New Single-Assay Test for Vaginitis Accurate as Traditional Tests

A new US Food and Drug Administration (FDA)-approved molecular test has been shown to be highly accurate for detecting major causes of vaginitis, according to a new study published in the Obstetrics & Gynecology journal.

Effective treatment for vaginitis, a common problem for women and one that both causes discomfort and leads to millions of doctor visits each year, depends on accurate diagnosis. However, the various types of vaginitis are diagnosed by means of several different tests. A single test that could accurately diagnose most of the major causes of vaginitis would be beneficial.

Researchers from Johns Hopkins University and colleagues compared the accuracy of an FDA-approved nucleic acid amplification vaginitis test against traditional diagnostic tests used to detect the 3 most common causes of vaginitis: bacterial vaginitis, vulvovaginal candidiasis, and trichomoniasis. 

Self-collected and clinician-collected vaginal swabs from 1740 symptomatic women at 10 clinical centers around the country were used. The reference tests were Amsel criteria and Nugent scoring for bacterial vaginosis,isolation of potential Candida microorganisms from inoculation of 2 culture media, and wet mount and culture for trichomoniasis.

Bacterial vaginosis was diagnosed in 56.5% of the women, vaginal candidiasis in 32.8%, and trichomoniasis in 8% of the women. Additionally, in 24% of the women, none of the 3 types of infection was present, and there was a coinfection rate of 20%. The molecular test proved highly accurate, with 90.5% sensitivity (95% confidence interval [CI], 88.3-92.2) and 85.8% specificity (95% CI, 83.0-88.3) for bacterial vaginitis. The molecular test showed 90.9% sensitivity (95% CI, 88.1-93.1) and 94.1% specificity (95% CI, 92.6-95.4) for Candida sp in general, along with 75.9% sensitivity/99.7% specificity for Candida glabrata. The test resulted in 93.1% sensitivity (95% CI, 87.4-96.3) and 99.3% specificity (95% CI, 98.7-99.6) for trichomoniasis.

The researchers concluded that while more research needs to be done, the single-assay test could become a valuable tool for detecting most common forms of vaginitis. 

Reference

Gaydos CA, Beqaj S, Schwebke JR, et al. Clinical validation of a test for the diagnosis of vaginitis. Obstet Gynecol. 2017;130:181-189.