Comparative Evaluation of Microscopy and Polymerase Chain Reaction Sensitivity in the Diagnosis of Trichomonas vaginalis Using Vaginal Swab Samples from Women in Ibadan, Oyo State, Nigeria

Abstract

Trichomoniasis in women remains a public health challenge due to high prevalence, inefficient and inaccurate diagnosis, especially in developing countries. This study aimed to determine the prevalence of trichomoniasis in women in Ibadan, using both microscopy and PCR techniques, and to investigate any possible association between Trichomonas vaginalis and Cervical Intraepithelial Neoplasia (CIN). Two vaginal swab samples were collected from 200 women (aged 20-60 years) attending the Obstetrics and Gynaecology Unit, University College Hospital, Ibadan, for Papanicolaou smear test. They were processed for microscopy and PCR analyses. Ninety-six vaginal swab samples gave quantifiable concentrations of DNA and were used for the analyses. The primer set Tv1/Tv2 was used for amplification of the T. vaginalis 18S ribosomal gene. Confidence intervals for sensitivity of the diagnostic techniques were determined using the Student’s t-test. Microscopy detected 25% of T. vaginalis (95% CI, 1.16−1.34, P<0.001) while PCR detected 87.5% (95% CI, 1.75−1.93, P<0.001). Using PCR as a standard, the percentage sensitivity of microscopy was 28.57%. Kappa value was 0.08. These findings showed that PCR was more sensitive to T. vaginalis using vaginal swab samples compared to microscopy. They also demonstrated a positive association between T. vaginalis and CIN. Negative cases got by microscopy should be further tested using molecular diagnostic techniques such as PCR.