Prevention of neonatal septicaemia due to group B streptococci.

Group B streptococcus is the leading cause of neonatal septicaemia. Major risk factors for early-onset disease are heavy maternal GBS colonization preterm delivery (and related low birthweight), preterm rupture of membranes, prelabour rupture of membranes, intrapartum fever, GBS urinary infection and low levels of maternal serum anti-GBS antibodies. Screening for maternal GBS colonization, a part of most current preventive strategies, can be targeted on all pregnant women or only on those with recognizable risk factors, and can be implemented antepartum or intrapartum. A culture in a selective broth is the 'gold standard' for detection of GBS colonization. The lower vagina (introitus) is the most suitable site for culturing, with the optional addition of an anorectal sample. The sensitivity of the available rapid GBS antigen tests for vagina samples seems too low to advocate their general use. Intrapartum prophylaxis with ampicillin, preferably targeted on GBS-colonized parturients with risk factors is, at present, the only strategy with established efficacy and safety to prevent early-onset infection. Vaginal chlorhexidine disinfection during labour in all women may, in addition offer a minor contribution to prevention. Late-onset GBS disease is unlikely to be reduced by these strategies. In the future, immunoprophylaxis may well prove to be the most safe and efficacious alternative to prevent GBS septicaemia, irrespective of age of onset, although protection of (very) preterm infants is unlikely.