Introduction. Infectious vaginitis, caused mostly by bacterial vaginosis (BV), Candida vaginitis (CV) and Trichomonas vaginitis (TV), is a common reason for primary care visits. Recent studies demonstrate the potential utility of molecular assays in replacing conventional diagnostic methods. Hypothesis/Gap Statement. Different diagnostic standards are in use for BV; published studies have evaluated molecular diagnostic tests against Amsel criteria, Nugent score or a combination of both. In the UK, Hay/Ison criteria are commonly used, but there are limited studies evaluating molecular diagnostic assays against these criteria. Aim. This study evaluated the performance of Hologic’s Aptima® BV and CV/TV assays relative to Hay/Ison criteria for BV and culture for CV in women with symptoms of vaginitis attending primary care centres in the UK. Methodology. Paired vaginal swabs were collected from women ≥18 years of age undergoing testing for Chlamydia trachomatis and Neisseria gonorrhoea using the Hologic Aptima Combo 2 (AC2) assay, alongside standard of care (SOC) testing for vaginitis (Hay/Ison criteria for BV; culture for CV). Samples received for AC2 testing were tested for vaginitis using Hologic Aptima BV and Aptima CV/TV assays. Sensitivity, specificity, positive and negative predictive values and diagnostic accuracy of Aptima BV and Aptima CV/TV assays relative to SOC methodology were determined. For discrepancy analysis, selected samples were evaluated further using third-party (Thermo Fisher) Vaginal Plus and pan-Candida real-time PCR. Results. This study included 2,152 women. The mean (standard deviation) age of participants was 35.1 (11.5) years. Sensitivity and specificity estimates for the Aptima BV assay were 98.8% and 77.7% and 94.9% and 88.3% for CV detection by Aptima CV/TV, respectively, relative to SOC. Overall diagnostic accuracy values were 80.2% for Aptima BV and 90.0% for Aptima CV/TV. Although not routinely tested for in our population, a limited evaluation of TV detection by the combined Aptima CV/TV assay relative to the monoplex Aptima TV assay in 75 women indicated sensitivity and specificity values of 87.5% and 100%, respectively. Conclusion. The Aptima BV and CV/TV assays demonstrated high sensitivity and specificity relative to SOC methodology in UK laboratories and are a viable alternative to conventional vaginitis testing.
Vipond et al. (Tue,) studied this question.