Prevalence of maternal group B streptococcal colonisation in European countries

Background. Group B streptococcus (GBS) is a leading cause of neonatal sepsis in many industrialised countries. However, the burden of perinatal GBS disease varies between these countries. We undertook a systematic review to determine the prevalence of maternal group B streptococcal colonisation, one of the most important risk factor for early onset neonatal infection, and to examine the serotype distribution of the GBS strains isolated and their susceptibility to antibiotics in European countries. Methods. We followed the standard methodology for systematic reviews. We prepared a protocol and a form for data extraction that identifies key characteristics on study and reporting quality. The search was conducted for the years 1996-2006 including electronic, hand searching and screening of reference lists. Results. Twenty-one studies presented data on 24,093 women from 13 countries. Among all studies, GBS vaginal colonisation rates ranged from 6.5 to 36%, with one-third of studies reporting rates of 20% or greater. The regional carriage rates were as follows: Eastern Europe 19.7-29.3%, Western Europe 11-21%, Scandinavia 24.3-36%, and Southern Europe 6.5-32%. GBS serotypes III, II and Ia were the most frequently identified serotypes. None of the GBS isolates were resistant to penicillin or ampicillin, whereas 3.8-21.2% showed resistance to erythromycin and 2.7-20% showed resistance to clindamycin. Conclusion. Although there is variation in the proportion of women colonised with GBS, the range of colonisation, the serotype distribution and antimicrobial susceptibility reported from European countries appears to be similar to that identified in overseas countries.