Michèle Vial

Neonatal group B streptococcal infection. Results of 33 months of universal maternal screening and antibioprophylaxis

OBJECTIVE To assess the efficacy and pitfalls of a protocol of generalized screening for group B Streptococcus (GBS) and intra-partum treatment of all carriers in a clinical setting. DESIGN A descriptive study and comparison with an historical group. SETTING A tertiary perinatal center. POPULATION All women attending prenatal care in our center and delivered after 37 weeks were eligible. Study period ranged from January 1994 to September 1996. Comparison group consisted in deliveries of years 1992 and 1993. METHODS Vaginal cultures were performed at 36 weeks on non-selective medium followed by intra-partum treatment of all carrier mothers. Rate of carriage, incidence of neonatal GBS sepsis, influence of risk factors and the reasons for failures were analysed. Comparison was made with an historical group. Statistical analysis was performed using a Chi-square test. RESULTS There were 5374 term deliveries during the study. 3906 were screened (72.7%) and 559 of them found positive for GBS (14.3%). We observed 46 early-onset GBS diseases (0.86% of term-births). 43.5% of infections occurred in babies born from mothers without risks factors at delivery. Negative GBS cultures at sampling accounted for 43.5% of protocol failures. Comparison of the incidence of early-onset GBS disease with the previous two years showed a significant drop (1.45-0.86%, P<0.05). CONCLUSIONS Our protocol revealed feasible and effective in reducing the incidence of early-onset GBS disease. Improvements must be studied particularly as to the predictive value of screening cultures.