Trichomonas Facts

What is trichomonas?

Trichomonas is a common sexually transmitted disease (STD) that affects both women and men, although symptoms are more common in women.


How common is trichomonas?

Trichomonas is the most common curable STD in young, sexually active women. An estimated 7.4 million new cases occur each year in women and men.


How do people get trichomonas?

Trichomonas is caused by the single-celled protozoan parasite, Trichomonas vaginalis. The vagina is the most common site of infection in women, and the urethra (urine canal) is the most common site of infection in men.

The parasite is sexually transmitted through penis-to-vagina intercourse or vulva-to-vulva (the genital area outside the vagina) contact with an infected partner. Women can acquire the disease from infected men or women, but men usually contract it only from infected women.


What are the signs and symptoms of trichomonas?

Most men with trichomonas do not have signs or symptoms; however, some men may temporarily have an irritation inside the penis, mild discharge, or slight burning after urination or ejaculation.

Some women have signs or symptoms of infection which include a frothy, yellow-green vaginal discharge with a strong odor. The infection also may cause discomfort during intercourse and urination, as well as irritation and itching of the female genital area. In rare cases, lower abdominal pain can occur. Symptoms usually appear in women within 5 to 28 days of exposure.


What are the complications of trichomonas?

The genital inflammation caused by trichomonas can increase a woman’s susceptibility to HIV infection if she is exposed to the virus. Having trichomonas may increase the chance that an HIV-infected woman passes HIV to her sex partner(s).


How does trichomonas affect a pregnant woman and her baby?

Pregnant women with trichomonas may have babies who are born early or with low birth weight (low birth weight is less than 5.5 pounds).


What is the treatment for trichomonas?

Trichomonas can usually be cured with prescription drugs, either metronidazole or tinidazole, given by mouth in a single dose. The symptoms of trichomonas in infected men may disappear within a few weeks without treatment. However, an infected man, even a man who has never had symptoms or whose symptoms have stopped, can continue to infect or re-infect a female partner until he has been treated. Therefore, both partners should be treated at the same time to eliminate the parasite. Persons being treated for trichomonas should avoid sex until they and their sex partners complete treatment and have no symptoms. Metronidazole can be used by pregnant women.

Having trichomonas once does not protect a person from getting it again. Following successful treatment, people can still be susceptible to re-infection.