Diagnostic accuracy of real-time polymerase chain reaction assay for the detection of Trichomonas vaginalis in clinical samples: A systematic review and meta-analysis

Background: Vaginal trichomoniasis is a highly prevalent parasitic infection associated with HIV acquisition and preterm birth. The ‘gold standard’ for its diagnosis requires 3–7 days to detect by culture. Rapid and accurate diagnosis, such as by nucleic acid amplification testing, is key to manage the disease, and control and prevent its transmission.

Aim: This review aimed to assess the overall accuracy of real-time polymerase chain reaction (RT-PCR)-based assays, for routine diagnosis of Trichomonas vaginalis in clinical vaginal samples from women with symptomatic/asymptomatic trichomoniasis, using Trichomonads culture as the gold standard.

Methods: MEDLINE, PubMed, EMBASE, and other sources were used to search for included studies published between 01January1995 and 31July2023. The search terms ‘real-time polymerase chain reaction’, ‘real-time’, ‘polymerase chain reaction’, ‘Trichomonas vaginalis’, ‘trichomonas’, ‘vaginalis’, ‘humans’, ‘rt pcr’, ‘nucleic acid amplification test’, ‘NAAT’, ‘trichomonad culture’, ‘women’ were included. Summary estimates were calculated for the overall accuracy of the assay compared to Trichomonads culture as the reference standard. Meta-analysis was conducted using a bivariate meta-regression model.

Results: Twenty-seven eligible studies met our inclusion criteria: sensitivity 99% (95%confidence interval [CI] 99–100), specificity 100% (95% CI 100–100), positive likelihood ratio 350.67 (167.42–734.49), negative likelihood ratio 0.02 (0.01–0.03), diagnostic odds ratio 23064.05 (95% CI 8532.13–62346.77), and area under receiver operating characteristics curve 0.99. There was significant heterogeneity in sensitivity and specificity (p < 0.001).Conclusion: Our results suggested that RT-PCR assays could be useful for the diagnosis of vaginal trichomoniasis with high sensitivity and specificity.

What this study adds: This article provides a comprehensive review of the effectiveness of RT-PCR assays for the diagnosis of trichomoniasis with high sensitivity and specificity in comparison to other methods in clinical laboratory practice. The goal is to present awareness/evidence that this assay is more accurate and rapid than other techniques.

Keywords: Trichomoniasis; Trichomonas vaginalis; real-time polymerase chain reaction assay; vaginal swabs; systematic review; meta-analysis