Trichomoniasis

Last Reviewed: November 2006

What is trichomoniasis?

Trichomoniasis is the number one cause of vaginal infections spread through sex. Each year, about 5 million American females get this sexually transmitted disease (STD). Most males with "trich" do not have symptoms so they do not get treated. That's why it's common for men to re-infect their partner(s). This STD can cause problems during pregnancy.

What causes trichomoniasis?

"Trich" is caused by a tiny parasite called Trichomonas vaginalis. It lives in moist, dark parts of the body. You can get this STD by having unprotected sex with someone who is infected. Unprotected sex is when you have sex without a condom. This includes oral, vaginal and anal sex.

What are the signs and symptoms?

The most common symptom is fluid from the vagina in women or urethra (opening in the penis) in men. This fluid is called a discharge. Most women have symptoms. Men usually don't have symptoms.

Women's symptoms may include:

  • A yellowish-green, foamy vaginal discharge. The color may vary from gray to green.
  • A musty odor
  • Vaginal redness or itchiness, or both
  • Occasional lower belly (abdominal) pain
  • Pain when urinating
  • Pain during sex

Men's symptoms may include:

  • Occasional pain when urinating and/or a discharge from the penis. This is called urethritis.

Can this STD cause any other problems if it's not treated?

Yes. A woman with untreated "trich" has a greater chance of having an infected uterus and fallopian tubes. This infection is called pelvic inflammatory disease or PID. If you have PID it can cause abdominal pain, fever, and perhaps the inability to have children (infertility), a pregnancy outside the uterus (ectopic pregnancy), and chronic pelvic pain. It's rare, but it is possible to die from an ectopic pregnancy.

If you have "trich" when you are pregnant, you and your baby may have some health problems. You may have an early (premature) delivery and your baby may have a low birth weight.

How will I know if I have trichomoniasis?

To know for sure you should visit a health care provider. He or she will take a sample of your discharge (from the vagina or penis). A microscope will be used to look at your discharge in the office or it will be sent to a lab for testing.

Is there a cure?

Yes. To cure your infection, your health care provider may give you an antibiotic called metronidazole (me troe ni' da zole) or Flagyl.

Do not drink alcohol while you are taking metranidazole and for at least three days after you finish treatment. If you do, you can get very sick. This medicine causes nausea, vomiting, cramps, and headaches if mixed with alcohol.

When can I have sex again?

It is best to wait one week after you and your partner(s) have finished your medicine before you have oral, vaginal or anal sex again. If you finish your medicine and you still have symptoms, return to your provider. Remember: You can get "trich" again if your sex partners are not treated.

What about my partner(s)?

Trichomoniasis is a sexually transmitted disease. Because of this, your sex partners should be checked and treated, if needed, even if they do not have symptoms.

Do not have sex if you think you have "trich" or you have been exposed. Visit a health care provider for a checkup. If you are sexually active, you and your partners should get a full physical checkup. This includes a complete sexual history and testing for common STDs. You should be checked for gonorrhea, chlamydia, syphilis, herpes, genital warts, trichomoniasis, and HIV.

Can I get this infection again?

Yes. You can get this STD again. Having it once does not mean you are immune. As soon as you get "trich" you can spread it until you take the right medicine and the infection is gone. You will be at risk for "trich" again if your partners do not take medicine and get rid of this STD before you have sex with them. This includes oral, anal or vaginal sex.

How can I prevent trichomoniasis?

Not having sex (abstinence) is the only sure way to avoid infection.

If you choose to be sexually active, use latex or polyurethane condoms every time you have oral, anal or vaginal sex. This will lower your chances of giving or getting this STD. But, using condoms will not totally stop your risk. This is because condoms are not 100 percent effective. Condoms do help prevent the spread of other STDs including HIV, the virus that causes AIDS.

Will anyone know the results of the exams?

Your test results and any treatment will be kept absolutely confidential. No one can find out your results, except you. If you are under 18 you can be checked and treated for STDs without getting permission from your parents.

To learn more:

If you have more questions about trichomoniasis, or you want to know how to find a clinic near you, call your local health department.

You may also call the National STD Hotline at 1-800-CDC-INFO 1-800-232-4636