Utility of microscopic techniques and quantitative real-time polymerase chain reaction for the diagnosis of vaginal...

The aim of the study was to evaluate the diagnostic value of Nugent score, wet mount microscopy, and polymerase chain reaction (PCR) test developed in Russia for bacterial vaginosis (BV) diagnosis.

One hundred Caucasian women were enrolled in this study. Three vaginal samples were taken from each participant: 1 for PCR analysis, 1 for Nugent score evaluation, and 1 for wet mount microscopy. The smears for microscopy were air-dried and sent to Femicare, Tienen, Belgium, for blinded analysis by microscopy. Multiplex real-time PCR was performed using primers and probes targeting Gardnerella vaginalis, Atopobium vaginae, Lactobacillus species, and total quantity of bacterial DNA (16SrRNA gene).

Agreement among the 3 methods was 72 (73.5%) of 98 samples. Agreement between Nugent score and PCR results was 77 (78.6%) of 98 samples; between wet mount microscopy and PCR, 81 (82.65%) of 98 samples; between wet mount microscopy and Nugent score, 84 (85.7%) of 98 samples. The sensitivity and specificity of the methods studied were as follows: 75% (21/28) and 97.1% (68/70) for Nugent score, 96.4% (27/28) and 94.3% (66/70) for wet mount microscopy, 92.8% (26/28) and 85.7% (60/70) for PCR, respectively.

This study demonstrated that wet mount microscopy is a superior method for BV diagnosis. The PCR test under study showed a high sensitivity and can be used for discrimination between normal flora and BV.