Trichomonas vaginitis is a vaginal infection due to the protozoa Trichomonas vaginalis.
The protozoa Trichomonas vaginalis can cause symptoms soon after they enter the vagina, or the protozoa can remain in the vagina or on the cervix for weeks or months without causing any symptoms. The bladder may also be infected. In men, the protozoa usually remain for only for a few days or weeks and may cause no symptoms.
Trichomonas genital infections (trichomoniasis—see Sexually Transmitted Diseases: Trichomoniasis) are almost always sexually transmitted. Women can be infected through sexual contact with men or women. But men can be infected through sexual contact only with women, not with men. Many people who have this infection have other sexually transmitted diseases. Because the protozoa can remain in women for a long time without causing symptoms, determining when the infection was acquired and thus from whom can be difficult or impossible.
This infection may occur in children. If it does, the cause may be sexual abuse.
Women may have a green or yellow vaginal discharge that is sometimes frothy, profuse, or both. It may smell fishy. The genital area may itch, and the vagina may be red and tender. As a result, sexual intercourse may be painful. Urination may also be painful if the bladder becomes infected.
The infection can lead to pelvic inflammatory disease and, in pregnant women, preterm labor and delivery.
Prevention and Treatment
Always using a condom during sexual intercourse can help prevent this infection from being transmitted.
A single dose of metronidazole or tinidazole taken by mouth cures up to 95% of women. Sex partners should be treated at the same time. People should not drink alcohol for at least 72 hours after they take metronidazole or tinidazole. Drinking alcohol while taking either drug can cause nausea, vomiting, cramps, flushing, and headaches.
During sexual intercourse, condoms should be used until the infection resolves to prevent transmission of the infection.
Last full review/revision March 2013 by David E. Soper, MD