Impact of a risk-based prevention policy on neonatal group B streptococcal disease

OBJECTIVE: Neonatal group B streptococcal infections can be prevented by intrapartum antibiotic prophylaxis. Beginning in 1992, women with obstetric risk factors at University of Miami-Jackson Memorial Medical Center were targeted to receive intrapartum antibiotic prophylaxis. We evaluated these preventive efforts. STUDY DESIGN: A case was defined as isolation of group B streptococci from a sterile site in an infant <7 days old born during the study period, 1992-1995. We reviewed systematic samples of women with preterm delivery and prolonged rupture of membranes to assess use of intrapartum antibiotic prophylaxis. RESULTS: Group B streptococcal cases declined from 1.7 cases/1000 live births to 0.2 cases/1000 live births (Poisson regression, P=.002). Intrapartum antibiotic prophylaxis use increased from 13% of preterm deliveries in 1992 to 42% in 1995, and from 20% of deliveries with prolonged rupture of membranes in 1992 to 72% in 1995 (chi(2) test for linear trend P = .007 and P < .001, respectively). CONCLUSION: Provision of intrapartum antibiotic prophylaxis on the basis of risk factors was associated with decreased group B streptococcal disease.