• Trichomoniasis is a sexually transmitted infection (STI).
  • It may cause a yellowy green, ‘frothy’ discharge that is often accompanied by an unpleasant odour and vaginal or vulval itching.
  • The infection can be treated with antibiotics.
  • You should either avoid sex or use condoms until the infection has been treated.

About trichomoniasis

Trichomoniasis is caused by the organism Trichomonas vaginalis. It is transmitted through sexual contact with a person who has this infection.

Trichomoniasis during pregnancy may lead to low birth weight babies and premature birth.

Symptoms of trichomoniasis

Trichomoniasis is detected more often in women and rarely in men. Some women don’t have any symptoms of infection. When symptoms are present, they may include: 

  • a yellowy green, ‘frothy’ discharge
  • an unpleasant odour
  • vaginal or vulval itching.

Men usually don’t develop symptoms, but they may be carriers of the infection. Symptoms in men may include a discharge from the penis and burning during urination.

Diagnosis of trichomoniasis

For women, a vaginal examination and swab is required. 

For men, a swab is taken from the penis if discharge is present. Otherwise, a urine sample can be collected.

Treatment for trichomoniasis

Antibiotics are used to treat trichomoniasis. This will involve one of either: 

  • metronidazole (Flagyl) – a single dose, taken with food
  • tinidazole (Fasigyn) – a single dose, taken with food.

Avoid drinking alcohol during treatment and for 48 hours after taking metronidazole, or for 72 hours after taking tinidazole.

Side effects of treatment for trichomoniasis

These medications may cause:

  • nausea or an upset stomach
  • a metallic taste in your mouth, which will disappear soon after the treatment is completed.

Preventing re-infection of trichomoniasis

If you have trichomoniasis, all sexual partners should be treated – regardless of whether or not they have symptoms. It is recommended that you either have no sex or have completely protected sex (use a condom before any physical contact occurs) until treatment is completed for both you and your partner. 

Recurrences of trichomoniasis can occur

Occasionally, trichomoniasis may recur after the initial infection has been treated. If this occurs, consult your GP, who may prescribe a longer course of treatment. 

Where to get help


More information

Sexually transmissible infections

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This page has been produced in consultation with and approved by: Melbourne Sexual Health Centre

Last updated: June 2020

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