A comparative study assessing the efficacy and acceptability of anorectal swabs for antenatal gbs screening

Abstract

Objectives To assess women's perception of pain and acceptability of low vaginal swab (LVS) and anorectal swab (ARS) for antenatal screening for Group B Streptococcus (GBS), and to compare the detection rate between these tests. Methods Separate LVS and ARS were collected at the 36-week antenatal visit, either by the patient herself or by her clinician. Acceptability and pain were evaluated on a Likert scale using a standardised questionnaire. Results A total of 278 women were recruited, with a median gestation of 36.3 weeks (IQR 36-37). Of these women, 96% undertook specimen self-collection. The overall prevalence of colonisation was 64/278 (23%); 52 women had positive LVS results (18.7%), and an additional 12 (5.5%; 95% CI 2.5-8.5) were negative on LVS but positive on ARS. Most women rated LVS (99%) and ARS (92%) to be either 'pain-free' or causing 'mild discomfort', and found the LVS (90%) and ARS (84%) to be either 'totally acceptable' or 'somewhat acceptable'. Conclusions The addition of an ARS resulted in an enhanced GBS positive rate, and most women found the test acceptable.