Which organism is the etiologic agent for trichomoniasis?

• A. Trichomonas vaginalis
• B. Gardnerella vaginalis
• C. Candida albicans
• D. Neisseria gonorrhoeae

Answer: (A)

Trichomoniasis is caused by a protozoan parasite that lives in the urogenital tract and is transmitted sexually. The organism responsible is Trichomonas vaginalis, a flagellated protozoan. It’s not a bacterium, and infection is diagnosed by finding motile trophozoites on a wet mount or by nucleic acid amplification testing. Clinically, it can cause vaginitis with discharge and itching, and is often sexually transmitted between partners. Other organisms listed cause different infections—Gardnerella vaginalis is linked to bacterial vaginosis, Candida albicans to candidal vaginitis, and Neisseria gonorrhoeae to gonorrhea—so the etiologic agent for trichomoniasis is Trichomonas vaginalis.