Epidemiology of bacterial meningitis in children: Aichi Prefecture, Japan, 1984-1993.

The details of 328 patients with bacterial meningitis, admitted from 1984 through 1993, were obtained from 46 departments of pediatrics of large hospitals through questionnaires. The incidence rate per 100,000 child-years was 2.32, being higher in children aged 0-4 years (rate, 7.22) than 5-15 years (rate, 0.49). The disease in the 274 (84%) etiologically diagnosed patients was due to Haemophilus influenzae (95), Streptococcus pneumoniae (56), Group B streptococci (GBS) (41), Escherichia coli (27), and other agents (55), including 7 patients with Mycobacterium tuberculosis infection. The short-term outcome (mean length of follow-up, 2 years, 11 months) of meningitis was death in 26 patients (8.2%) and sequelae in 49 (16.0%), including 26 children with multiple residual impairment. Tuberculous, pneumococcal, and GBS meningitis with a poor outcome increased during the late period (1989-1993) of the 10-year study. The annual infant mortality rate for purulent meningitis decreased from 3.7 to 1.4 per 100,000 population between 1984 and 1993. The incidence of a poor outcome (death and sequelae) in newborns decreased by half during the late period.