Spontaneous resolution of Trichomonas vaginalis infection in men.

Objectives: We aimed to investigate the early natural history of Trichomonas vaginalis in men recently testing positive for this infection by a nucleic acid amplification test (NAAT). We hypothesised that 50% of men would spontaneously resolve their infection (in the absence of treatment) on repeat T. vaginalis NAAT.

Methods: Men ages ≥18 years at the Jefferson County Health Department Sexual Health Clinic testing positive for T. vaginalis by NAAT during standard-of-care (SOC) within the past 30 days and presenting to the clinic for treatment were approached. At enrolment, participants completed a questionnaire, provided urine for repeat T. vaginalis NAAT, and were treated with 2 g oral metronidazole. Those with a repeat positive enrolment NAAT were seen for a 4-week test-of-cure (TOC) visit. At TOC, men provided urine for repeat NAAT. We determined the proportion of men with spontaneous resolution of T. vaginalis and evaluated predictors of spontaneous resolution. In those with a repeat positive enrolment T. vaginalis NAAT, we evaluated the proportion with persistent infection at TOC as a secondary outcome.

Results: Between October 2021 and January 2023, 53 men with a recent positive SOC T. vaginalis NAAT were approached; 37 (69.8%) participated. The mean participant age was 32.9 years (SD 9.9); all identified as Black. The majority (97.3%) reported sex with women only; 35.1% reported sex with >1 partner in the last month. At enrolment, 26/37 (70.3%) had a repeat positive T. vaginalis NAAT in the absence of treatment after an average of 8.4 days (SD 5.9). Sexual partner gender, number of recent sexual partners, genital symptoms, unprotected sex with any partner and recent antibiotic use were not associated with spontaneous resolution. Of the 26 men attending a TOC visit, 17 (65.4%) returned and all except one (94.1%) were cured.

Conclusion: Most men do not spontaneously clear T. vaginalis infection during early repeat testing.