Prevalence of Trichomonas Infection in Males
Trichomonas vaginalis infection occurs in approximately 0.5% of US males aged 18-59 years overall, but prevalence varies dramatically by race, with Black males having rates as high as 3.6%. 1
Population-Level Prevalence Data
The most recent national surveillance data from NHANES (2013-2016) provides the clearest picture of male trichomoniasis prevalence:
- Overall prevalence: 0.49% in men aged 18-59 years 1
- Black males: 3.6% - representing a striking racial disparity consistent with other STIs 1
- No significant age association was found, unlike in females where infection is common across all age groups 1
This contrasts with females, where adolescent prevalence ranges from 2.1% to 14.4%, and infection remains common in older women as well. 2 The racial disparity mirrors that seen in women, with prevalence rates 10 times higher among non-Hispanic African Americans compared to non-Hispanic white and Mexican American populations. 2
Prevalence Among Male Partners of Infected Women
When specifically examining male sexual partners of women diagnosed with trichomoniasis, the infection rate is dramatically higher at 71.7%. 3 This high concordance rate has critical implications:
- 177 of 247 male partners (71.7%; 95% CI 66.0%-77.3%) tested positive 3
- 77.3% of infected male partners were asymptomatic, making them efficient vectors for transmission 3
- Younger male age (20-39 years) was an independent risk factor for concordant infection 3
- Female vaginal pH >4.5 was independently associated with male partner infection (adjusted OR 2.5) 3
Clinical Significance of the "Hidden Reservoir"
Approximately 80% of male infections are asymptomatic, which creates a substantial reservoir for ongoing transmission. 2 This asymptomatic nature is why the infection persists at such high rates despite being treatable:
- Males can unknowingly spread infection to female partners 4
- When symptomatic, males may experience urethritis, epididymitis, and prostatitis 2
- Male infection has been associated with reduced fertility and amplified HIV risk 4
Risk Factors Associated with Male Infection
Higher infection rates were significantly associated with: 1
- Smoking status
- HSV-2 co-infection
- Early age at first sexual intercourse
- Less consistent condom use
- Higher number of lifetime sexual partners
Diagnostic Challenges Contributing to Underestimation
The true prevalence in males may be underestimated due to historical diagnostic limitations:
- Traditional wet mount has only 60% sensitivity 2
- NAATs demonstrate superior sensitivity for trichomonas diagnosis in men, though not all are FDA-cleared for male specimens 2
- Laboratories that have validated NAAT performance on male specimens may perform testing 2
- Culture sensitivity is approximately 70% compared to NAAT methods 2
Common Pitfall to Avoid
The most critical error is failing to recognize that T. vaginalis is likely the most common nonviral STI based on population studies, yet it remains non-reportable and vastly underdiagnosed in males. 2, 5 The high partner concordance rate (71.7%) necessitates simultaneous treatment of all sexual partners to prevent the reinfection cycle that perpetuates this "hidden epidemic." 3