Trichomonas vaginalis

From Biology-Online Dictionary
Jump to: navigation, search



A parasitic flagellated protozoan that may infect the vagina and the urethra of women and the urethra and prostate gland of men, and cause trichomoniasis


Trichomoniasis is a sexually transmitted infection resulting in vaginitis in women. It is marked by a copious, frothy, malodorous discharge and itching in women whereas it is asymptomatic in men. It is caused by trichomonads, such as Trichomonas vaginalis.

Trichomonas vaginalis is a parasitic flagellated protozoan. It is found in the vagina and urethra of women. In men, it is found in the urethra and the prostate gland. Transmission is usually by direct skin-to-skin contact with the infected individual, such as by vaginal intercourse. The presence of this protozoan in women may produce a characteristic strawberry cervix (i.e. a reddish cervix with pinpoint areas of exudation) during diagnostic examination. The appearance is caused by capillary dilation as an inflammatory response.

The first person to describe this protozoon was Alfred Francois Donné (1801–1878). He was able to observe Trichomonas vaginalis derived from vaginal or cervical secretion samples through the microscope in 1836.

Scientific classification:

  • Phylum: Metamonada
  • Class: Parabasalia
  • Order: Trichomonadida
  • Family: Trichomonadidae
  • Genus: Trichomonas
  • Species: T. vaginalis [Donné 1836]

See also: