Clinical features and epidemiology of septicaemia and meningitis in neonates due to Streptococcus agalactiae in Copenhagen county, Denmark: a 10 year survey from 1992 to 2001

AIM: To elucidate the clinical and biochemical features, and to estimate the incidence and outcome of invasive culture-verified group B streptococcal (GBS) septicaemia/meningitis in neonates in Denmark. METHODS: Clinical microbiology laboratory records in patients 0-3 mo of age were searched for culture-verified GBS during 1992-2001 in Copenhagen County. Clinical records at the neonatal intensive care unit were reviewed retrospectively. Selected clinical and biochemical parameters were evaluated. RESULTS: 61 neonates had culture-verified GBS septicaemia/meningitis. The mean annual incidence was 0.76 cases per 1000 livebirths (range 0.0-1.91). A significant decrease in incidence was observed in the latest 3 y. The male:female ratio was 1.3:1. Eighty percent of the neonates had early-onset GBS within 24 h, 57% with symptoms at birth. Predominant initial symptoms were respiratory (72%), cardiovascular (69%) and neurological (63%). Only 4% developed GBS by day 7-90. Seventy-five percent had maternal or neonatal risk factors for early-onset GBS disease; 21% had clinical asphyxia, 37% of the mothers had premature rupture of membranes and 31% of the mothers were febrile. Initial C-reactive protein (CRP) was low, but increased significantly after more than 12 h duration of symptoms in 82% of patients. Leucopenia was an important initial haematological marker. CONCLUSION: The incidence of early-onset GBS has decreased significantly in Denmark, probably because of preventive measures in pregnancy and during birth. Respiratory symptoms are early signs of early-onset GBS. Initial leucopenia and a late (12-48 h) increase in CRP are valuable markers for invasive GBS.