Childhood Bacterial Meningitis Trends in Japan from 2009 to 2010

Abstract

We conducted a pediatric survey of bacterial meningitis epidemiology from January 2009 to December 2010 in Japan, and obtained the following results for 314 cases (186 boys, 124 girls, and 4 with gender not reported). Children younger than one year old accounted for the majority of cases (51.2%, 161/314), and the incidence decreased with increasing age. Haemophilus influenzae (in children aged 1 month to 5 years old) was the most common cause of infection (53.2%), followed by Streptococcus pneumoniae (1 month to 12 years, 24.2%), Streptococcus agalactiae (0-4 months, 7.6%), and Escherichia coli (0-3 months, 3.2%). Susceptibility tests showed that 50.1% (78/153) of the H. influenzae isolates and 63.0% (46/73) of the S. pneumoniae isolates were drug-resistant. Combinations of ampicillin and cephem or carbapenem and other beta-lactams were mainly used as the initial antibiotics for patients under 4 months of age (77.8%, 42/54), and a carbapenem and other beta-lactam combination was used for patients aged 4 months and older (76.4%, 198/259). The final antibiotics for H. influenzae and S. pneumoniae were mainly cefotaxime (CTX) or ceftriaxone (CTRX) and carbapenem, respectively. The overall fatality rate was 2.0% (6/305). Since the Haemophilus influenzae type b vaccine (Hib vaccine) and the 7 valent pneumococcal conjugate vaccine (PCV7) are not widely used in Japan, only 5 patients in our cohort (all with meningitis not caused by H. influenzae) had been immunized with the Hib vaccine, and none had been immunized with the PCV7 vaccine. No remarkable changes in the characteristics of pediatric meningitis have been observed for several years in Japan.