Self-collected versus health-care professional taken swab for identification of vaginal-rectal colonisation with group B streptococcus in late pregnancy: a systematic review

Abstract

Background: Testing for group B streptococcus (GBS) requires a vaginal-rectal swab in late pregnancy.

Objective: A systematic review of the test accuracy of a self-collected swab compared with a health-care professional collected swab in the diagnosis of GBS colonisation.

Search strategy: The Cochrane Library (including the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects [DARE] and the Cochrane Central Register of Controlled Trials [CENTRAL]), EMBASE, MEDLINE and Trip were searched in May 2022.

Selection criteria: Randomised trials, test accuracy studies or diagnostic yield studies that compared the accuracy of a self-collected vaginal-rectal swab, compared to that taken by a health-care professional, for the detection of GBS colonisation in the third trimester.

Data collection and analysis: Two researchers independently screened, selected studies, extracted data and assessed study quality.

Main results: 10 studies, with 2578 women were included. Pooled sensitivity of self-collected swabs was 0.90 (95% confidence interval [CI] 0.81 to 0.95) and pooled specificity was 0.98 (95% CI 0.96 to 0.99).

Conclusion: This study provides reassuring evidence that self-collected swabs for maternal GBS colonisation are highly accurate relative to swabs collected by health-care professionals. Women requiring a swab for GBS colonisation can self-swab with appropriate instructions if they choose.

Funding: Personal fellowship from the University of Nottingham for KFW.

Keywords: Colonisation; Culture; Group B agalactiae; Group B streptococcus; Health-care professional swab; Pregnancy; Screening; Self-collected swab; Self-swab; Third trimester.