Diagnosis of Trichomonas Vaginalis from Vaginal Specimens by Wet Mount Microscopy, In Pouch TV Culture System, and PCR

J Glob Infect Dis. 2012 Jan;4(1):22-5. doi: 10.4103/0974-777X.93756.


Background: In recent years, trichomoniasis has emerged as the most common sexually transmitted disease and limited data are available on the effective screening technique for the diagnosis of Trichomonas vaginalis.

Aim: The aim was to compare and evaluate different diagnostic methods like wet mount microscopy, In Pouch TV culture, and Polymerase chain reaction (PCR) to establish which method or combination of methods was most effective for detection of Trichomonas vaginalis in vaginal swab specimens.

Settings and design: This is a cross-sectional study.

Materials and methods: A total of 200 patients complaining of vaginal discharge were included in the study. Three vaginal swabs were screened for trichomoniasis by wet mount microscopy, In Pouch TV culture system and PCR, using TVK3 and TVK7 specific primers.

Results: Of the 200 cases studied, 36 (18%) were positive by wet mount microscopy, 44 (22%) by In Pouch TV culture system and 60(30%) by PCR. Sensitivity and specificity of wet mount were 60% and 100%, respectively, whereas sensitivity and specificity of the In Pouch TV culture system were 73.33% and 100%, respectively when compared to PCR.

Conclusion: Comparison of different methods showed that at least two techniques, such as wet mount microscopy and culture have a better chance of detection of T. vaginalis infection. Diagnosis of trichomoniasis by PCR was found to be highly specific and sensitive, but its availability and cost effectiveness limit its use in routine diagnostic laboratories.

Keywords: In Pouch TV culture; PCR; Trichomonas vaginalis; Vaginal discharge; Wet mount microscopy.