Genital group B streptococcus carrier rate and serotype distribution in Korean pregnant women: implications for group B streptococcal disease in Korean neonates

Aims: We investigated the genital group B streptococcus (GBS) carrier rate in Korean pregnant women and the serotype distribution in face of the recent increase of late-onset GBS disease in Korea. Methods: GBS screening was performed on 4045 healthy pregnant women at 35-37 weeks' gestation. In case of positive GBS culture, serotyping was performed by using GBS typing antisera. Results: When both vaginal and anorectal culture were performed, the GBS carrier rate was 10.0% (n=121/1205), which is the highest rate ever reported in Korea. Type III was more common (36%), and type Ia (13%) and Ib (7%) were less prevalent. Conclusions: Increased maternal genital GBS carrier rate and difference in serotype distribution pattern of GBS may be related to the recent increase of late-onset GBS disease in Korea.