Group B streptococcal infection: a review and update.

The problems posed by the sudden increase in serious group B streptococcal disease among infants since the early 1970s are described and discussed. Virtually all offspring of colonised mothers harbour the organism and infection develops in about 1% of these infants. The mortality rate, even with immediate antibiotic treatment of early onset disease, is 30%; delay in treatment leads to much higher mortality. Late onset disease starting around the seventh to ninth day of life, but sometimes as late as the second month, is less frequently fatal. Preventive measures include active and passive immunisation or intravenous ampicillin during labour. Experimental evidence indicates that each of these methods gives protection.