By Kathleen M. Murphy, Ph.D. & Kenneth E. Youens, M.D. 

 

Background: Trichomonas vaginalis (TV) is the most common cause of curable sexually transmitted infection in theUnited States, with an estimated 7.4 million new cases occurring each year. A recent study of the prevalence of TV inthe United States reported rates of infection of 8% in women ages 18-39 years, 9-13% in women ages 40-49 years, and13% in women over 50 years of age. The authors concluded that “The high TV prevalence in all age groups suggeststhat all women being screened for CT/NG should also be screened for TV.”1

Infections in women typically cause vaginitis, urethritis, and cervicitis. Common symptoms include vaginal discharge,vulvovaginal irritation, and/or dysuria, but it is estimated that up to half of TV infections are asymptomatic.2

In pregnancy, TV infection increases the risk of premature labor, premature rupture of membranes, and low birthweight.3 Rare manifestations of trichomoniasis include pelvic inflammatory disease, tubal infertility, and post-abortionor post-hysterectomy infection.

 

 

Diagnosis of TV infection has traditionally been performed by microscopy of vaginal secretions, but this technique requires immediate evaluation of a wet preparation and is only about 60-70% sensitive. Modern nucleic acid-based testing for TV is convenient, accurate, and more sensitive than traditional methods.

 

The Assay Performed at ProPath: The FDA-approved APTIMA Trichomonas vaginalis Assay (Gen-Probe) uses a target amplification method to detect nucleic acid sequences that are specific to TV. The sensitivity and specificity of the testare each reported to be > 99%.2

 

Specimens

Liquid-based cytology specimens collected in ThinPrep (PreservCyt) or SurePath media.

Endocervical and vaginal swab specimens collected and transported in the APTIMA Unisex collection kit transport medium and tube.

Urine collected and transported in the APTIMA urine collection kit and transport tubes.

 

 

References:

1. Ginocchio CC, Chapin K, Smith JS, et al. 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. Journal of clinical microbiology. 2012;50(8):2601–8.

2. Gen-Probe APTIMA Trichomonas package insert.

3. http://www.cdc.gov/std/treatment/2010/vaginal-discharge.htm.

4. BD Affirm VPIII Package insert.

5. Wiese W, Patel SR, Patel SC, Ohl CA, Estrada CA. A meta analysis of the Papanicolaou smear and wet mount for the diagnosis of vaginal trichomoniasis. The American journal of medicine. 2000;108(4):301–8.