Treatment of Trichomonas Vaginalis Infection

Treatment Recommendations

The Centers for Disease Control and Prevention recommends treating patients with Trichomonas vaginalis infection and severe inflammation with oral metronidazole 2g as a single dose or 500mg twice daily for 7 days, and a repeat Pap smear should be performed 3 months after treatment 1, 2, 3
The recommended regimen is metronidazole 2g orally in a single dose, with an alternative regimen of metronidazole 500mg twice daily for 7 days, both demonstrating approximately 95% cure rates in clinical trials 1, 2, 3
Sex partners should also be treated to prevent reinfection, and patients should avoid sexual intercourse until both patient and partner(s) complete treatment and are asymptomatic 1, 2, 3

If treatment fails with either regimen, retreat with metronidazole 500mg twice daily for 7 days, and for repeated failure, use metronidazole 2g once daily for 3-5 days 1, 3
Persistent infections may require consultation with a specialist and susceptibility testing of T. vaginalis to metronidazole 3

T. vaginalis infection is associated with increased risk of HIV acquisition and transmission, adverse pregnancy outcomes, and potential association with cervical cancer, as well as persistent inflammation that can interfere with accurate cytological assessment 1, 2
If the patient has allergies to metronidazole, limited alternative options exist, and tinidazole may be considered for patients who fail metronidazole therapy 1, 3
For pregnant patients, treatment is contraindicated in the first trimester but can be administered after the first trimester with 2g metronidazole as a single dose 1, 3

Failure to treat sexual partners significantly increases risk of reinfection, and inadequate follow-up can lead to missed abnormal cytology due to inflammation from T. vaginalis 1, 3
Using topical metronidazole (gel) has poor efficacy (<50%) against T. vaginalis and is not recommended, and ignoring treatment failures may indicate drug resistance (occurs in approximately 4-5% of cases) 3

Premature rupture of membranes, preterm delivery, and low birthweight are well-established complications requiring treatment of all symptomatic pregnant women, according to the American Family Physician 4
Post-partum endometritis risk is increased in infected women, as reported by the American Family Physician 4
The American Family Physician recommends that follow-up is unnecessary for initially asymptomatic patients who become asymptomatic after treatment 4

Concurrent treatment of sexual partners is mandatory to prevent reinfection and reduce transmission, as stated by the American Family Physician 4