STIs

Trichomoniasis

AlsotrichTV infectionTrichomonas vaginalistrichomonastrichomonas infection

Not yet reviewed by a clinician. This health entry was written from the public-health sources listed below and is general information only. It is not medical advice.

Definition

Trichomoniasis is a common STI caused by a tiny parasite, often without symptoms, and is cured with a course of antibiotics.

At a glance

  • Trichomoniasis is caused by the parasite Trichomonas vaginalis.
  • It is one of the most common curable STIs in the world.
  • Many people have no symptoms.
  • It is diagnosed with a swab or urine test.
  • Partners are treated at the same time to avoid passing it back and forth.

In detail

Trichomoniasis is caused by the parasite Trichomonas vaginalis and passes between partners during vaginal sex or by sharing sex toys. It is one of the most common curable STIs in the world.

Many people have no symptoms. Others notice unusual discharge, itching, soreness, or discomfort when urinating. The infection is diagnosed with a swab or urine test.

Treatment is usually a course of the antibiotic metronidazole, and partners are treated at the same time to avoid passing it back and forth. Untreated infection can raise the risk of other STIs and of complications in pregnancy.

In a sentence

  • The nurse explained that trichomoniasis is caused by a parasite, not a bacterium or virus.
  • Trich is often mentioned in clinic leaflets as a common, curable infection.

Where the word comes from

The genus name Trichomonas combines Greek roots for "hair" and "single unit", referring to the hair-like strands the single-celled parasite uses to move.

Not to be confused with

  • Bacterial vaginosis

    BV is an imbalance of normal vaginal bacteria, not an STI, although symptoms can look similar.

  • Thrush

    Thrush is a yeast overgrowth and is not usually sexually transmitted.

Common questions

How is trichomoniasis treated?

It is usually cured with a course of the antibiotic metronidazole. Partners are treated at the same time so the infection is not passed back. A sexual health clinic or doctor can advise on your own situation.

Is trichomoniasis serious?

It is curable and often mild, but untreated infection can raise the risk of other STIs and of complications in pregnancy, so it is worth testing and treating.

Related terms

Sources

  1. WHOTrichomoniasis fact sheet
  2. NHSTrichomoniasis
  3. Planned ParenthoodTrichomoniasis