Prevention of neonatal group B streptococcal disease: intrapartum detection and chemoprophylaxis of heavily colonized parturients.

Parturients with heavy vaginal colonization of group B streptococci were selected randomly to receive either penicillin or no antibiotic. A simple and fast latex agglutination test, applied in 8977 consecutive parturients, detected 412 women with heavy colonization with group B streptococcus, 199 of whom were eligible for the study. The offspring of penicillin-treated women had a lower incidence of early-onset group B streptococcal disease (1.1%; 95% confidence interval 0-3.4%) than the controls (9.0%; 95% confidence interval 3.6--14.4%) (P less than .01). Among the offspring of streptolatex-negative parturients, the incidence of streptococcal disease was very low (0.07%). Thus, antibiotic prophylaxis of latex agglutination test-positive parturients would reduce the total incidence of group B streptococcal disease in the newborn by 25-80%.