Editorial commentary: Trichomonas vaginalis testing and screening in a high-risk population: is this a glimpse into the future?

Trichomonas vaginalis (TV) is often referred to as the “neglected” sexually transmitted infection [1–3]. Although the estimated annual incidence of TV in the United States and worldwide exceeds that of chlamydia and gonorrhea combined, there are no established screening, surveillance, or control programs for men or women [4, 5]. Currently, the Centers for Disease Control and Prevention (CDC) sexually transmitted disease (STD) treatment guidelines recommend TV screening for all human immunodeficiency virus (HIV)–infected women when care is initiated, then at least annually, and TV testing for all symptomatic women presenting with vaginal discharge [6]. The CDC guidelines also recommend that screening be considered for asymptomatic women at high risk for infection, such as those with new or multiple sex partners, those with a history of STDs, or women in high-prevalence settings. In the 2014 UK national guideline on the management of TV, testing is recommended for symptomatic women and for men who are TV contacts [7]. This guideline also recommends that testing be considered for men with persistent urethritis. There are no TV screening recommendations in the UK guideline either. The diagnostic sensitivity of TV detection has increased tremendously as TV detection has progressed from wet mount (sensitivity of 50%–65%) to the highly sensitive TV nucleic acid amplification tests (NAATs; sensitivity of 95%–100%). Currently there are 2 commercially available US Food and Drug Administration– cleared TV NAATs on the market, and others are on the horizon [8–10]. Having these TV NAATs available on multiple platforms will lead to widespread availability and use, allowing for many unanswered questions about TV infection to be addressed. This new information could potentially lead to removal of the TV designation as the “neglected” sexually transmitted infection [1]. In this issue of Clinical Infectious Diseases, Muzny and colleagues present a retrospective analysis of the implementation of routine TV testing and screening using a NAAT at the Jefferson County Health Department STD Clinic in Birmingham, Alabama [11]. The objectives of the study were to determine if there was added benefit to implementing routine TV testing and to determine the correlates of TV infection in their clinic population. Endocervical, urethral, or urine specimens from 6335 men and women were tested using a TV NAAT. The prevalence of TV was 27% in women and 9.8% in men. One-third of women who tested positive by wet mount and one-third who tested positive by NAAT were found to be asymptomatic. In addition, the prevalence of TV based on wet prep was 19.6%, whereas that based on NAAT was 27%. These data lead one to conclude that TV infections would have been missed in one-third of women in the absence of TV testing and screening. Using these data as an example, control of TV infection in a population would never be accomplished using a diagnostic method that missed 30% of women with the infection. This 30% of women would have had encounters with medical providers, yet TV infection would have gone undetected and untreated. Is it good clinical practice to miss this tremendous opportunity when TV NAATs are available and the recommended treatment is fairly inexpensive and administered as a single dose? Muzny et al also demonstrate that correlates of TV infection in both men and women were age >40 years and African American race. The recognition of high TV infection rates in patients who are Received 6 February 2014; accepted 5 June 2014; electronically published 13 June 2014. Correspondence: Stephanie N. Taylor, MD, Section of Infectious Diseases, LSU Health Sciences Center, 1542 Tulane Ave, New Orleans, LA 70112 ([email protected]). Clinical Infectious Diseases 2014;59(6):842–4 © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals. [email protected]. DOI: 10.1093/cid/ciu448