The value of an antigenic fraction of Cysticercus cellulosae in the serodiagnosis of cysticercosis

Fractions of Taenia solium cysticerci were isolated using preparative isoelectric focusing. A fraction isoelectric between pH 7.8 and 10.0 was found to be most effective as an antigen in an enzyme-linked immunosorbent assay (ELISA) for anti-cyst antibodies. The efficacy of this fraction and of a total homogenate of the cysticerci to detect cases of neurocysticercosis by ELISA was compared. The partially purified fraction showed a sensitivity of 80% and specificity of 99.5%. The total homogenate had a sensitivity of 75% and a specificity of 99%. Cross-reactions occurred with sera from patients with hydatid disease. In patients with other parasitic infections the specificity of the isolated fraction (3/120) was considerably better than that of the total homogenate (16/120). Cysticercosis in man is caused by infection with the larval stage of the zoonotic pork tapeworm Taenia solium. The disease is largely one of developing countries and is prevalent in Latin America, Eastern Europe, the Far East and large parts of Africa. In the Republic of South Africa the prevalence of cysticercosis has been estimated as 8.5% amongst rural blacks, and in certain high incidence areas over 20%.