What is a trichomoniasis test?

Trichomoniasis, often called trich, is one of the most common sexually transmitted diseases (STDs). It's caused by infection with a parasite. The parasite that causes this STD is a tiny single-celled life form. A trichomoniasis infection mostly involves the genital area.

Trichomoniasis testing usually looks for the parasite in a sample of body fluid that's swabbed from the infected area. In women, the infection is usually in the vagina. In men, the infection is usually in the urethra, a tube in the penis that carries urine (pee) out of the body. A urine sample may also be used.

You can get trichomoniasis by having sex without a condom with a partner who has the infection. Women can get the disease from men or women who are infected. Men usually get it only from women who are infected. Trichomoniasis is more common in women.

Most people who have trichomoniasis infections don't have any symptoms. That means you can have trichomoniasis and pass it to a sex partner without knowing it. The infections are rarely serious, and they can be cured with antibiotics. But if trichomoniasis isn't treated, it can:

• Increase your risk of getting or spreading other STDs, including HIV
• Cause infections in the prostate gland (a gland in the male reproduction system)
• Increase the chance of problems in pregnancy, including:
  • Giving birth too early (premature birth)
  • Having a baby with a low birth weight (less than five and a half pounds)

If you think you could have an infection, it's important to get tested so you can get treatment if you need it.

Other names: T. vaginalis, trichomonas vaginalis testing, wet prep

What is it used for?

Trichomoniasis testing is used to:

• Diagnose trichomoniasis infections in people who have symptoms.
• Screen for infection in women who have a high risk of infection.
• Check for infection after treatment for trichomoniasis is finished. This is done because people are often reinfected if their partners don't get tested and treated for the disease. Also, some parasites may be resistant to certain medicine. This means that they have changed so that the medicine no longer works well to get rid of them.

A trichomoniasis infection can increase your risk for different STDs. So, the test is often done with other STD.

Why do I need a trichomoniasis test?

You may need to get tested for trichomoniasis:

• If you have symptoms that could be an STD. Usually, trichomoniasis doesn't cause symptoms, But when they happen, they usually show up within 5 to 28 days after getting the infection. Some people may develop symptoms much later. The symptoms can come and go. They may range from mild to severe and include:
  • In women:
    • Itching, burning, redness or soreness around the genitals
    • Discomfort when urinating (peeing) or having sex
    • A clear, white, yellowish, or greenish vaginal discharge with a fishy smell
  • In men:
    • Itching or irritation inside the penis
    • Burning after urinating or ejaculating (releasing semen)
    • Abnormal discharge from the penis
• If you're a woman with a high risk for getting an STD. Even if you don't have symptoms, your health care provider may recommend testing if you have:
  • Sex without using a condom
  • Multiple sex partners
  • Had other trichomoniasis in the past or other STDs
• If you've completed treatment for trichomoniasis. You may need to be checked to see if you've been infected again.

Talk with your provider about your need for testing.

What happens during a trichomoniasis test?

Before your trichomoniasis test, your provider will usually ask about your symptoms and examine your genitals for signs of infection.

Next, your provider will usually use a small brush or swab to take a sample of body fluid. The same will be taken from either the urethra in the penis, or the vagina and/or cervix, which is the lower part of the uterus. You may feel some brief discomfort when the sample is taken.

You may also need to provide a urine sample for testing. A health care professional may give you a cleansing wipe, a small container, and instructions for how to use the "clean catch" method to collect your sample. It's important to follow these instructions so that germs from your skin don't get into the sample.

You can also buy at-home collection kits to test for trichomoniasis and other STDs. With these kits, you collect a sample of urine or vaginal fluid to send to a lab for testing. It's important to follow all the instructions carefully. And be sure to discuss the results with your provider because you may need more testing.

Will I need to do anything to prepare for the test?

You don't need any special preparations for a trichomoniasis test.

Are there any risks to the test?

There are no known risks to having a trichomoniasis test.

What do the results mean?

In most cases, your first test for trichomoniasis will check a sample of body fluid under a microscope to look for parasites. This test is called "wet prep microscopy." It's often done first because it's quick and inexpensive.

The results of a wet prep microscopy test will be either negative or positive:

• A negative result means that no parasites were seen in your sample. But wet prep microscopy results aren't always accurate. So, if your provider thinks you have trichomoniasis, more accurate tests may be done on your sample. They include:
  • Nucleic acid amplification tests (NAATs). These tests look for genetic material from the parasites that cause trichomoniasis.
  • Rapid antigen tests. These tests are only done on samples of vaginal fluid. They look for certain proteins, called antigens, from the parasite. Rapid antigen tests can be done at your provider's office. The results are usually ready in under 15 minutes.
  • Culture tests. For these tests, your sample is sent to a lab, where the cells will grow for up to a week. Then the sample will be checked under a microscope. If your sample had parasites, there will now be more of them, so they'll be easier to find.
• A positive result means that parasites were found in your sample. You have a trichomoniasis infection. Your provider will prescribe medicine to cure the infection. Be sure to:
  • Finish all your medicine according to your provider's instructions.
  • Tell your recent sexual partners about your infection so they can get tested, too.
  • Let your provider know if you still have symptoms after treatment.
  • Get tested for other STDs.

Learn more about laboratory tests, reference ranges, and understanding results.

Is there anything else I need to know about a trichomoniasis test?

The best way to prevent trichomoniasis or other STDs is to not have sex. If you are sexually active, you can reduce your risk of infection by:

• Having sex with one partner who has tested negative for STDs and has sex only with you
• Using condoms correctly every time you have sex