Respiratory syncytial virus infections in SR Croatia, Yugoslavia.

The prevalence of respiratory syncytial virus (RSV) infection was studied during three consecutive annual outbreaks (1983-1986) in SR Croatia, Yugoslavia. A total of 1,238 subjects were examined, using RSV isolation and immunofluorescent (DTFA) methods, with 1,042 showing the signs of respiratory infection and 207 of these having a positive RSV finding. Generally, the prevalence of mild upper respiratory infection (URTI) was 18%, reaching a peak of 30% at 1 year of age. The prevalence of severe lower respiratory tract infections with bronchiolitis, pneumonia, and croup accounted for 51, 34.4, and 28.3% respectively. The highest incidence of RSV infection among respiratory cases was observed in the first 6 months of life (49.4%), being particularly high at the second month among those with URTI, bronchiolitis, pneumonia, and croup (76.2%). Both sexes were equally susceptible to RSV infection (20.51% females, 19.03% males). RSV infections, seasonal incidence ranged from 25.55 to 30.31% in 1983/84 and 1984/85 respectively and dropped sharply to 8.93% in 1985/86.