Alarming regional differences in prevalence and antimicrobial susceptibility of group B streptococci in pregnant women: A systematic review and meta-analysis.

Group B streptococcus (GBS) is a leading cause of morbidity and mortality in infants. This study aimed to estimate the prevalence, antimicrobial susceptibility and serotype distribution of GBS isolates in pregnant women worldwide. Studies were identified by searching several English and Chinese electronic databases and reviewing relevant articles. Effect estimates were pooled using fixed- or random-effects models. Twenty-eight studies were included in this systematic review. The pooled prevalence of GBS carriage in pregnant women was 10%, being significantly lower in Asia (7%) compared with non-Asian countries (19%). Most of the GBS isolates were susceptible to penicillin, ampicillin and vancomycin. The pooled rates of resistance to erythromycin and clindamycin were 25% and 27%, respectively, and were notably higher in Asia compared with non-Asian countries. The pooled rate of resistance to tetracycline was 73%, with similar high levels in Asia and non-Asian countries. The most prevalent serotypes of GBS isolates were serotypes III, V and Ia. These findings suggest that penicillin is still the first choice for intrapartum prophylaxis of GBS diseases and support growing concern about antibiotic use (especially erythromycin and clindamycin) in Asia.