ABSTRACT
Observing animals on slides of purulent discharges from the genital tracts of men and women, Donne in 1830 termed the organisms Trichomonas vaginale. The name Trichomonas vaginalis was suggested two years later by Ehrenberg. Since then, over 100 separate species of the genus Trichomonas have been reported, but only three have been isolated in humans. Trichomonas vaginalis is the only species of the trichomonads that is pathogenic for humans. T. tenax and T. hominis infect the human gastrointestinal tract, but as harmless commensals.
