Correlation of leukorrhea and Trichomonas vaginalis infection

Trichomonas vaginalis is a common sexually transmitted infection (STI) causing vaginitis. Microscopy has poor sensitivity but is used for diagnosis of trichomoniasis in resource-poor settings. We aimed to provide a more reliable diagnosis of trichomoniasis by investigating an association with leukorrhea. Women presenting for evaluation of vaginal discharge, STI exposure, or preventative gynecologic examination were evaluated for Trichomonas infection. Vaginal pH was determined and microscopy was performed by the provider, who recorded the number of polymorphonuclear leukocytes (PMNLs) per epithelial cell and the presence of clue cells, yeast, and/or motile trichomonads. Leukorrhea was defined as greater than one PMNL per epithelial cell. Culture and a nucleic acid amplification test (NAAT) were used to detect T. vaginalis. Patients were evaluated for Chlamydia trachomatis and Neisseria gonorrhoeae using NAATs and bacterial vaginosis using Gram stains. Two hundred ninety-four women were enrolled, and 16% were found to have Trichomonas (46/294). Trichomonas infection was more common in parous non-Hispanic, black women, who reported low rates of contraceptive use (33% versus 17%; P = 0.02) and a STI history (85% versus 55%; P = 0.002). These women were more likely to report vaginal discharge (76% versus 59%; P = 0.02) and have an elevated vaginal pH (87% versus 48%; P < 0.001) and gonorrhea infection (15% versus 4%; P = 0.002). Leukorrhea was associated with a 4-fold-increased risk of Trichomonas infection. Leukorrhea on microscopy was associated with Trichomonas vaginitis. Patients with leukorrhea should be evaluated with more-sensitive tests for T. vaginalis, preferably NAATs, if microscopy is negative.