Trichomonas vaginalis as a cause of urethritis in Malawian men

Background and Objectives: Trichomonas vaginalis is one of the most common sexually transmitted infections. In Malawi, rates of trichomoniasis in wome n are high. The prevalence of T. vaginalis infection in men is expected to be high but has not previously been documented. Goals: We sought to determine the prevalence of trichomoniasis in Malawian men with and without urethritis, to evaluate a polymerase chain reaction de tection assay for T. vaginalis in urethral swabs and to examine the effect of T. vaginalis infection on excretion of human immunodeficiency virus (HIV ) in semen. Study Design: Men presenting at the Sexually Transmitted Diseases (STD) and Dermatology Clinics in Malawi were enrolled in a cross-sectional study. We compared a polymerase chain reaction-based test for T. vaginalis detection with wet-mount microscopy and culture of urethral swabs. HIS' serology was determined by enzyme-linked immunosorbent assay (ELISA), and HIV-1 RNA con centrations in semen were measured by quantitative nucleic acid sequence-ba sed analysis. Results: T. vaginalis was detected in 51 of 293 men. The estimated prevalen ce among symptomatic men was 20.8% and among asymptomatic men, 12.2%. Polym erase chain reaction performed with a sensitivity of 0.82 (95% CI: 0.66-0.9 2) and specificity of 0.95 (95% CI: 0.91-0.97) compared to wet-mount micros copy and culture. There was no difference in the rate of HIV seropositivity in men with and without T. vaginalis infection. However, in men with sympt omatic urethritis, the median HIV RNA concentration in seminal plasma from men with T. vaginalis was significantly higher that in seminal plasma from HIV-positive men without trichomonas.