How is trichomoniasis treated and how do you become infected with it? #1130/6


TRICHOMONIASIS caused by trichomonas vaginalis, a motile protozoan with an undulating membrane and four flagella, is transmitted from one person to another by sexual intercourse.

Prevalence: Trichomoniasis is the most common curable STI in the
United States and worldwide. Each year an estimated 3 million U.S. women become infected.

Symptoms: Excessive, frothy, diffuse, yellow-green vaginal discharge is common, although clinical presentation varies from no signs or symptoms to erythema, edema, and pruritis of the external genitalia. Dysuria and dyspareunia are also frequent. The type of symptoms or signs alone does not distinguish the microbial etiology. Male sex partners may develop urethritis, balanitis, or cutaneous lesions on the penis; however, the majority of males infected with T. vaginalis are asymptomatic.

Diagnosis: Trichomoniasis is diagnosed when a vaginal culture or antigen test is positive for T. vaginalis OR typical motile trichomonads are identified in a saline wet mount of vaginal discharge. Examine vaginal secretions to verify the finding of trichomonads on a Pap smear, as this test is relatively non-specific for the diagnosis.

Treatment: Metronidazole 2.0 g orally at one time. Alternative regimens are metronidazole 500 mg orally twice daily for 7 days or tinidazole 2 g orally at one time. Most treatment failures are due to failure to treat the index patient’s sex partners; initial management should include re-treatment of the patient and partners with single-dose metronidazole (2.0 g).
Metronidazole-resistant T. vaginalis, although uncommon, can occur. Most treatment failures respond to higher doses of metronidazole therapy or to a single dose of tinidazole (2 g). Sex partners should be simultaneously treated with the same regimen as the index client.  Potential complications: Secondary excoriation may occur. Recurrent infections are common. Trichomoniasis has been associated with an increased risk of salpingitis, low birth-weight, prematurity, and acquisition of HIV.

Behavioral messages to emphasize: Understand how to take or use prescribed medications. Return if the problem is not cured or recurs. Make sure sex partner(s) are treated. Use condoms to prevent future infections. Avoid drinking alcohol until 24 hours after completing metronidazole therapy.


Key Words: common, corable STI, frothy, diffuse, yellow-green vaginal discharge, Metronidazole, therapy, Dysuria, dyspareunia, urethritis, balanitis, cutaneous lesions, penis, T.vaginalis, vaginal discharge, Pap smears


Posted 11-21-2006, Updated 11-30-2006, Updated 12-9-2006, Updated 2-27-2009


Posted on

February 27, 2009