Improved detection by DNA amplification of Trichomonas vaginalis in males.

Trichomoniasis is a sexually transmitted infection that is highly prevalent worldwide and has been linked to preterm birth and human immunodeficiency virus acquisition. In females, trichomoniasis causes vaginitis, while in males, it is frequently asymptomatic but can be a cause of urethritis. Control efforts have been hampered by the lack of a sensitive diagnostic technique for this infection in males. Men attending a sexually transmitted disease (STD) clinic for a new complaint were screened for Trichomonas vaginalis by culture and by PCR analysis of urine and urethral-swab specimens. The prevalence of Trichomonas determined by culture was 5% (15 of 300 specimens), compared to 17% (52 of 300) determined by PCR. Urine specimens yielded a greater number of positive results by PCR than did urethral-swab specimens. The sensitivity of PCR analysis of urine specimens in comparison to that of culture was 100%. The use of PCR techniques in urine specimen-based detection of T. vaginalis was highly sensitive and revealed a prevalence of infection more than three times that revealed by culture for men at high risk for STDs.