Preventing perinatal group B streptococcal infection: the jury is still out.

Abstract

EVER SINCE GROUPB streptococcus (GBS) emerged as the commonest cause of perinatal sepsis in the late 1970s, there has been controversy about prevention strategies. A few hospitals in Australia were among the first in the world to introduce routine antenatal screening for GBS carriage and intrapartum antibiotic prophylaxis for carriers. This approach was later vindicated by randomised controlled trials in selected carriers and the demonstration of lower rates of sepsis after intrapartum prophylaxis compared with historical rates. However, problems remain. Group B streptococcus is a normal vaginal commensal in healthy women, but colonisation is often intermittent, and rates of colonisation can vary from 18% to 27%, depending on the detection method. Moreover, vaginal carriage is a very crude predictor of perinatal sepsis, with fewer than 1% of the infants of carriers affected (1–2/1000 overall) without intervention.