Clinical Information

SureSwab®, Trichomonas vaginalis RNA, Qualitative, TMA - The SureSwab® Trichomonas vaginalis RNA, Qualitative Transcription-Mediated Amplification (TMA) assay is a nucleic acid amplification test that uses TMA for detection of T. vaginalis RNA in vaginal swabs (preferred), female urine, or endocervical swabs. It is used in the screening and diagnosis of trichomoniasis. When the clinical performance of this assay was evaluated, sensitivity was 100% in vaginal swab, endocervical swab, and PreservCyt Solution liquid PAP specimens. Specificity was 98.2% in vaginal swab specimens and 98.1% in endocervical swab specimens.

Trichomoniasis is one of the most common sexually transmitted infections (STIs) in the United States, with an estimated 1.1 million new cases each year [3]. It is curable. About 70% of people infected with T. vaginalis are asymptomatic, though symptoms may show up after the infection has been present for some time. In women, symptoms include vaginal and/or urethral discharge, painful urination and genital burning and discomfort.

In women, untreated T. vaginalis infection can lead to infertility, pelvic inflammatory disease, and cervical neoplasia. T. vaginalis infection is associated with a 2- to 3-fold increased risk of HIV infection in women, as well as increased risk of preterm labor.

The Centers for Disease Control and Prevention (CDC) recommends T. vaginalis testing for women with vaginal discharge or cervicitis. Because of the high rate of reinfection in individuals treated for T. vaginalis, CDC also recommends repeat testing 3 months after treatment. Additionally, screening is recommended for HIV-infected women at the first HIV-related visit, with follow-up T. vaginalis testing annually. For pregnant women with HIV infection, T. vaginalis screening is recommended at the first prenatal visit.

In a study of 933 symptomatic and asymptomatic women tested for T. vaginalis using a TMA-based assay, clinical sensitivity and specificity for various specimens were as follows: 100% and 99%, respectively, for vaginal swabs; 95.2% and 98.9% for urine; and 100% and 99.4% for for endocervical swabs.

A "detected" result is consistent with T. vaginalis infection. False-positive results could be obtained from sampling less than 2 weeks after cessation of therapy, since TMA-based tests can detect nucleic acids from dead organisms. A "not detected" result is consistent with the absence of T. vaginalis infection. False-negative results could be obtained due to an organism concentration below the assay detection limit.