Complement Fixation Tests as an Aid in the Differential Diagnosis of Extra-Intestinal Amebiasis 1

Abstract

Summary Complement fixation tests were performed on 2592 individuals in a general hospital using a commercially prepared Endamoeba histolytica antigen. Positive reactions were obtained with the sera from 86 per cent of the cases of extraintestinal amebiasis, 15 per cent of the cases of intestinal amebiasis only and 0.7 per cent of the cases that had equivocal or no evidence of amebiasis. The type of antigen employed is of especial value, therefore, in drawing attention to the possible presence of E. histolytica infections other than intestinal and as an aid in the differential diagnosis of hepatic and pulmonary conditions.