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Trichomonas Vaginalis

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What is it?

Trichomonas (Trich; Trichomoniasis) is caused by a microscopic parasite called Trichomonas vaginalis. It is usually sexually transmitted but it can also survive for 24 hours on wet towels and bathing suits. This fact explains why trichomonas occasionally occurs without sexual contact.

What are the symptoms?

Women Men
  • No symptoms.
  • Frothy, green vaginal discharge.
  • Unpleasant odour.
  • Intense vaginal itching.
  • Redness and pain in vaginal area.
  • Frequent passing of urine.
  • No symptoms.
  • Discharge from penis.
  • Burning when passing urine.
  • Irritation around tip of penis.

How is it diagnosed?

Women: A vaginal swab is usually necessary. Occasionally trichomonas will show up on a routine Pap test.

Men: A swab is taken from the tip of the penis. Regardless of test results, men are treated when their female partner has trichomonas.

How is it treated?

The most effective treatment for trichomonas is metronidazole, also called Flagyl, Metryl, or Protostat. Your doctor may prescribe either pills or a cream. Trichomonas is almost always cured with Flagyl. If the symptoms do not go away, talk with your doctor.


Some people may feel sick to their stomach or have diarrhea while taking Flagyl. Others have noticed a dry metallic taste in their mouth and a dry vagina.

  • Alcohol (beer, wine, liquor) should be avoided while taking Flagyl and for 48 hours after finishing treatment.
  • Do not have intercourse during treatment.
  • Do not take Flagyl during the first three months of pregnancy. Another vaginal cream will be prescribed.
  • Trichomonas is not believed to affect your ability to have children.

Is followup important?

Yes. A followup test will show that treatment has worked. Condoms should be used until this followup test is done.

For more information, please contact a member of Haldimand-Norfolk Health Unit’s Communicable Disease Team.

Simcoe Office: 519.426.6170 / 905.318.6623
Caledonia Office: 905.318.5367

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