Associate Professor of Medicine, Epidemiology, and Obstetrics & Gynecology Division of Infectious Diseases, University of Alabama at Birmingham Birmingham, Alabama, United States
Background: The natural history of Trichomonas vaginalis in men is poorly understood, particularly the frequency of spontaneous resolution. Additionally, research on the optimal treatment in men is limited as the current recommended therapy (single-dose 2-g oral metronidazole [MTZ]) is largely based on studies in women. Here, we investigate the natural history of T. vaginalis in men recently testing positive by a nucleic acid amplification test (NAAT) during standard-of-care (SOC). For those testing positive on repeat enrollment NAAT testing, we evaluated the persistence of T. vaginalis after treatment with 2-g oral MTZ at a 4-week test-of-cure (TOC) visit.
Methods: Men ages ≥18 years at the Jefferson County Health Department (JCDH) Sexual Health Clinic testing positive for T. vaginalis by NAAT during SOC within the past 30 days and presenting to the clinic for treatment were approached. At enrollment, participants completed a study questionnaire, provided a urine specimen for repeat T. vaginalis NAAT, and were treated with 2-g oral MTZ. Those with a repeat positive enrollment NAAT were given an appointment for a 4-week TOC. At TOC, men provided another urine specimen for T. vaginalis NAAT. We evaluated predictors of spontaneous resolution.
Results: Between October 2021-January 2023, 53 men with a positive SOC T. vaginalis NAAT were approached for the study; 37 (69.8%) agreed to participate. Mean age of the 37 men was 32.9 years (SD 9.9); all were African American. All but one (97.3%) reported sex only with women and most (81.1%) reported >1 sexual partner in the past month. At enrollment, 26/37 (70.3%) had a repeat positive T. vaginalis NAAT in the absence of treatment after an average of 6.3 (SD 4.2) days. Symptoms, number of sexual partners during the past 30 days, and sexual exposure between SOC and enrollment NAAT testing were not associated with spontaneous resolution. Of the 26 men given a TOC visit, 17 (65.4%) returned and all except one (94.1%) were cured.
Conclusion: As enrollment continues, preliminary data suggest that most men do not spontaneously clear their T. vaginalis infection during early repeat testing. In addition, most men who receive single-dose 2-g oral MTZ are cured.