Early-onset group B streptococcal disease in the United States: potential for further reduction.

OBJECTIVE: To describe lapses in adherence to group B streptococcus (GBS) prevention guidelines among cases of early-onset GBS disease in term and preterm neonates and to estimate the potential for further reduction in disease burden under current prevention strategies. METHODS: We reviewed labor and delivery and prenatal records of mothers of neonates with early-onset GBS disease (aged younger than 7 days with GBS isolated from a normally sterile site) identified at population-based surveillance sites in 2008-2009. We interviewed prenatal care providers about GBS screening practices and obtained relevant laboratory records. We evaluated the data for errors in prenatal screening, laboratory methods, communication of results, and intrapartum antibiotic prophylaxis. Using published data on screening sensitivity and intrapartum prophylaxis effectiveness, we estimated the potential reduction in cases under optimal prevention implementation. RESULTS: Among 309 cases, 179 (57.9%) had one or more implementation errors. The most common error type in term and preterm case-patients was prenatal screening (80 of 222 [36.0%]) and intrapartum prophylaxis (46 of 85 [54.1%]), respectively. We estimated that under optimal implementation, cases of early-onset GBS disease could be reduced by 26-59% with the largest benefit from a single intervention coming from improved use of intrapartum prophylaxis (16% decrease). CONCLUSION: Further reduction of early-onset GBS disease burden is possible under current prevention strategies, particularly with improved implementation of antibiotic prophylaxis. However, even with perfect adherence to recommended practices, the decline in cases may be modest. Therefore, novel prevention approaches such as improved intrapartum assays and vaccines are also needed.