Last Updated: May 1, 2019
HealthLinkBC File Number: 08p
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What is trichomoniasis?

Trichomoniasis is a sexually transmitted infection (STI) caused by a parasite called Trichomonas vaginalis. It is commonly called ‘trich’ (sounds like “trick”). The infection may occur in the vagina or in the urethra (the tube that carries urine from the bladder).

To find out if you have trichomoniasis, you need to see a health care provider and have lab tests done. Currently, lab tests can only find trichomoniasis in women; testing for men is not routinely available or recommended.

How is it spread?

Trichomoniasis is spread by having vaginal sex with a person who is infected with the parasite.

What are the symptoms?

It is possible to have trichomoniasis and not have any symptoms.

For women symptoms can include:

  • Change in amount and/or colour (often whitish-yellow, frothy) fluid from the vagina
  • Itching, burning, redness and/or soreness of the genitals
  • Pain or a burning feeling when urinating or during sex

For men symptoms can include:

  • Unusual fluid from the penis
  • Pain or burning feeling when urinating
  • Itching or irritation in the urethra – the tube that passes urine

What are the potential complications?

If treated in time, trichomoniasis causes no lasting concerns. In men, it may be linked with infertility or lower sperm count. If you are pregnant and have trichomoniasis, your baby may be born early (premature) and/or with a low birth weight. It is also associated with a higher chance of getting and passing HIV, other STIs and an increased risk for pelvic inflammatory disease (PID). See HealthLinkBC File #08c Pelvic inflammatory disease (PID) for more information.

What is the treatment?

Trichomoniasis is usually treated with antibiotic pills called metronidazole. Nausea and vomiting and other serious side effects commonly occur if you drink alcohol within 12 hours before, during and 24 to 72 hours after taking metronidazole. To effectively treat the infection, it is important to follow the instructions for taking the treatment carefully and finish all the pills.

Sexual partners from the last 2 months also need treatment. If you have not had a sexual partner in the last 2 months, then your last sexual partner will need treatment. It takes time for the infection to clear from the body, so it is important that you do not have any oral, vaginal or anal sex for 7 days after you and your partner(s) start the antibiotic treatment.

If you or your partner(s) do not finish the treatment, miss pills or have unprotected sex before finishing all of the medication, the infection could stay in your body or may be passed back to you or your partner(s) and cause health problems later. If this happens, talk with your health care provider who will help you to decide if you or your partners need more treatment.

Re-testing after treatment is not necessary unless symptoms persist.

How can I reduce my chance of getting a sexually transmitted infection (STI)?

Practice safer sex by using a condom

When used correctly, external (“male”) and internal (“female”) condoms help prevent the spread of many STIs during vaginal, anal and oral sex. Condoms are less effective at protecting against STIs transmitted by skin-to-skin contact, such as herpes simplex virus, genital warts (human papillomavirus (HPV)) and syphilis (when sores are present).

Important things to remember when using condoms:

  • Check the condom package for damage. Do not use a damaged condom
  • Check the expiry date. Do not use a condom after its expiry date
  • Carefully open the package so that the condom does not tear. Do not use a torn condom
  • Keep condoms away from sharp objects such as rings, studs or piercings
  • Store condoms at room temperature
  • Use a new condom every time you have sex. Do not reuse condoms
  • Do not use 2 condoms at once. Using 2 condoms together may result in a condom breaking
  • Use only water-based lubricants with external (“male”) latex condoms. Oil-based lubricants, such as petroleum jelly, lotion or baby oil, can weaken and destroy latex
  • Water or oil-based lubricant may be used with polyurethane/nitrile condoms
  • Use only condoms made of latex or polyurethane/nitrile/polyisoprene rubbers. Latex and polyurethane condoms are the best types of condoms to use to help prevent pregnancy and STIs. (Lambskin and sheepskin condoms can help prevent pregnancy but don’t work as well as latex or polyurethane condoms to prevent STIs)
  • Avoid using condoms with spermicides containing nonoxynol-9 (N-9) as it can irritate tissue and may increase the chance of getting an STI

Get vaccinated

Some STIs, such as hepatitis A, B and human papillomavirus (HPV) can be prevented with vaccines. Talk to your health care provider about how to get these vaccinations.

Know your sexual health status

If you have recently changed sexual partners, or have multiple sex partners, getting regularly tested for STIs will tell you if you have an infection. Some people can have an STI and not have any symptoms. Finding and treating an STI reduces the chances of passing infections on to your partner(s).

The more partners you have, the higher your chances of getting exposed to STIs.

Talk about prevention

Talk to your partner(s) about STIs and how you would like to prevent them before having sex. If you are having trouble discussing safer sex with your partner(s), talk about it with your health care provider or a counsellor.

For tips on how to talk to your partner(s), visit the BC Centre for Disease Control (BCCDC) Smart Sex Resource

Informing Partners

If you have a sexually transmitted infection and are sexually active, it is important to tell your sexual partner(s). This will enable them to make decisions about their health and getting tested.

For More Information

For more information on how you can reduce your chance of getting an STI, see HealthLinkBC File #08o Preventing sexually transmitted infections (STIs).