HealthLinkBC File Number: 
Sexually Transmitted Infections Series
Last Updated: 
November 2013

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").

How is it spread?

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

What are the symptoms?

For women, symptoms include a thin, whitish-yellow/green frothy or foamy vaginal discharge. The vagina may become reddened, sore and itchy, and sexual intercourse and urinating may be painful.

Men who are infected with the trichomoniasis parasite usually do not experience any symptoms, although some feel a slight burning when urinating.

To find out if you have trichomoniasis, visit your health care provider for a physical exam and to have lab tests completed. Currently, lab tests can only detect trichomoniasis in women, there are currently no lab tests to detect trichomoniasis in men.

What is the treatment for trichomoniasis?

Trichomoniasis is usually treated with antibiotic pills called Metronidazole. It is common for people to experience nausea and vomiting and other serious side effects if they drink alcohol within 24 hours of taking it.

The person(s) you have sex with should also be treated even if they have no symptoms. To avoid re-infection, do not have sex until 7 days after you and your partner(s) have finished the treatment.

Will my birth control pills work if I am taking antibiotics?

Birth control pills may not work as well when you are taking certain antibiotics. If you are being treated with antibiotics, keep taking your birth control pills and use a second form of birth control, such as a condom, until your next period after completing the antibiotics.

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

Practice safe sex by using a condom

When used as directed, male and female condoms help prevent the spread of many STIs, including HIV, during vaginal, anal and oral sex. Condoms are less effective at protecting against STIs transmitted by skin-to-skin contact, such as herpes simplex, genital warts (human papillomavirus or HPV), and syphilis.

Important things to remember when using condoms:

  • Check the condom package for damage and to ensure the expiry date has not passed.
  • Carefully open the package so that the condom does not tear.
  • Keep condoms away from sharp objects such as rings, studs, or piercings.
  • Store condoms at room temperature.
  • A new condom should be used every time you have sex.
  • Use only water-based lubricants with male latex condoms. Oil-based lubricants, such as petroleum jelly, lotion, or baby oil can weaken and destroy latex.
  • Avoid using spermicides containing nonoxynol-9 (N-9). It irritates sexual 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. Finding and treating an STI, (including HIV) reduces the chances of passing the infection on to your partner.

The more partners you have, the more likely you are to be exposed to a sexually transmitted infection.

Talk about prevention

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

For tips on how to talk to your partner, visit the BC Centre for Disease Control (BCCDC) SmartSexResource at

Informing Partners

If you have a sexually transmitted infection and are sexually active, it is important to tell your sexual partners. 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).

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Is it an emergency?

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If you are concerned about a possible poisoning or exposure to a toxic substance, call Poison Control now at 1-800-567-8911.

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