of sunshine per month. Rapid immunofluorescence diagnosis of RSV on cells from nasopharyngeal secretions was adopted and became comparable to cell culture technique. The rapid method has become an important adjunct to the clinical management of these patients and the method will form the basis for further epidemiological studies.