Very low sensitivity of wet mount microscopy compared to PCR against culture in the diagnosis of vaginal trichomoniasis in Uganda: a cross sectional study

Abstract

Background Trichomonas vaginalis (TV) causes the Trichomoniasis Syndrome composed of vaginitis in women, urethritis in men and tube infection in both sexes. This infection is strongly associated with premature rupture of membranes, preterm delivery, low birth weight, promoting HIV sexual transmission and infertility. Prevention of these complications requires accurate early detection and effective treatment of infected individuals. In the resource limited settings, the wet mount microscopy (WMM) is often the only available test for laboratory detection of TV, but its accuracy and that of polymerase chain reaction (PCR) tools in Uganda remain poorly studied. The aim of this cross-sectional study was to compare the diagnostic accuracy of the WMM and PCR against culture as reference standard for the direct diagnosis of TV among symptomatic women. Three high vaginal swabs were collected from each of one hundred fifty women presenting with symptoms suggestive of active vaginal trichomoniasis at the sexually transmitted diseases clinic of Mulago National Referral Hospital Kampala, Uganda. The swabs were tested for TV with WMM, in-house PCR and TV culture. Results were analysed using excel 2007, SPSS v16, and Meta-disc software to determine the diagnostic accuracy of the tests.ResultsThe sensitivity, specificity and kappa agreement of the WMM was 25% (95% CI 5.5–57.2%), 100% (95% CI 97–100) and 0.38, respectively. Corresponding values for the PCR were 91.7% (95% CI 61.5–99.8), 99.3% (95% CI 96–100) and 0.91, respectively.ConclusionAmong the TV symptomatic women, the sensitivity of the WMM was very low, with two-thirds of the patients missing a diagnosis while the in-house PCR was highly sensitive and specific. Feasibility studies aimed at incorporating PCR tools in algorithms for diagnosis of TV infection in resource-limited settings are recommended.Electronic supplementary materialThe online version of this article (doi:10.1186/s13104-017-2581-1) contains supplementary material, which is available to authorized users.

Frequency of Trichomoniasis and Related Risk Factors in the Women Referred to Bandar Abbas Health Centers, Iran, 2017-2018

“…The prevalence of T. vaginalis in women differs in different populations, where it is ten times higher than men. The infection comprises the risks of premature delivery birth, low birth weight, infertility, and cervical cancer (6,7). Clinical manifestations of the parasite are different in men and women.…”

A hospital-based study on the prevalence of trichomoniasis and evaluation of accuracy of various diagnostic techniques

“…Although a study from Aligarh[ 19 ] reported similar positivity rate by acridine orange staining, nonetheless, they could detect only 66% positive cases by wet mount microscopy as in a study from Karnataka[ 20 ] with a resultant lower sensitivity (60%). Studies from Uganda (25%)[ 21 ] and Egypt (33.3%)[ 22 ] have even lower sensitivity of wet mount microscopy. A delay in transport of the sample with resultant reduced motility of the organism can compromise with sensitivity of this technique.…”

From Wet Mount to Nucleic Acid Amplification Techniques: Current Diagnostic Methods and Future Perspectives Based on Patenting of New Assays, Stains, and Diagnostic Images for Trichomonas vaginalis Detection

“…Among the T. vaginalispositive women, a decrease was observed in the sensitivity of the WMM, compromising treatment of two-thirds of the patients. The authors recommend further research to integrate PCR tools into diagnostic algorithms for trichomoniasis [25].…”