[Epidemic of aseptic meningitis with echovirus type 6 in Gifu Prefecture in 1992].

From January to December in 1992, an epidemic of aseptic meningitis occurred in Gifu Prefecture in children. Epidemiological, virological and serological investigations were performed. The results are as follows: 1) Cases involved ranged from 0 to 15 years of age, and 75.9% of them were in the 3 to 7 year of age group. 2) Six types of viruses were isolated from 73 of 108 cases (67.6%), and the Echovirus 6 was recovered from 68 cases (93.2%). 3) In 1992 by the cross neutralizing test between the prototype and isolated strains of Echovirus 6, a remarkable antigenic variation was not found. 4) In serological studies, the positive rates of neutralizing antibodies to Echovirus 6 in infant sera aged 0-9 years in 1992-1993, was 41.1%. The highest positive rates of antibodies was in the 5 year age group.