Trichomonas vaginalis polymerase chain reaction compared with standard diagnostic and therapeutic protocols for detection and treatment of vaginal trichomoniasis.

Wet preparation has limited sensitivity for diagnosis of Trichomonas vaginalis (TV) infection. An observational study of 337 women was conducted to evaluate a new polymerase chain reaction (PCR) test for TV. The sensitivities of wet preparation and TV culture were 52% (95% confidence interval [CI], 41-62) and 78% (95% CI, 69-86), respectively. TV PCR had a sensitivity of 84% (95% CI, 75-90) and a specificity of 94% (95% CI, 90-97). Metronidazole was provided to 67 (69%) of 97 women with TV because of TV on wet preparation, exposure to TV, or a diagnosis of bacterial vaginosis or pelvic inflammatory disease; however, if TV PCR had been used for diagnosis, 81 (84%) of 97 women with TV would have been treated (P=.02). TV is significantly undertreated using standard algorithms for metronidazole therapy. Given the association of trichomoniasis with perinatal morbidity and HIV transmission, women in high-risk groups may benefit from TV PCR.