Cross reactions in the immunodiagnosis of schistosomiasis and cysticercosis by a cerebrospinal fluid enzyme-linked immunosorbent assay.

Cerebrospinal fluid was collected from 3 groups of patients (suspected cysticercosis patients, myelopathy patients, and neurological patients) and assayed for antibodies to Cysticercus cellulosae and schistosome soluble egg antigen. In the myelopathy and neurological patients there was a significant correlation (P less than 0.05) between seropositivity for the two diseases. Samples which were positive in both assays were tested by inhibition assay with the heterologous antigen to determine the specificity of the reaction. In one of 5 cases the reaction to cysticercus antigen was completely inhibited by addition of schistosome soluble egg antigen. In the reverse assay there was minimal inhibition by cysticercus antigen.