What is Trichomoniasis?
Trichomoniasis (trick-o-mon-I-AS-is) — sometimes called just "trich" (trick) — is a sexually transmitted disease (STD) caused by a small parasite called Trichomonas vaginalis.
According to the Centers for Disease Control and Prevention (CDC), there are about 7.4 million new cases of trichomoniasis in the United States each year. In fact, it's the most common curable STD among young women who are sexually active, although it's also found in men.
Trich typically infects the vagina in women, and the urethra (the tube that carries urine and semen out of the body) in men. Both men and women can catch trich by having unprotected penis-vagina intercourse with an infected partner. Women are also at risk for trich from an infected female partner through vulva-to-vulva contact … but men rarely contract the parasite from other men.