The clinical spectrum of Trichomonas vaginalis infection and challenges to management.

Trichomonas vaginalis is the most common curable sexually transmitted infection worldwide. T vaginalis infections in women can range from asymptomatic to acute inflammatory vaginitis. In men, this infection is typically asymptomatic but is increasingly being recognised as a cause of non-gonococcal urethritis. Diagnosis of T vaginalis has traditionally been made by direct microscopic examination of a wet mount of vaginal fluid or through the use of culture. The recent commercial availability of nucleic acid amplification tests for the detection of T vaginalis has seen these replace culture as the gold standard for diagnosis. Nitroimidazoles (ie, metronidazole and tinidazole) are the mainstay of therapy. In the case of treatment failure due to drug resistance or in the case of a severe nitroimidazole allergy, alternative intravaginal therapies exist, although their effectiveness has not been evaluated systematically. Novel systemic agents other than nitroimidazoles for the treatment of T vaginalis are needed, and efforts to promote and support antimicrobial drug development in this setting are necessary.