Trichomonas is a common sexually transmitted infection (STI) caused by a small organism called Trichomonas vaginalis.  At any given time, up to 35 per cent of people could have a trichomonas infection. Trichomonas is easily treated with antibiotics.

  • How it's spread

    Trichomonas is spread through unprotected vaginal intercourse with an infected partner.

  • What are the symptoms?

    In up to 50 per cent of cases, you can have no symptoms but can still pass trichomonas to someone else without knowing it.  Symptoms can appear from four to 28 days after contact and may include the following:

    Vaginal infection: Individuals with symptoms may notice increased vaginal discharge that may be yellow or off-white in colour.  It is usually watery, frothy, or bubbly and may smell bad.  This discharge may cause itchiness, redness, and soreness. Abnormal vaginal bleeding may also occur such as bleeding immediately after vaginal penetration.

    You may also experience abdominal or pelvic pain. Vaginal intercourse and urination may be painful. If you are having urinary tract infection symptoms, it is also recommended that you test for sexually transmitted infections such as chlamydia, gonorrhea, and trichomonas.

    Urethral/penile infection: Individuals often have no symptoms but those with symptoms may notice a burning feeling during urination, or irritation/ redness at the urethral opening.

  • How is it diagnosed?

    If vaginal discharge is present, a sample is taken and sent to a laboratory for testing. In many cases, trichomonas will not show up on a test. This means that you could still have trichomonas even if your tests are negative. Trichomonas can also show up on Pap test results.

  • What are the complications?

    Trichomonas is rarely dangerous but it can be uncomfortable.  In rare cases, untreated Trichomonas can lead to vulvovaginitis (inflammation and irritation of the vulva and vagina) and this can cause pelvic inflammatory disease (PID).

    If you are pregnant or suspect that you are pregnant, possible reproductive complications may include increased risk for infections, post-caesarean infection, premature rupture of membranes and pre-term birth.

    Trichomonas infection can also increase your risk of contracting HIV.

  • How is it treated?

    The most effective treatment for trichomonas is a drug called metronidazole or Flagyl.  A single dose of Flagyl taken orally cures over 90 per cent of cases.  Flagyl can cause nausea and vomiting, especially in combination with alcohol.  Flagyl is safe in pregnancy.

  • What about my sexual partner(s)?

    All sexual partners within the past two months should be examined and treated.  They should be treated even if their tests results are negative.  If you have not had sex in the past two months, your last partner(s) should be tested and treated.  Inform your partner(s) that not having symptoms does not mean that they do not have trichomonas.

  • Prevention

    Using a condom will greatly reduce the possibility of being infected with trichomonas or other sexually transmitted infections.