Update on group B streptococcal infections: perinatal and neonatal periods.

Group B Streptococcus (GBS), one of the beta-Hemolytic streptococci, remains a leading cause of neonatal sepsis in the United States. The first consensus guidelines for the prevention of neonatal GBS disease were published in 1996, recommending intrapartum antibiotic prophylaxis on the basis of screening-based or risk-based strategies. Since then, there has been a 70% decrease in the rate of early-onset GBS disease. On the basis of evidence-validating superiority of this screening-based strategy, new national guidelines were released in 2002. Data from the Centers for Disease Control and Prevention in 2005 showed a continued decrease in the annual incidence of early-onset GBS infection. The screening-based strategy involves universal screening of all pregnant women at 35 to 37 weeks' gestation for vaginal and rectal GBS colonization and recommends intrapartum antibiotic prophylaxis for all GBS carriers (unless delivered by planned cesarean section before the onset of labor in a woman with intact membranes) with penicillin-G (or ampicillin). For mothers with severe penicillin allergy, clindamycin or erythromycin is recommended, when GBS' sensitivity is known; otherwise, vancomycin is recommended. Cefazolin is recommended for individuals with mild penicillin allergy. Severe anaphylactic reactions to penicillin were extremely rare. Emergence of antibiotic resistance to penicillin is still a theoretical possibility. This article provides a detailed account of recommendations for screening, diagnosing, and treating GBS disease in newborns.