A national survey of severe group B streptococcal infections in neonates and young infants in Denmark, 1978-83.

During a six-year period, 1978-83, 80 cases of culture proven group B streptococcal (GBS) bacteraemia and meningitis were identified in neonates and young infants up to 12 weeks of age in a national retrospective survey. Two thirds (68%) were early onset disease (EOD) while one third was late onset disease (LOD) occurring later than the seventh day of life. The overall incidence for the period was 0.24 per 1,000 live-born with a trend towards decline through the period. EOD was associated with low birthweight, twin delivery and congenital anomalies as well as with obstetric risk factors like premature or prolonged rupture of membranes and intrapartum fever. The overall case fatality rate was 23%, both in EOD and LOD. Seven (11%) of the surviving infants, six of whom had had meningitis, developed neurological sequelae. Newborns that showed signs of infection with 12 hours of delivery were at a significantly higher risk of running a fulminant course than newborns whose infections developed later (p = 0.02). Nosocomial transmission of GBS seemed limited and most hospital-acquired cases were unconnected.