Tissue destruction and invasion by Entamoeba histolytica

Entamoeba histolytica is the causative agent of amebiasis, a disease that is a major source of morbidity and mortality in the developing world. The potent cytotoxic activity of the parasite appears to underlie disease pathogenesis, though the mechanism is unknown. Recently, progress has been made in determining that the parasite activates apoptosis in target cells and some putative effectors have been identified. Recent studies have also begun to unravel the genetic determinants that influence infection outcome. Thus we are beginning to get a clearer picture of how this parasite manages to infect, invade and ultimately inflict devastating tissue destruction. Overview of amebiasis Entamoeba histolytica is a protozoan parasite and the causative agent of amebiasis in humans. Parasite cysts are transmitted through contaminated food and water, making the incidence of disease high in areas of poor sanitation. E. histolytica is responsible for an estimated 35 to 50 million cases of symptomatic disease and approximately 100,000 deaths annually [1]. Parasite destruction of host tissue appears to be the basis of disease (Figure 1). The majority of morbidity and mortality occurs in Asia, Central and South America an