Treatment and Prevention of Trichomoniasis

Diagnosis and Treatment

• The Centers for Disease Control and Prevention recommends that pregnant women with trichomoniasis should be treated with metronidazole 2 g orally as a single dose after the first trimester 1, 2
• Metronidazole is contraindicated during the first trimester of pregnancy due to concerns about fetal organogenesis, as the drug crosses the placental barrier rapidly and its effects on early fetal development are not fully known 1, 2
• Treatment after the first trimester is warranted because trichomoniasis is associated with serious adverse pregnancy outcomes including premature rupture of membranes and preterm delivery 1, 3
• If a pregnant woman presents with symptomatic trichomoniasis during the first trimester, treatment must be delayed until the second trimester begins 1
• The single 2 g dose is specifically recommended for pregnant women rather than the 7-day regimen to minimize total fetal drug exposure 1, 3, 2

Partner Treatment and Prevention

• All sexual partners must be treated simultaneously with the same metronidazole regimen, regardless of symptoms, as most infected men are asymptomatic 4, 5, 2
• Patients must abstain from sexual intercourse until both partners complete treatment and are asymptomatic to prevent reinfection 4, 5, 2
• Failure to treat partners is the most common cause of treatment failure and reinfection 5
• Patients must avoid all alcohol during treatment and for at least 24 hours after the last dose to prevent severe disulfiram-like reactions 4, 5

Transmission and Epidemiology

• Trichomoniasis is contracted through sexual contact with an infected partner 1, 3
• Trichomonas vaginalis is a sexually transmitted protozoan that causes the most common non-viral sexually transmitted infection worldwide 1, 3
• Most infected men are asymptomatic carriers, making them unknowing vectors of transmission to female partners 1, 4
• Among women, the majority develop symptoms including diffuse, malodorous yellow-green vaginal discharge with vulvar irritation, though some women have minimal symptoms 1, 3
• The asymptomatic nature of infection in men explains why partner treatment is essential even without confirmed testing—untreated partners will reinfect treated patients 4, 5
• This is a reportable sexually transmitted infection that requires evaluation and treatment of all recent sexual contacts 1, 3

Trichomonas Vaginalis Treatment Guidelines

Recommended Treatment Regimens

• The Centers for Disease Control and Prevention recommends metronidazole 2 grams orally as a single dose as an acceptable alternative treatment regimen when patient compliance with multi-day therapy is unreliable and directly observed therapy can be provided, or when cost is a significant barrier to treatment 6
• The Centers for Disease Control and Prevention suggests that patients must abstain from sexual intercourse until both partners complete treatment and are asymptomatic 6
• For treatment failure management, the Centers for Disease Control and Prevention recommends re-treating with metronidazole 500 mg twice daily for 7 days for the first recurrence 6
• The Centers for Disease Control and Prevention advises that for second failure, metronidazole 2 grams orally once daily for 3-5 days should be used 6
• The Centers for Disease Control and Prevention recommends that for persistent failure after excluding reinfection, an infectious disease specialist should be consulted for susceptibility testing 6
• The Centers for Disease Control and Prevention states that HIV-infected patients should receive the same treatment regimen as HIV-negative patients 6
• The Centers for Disease Control and Prevention warns against using metronidazole gel for trichomoniasis treatment, as it achieves less than 50% efficacy 6
• The Centers for Disease Control and Prevention advises against using topical antimicrobials other than metronidazole, as they have even lower cure rates (<50%) 6
• The Centers for Disease Control and Prevention recommends that follow-up is unnecessary for patients who become asymptomatic after treatment or who are initially asymptomatic 6