Self-taken vaginal swabs versus clinician-taken for detection of candida and bacterial vaginosis: a case-control study in primary care

Br J Gen Pract. 2017 Dec;67(665):e824-e829. doi: 10.3399/bjgp17X693629.

Abstract

Background: Vaginal discharge and vulvitis are common presenting symptoms in general practice. Few studies have specifically looked at the validity of self-taken low vulvovaginal swabs (LVS) for the diagnosis of vulvovaginal candidiasis (VVC) and bacterial vaginosis (BV).

Aim: To assess if patient self-taken LVS are a valid alternative to clinician-taken high vaginal swabs (HVS) for the detection of VVC and BV.

Design and setting: Case-control study with the patient acting as their own control in an urban sexual health centre in Newcastle upon Tyne, UK.

Method: Females aged 16-65 years attending with symptomatic vaginal discharge, vulval irritation, genital pain, and an offensive genital smell were recruited into the study. Participants took a self-taken LVS before vaginal examination, during which a clinician took an HVS (reference standard). Main outcome measures were the diagnosis of BV or VVC infection.

Results: A total of 104 females were enrolled. Of those, 45 were diagnosed with VVC and 26 with BV. The sensitivities of self-taken LVS for VVC and BV were 95.5% and 88.5% respectively. Cohen's κ coefficient showed 'strong agreement' for the detection of both VVC and BV. Vulval itching was the most common symptom associated with VVC (69%), whereas 50% of females diagnosed with BV presented with an offensive discharge. Both symptoms had poor positive predictive values (0.63 and 0.50, respectively).

Conclusion: Self-taken LVS appears to be a valid alternative to clinician-taken HVS for detecting VVC and BV infections. Symptoms were found to be a poor indicator of underlying infection.

Keywords: bacterial vaginosis; general practice; vaginal examinations; vulvovaginal candidiasis.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Bacteriological Techniques
  • Candidiasis, Vulvovaginal / diagnosis*
  • Candidiasis, Vulvovaginal / microbiology*
  • Case-Control Studies
  • Female
  • Humans
  • Middle Aged
  • Practice Guidelines as Topic
  • Predictive Value of Tests
  • Primary Health Care*
  • Self Care*
  • Specimen Handling
  • United Kingdom
  • Vagina / microbiology
  • Vaginal Discharge / microbiology
  • Vaginal Smears* / instrumentation
  • Vaginosis, Bacterial / diagnosis*
  • Vaginosis, Bacterial / microbiology*
  • Young Adult