Risk of acute otitis media in relation to the viral etiology of infections in children.

We carried out a prospective case-control study to analyze the etiology of respiratory tract infections among children with and without acute otitis media (AOM). Of the 658 patients admitted to our hospital during the period concerned, 197 (29.9%) had AOM, and for each such child the next patient of the same age was chosen as a control. The total number of virologically positive samples was 99 (50.3%) among the patients with AOM vs. 93 (47.2%) among the controls. The only etiologic agent that was more common in the patients with AOM was respiratory syncytial virus, found in 31 cases vs. 15 controls (relative risk [2.27]; 95% confidence interval, 1.18-4.35; P < .02). Our results confirm earlier observations from uncontrolled studies regarding the fact that respiratory syncytial virus is especially liable to cause AOM. Since respiratory syncytial virus is causing predictable epidemics, this finding could be useful for the timing of efforts to prevent AOM in young infants.