Evaluation of polymerase chain reaction assays for the diagnosis of Trichomonas vaginalis infection in Russia

Abstract

Background In Russia, the microscopy- and culture-based diagnostics of trichomoniasis is mainly suboptimal. Recent years, domestically produced diagnostic PCR assays have been implemented; however, any evaluation of these PCRs has never been internationally reported. Objective To assess the performance characteristics of PCR assays developed and currently used in Russia to detect Trichomonas vaginalis. Materials and methods Five PCR assays were assessed on 448 samples (317 vaginal and 131 male urethral) collected from symptomatic attendees of youth centres (n = 415) and patients of a dermatovenereological dispensary that were previously diagnosed with trichomoniasis (n = 33). As reference assay, a sensitive and specific real-time multiplex PCR was used. Results T. vaginalis DNA was detected in five (all females) of the 415 patients of youth centres (1.2%). All 33 patients previously diagnosed at the venereological dispensary proved to be true positive. For 445 (99.3%) of these 448 samples identical results were obtained by all PCRs, 35 positive and 410 negative. The three discordant samples were positive in all PCRs except one conventional PCR assay. The sensitivities of the PCRs were 94.3–100% and 66.7–100% for vaginal and urethral swabs, respectively. All evaluated assays were 100% specific. The detection limits of the different PCRs ranged from 0.1 to 5 genome equivalents per reaction. Conclusion The PCR assays currently used in Russia for the detection of T. vaginalis have in general high sensitivities and excellent specificities for both vaginal samples and urethral samples from males.