What is trichomoniasis?

Trichomoniasis is an infection with a one-cell parasite spread by sexual contact (sexually transmitted disease or STD). It is sometimes called a Trichomonas infection or trich (say "trick").

Both men and women can get a trich infection, but it is more common in women. Trich in pregnant women can cause problems with the pregnancy.

What causes trich?

Trich is caused by a one-cell parasite.

• In women, the parasite usually infects the vagina, urethra, cervix, bladder, and glands in the genital area. See a picture of the female reproductive system.
• In men, the parasite infects the urethra or under the foreskin of the penis if it is not circumcised. See a picture of the male reproductive system.

What are the symptoms?

Many women and most men do not have any symptoms of trich. But when you do have symptoms, they usually start within 1 week after you were infected. In some cases, it can take 1 to 6 months for symptoms to start.

In women, symptoms include:

• Changes in your vaginal discharge. You may notice a color or odor that is not normal.
• Vaginal itching.
• Pain during urination or sex.

In men, symptoms include:

• An abnormal discharge from the penis.
• Irritation of the tip of the penis.
• A burning feeling when you urinate.

The time from contact with the trich parasite until you get symptoms is usually 5 to 28 days.¹ This is called the incubation period. You can spread trich to others during this time and until you finish the prescribed medicine. You should avoid all sexual contact until you finish taking your medicine and the symptoms are gone.

How is trich diagnosed?

Your doctor can tell if you have trich by asking about your past health and doing a physical exam. He or she may order lab tests to find the parasite that causes trich. In women, the parasite may sometimes be found during a routine Pap test. This test is done as part of a regular pelvic exam.

How is it treated?

Your doctor will prescribe medicine called metronidazole or tinidazole to treat trich. These kill the parasite that causes the infection. The medicine is usually taken by mouth as pills, tablets, or capsules. No medicine given in the vagina will cure trich.

It is important to treat trich. Treatment will:

• Reduce your symptoms.
• Prevent you from spreading trich to others. Make sure that your sex partner(s) will be treated at the same time that you get treatment so that you don't get infected again. Avoid all sexual contact until you finish taking the medicine and until your symptoms are gone.
• Reduce the risk of pelvic infections. These may lead to women not being able to get pregnant (infertility). Trich can also lead to infertility in men.
• Reduce the risk of infection after any pelvic surgery.
• Reduce the risk of getting other STDs, especially HIV.