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 Diamond's medium. RESULTS: T: vaginalis was identified in specimens from 95 (15.4%) of the 615 patients. Cultures in Diamond's 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.