Trichomonas facts

What is trichomonas

Trichomonas is a sexually transmitted infection (STI) caused by protozoa. It also called "trich." It infects people of all genders, but causes more symptoms in a person with a vagina.

How trichomonas spreads

Trichomonas is passed from one person to another during vaginal sex. We do not think that trichomonas can be passed through oral or anal sex.

Symptoms of trichomonas

Vaginal symptoms:

• Yellow-green or gray, bubbly fluid from the vagina that may have an unpleasant odor.
• Itching or burning on or around the vagina.
• Pain or burning with urination.
• Vaginal secretions (fluids) are examined under the microscope by a clinician to make the diagnosis.
• We can also send a sample of urine or a vaginal swab to diagnose the infection.

Symptoms in penis:

• Often people with penises do not have any symptoms or problems and would not know they are infected.
• May have discomfort and itching in the penis, rarely discharge.
• Rarely, pain or burning with urination.
• We can send a sample of the urine to the lab to check for the infection. We usually do this when your partner has trichomonas.

How to avoid getting trichomonas

If you’re thinking of having sex with a new partner:

• Condoms are effective in reducing the risk of infection.
• Do not have sex if you or a sexual partner has symptoms of an STI, including discharge, burning with urination, rash, or genital sores.

How to treat trichomonas

• Your clinician will give you an antibiotic called metronidazole that will cure trichomonas. Partners with a penis should be treated even though they may not have any symptoms.
• If you may be pregnant, tell your doctor.
• Avoid having vaginal sex for one full week after you start treatment. If you do have sex, use a condom to avoid re-infection.

This information is provided by San Francisco City Clinic.

Visit our homepage at sf.gov/cityclinic.

Information last revised January 2024