What Is Trichomoniasis?
Trichomoniasis is a common sexually transmitted disease (STD) caused by the protozoan Trichomonas vaginalis. An estimated 3.7 million people in the U.S. have the infection, and women are affected more often than men.
In women, the lower genital tract (vulva, vagina, cervix, or urethra) is most commonly infected and in men, it’s the inside of the penis (urethra).
What Are Symptoms of Trichomoniasis?
Up to 85% of women who get trichomoniasis may be asymptomatic, though most eventually develop symptoms. Symptoms of trichomoniasis in women can range from mild to severe and may include:
Puss-filled thin discharge with a foul odor (may appear green-yellow and frothy)
- Pain or discomfort when urinating
- Urinary frequency
- Lower abdominal pain
- Painful sexual intercourse
- Bleeding after sex
- Symptoms may be worse during menstruation
- Vulvar redness
- Preterm delivery, and delivery of a low birth weight infant in pregnant women
Babies born to mothers who have trichomoniasis may become infected during delivery. Symptoms of trichomoniasis in newborns include:
Symptoms of trichomoniasis in men include:
What Causes Trichomoniasis?
Trichomoniasis is caused by the protozoan Trichomonas vaginalis that is passed from person-to-person during sex.
Men can transmit the parasite from their penis to a woman’s vagina, and a woman can transmit the infection from her vagina to a penis. It can also spread vagina to vagina, though it is not common for the infection to spread to other body parts such as the mouth or anus.
How Is Trichomoniasis Diagnosed?
Trichomoniasis is diagnosed based on laboratory testing to confirm T. vaginalis:
- Motile trichomonads on wet mount
- Positive culture
- Positive nucleic acid amplification test
- Positive rapid antigen or nucleic acid probe test
In the U.S., the Centers for Disease Control (CDC) recommends T. vaginalis screening in all HIV-infected women, annually and at initial prenatal visits. Screening is also considered for women who do not have HIV but are at increased risk of Trichomonas infection, such as those who have new or multiple partners or a history of sexually transmitted infections.
Routine T. vaginalis screening for men is not recommended.
What Is the Treatment for Trichomoniasis?
Trichomoniasis is treated with the following antibiotics:
About 20% of people who have trichomoniasis become infected again within 3 months after treatment. To avoid reinfection, all sex partners of the infected person should be treated with antibiotics at the same time.
What Are Complications of Trichomoniasis?
Complications of trichomoniasis include:
How Do You Prevent Trichomoniasis?
The only way to avoid getting trichomoniasis and other STDs is avoiding vaginal, anal, or oral sex. For people who are sexually active, reduce the risk of getting trichomoniasis: