A correlative study of the three immunological tests, complement fixation, indirect hemagglutination and intradermal tests was carried out on 79 patients with hydatid disease and 105 patients with miscellaneous conditions. The mean percentages of positive reactors among the 79 patients with hydatid disease tested by complement fixation, intradermal and indirect hemagglutination tests were, respectively, 77.2, 88.6 and 87.3. Among the 105 patients with conditions other than hydatid disease the percentages of positive results were 5.9 in complement fixation, 18.1 in intradermal and 0 in indirect hemagglutination tests. On the basis of these findings it may be stated that indirect hemagglutination as applied for the diagnosis of hydatid disease is a more specific test than are complement fixation and intradermal tests.
Present address: Department of Tropical Medicine and Public Health, Tulane University, School of Medicine, New Orleans 12, La.