Optimization of <i>Trichomonas vaginalis</i> Diagnosis during Pregnancy at a University Hospital, Argentina

Abstract

The aim of this study was to evaluate different methods for Trichomonas vaginalis diagnosis during pregnancy in order to prevent maternal and perinatal complications. A total of 386 vaginal exudates from pregnant women were analyzed. T. vaginalis was investigated by 3 types of microscopic examinations direct wet mount with physiologic saline solution, prolonged May-Grunwald Giemsa (MGG) staining, and wet mount with sodium-acetate-formalin (SAF)/methylene blue method. PCR for 18S rRNA gene as well as culture in liquid medium were performed. The sensitivity and specificity of the microscopic examinations were evaluated considering the culture media positivity or the PCR techniques as gold standard. The frequency of T. vaginalis infection was 6.2% by culture and/or PCR, 5.2% by PCR, 4.7% by culture, 3.1% by SAF/methylene blue method and 2.8% by direct wet smear and prolonged MGG staining. The sensitivities were 83.3%, 75.0%, 50.0%, and 45.8% for PCR, culture, SAF/methylene blue method, and direct wet smear-prolonged MGG staining, respectively. The specificity was 100% for all the assessed methods. Microscopic examinations showed low sensitivity, mainly in asymptomatic pregnant patients. It is necessary to improve the detection of T. vaginalis using combined methods providing higher sensitivity, such as culture and PCR, mainly in asymptomatic pregnant patients, in order to prevent maternal and perinatal complications.

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

“…In our study, even when the wet preparation was performed at the sample collection site, by the experienced reader who routinely performs the wet preparations at the clinic, its sensitivity (25%) was still poor. Various studies using related but not exactly the same study designs report the sensitivity of WMM to range from around 38 to 65% [4, 11, 18, 23]. Testardini et al reported sensitivity of WMM of 45.8% in all the patients studied but it increased to 87.5% in symptomatic patients but in their study, one millilitre of physiologic saline was used instead three drops [4].…”

“…The prevalence of TV infection in this study was 8.6% based on all positive tests. Various studies report different prevalence values ranging from 13 to 41% based on the methods used, study settings, social-demographics and symptomatology of studied populations [ 4 , 9 , 10 ]. In high-risk populations such as female sex workers in sub-Saharan Africa (SSA), the prevalence of active TV infection can be as high as 47% [ 21 ].…”

“…Various studies using related but not exactly the same study designs report the sensitivity of WMM to range from around 38 to 65% [ 4 , 11 , 18 , 23 ]. Testardini et al reported sensitivity of WMM of 45.8% in all the patients studied but it increased to 87.5% in symptomatic patients but in their study, one millilitre of physiologic saline was used instead three drops [ 4 ]. Use of three drops instead of 1 ml of physiologic saline solution could be a limitation leading to the lower sensitivity of WMM obtained in our study.…”

“…Trichomonas vaginalis (TV) is an extracellular, facultative anaerobic infection of the human urogenital tract. Infection is associated with premature rupture of membranes, preterm delivery, low birth weight, HIV sexual transmission [ 1 ], and pelvic inflammatory disease [ 2 – 4 ]. The WHO estimates that at least 174 million cases of infection are acquired annually worldwide, majority in regions of low income settings [ 5 , 6 ].…”

Development of a convenient detection method for Trichomonas vaginalis based on loop-mediated isothermal amplification targeting adhesion protein 65

“…Among the diagnostic methods, the wet mount microscopy is low in cost, but poor in sensitivity [23]. The method of culture T. vaginalis is widely recognized as the "gold standard" for diagnosing trichomoniasis [24]. The sensitivity of the diagnostic method is high, but it takes a long time and requires high quality specimens, and microscopic examiner needs to be professional and experienced.…”