Molecular Testing for Trichomonas vaginalis in Women: Results from a Prospective U.S. Clinical Trial

Abstract

Trichomoniasis is a common sexually transmitted disease associated with preterm birth, low birth weight, and increased susceptibility to infection with other pathogenic sexually transmitted microorganisms. Nucleic acid amplification tests for Trichomonas vaginalis have improved sensitivity for detecting infected individuals compared to existing culture-based methods. This prospective, multicenter U.S. clinical trial evaluated the performance of the automated Aptima T. vaginalis assay for detecting T. vaginalis in 1,025 asymptomatic and symptomatic women. Vaginal swab, endocervical swab, ThinPrep PreservCyt, and urine specimens were collected. Subject infection status was determined by wet-mount microscopy and culture. Aptima T. vaginalis assay performance was determined for each specimen type by comparison to subject infection status. Of 933 subjects analyzed, 59.9% were symptomatic. Aptima T. vaginalis clinical sensitivity and specificity were, respectively, 100% and 99.0% for vaginal swabs, 100% and 99.4% for endocervical swabs, 100% and 99.6% in ThinPrep samples, and 95.2% and 98.9% in urine specimens. Aptima T. vaginalis performance levels were similar in asymptomatic and symptomatic subjects. This study validates the clinical performance of the Aptima T. vaginalis assay for screening asymptomatic and symptomatic women for T. vaginalis infection.Trichomoniasis, a common sexually transmitted disease (STD) caused by the protozoan Trichomonas vaginalis, affects approximately 180 million persons per year worldwide, making it the most common nonviral STD agent in the world. An estimated 7.4 million new cases occur annually in the United States (1), and the disease has an overall prevalence of 3.1% (24). Both women and men can be infected, although symptoms are more common in women. Symptomatic women have a diffuse, malodorous, yellow-green vaginal discharge with vulvar irritation which may be confused with bacterial vaginosis. Infected men may temporarily have urethral irritation, mild discharge, or slight burning after urination or ejaculation (5). Many infections do not produce symptoms and when left untreated may lead to preterm birth, low birth weight, and pelvic inflammatory disease (5). T. vaginalis infection also increases susceptibility to infection with HIV (14,22,23). Effective and inexpensive antibiotic therapy for T. vaginalis infection is readily available, and detection and treatment of T. vaginalis in symptomatic or asymptomatic women with a high risk of STD are important to prevent disease acquisition, transmission, and associated complications.Currently, the gold standard for the diagnosis of T. vaginalis infection is culture; however, the sensitivity of commercially available culture has been reported to be 75% to 89% compared to amplified methods (13,20). Tests with improved sensitivity are needed to diagnose this prevalent STD. The Aptima Trichomonas vaginalis assay, an FDA-cleared, fully automated nucleic acid amplification test, has demonstrated high sensitivity and specificity compared to c...

Three-Year History of Transcription-Mediated Amplification-Based Trichomonas vaginalis Analyte-Specific Reagent Testing in a Subacute Care Patient Population

“…Although the overall prevalence of T. vaginalis in women was approximately 10 to 15% less in this subacute care demographic compared to emergent care populations (16,23,24), significant T. vaginalis detection rates in both males and females (Table 2), as well as statistically increased T. vaginalis detection rates over those of C. trachomatis and N. gonorrhoeae provide evidence supporting consistent molecular screening for this agent. Indeed, appreciable T. vaginalis detection rates have been demonstrated in both symptomatic and asymptomatic populations (25,27,28). …”

Prevalence of Trichomonas vaginalis and Coinfection with Chlamydia trachomatis and Neisseria gonorrhoeae in the United States as Determined by the Aptima Trichomonas vaginalis Nucleic Acid Amplification Assay

“…Sample types include urine, clinician-collected vaginal swabs (CVS), endocervical swabs (ES), and PreservCyt solution (Hologic Incorporated, Bedford, MA) for liquid-based cytology (PCyt). A multicenter study that determined ATV performance for FDA clearance demonstrated that assay sensitivity ranged from 95.2% for urine to 100% for CVS, ES, and PCyt samples (28). ATV was highly specific for T. vaginalis (Ն98.9%) (28).…”

The ABCs of STIs: An Update on Sexually Transmitted Infections

“…However, this method has poor sensitivity, as the organism is reportedly detected in only 60%-70% of cases (104 ). The gold standard for detection of T. vaginalis, molecular testing by NAAT, has reported sensitivity and specificity of 95%-100% (105,106 ). FDA-cleared NAAT assays are available that test vaginal, cervical, or urine specimens from women and, recently, urine specimens from men.…”