Cerebrospinal echinococcosis: serodiagnosis using different hydatid cyst fluid antigens

Cerebrospinal hydatid disease diagnosis may impose some problems, as ultrasonography is not applicable and serology may not detect the low antibody titre often associated with intracranial or orbital cystic echinococcosis. Serological tests were performed on 14 cases with intracranial or spinal cystic lesions, out of which 9 were cases of hydatidosis, in addition to 26 cases with other parasitic diseases as detected by stool examination. The sensitivity of all tests and antigens used did not exceed 6 out of the 9 positive cases, and achieved by the Eg1 and Eg2 when applied in the ELISA. The specificity of this technique using the two antigens was 92.3%& 76.9%, respectively. Semi-purified Em1 and purified 44 KDa used in the ELISA, crude Eg1 used for the CIEP and the crude commercial antigen of the IHAT, all gave lower sensitivities than the former two antigens, yet their specificities amounted to 100%. In conclusion, for diagnosis of cerebrospinal hydatidosis the home-prepared Eg1 antigen is recommended in the ELISA system, as it is relatively easily prepared from available resources to be supplemented with radio-imaging techniques especially Magnetic Resonance Imaging and/or MR spectroscopy, the latter being very helpful in clearly differentiating various types of intracranial cysts.