INTRODUCTION Amebiasis may be defined as any pathological condition caused wholly or in part by protozoa of the genus Endamoeba.
Although undoubtedly of great antiquity, no important step was taken separating amebic infections from “bloody flux” until Loesch discovered amebas in dysenteric stools in 1875. During the succeeding years amebas not only have been established as the cause of specific types of colitis, but the list has grown and includes involvement of the liver, lung, brain, pericardium, abdominal wall, oral cavity, appendix, cellular tissues, bladder and probably invasion of the blood stream.
That there are several species of the parasites, some pathogenic and others either less pathogenic or entirely harmless, also is quite generally accepted. The methods of differentiation between the different species inhabiting man, although quite complete from the protozoologic standpoint, have not been settled to the satisfaction of clinicians working in the tropics, at least upon the point of pathogenesis.