Trichomonas

• Trichomonas species


  • Trichomonas hominis
  • Trichomonas tenax
  • Trichomonas vaginalis

  
• Trichomonas hominis


  • No cyst stage
  • 4 free flagella
  • 5th flagellum along outer margin of undulating membrane
  • Axostyle
  • Cytostome at anterior end

  
• All three Trichomonas species (T. tenax, T. vaginalis, T. hominis) are parasitic to man and do not produce cysts

  
• Trichomonas hominis


  • Common intestinal flagellate next to G. lamblia
  • Inhabits the cecum feeding on enteric bacteria using its cytostome
  • Does not invade intestinal tissue

  
• Trichomonas tenax


  • No cyst stage
  • 4 free flagella
  • 5th flagellum along outer margin of undulating membrane
  • Undulating membrane 2/3 of the body
  • Axostyle
  • Cytostome at anterior end
• Trichomonas tenax


  • Harmless commensal of the mouth living in tartar around teeth, cavities of carious teeth, necrotic mucosal cells of gingival margins, pus pockets in tonsillar follicles
  • Transmission: Droplet spray from the mouth, kissing, contaminated dishes, and drinking glasses
  • Not observed among those with good oral hygiene
  • No specific treatment
• Trichomonas vaginalis


  • No cyst stage, only Trophozoite
  • Urogenital flagellates
  • Worldwide distribution
  • Sexual transmission

  
• Trichomonas vaginalis Trophozoites


  • Known to survive in urine, wet sponges, damp towels for several hours as well as in water for about 40 minutes
  • Motile for 1 – 2 hours in vaginal secretions
  • Thrive in slightly alkaline and slightly acidic environment which is seen in an unhealthy vagina
  • Siderophil granules can also sometimes be appreciated inside the trophozoite

  
• Trichomonas vaginalis


  • Normally inhabits vagina, urethra, prostate gland
  • Feeding on bacteria and leukocytes of vagina – preference for acidic vaginal environment
  • Movement: undulating, jerky movement

  
• Trichomonas vaginalis transmission


  • Sexual intercourse (high incidence in ages and populations at risk for venereal diseases)
  • Non-venereal: Communal bathing and sharing of douche equipment
  • Also through the use of contaminated toilet seat and tissues
  • Can also be transmitted in birthing, passage in the infected birth canal (2 – 17% of cases)

  
• Trichomonas vaginalis Pathology


  • Incubation Period: 5 to 28 days
  • Women: symptomatic - Vaginitis with a purulent discharge is the prominent symptom, accompanied by vulvar and cervical lesions, abdominal pain, dysuria, and dyspareunia, Pruritic vaginitis and chronic trichomoniasis, Some complications could also lead to ascites – if there is occurrence of transvaginal-peritoneal migration, and also vaginitis emphysematosa – gas-filled blebs in the vaginal epithelium/mucosa
  • Men: usually asymptomatic, Occasionally, urethritis, epididymitis, and prostatitis can occur

  
• Trichomonas vaginalis Infection


  • Acute onset of vulvar and vaginal pruritus and greenish or yellowish vaginal discharge
  • Women: Vulvitis, dysuria, urethritis, postpartum endometritis
  • Men: Prostatitis, reversible sterility or symptomless

  
• Trichomonas vaginalis Symptoms


  • Only 30% of infected persons show any symptoms, More common in females, 5 – 28 days
  • Men: Itching / Irritation of penis, Burning sensation, Discharge
  • Women: "Strawberry cervix" (2%), Itching, Burning, Redness, Soreness of genitals, Discomfort during urination, Odorous yellow-green discharge (12%)

  
• Trichomonas vaginalis Diagnosis


  1. Vaginal swab: pH >4/5, From posterior fornix using NSS wet mount (hanging drop method): 60 – 70% sensitivity, Wet mount from urethral discharge in males

  2. Urine: prostatic massage before urine collection / centrifuged

  3. Gram; Giemsa staining; Papanicolaou; acridine orange, Romanowsky

  4. Direct fluorescent antibody; latex agglutination

  5. PCR: males (not widely used)

  6. Culture (diamond medium): Gold standard, In pouch TV test

  
• Trichomonas vaginalis Treatment


  • Metronidazole (include sexual partner)
  • Treatment failure: Reinfection from untreated sexual partner, Noncompliance, Hepatic inactivation of drug, Drug resistance

  
• Trichomonas species comparison


  • T. vaginalis: Size 7 – 23 u, Pear-shaped, Single ovoid nucleus, Undulating membrane extend up to half of body length, Habitat: Vagina, prostate, urethra
  • T. tenax: Size 5 – 12 u, Pear-shaped, Single ovoid nucleus, Undulating membrane extend up to 2/3 of body length, Habitat: Oral cavity
  • T. hominis: Size 5 – 14 u, Pear-shaped, Single ovoid nucleus, Undulating membrane extend up to the whole length with free trailing end, Habitat: Cecum

  
• Trichomonas vaginalis resides in the female lower genital tract and the male urethra and prostate, where it replicates by binary fission. The parasite does not appear to have a cyst form, and does not survive well in the external environment. Trichomonas vaginalis is transmitted among humans, its only known host, primarily by sexual intercourse.