Early-onset group B streptococcal disease following culture-based screening in Japan: A single center study

Aim: We investigated trends in early-onset group B streptococcal disease (EOD) after the introduction of culture-based screening in Japan. Material and Methods: A retrospective cohort study examined EOD trends in 9506 pregnancies and 10 715 neonates at our center from 2002 to 2009. Results: EOD occurred in four neonates (4/7332: 0.55/1000 live births). The EOD incidence among infants born to women positive for GBS by screening was 0.90 cases per 1000 live births (1/1107). In contrast, the EOD incidence among infants negative by GBS screening was 0.48 cases per 1000 live births (3/6225). Thus, of the four affected neonates, three had mothers who tested negative on antepartum GBS screening. Two neonates had symptoms of infection during labor and intrapartum antibiotic agents were administered. The other two neonates received no antibiotics because deliveries were uneventful and they were negative on GBS screening. Conclusion: The incidence of EOD is 0.90 cases per 1000 live births among GBS-positive women and 0.48 cases per 1000 live births among GBS-negative women. The results of our study implied that EOD can develop regardless of GBS screening and intrapartum clinical course, although the method of sample collection, indications for antibiotic prophylaxis, and the antibiotics regimen should be considered.