Group B Streptococcus in surgical site and non-invasive bacterial infections worldwide: A systematic review and meta-analysis.

Objectives: The epidemiology of disease caused by group B Streptococcus (GBS; Streptococcus agalactiae) outside pregnancy and the neonatal period is poorly characterized. The aim of this study was to quantify the role of GBS as a cause of surgical site and non-invasive infections at all ages.

Methods: A systematic review (PROSPERO CRD42017068914) and meta-analysis of GBS as a proportion (%) of bacterial isolates from surgical site infection (SSI), skin/soft tissue infection (SSTI), urinary tract infection (UTI), and respiratory tract infection (RTI) was conducted.

Results: Seventy-four studies and data sources were included, covering 67 countries. In orthopaedic surgery, GBS accounted for 0.37% (95% confidence interval (CI) 0.08-1.68%), 0.87% (95% CI 0.33-2.28%), and 1.46% (95% CI 0.49-4.29%) of superficial, deep, and organ/space SSI, respectively. GBS played a more significant role as a cause of post-caesarean section SSI, detected in 2.92% (95% CI 1.51-5.55%), 1.93% (95% CI 0.97-3.81%), and 9.69% (95% CI 6.72-13.8%) of superficial, deep, and organ/space SSI. Of the SSTI isolates, 1.89% (95% CI 1.16-3.05%) were GBS. The prevalence of GBS in community and hospital UTI isolates was 1.61% (1.13-2.30%) and 0.73% (0.43-1.23%), respectively. GBS was uncommonly associated with RTI, accounting for 0.35% (95% CI 0.19-0.63%) of community and 0.27% (95% CI 0.15-0.48%) of hospital RTI isolates.

Conclusions: GBS is implicated in a small proportion of surgical site and non-invasive infections, but a substantial proportion of invasive SSI post-caesarean section.