Evaluation of cysticercus fasciolaris antigen for the immunodiagnosis of neurocysticercosis.

Cysticercus cellulosae antigen has been frequently used to detect antibodies for immunodiagnosis of neurocysticercosis. We have, for the first time, used membrane extract of cysticercus fasciolaris, the larval stage of Taenia taeniaeformis, in ELISA, with successful results. IgM and IgG antibodies against cysticercus were measured in serum from cases of neurocysticercosis (217), normal and diseased controls (89). 203 sera from cases of neurocysticercosis were positive for either or both IgG and IgM antibodies while 157/217 cases showed IgM and 158/217 showed IgG antibodies. Ten controls showed false postivity in IgG ELISA. Eight of these cases also had IgM antibodies. The test had an overall sensitivity of 93.54% and a specificity of 84.2% with a positive predictive value of 93.54% and a negative predictive value of 84.2%. Cysticercus fasciolaris can be conveniently produced in the experimental laboratory host, Rattus rattus, and would be of practical value in the immunodiagnosis of cysticercosis in humans.