Impact of influenza virus infection as a cause of pediatric hospitalization.

From winter 1989 to spring 1990, a severe epidemic caused by influenza A (H3N2) and B viruses developed in Japan. During the epidemic (December 1989 to February 1990), 244 children were admitted to the pediatric ward of Nippon Kokan Hospital: 53 (21.7%) were hospitalized with influenza virus infection, 22 (9.0%) with rotavirus gastroenteritis, and 17 (7.0%) with respiratory syncytial virus infection. Among those with influenza, 24 had type A and 29 had type B. Most were young healthy children without underlying illnesses (mean age, 4.8 +/- 3.4 years). The impact of the influenza epidemic on pediatric hospitalization is probably much greater than generally thought when a severe epidemic occurs.