ABSTRACT
Donne, in 1830, observed organisms on slides of purulent discharges from the genital tracts of men and women and named them 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. T. 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.
