A purified antigenic fraction of sheep hydatid fluid containing two major lipoprotein components was evaluated in hemagglutination, immunoelectrophoretic, and skin hypersensitivity tests for the diagnosis of 91 cases of human hydatidosis. Most of the serological reactors could be detected by this fraction, though a significant proportion reacted with other components of sheep hydatid fluid that had been eliminated during the fractionation procedure. About 80% of the patients had positive immediate skin reactions after the inoculation of 1.5 µg protein antigen, and there was little evidence of nonspecific reactivity. The relevance of these findings to current problems of immunodiagnosis of hydatid disease was discussed.
Present address: Department of Microbiology and Public Health, Michigan State University, East Lansing, Michigan 48823.
Present address: Médicine Expèrimentale, Collège de France, Paris Ve, France.