Warning:

This document is being maintained for historical purposes, but is now out of date. To view current guidelines please visit:

• STD Treatment Guidelines   at http://www.cdc.gov/STD/treatment

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1993 Sexually Transmitted Diseases Treatment Guidelines

09/24/1993

SUGGESTED CITATION
Centers for Disease Control and Prevention. 1993 Sexually
transmitted diseases treatment guidelines. MMWR 1993;42(No. RR-14):
{inclusive page numbers}.

CIO Responsible for this publication:
National Center for Prevention Services,
Division of Sexually Transmitted Diseases and HIV Prevention

Trichomoniasis
     
     Trichomoniasis is caused by the protozoan T. vaginalis. The
majority of men infected with T. vaginalis are asymptomatic, but
many women are symptomatic. Among women, T. vaginalis typically
causes a diffuse, malodorous, yellow-green discharge with vulvar
irritation. There is recent evidence of a possible relationship
between vaginal trichomoniasis and adverse pregnancy outcomes,
particularly premature rupture of the membranes and preterm
delivery.

Recommended Regimen -
     Metronidazole 2 g orally in a single dose.

Alternative Regimen -
     Metronidazole 500 mg twice daily for 7 days.

     Only metronidazole is available in the United States for the
treatment of trichomoniasis. In randomized clinical trials, both of
the recommended metronidazole regimens have resulted in cure rates
of approximately 95%. Treatment of the patient and sex partner
results in relief of symptoms, microbiologic cure, and reduction of
transmission. Metronidazole gel has been approved for the treatment
of BV but it has not been studied for the treatment of
trichomoniasis. Earlier preparations of metronidazole for topical
vaginal therapy demonstrated low efficacy against trichomoniasis.

Follow-Up
     Follow-up is unnecessary for men and for women who become
asymptomatic after treatment.

     Infections by strains of T. vaginalis with diminished
susceptibility to metronidazole occur. However, most of these
organisms respond to higher doses of metronidazole. If failure
occurs with either regimen, the patient should be retreated with
metronidazole 500 mg 2 times a day for 7 days. If repeated failure
occurs, the patient should be treated with a single 2 g dose of
metronidazole once daily for 3-5 days.

     Patients with culture-documented infection who do not respond
to the regimens described in this report and in whom reinfection
has been excluded, should be managed in consultation with an
expert. Evaluation of such cases should include determination of
the susceptibility of T. vaginalis to metronidazole.

Management of Sex Partners
     Sex partners should be treated. Patients should be instructed
to avoid sex until patient and partner(s) are cured. In the absence
of microbiologic test-of-cure, this means when therapy has been
completed and patient and partner(s) are without symptoms.

Special Considerations

Allergy, Intolerance, or Adverse Reactions
     Effective alternatives to therapy with metronidazole are not
available.

Pregnancy -
     The use of metronidazole is contraindicated in the first
trimester of pregnancy. Patients may be treated after the first
trimester with 2 g of metronidazole in a single dose.

HIV Infection -
     Persons with HIV infection and trichomoniasis should receive
the same treatment as persons without HIV.

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