A prefecture-wide survey of mumps meningitis associated with measles, mumps and rubella vaccine.

A survey of untoward reactions, especially central nervous system reactions, after the administration of a newly introduced measles, mumps and rubella (MMR) vaccine in Gunma Prefecture, Japan, was initiated soon after 4 patients were hospitalized for aseptic meningitis. Thirty-five, 6 and 2 children developed meningitis, convulsive disorders and parotitis, respectively, within 2 months after MMR vaccination during the 8-month period extending from April to November, 1989. The time lag between MMR vaccination and meningitis ranged from 14 to 28 days in the 35 cases of meningitis. Mumps virus, isolated from the cerebrospinal fluid in 13 patients with aseptic meningitis, was characterized by determination of the nucleotide sequences of the P gene as mumps vaccine strain. The incidence of aseptic meningitis with positive mumps vaccine virus was estimated to be 0.11% (0.3% as a whole) during the 8 months from April to November and increased to 0.3% (0.7% as a whole) in September and October. We conclude that the incidence of aseptic meningitis after MMR vaccination seems to be higher than that reported previously.