Diagnosis of Trichomonas vaginalis from vaginal specimens by wet mount microscopy, in pouch TV culture system, and PCR

Abstract

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.AimThe 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.ResultsOf 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.ConclusionComparison 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.

Trichomonas vaginalis Infections are Rare Among Young Patients Attending an STI Clinic in Sweden

“…If appropriately performed by an experienced microscopist, the specificity can be high; however, the sensitivity is suboptimal, i.e. in comparison with nucleic acid amplification tests (NAATs) 44-68% in women and even lower in men (2,(7)(8)(9). In-house culture or, e.g.…”

“…In-house culture or, e.g. the commercial InPouch TV culture system (BioMed Diagnostics, White City, USA), have a higher sensitivity; however, this method requires 5-7 days for completion and is rarely used in many settings (2,7,8). Several in-house NAATs that offer improved sensitivity for detection of T. vaginalis have been developed (2).…”

Interactions Among Urogenital, Intestinal, Skin, and Oral Infections in Pregnant and Lactating Panamanian Ngäbe Women: A Neglected Public Health Challenge

“…The swab was placed in a tube with 1 mL sterile saline solution, immediately refrigerated and kept on ice during transport to the laboratory. Direct microscopic examination of wet mounts was done by an experienced laboratory technician for mobile forms of Trichomonas vaginalis (sensitivity of 60%) 49 and budding yeast cells and/or hyphae of vaginal yeast infection (sensitivity 65-85%). 48 Severity of vaginal yeast was scored according to the number per high-power field (hpf) as 0 (absent), 1+ (1/hpf), 2+ (2/hpf), 3+ (3/hpf), or 4+ (4 or more/hpf).…”

Trichomonas vaginalis: Clinical relevance, pathogenicity and diagnosis

“…Despite these advantages microscopic evaluation is not considered the optimal detection method, due to the low sensitivity afforded by this technique. Microscopy has been shown to have a sensitivity of around 60%, when compared with PCR based methods (Patil et al, 2012). Microscopy is unlikely to detect low level infections, in which the organism load in the sample may be under 10 4 cells/ml, and therefore will potentially not be included in the fields examined on the slide (Garber, 2005).…”