Longitudinal investigation of epidemiologic feature of adenovirus infections in acute respiratory illnesses among children in Yamagata, Japan (1986-1991).

Using human embryonic fibroblast (HEF) and HEp-2 cell cultures, adenoviruses were isolated from 989 (3.7%) out of 26,793 pediatric patients with ARI in Yamagata, Japan from January, 1986 to December, 1991. All isolates were identified as types 1 (Ad1)-6 and no other serotypes were identified. Epidemiologic feature was different depending on the subgenus group. Ad1, 2, 5 and 6 (group C) were endemic and the infections occurred frequently in the summer season. Ad3 (group B) was epidemic in the autumn to winter season, although the virus was isolated every month in non-epidemic season. No seasonal distribution of Ad4 (group E) could be determined because the number of patients was limited. Neutralizing antibody positive ratio for group C were more than 40% at 1-2 years of age and almost 100% by 10 years of age but those for Ad3 (group B) were 40% by 10 years of age. The neutralizing antibodies for Ad4 (group E) or Ad7 (group B) became negative by 10 years of age. With group C infections, most cases were infants and young children less than 2 years of age, but Ad3 infections were older children with the peak at 4 and 5 years of age.