Current status and clinical presentations of invasive neonatal Group B streptococcal infections in Korea

Background: Group B streptococcus (GBS) is the most common cause of invasive neonatal infections in developed countries. The incidence of early-onset GBS disease in Korea is known to be much lower than that in other developed countries; however neonatal GBS disease has been frequently reported in recent years in Korea. This retrospective study sought to determine the current status and clinical presentation of neonatal GBS disease in Korea. Methods: From January 1996 through December 2005, GBS cases (n= 157) diagnosed in blood, cerebrospinal fluid, or other sterile body fluids among infants <3 months of age from 14 university hospitals in Korea were identified. Age of onset, diagnosis, underlying medical conditions, and outcomes were investigated by reviewing the medical records. Results: A total of 157 cases were identified during the study period. Of the cases, 32 were early-onset disease (EOD) and 125 were late-onset disease (LOD). Twenty-six of the EOD cases had symptoms during the first 24 h after birth. One hundred of the 157 GBS cases were diagnosed as meningitis. The mortality rate of EOD was 20.7%. The case fatality rate of LOD was 7.2% and 25.2% of LOD cases had sequelae. Conclusions: GBS is becoming an important cause of invasive neonatal infections in Korea, with LOD being more common. It may not be currently necessary to adopt the prevention guidelines of perinatal GBS disease in Korea. However, studies of maternal GBS carriage rates and neonatal GBS disease will continue.