[The relationship of clinical manifestations and age distribution in enterovirus infections--viral isolation and seroepidemiology in Aichi Prefecture].

We studied the epidemiology of enterovirus infection in Aichi Prefecture from 1985 to 1989. We examined the age distribution of aseptic meningitis patients (AM) and exanthematous disease patients (Ex) and a seroepidemiological study of echovirus type 7 (E7), E9, E18 and group A coxsackievirus type 9 (CA9), was performed. The results is as follows: 1) E7, E9, E18 and CA9 were isolated from AM and Ex but E6, E11 and group B Coxsackie viruses (CB) were isolated in fewer cases from Ex. 2) The AM was consistently increased from June to August. Whereas the Ex was seen in all seasons but a slight increase was noted between June to July, and enteroviruses (EV) isolation was increased in this season. 3) The AM occurred in 0 year olds and 4 year olds whereas the Ex was seen in 0 to 1 years. EV was mainly isolated from 0-1 year olds. 4) The relationship of clinical manifestations and age was very clear in E9 and E18, a higher proportion of children at 1 years or under were those of the Ex and most children of the latter part of 4 years were those of the AM. The Ex had the same results with E7 and CA9 but AM was increased in 0 years and 4 year olds. 5) We studied the age distributions of neutralizing antibodies against E7, E9, E18 and CA9. The positive rate of neutralizing antibody after prevalence rose between 2-5 years of age. There were few patients among the 2 to 3 year olds but the neutralizing antibody was raised in this age. I considered that reason the enteroviruses infected mainly the 2 to 6 year olds showing no clinical symptoms where as some of the 3 year olds had aseptic meningitis and some under 1 year had symptoms of exanthematous diseases.