It is caused by a protozoa, Entamoeba Histolytica. It is commonly spread by water contaminated by faeces or from food served by contaminated hands. Even vegetables grown in soil contaminated by faeces can transmit the disease. It can also spread to other organs like the liver, lungs, and brain by invading the venous system of the intestines. If it invades the liver, it causes formation of the typical anchovy paste like pus.
Asymptomatic carriers pass cysts in the faeces.
It can either occur as intestinal or extra-intestinal amoebiasis. The most common type of amoebic infection is asymptomatic cyst passage. Fulminant infection with high grade fever, severe abdominal pain and profuse diarrhoea occurs in children and in patients receiving steroids. Severe gastric distention of the bowel can occur. Extra-intestinal amoebiasis Patients show symptoms of fever and right upper abdominal pain.