Trichomoniasis, caused by the protozoan Trichomonas vaginalis, is the most common curable STD in sexually active women.
Approximately 70% of people with trichomoniasis will have no symptoms. In women, a malodorous, yellow-green vaginal discharge with vulvar irritation can occur. In men, trichomoniasis can cause urethral discharge or dysuria.
Diagnosis of vaginal trichomoniasis is commonly performed by microscopy of vaginal secretions, although this method has a sensitivity of only approximately 60-70%, and requires evaluation of a wet preparation slide for optimal results. Other FDA-cleared tests for trichomoniasis in women include immunochromatographic capillary flow dipstick tests that can be performed at the point of care. Culture for T. vaginalis is also considered a sensitive and specific method of detection, and is commonly used when microscopy is negative. Among women, nucleic acid amplification testing is the most sensitive and specific test available for diagnosis.