Abstract

Trichomonas vaginalis, a flagellate protozoan parasite is responsible for trichomoniasis, the number one non-virally sexually transmitted disease. Although both men and women are infected, it causes disease almost exclusively in women. There are up to 250 to 350 million new cases oftrichomonad vaginitis annually worldwide. T. vaginalis has the ability to attach to host cells (cytoadherence) thereby establishing infection as the organism overcomes the constant secretion of the vagina. Two classes of proteins are involved in cytoadherence of T. vaginalis, these are the four adhesion proteins AP65, AP51, AP33 and AP23 and Cysteine proteinase. Although, the exact mechanism of its pathogenesis has not been clearly elucidated, many mechanisms are thought to be involved. These include cell-to-cell adhesion, hemolysis, cell detaching factors, excretion of soluble factors and evasion of the host immune system. Trichomoniasis is strongly associated with several complications in pregnancy and with an increase in the transmission of human immunodeficiency virus.

Key words: Trichomonas vaginalis, cytoadherence, pathogenesis.