Comparison of Wet Mount Microscopy and Giemsa Staining to PCR in the Diagnosis of Vaginal Trichomoniasis in a Tertiary Level Hospital of Bangladesh.

Abstract

Trichomonas vaginalis (T vaginalis) is the most prevalent non-viral sexually transmitted infection of the reproductive age group, which may lead to various complications, if left untreated. This study aimed to diagnose Trichomonas vaginalis infection by different diagnostic procedures and to evaluate the efficacy of different diagnostic procedures. This cross-sectional descriptive study was conducted among 102 women with vaginal discharge at the Department of Obstetrics & Gynecology at Mymensingh Medical College Hospital (MMCH) from July 2019 to December 2020. Three ectocervical swabs were collected from each patient. Saline wet mount microscopy, giemsa staining and PCR were performed for each patient. Data were collected using a structured questionnaire and analyzed using Excel 2007, statistical package for social sciences (SPSS) version 26.0. The PCR assay detected Trichomonas vaginalis positivity in 6(5.9%) of 102 patients, followed by Giemsa staining 4.9% and Wet mount examination 2.9%. Wet mount microscopy showed less sensitivity 33.33%, but high specificity 98.95%, 66.67% positive predictive value, 95.96% negative predictive value and accuracy 95.09%. The sensitivity, specificity, PPV, NPV and accuracy of Giemsa staining were 66.67%, 98.96%, 80.0%, 97.94% and 97.06% respectively. Statistical significance was observed when both WMM and Giemsa staining were compared to gold standard test PCR. In resource limited settings, a wet mount is a good option for diagnosis of T vaginalis infection as giemsa staining requires heavy T vaginalis infection to be positive. But wherever facilities are available, PCR should be performed.