Invasive group B streptococcal infections in a tertiary care hospital between 1998 and 2007 in Japan

Abstract

To clarify clinical and microbiological features of invasive group B Streptococcus (GBS) disease in Japan. This was a retrospective review for the period 1998-2007 of patients across all age groups in Nishi-Kobe Medical Center. Invasive GBS disease was defined as GBS isolation from a normally sterile site or skin/soft tissues. Six infant and 52 adult cases of invasive infection were identified. Diagnosis was limited to bacteremia and meningitis in infants, but varied widely in adults with skin/soft tissue infections and bacteremia being common. The overall fatality rate was 16%. An approximately 2.8-fold increase was found in the incidence among adult patients from the first to the second 5-year period. The most frequent underlying condition was diabetes, with the majority (18/23) of such patients showing poor control (HbA1c >8.0%). Amputation at the knee, ankle, or toes was performed in six diabetic adults with skin/soft tissue infections. Of the strains serotyped, types Ib and III predominated. All 58 strains were susceptible to penicillin; 2% were resistant to erythromycin and 3% were resistant to clindamycin. This is the first epidemiological report describing invasive GBS disease in Japan. A significant increase in adult patients was noted, and mortality and morbidity remain substantial.