Evaluation of Whole and Purified Hydatid Fluid Antigens in the Diagnosis of Human Hydatidosis by the Immunoelectrophoresis Test *

Abstract
Whole sheep hydatid cyst fluid (WHF) and purified hydatid fluid antigens (PHF) were evaluated in the immunoelectrophoresis (IEP) test for the diagnosis of human hydatid disease. A higher sensitivity was obtained using the PHF than with the WHF antigen but false positive results were observed with the former in 22.4% of the 102 non-hydatid sera examined. Using the presence of arc 5 as the criterion of positivity however, no false positives were observed in non-hydatid sera with the WHF antigen. It is postulated that the number of bands other than arc 5 may be of value in the diagnosis of hydatid disease by the IEP test, in cases where this diagnostic arc is absent.