Trichomonas vaginalis

Summary

Trichomonas vaginalis, also shortened as Trichomonas or simply “trick”, is a flagellated parasite that is sexually transmitted. A Trichomonas infection is formally called trichomoniasis, and includes vaginitis, characterized by a yellow-green colored vaginal discharge. Trichomoniasis can also present with cervicitis with the appearance of a “strawberry cervix” on speculum exam. 

Trichomonas can be diagnosed by wet mount microscopy, in which the vaginal discharge discussed earlier is prepared on a slide, revealing motile trichomonads or swimming flagellated parasites.

The first line treatment for trichomonas is metronidazole.

Key Points

• Trichomonas vaginalis
  • Characteristics
    • Flagellated protozoan parasite
  • Transmission
    • Sexually transmitted
      • Coinfection with other STIs is common
      • Look for history of multiple sexual partners without protection
  • Presentation: Trichomoniasis
    • Vaginitis
      • Parasite infects squamous epithelium in vaginal mucosa
      • Yellow-green vaginal discharge
        • May be foul-smelling
        • Contrast vs. Gardnerella, which causes grey-white discharge
      • Itching, burning, and other discomfort may be seen
      • Vaginal pH may be elevated
    • Urethritis may be seen in men
  • Diagnosis
    • Motile trichomonads on wet mount (saline) microscopy
      • Flagellated pear-shaped or round organisms with jerky and spinning movements are seen
    • PCR/NAAT
      • Used when microscopy is inconclusive but trichomonas is still suspected
    • Strawberry cervix
      •  Bright red inflamed cervix seen on speculum exam
  • Treatment
    • Metronidazole for patient and partner
      • Tinidazole may also be used
        • Causes less GI side effects, but more expensive