Amoebiasis is a common disease in regions of the world where human sanitation is poor, and the cysts produced by these parasite can be carried from feces to water supplies. Most amoebic infections are benign, and the parasite simply feeds on bacteria and other debris in the lumen of the intestine. However, some species can lyse host cells and initiate an ulcer which can become infected secondarily, and can even introduce the amebas into the bloodstream. In severe cases the intestine becomes perforated and death may result.