HealthLinkBC File Number: 
Last Updated: 
December 2016

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”). In women, the infection may occur in the vagina. In men, the infection may occur 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; there are no lab tests to find trichomoniasis in men.

How is it spread?

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

What are the symptoms?

For women, symptoms include a thin, whitish-yellow frothy vaginal discharge. The vagina may become reddened, sore, 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 or may notice fluid from the penis or redness at the end of the penis.

What are the complications?

If treated in time, trichomoniasis causes no lasting concerns. In men, it may be linked with infertility or lower sperm count. If a pregnant women has trichomoniasis, her baby may be born early (premature) and/or with a low birth weight. It is also associated with a higher chance of getting HIV, other STIs and an increased risk for pelvic infections.

What is the treatment?

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 12 hours before, during and 24 to 48 hours after taking it. In order 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 need to be treated. It takes time for the infection to be cleared 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. Re-testing after treatment is not necessary unless symptoms persist.

Will my birth control work if I am taking antibiotics?

There is very little evidence to show that antibiotics make hormonal forms of birth control not work very well. Examples of hormonal birth control include the pill, the patch, the ring, or the shot. If you are being treated with antibiotics, it is important to keep using your birth control as you normally would. If you have concerns, use condoms until your next period comes after completing the antibiotics, or speak to your health care provider for more information.

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

Practice safer sex by using a condom

When used correctly, male and 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, 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 condom that has been damaged.
  • Check the expiry date. Do not use a condom that is outdated.
  • Carefully open the package so that the condom does not tear. Do not use a condom that has been torn.
  • 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. Do not reuse condoms.
  • Do not use 2 condoms at once.
  • 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.
  • Water or oil-based lubricant may be used with polyurethane condoms.
  • Use only condoms that are made of latex or polyurethane (plastic). Latex condoms and polyurethane condoms are the best types of condoms to use to help prevent pregnancy and STIs. (Animal skin condoms can help prevent pregnancy but don’t work as well as latex or polyurethane condoms to prevent STIs.)

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 more likely you are to be 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 counselor.

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).

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Is it an emergency?

If you or someone in your care has chest pains, difficulty breathing, or severe bleeding, it could be a life-threatening emergency. Call 9-1-1 or the local emergency number immediately.
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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