Estimation of Annual Incidence, Age-Specific Incidence Rate, and Cumulative Risk of Rotavirus Gastroenteritis among Children in Japan.

摘要

Rotavirus gastroenteritis is a common childhood infection, but the exact morbidity of the disease is not well described in Japan. We aimed at estimating morbidity measures to determine the magnitude of rotavirus gastroenteritis. An estimate for acute infectious gastroenteritis of all causes, to which rotavirus gastroenteritis belongs, has been available since the enactment in 1999 of the Law concerning the Prevention of Infectious Diseases and Medical Care of Patients with Infectious Diseases. Using this estimate and another estimate for the detection proportion of rotavirus among outpatients with acute infectious gastroenteritis, we calculated the annual incidence, the age-specific annual incidence rate, and the cumulative risk by the age of 6 years for rotavirus gastroenteritis. The latter estimate was obtained by a meta-analysis of four independent studies previously performed in Japan. According to our estimates, approximately 800,000 children in Japan under the age of 6 years visit pediatric practices or the outpatient department of hospitals because of rotavirus gastroenteritis at a rate of 11 cases/100 persons/year, and one in two children will visit pediatricians before they go to primary school. Such pediatrician visits most frequently occur at the age of 1 year (27 cases/100 persons/year). Thus, the magnitude of the burden of rotavirus disease among Japanese children is substantial.