Diagnostic performance of DNA probe-based and PCR-based molecular vaginitis testing

Vaginitis is usually diagnosed empirically, microscopically, via cultures, or by molecular testing for the detection of bacterial vaginosis (BV), vulvovaginal candidiasis (VVC), or Trichomonas vaginalis (TV). The DNA probe–based technique detects BV by identifying Gardnerella vaginalis, VVC by identifying Candida spp., while real-time PCR-based detection methods identify BV by algorithmic analysis of the absence or presence of known vaginal flora. We examined 8,878 total orders placed for DNA probe–based identification (ID) and 10,464 total orders placed for molecular panel ID. We found that PCR-based BV test positivity reduced from 30% to 23% compared with the population tested with DNA probe–based testing. We also found that PCR-based testing VVC positivity increased from 6.3% and 11.6% when compared with DNA probe–based testing. Bayesian generalized linear analysis estimated a lower mean proportion of positive tests for BV in PCR-based molecular panels than DNA probe testing suggesting an under-call of BV. The same models estimated a higher mean proportion of positive tests for molecular vaginal panels than DNA probe testing suggesting an increased detection of candidal vaginitis. In addition, the mean (SD) age for patients with Candida albicans was 40.5 (40.0–41.1) years. Patients with Candida glabrata (now N. glabrata) were 5.2–8.1 (mean 6.7) years older than patients with Candida albicans. Our retrospective data analysis found that BD Max MVP’s ability to discriminate between vaginal candidiasis versus other yeast will help to implement CDC (Centers for Disease Control and Prevention)-recommended treatment options. We also believe that providers’ inattention to non-albicans treatment could be an issue nationwide. IMPORTANCE: Using retrospective data from U.S. Food and Drug Administration-approved/cleared molecular vaginal panels, molecular methods were found to have higher detection for Candida vaginitis and lower detection for bacterial vaginitis when compared to probe-based methods. In addition, the differentiation of Candida and non-Candida yeast has not reached the physician community as we observed noncompliance in recommended therapy. Furthermore, the pros and cons of migrating to molecular testing from conventional microscopy for identifying bacterial vaginitis and fungal vaginitis have been examined and reported in this paper. Interestingly, the mean (SD) age for patients with Candida albicans was 40.5 (40.0–41.1) years. Patients with N. glabrata were 5.2–8.1 (mean 6.7) years older than patients with Candida albicans.