Compared to the Becton Dickenson Affirm™ VPIII Ambient Temperature Transport System (Affirm), the Becton Dickenson MAX™ UVE Specimen Collection Kit (MAX VP) provided better specificity for the detection of bacterial vaginosis (BV) and vaginal candidiasis (VC); however, no difference in specificity was found in the detection of trichomoniasis, according to a study published in the European Journal of Clinical Microbiology and Infectious Diseases.
Compared with Affirm, which uses a DNA-probe technology, “MAX VP is the first microbiome-based [polymerase chain reaction] assay that detects BV, VC, and [trichomoniasis] in one collection kit,” according to the manufacturer of both products, Becton Dickenson (BD Life Sciences). MAX VP was approved by the US Food and Drug Administration in October 2016.
Women with vaginitis often have multiple symptoms, including discharge (55%), itching (50%), and odor (43%). In this study, a total of 200 symptomatic women (mean age, 30.5 years) were included, and 4 vaginal swab specimens were collected from each patient (Affirm, MAX VP, Hologic Aptima® Vaginal Swab Specimen Collection Kit, and BDE Swab™ collection and transport system). Candida spp culture, Gram stain, and Trichomonas vaginalis assay were used for analysis.
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Prior to diagnosis, the average duration of symptoms was 19.7 days, with 13 patients reporting >6 months of symptoms. BV was the most common condition detected (41.6%), followed by Candida spp (32.1%) and trichomoniasis (4.2%).
Results of the study found that the “sensitivity and specificity of MAX VP for BV was 96.2% and 96.1%, respectively, compared to 96.2% and 81.6% for Affirm,” wrote the authors. For Candida spp, the sensitivity and specificity were 98.4% and 95.4% with MAX VP, respectively, compared with 69.4% and 100% with Affirm. Both MAX VP and Affirm showed 100% concordance for detection of trichomoniasis.
Of importance to treatment, MAX VP was able to differentiate between C glabrata and C krusei, which are important causes of VC, from C albicans. According to the authors, C krusei is resistant to antifungal agents, and 50% of C glabrata have decreased sensitivity to fluconazole. Increased recognition of the prevalence of VC not caused by C albicans and of recurrent VC may provide additional information to optimize treatment options.
“The results of this study demonstrate that MAX VP provides better specificity for the detection of BV compared to Affirm with no difference in sensitivity, whereas it provides superior sensitivity, with specificity that is at least as good, when compared to Affirm for the detection of Candida spp; an equivalent performance for [trichomoniasis] in symptomatic patients was observed for MAX VP compared to Affirm,” the authors concluded.
The study was supported by BD Life Sciences – Diagnostic Systems (Sparks, MD).
Reference
Thompson A, Timm K, Borders N, Montoya L, Culbreath K. Diagnostic performance of two molecular assays for the detection of vaginitis in symptomatic women [published online September 9, 2019]. Eur J Microbiol Infect Dis. doi: 10.1007/s10096-019-03694-w
