Trichomoniasis

Background

• Trichomoniasis is a sexually transmitted infection with the urogenital protozoan Trichomonas vaginalis that typically causes minimal to mild genital symptoms but may also manifest as vulvovaginitis in female patients or urethritis in male patients.
• Vaginal trichomoniasis may be associated with an increased risk for HIV acquisition, cervical cancer, and prostate cancer. Vaginal trichomoniasis may also be associated with adverse pregnancy outcomes, including premature rupture of membranes and preterm delivery.

Evaluation

• Common symptoms in female patients include vulvar pruritus, burning, profuse vaginal discharge, rancid odor, and postcoital bleeding, although many are asymptomatic. Male patients may not have symptoms or may have symptoms of urethritis, epididymitis, or prostatitis.
• Nucleic acid amplification testing is recommended for the diagnosis of trichomoniasis (Strong recommendation).
• Alternative diagnostic options include:
  • FDA-approved rapid diagnostic tests, including immuno-chromatographic assay test (OSOM Trichomonas Rapid test) and nucleic acid probe testing (Affirm VP III test)
  • culture of vaginal secretions in female patients and of urethral swab, urine, or semen in male patients
• Microscopic exam of wet mount preparation of vaginal secretions mixed with normal saline is the most common diagnostic evaluation for T. vaginalis infection in female patients but is limited by poor sensitivity, and negative wet mount specimens require confirmatory testing.

Management

• Treatment regimens in nonpregnant patients:
  • Centers for Disease Control and Prevention treatment guidelines:
    • recommended treatment in female patients is metronidazole 500 mg orally twice daily for 7 days
    • recommended treatment in male patients is metronidazole 2 g orally in single dose
    • alternative treatment in female and male patients is tinidazole 2 g orally in single dose
  • American College of Obstetricians and Gynecologists treatment guidelines:
    • metronidazole 500 mg orally twice daily for 7 days (Strong recommendation)
    • tinidazole 2 g orally in single dose as an alternative treatment regimen
• Treatment considerations in pregnant and lactating patients:
  • Pregnant patients should be treated for symptomatic infection with metronidazole 500 mg orally twice daily for 7 days and should be counseled regarding the risks and benefits of treatment as well as the need for partner treatment and condom use to prevent future transmission.
  • Although multiple studies have shown no evidence of adverse effects to infants exposed to metronidazole via breastmilk, lactating patients being treated with metronidazole can consider abstaining from breastfeeding during treatment and for 12-24 hours after the last dose.
  • Tinidazole should be avoided in pregnant patients. Lactating patients treated with tinidazole should abstain from breastfeeding for 3 days after the last dose of tinidazole.
• Treat sexual partners concurrently and advise patients to avoid sex until treatment is completed and all symptoms have resolved.
• Retesting at 3 months is recommended due to high rates of reinfection (Strong recommendation).