Evaluation of a deoxyribonucleic acid probe for the detection of Trichomonas vaginalis in vaginal secretions

OBJECTIVE: Our purpose was to compare Affirm VP, a new deoxyribonucleic acid probe test, with standard “wet preparation” microscopic examinations and culture for the identification of Trichomonas vaginalis organisms in vaginal secretions. STUDY DESIGN: We examined vaginal samples from 615 women with symptoms or signs of vaginitis for T. vaginalis using the deoxyribonucleic acid probe test, microscopic examination of wet preparations of vaginal secretions, and culture in modified Diamondʹs medium. RESULTS:T. vaginalis was identified in specimens from 95 (15.4%) of the 615 patients. Cultures in Diamondʹs medium identified 93 (98%) of the 95 infected patients. Vaginal wet preparation identified 76 (80%) of the infected women. The deoxyribonucleic acid probe test detected 86 (90.5%) of the 95 infected patients. There was one false-positive deoxyribonucleic acid probe test (specificity 519/520: 99.8%). CONCLUSION: The Affirm VP deoxyribonucleic acid probe test had a sensitivity of 90% and a specificity of 99.8% for the identification of T. vaginalis organisms in women with symptoms with a high prevalence of trichomoniasis. Such a nonculture test may be of considerable benefit in diagnosing T. vaginalis infections, especially in settings where microscopy, culture, or both are unavailable, inconvenient, or unreliably performed. (AM J OBSTET GYNECOL 1996;174:1339-42.)