Emergence of group B streptococci in obstetric and perinatal infections.

A retrospective study of obstetric and perinatal illness due to group B streptococci during 1972-4 based on bacteriological referrals from Aberdeen Maternity Hospital and Special Nursery disclosed (1) a wide spectrum of maternal morbidity, particularly associated with amniotomy and a prolonged rupture-delivery interval, and (2) the emergence of the group B streptococcus as a major cause of serious neonatal infection in infants of low birth weight, often in the absence of maternal pyrexia. The group B isolates appeared to show a previously undocumented increased resistance to the aminoglycosides gentamicin and kanamycin. A prospective study of 369 random deliveries in Aberdeen Maternity Hospital showed a group B vaginal carriage rate of 49/1000; a neonatal colonization rate of 19/1000; maternal and neonatal morbidity rates of 16 and 2-7/1000, respectively; and an overall neonatal mortality of 1/1000 live births.