LONGITUDINAL INVESTIGATION OF EPIDEMIOLOGIC FEATURE OF ADENOVIRUS INFECTIONS IN ACUTE RESPIRATORY ILLNESSES AMONG CHILDREN IN YAMAGATA, JAPAN (1986-1991)

Using human embryonic fibroblast (HEP) and HEp-2 cell cultures, adenov iruses mere isolated from 989 (3.7%) out of 26,793 pediatic patients w ith ARI in Yamagata, Japan from January, 1986 to December, 1991. All i solates mere identified as types 1 (Adl)-6 and no other serotypes were identified. Epidemiologic feature was different depending on the subg enus group. Adl, 2, 5 and 6 (group C) mere endemic and the infections occurred frequently in the summer season. Ad3 (group B) was epidemic i n the autumn to minter season, although the virus mas isolated every m onth in non-epidemic season. No seasonal distribution of Ad4 (group E) could be determined because the number of patients was limited. Neutr alizing antibody positive ratio for group C mere more than 40% at 1-2 years of age and almost 100% by 10 years of age but those for Ad3 (gro up 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 g roup C infections, most cases mere infants and young children less tha n 2 years of age, but Ad3 infections mere older children with the peak at 4 and 5 years of age.