[Late onset group B Streptococcus infection: 7 year experience in a tertiary hospital (2000-2006)]

Group B Streptococcus (GBS) is a major cause of neonatal infection. Two forms of the disease have been described according to the age of presentation: early, beginning in the first 6 days of life, and late, occurring from day 7 up to 3 months of age.

To analyze the epidemiology of the late onset form of GBS disease in a tertiary hospital after implementing preventive strategies aimed to reduce the rate of vertical transmission.

We retrospectively reviewed the medical records of children diagnosed with late GBS infection between January 2000 and December 2006. Diagnostic criteria included a positive blood culture and/or a positive cerebrospinal fluid (CSF) culture for GBS in any patient aged between 7 and 89 days.

24 patients were identified, most of them presenting after January 2005. Median age was 36.2 days (range 9 to 81). GBS isolates in blood were found in 20 patients, 1 in CSF and 3 in both. Most frequently children presented with fever (70.8 %) and irritability (54.1 %). Five patients (20.8 %) had a cellulitis-adenitis syndrome. Cefotaxime and ampicillin were the most often used antibiotic combination. No ampicillin resistances were found.

The number of children with late GBS disease has increased in our center. Accordingly, the recent recommendations for the prevention of perinatal GBS vertical transmission were not effective for reducing late GBS infection. This may be due to horizontal infections from maternal sources, community or cross infections. It is important to maintain clinical suspicion of late GBS infection and start early antibiotic treatment.