Trichomoniasis: Learn About the Most Prevalent STD on the Planet and How to Prevent it

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Many people have heard of syphillis and herpes, but may ask themselves, “What is trichomoniasis?” Trichomoniasis is a sexually transmitted infection caused by a one-celled parasite called trichomonas vaginalis. The Center for Disease Control reports that each year eight million people will become infected with the disease in North America, alone. Although it is easily treatable with antibiotics, it is the most common sexually transmitted disease (STD) in the world.

Trichomoniasis is most commonly spread through unprotected vaginal intercourse or vulva-to-vulva contact, but can be transmitted through anal or oral sex. In rare instances, the disease can be spread by contact with a moist infected object, such as a swimsuit or washcloth.

Risk Factors of Trichomoniasis

Women who have trichomoniasis during pregnancy run the risk of delivering prematurely, and giving birth to a baby with a low birth weight. The trichomonas vaginalis microorganism can be passed to an infant via the birth canal.

The disease causes small “strawberry” colored sores that inflame the walls of the vagina and the cervix. These tiny ulcerations make it easier for women to contract the HIV virus.

Men may develop urethritis if the trichomoniasis infection is left untreated.

There is a high risk of re-infection if both sex partners are not treated with antibiotics simultaneously. Since men can be asymptomatic, they may unwittingly pass the infection on to their partners.

Signs and Symptoms in Men and Women

Many men show no symptoms of infection. They may notice a slight discharge or experience a burning sensation when they ejaculate or urinate. The inside of the penis may appear red or irritated.

Symptoms of trichomoniasis appear in both sexes within 4 to 28 days of exposure to the bacteria.

Women may notice itching in or around the vagina or vulva. They may have a foul vaginal odor, accompanied by a foamy green or yellow discharge. Pain during intercourse or urination is not uncommon.

Diagnosis and Treatment of Trichomoniasis

For women, a vaginal swab will be taken during a pelvic examination. In men, a swab of the urethra is required. Samples will be sent to the laboratory to determine the presence of the parasite.

A single dose of a drug called metronidazole will be given to treat the STD. Sometimes, longer treatment of 3 to 5 days is warranted. An antibiotic called tinidazole is prescribed for individuals who fail to respond to metronidazole.

To prevent re-infection, individuals or couples diagnosed with trichomoniasis should follow their physician’s advice regarding the length of time to refrain from sex during treatment.


Monogamous sex with an uninfected partner is the surest way to prevent infection. The use of polyurethane female condoms and latex male condoms, when appropriately used, can reduce the spread of the infection. Spreading the word about the diagnosis, treatment and prevention is the best way to answer anyone who may ask, “What is trichomoniasis?”


Mayo Clinic: Trichomoniasis -

Department of Health and Human Services Centers for Disease Control and Prevention: Trichomoniasis CDC Fact Sheet -