Evaluation of DNA Based Techniques for the Diagnosis of Human Vaginal Trichomoniasis in North Indian Population

Abstract

Introduction: Human trichomoniasis due to Trichomonas vaginalis is a curable sexually transmitted infection. It may lead to symptomatic vaginitis or asymptomatic carrier state. The symptoms and signs mimic other pathologies and conventional techniques of diagnosis have its own limitations. Therefore, the present study aimed to evaluate a newly established in-house PCR based assay on pfoB gene and compared it with conventional wet smear examination method and 18S rRNA gene based PCR technique for the diagnosis of T. vaginalis in symptomatic and asymptomatic subjects. Materials and Methods: Four hundred women in age group 20-57 years attending the Obstetrics and Gynecology out Patients Department (OPD) of Nehru Hospital attached to Post Graduate Institute of Medical education and Research (PGIMER) Chandigarh, India were included in the study. Based on the symptoms and signs, 344 (86%) women were categorized as symptomatic and 56 (14%) as asymptomatic. Vaginal swabs collected from all the women were processed by three techniques including wet smear, 18S rRNA and the pfoB gene based PCR techniques for the detection of T. vaginalis. Results: The main presenting symptom in majority of symptomatic patients was vaginal discharge. The highest numbers of T. vaginalis positive patients were found in the sexually active age group of 20 to 40 years. The amplifications of pfoB and 18S rRNA gene by PCR revealed significantly higher positive cases (20.7% and 18.6%, respectively) than the wet smear (6.6%) method. The diagnostic efficacy and kappa value estimated by the three techniques were 86.8-100% and 35.5-66%, respectively. Conclusions: The combined application of any two of the three techniques used in the present study may be useful for the diagnosis of T. vaginalis infection in symptomatic and asymptomatic subjects. This information may help clinicians to make a timely and accurate diagnosis.