An unseasonable winter outbreak of echovirus type 30 meningitis.

During the winter of late October, 1990 to March, 1991, echovirus type 30 meningitis affected 10 children aged 3-9 years of age in Mikuni, Japan. Five patients presented with constipation, four had diarrhoea, while five complained of severe abdominal pain, in addition to typical symptoms and signs compatible with aseptic meningitis. Echovirus type 30 was isolated from the CSF of nine, from the faeces of 10, and from the throats of eight children. All showed a significant antibody response to echovirus type 30 in paired samples of serum. Antigenic variation and thermostability of a representative isolate indicated some changes in virus structural proteins, possibly reflecting an altered tropism for tissues in the gastrointestinal tract.