Life cycle of Trichomonas vaginalis

 
     
  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  .