Risk factors for group B streptococcus early-onset disease: an Italian, area-based, case-control study.

Purpose: Intrapartum antibiotic prophylaxis (IAP) prevents group B streptococcus (GBS) early-onset disease (EOD). No European study evaluates the relative impact of risk factors (RFs) for EOD after a screening-based strategy and widespread IAP use We aimed to evaluate the risks of EOD in an Italian region where a screening-based strategy for preventing EOD was implemented.Materials and methods: Cases of EOD born at or above 35 weeks' gestation were reviewed and matched with controls.Results: There were 109 cases of EOD among 532,154 live births. Most cases had negative GBS prenatal screening (56/91, 61.5%) and were unexposed to IAP (86/109, 78.9%). At multivariate analysis, GBS bacteriuria (OR = 6.99), positive prenatal screening (OR = 13.7) and maternal intrapartum fever (OR = 188.3) were associated with an increased risk of EOD, whereas intrapartum beta-lactam antibiotics were associated with a decreased risk of EOD (≥4 h: OR = 0.008; <4 h: OR = 0.04). Neonates born to nonfebrile, GBS positive pregnant women, receiving beta-lactam antibiotics had very low probability of EOD, particularly if IAP was adequate.Conclusions: GBS positive prenatal screening, GBS bacteriuria and intrapartum fever are associated with EOD. Intrapartum beta-lactam antibiotics reduce the probability of EOD in neonates born to nonfebrile mothers.

Strategies for preventing early-onset sepsis and for managing neonates at-risk: wide variability across six Western countries.

Objective: Group B streptococcus (GBS) early-onset sepsis (EOS) has declined after widespread intrapartum antibiotic prophylaxis. However, strategies for preventing EOS may differ across countries. The analysis of their strategies allows to compare the effectiveness of prevention in different countries and suggests opportunities for improvement. Methods: We compared six western countries. Prevention strategies, incidence rates of EOS and approaches for managing neonates at-risk were analysed. Countries were selected because of availability of recommendations for prevention and sufficient epidemiological data for comparison. Results: Five of six countries recommend antenatal vagino-rectal screening. The decline of GBS cases is relevant in most countries, particularly in those with a screening-based strategy, which have reached incidence rates from 0.1 to 0.3/1000 live births and zero or close to zero mortality in full-term newborns. The recommendation for managing asymptomatic neonates at risk for EOS varies according to gestational age and ranges from observation only to laboratory testing plus empirical antibiotics. Chorioamnionitis (suspected or confirmed) is the main indication for carry out laboratory testing and for administering empirical antibiotics. Conclusions: Wide variations exists in preventing EOS. They depend on national epidemiology of GBS infections, compliance, cost, and feasibility of the strategy. The extreme variability of approaches for managing neonates at risk for EOS reflects the even greater uncertainty regarding this issue, and may explain the persisting, great use of resources to prevent a disease that has become very rare nowadays.