For many decades, clinicians worldwide have used direct microscopic examination of vaginal wet-mount preparations to identify Trichomonas vaginalis infections and have unquestioningly treated patients for this sexually transmitted infection solely on the basis of Papanicolaou-stained cervical smear reports. In this issue of THE JOURNAL, Krieger et al1 have raised questions about the accuracy of these procedures. In a patient population with a Trichomonas prevalence of 15%, they found that the vaginal wet mount unerringly detected only 60% of the T vaginalis infections. Papanicolaou smears were positive or suspicious for trichomonads in 63% of the infections, but 31% of the time they falsely identified infection when it was absent. These findings corroborate the findings of other investigators who have reported poor sensitivity with the wet mount (≤60%)2-5 or who have documented false-positive Papanicolaou findings in the absence of other evidence of T vaginalis infection.3,6,7
See also p 1223.
Lossick JG. The Diagnosis of Vaginal Trichomoniasis. JAMA. 1988;259(8):1230. doi:10.1001/jama.1988.03720080064030