Comparison of Sensitivity and Specificity of Native ELISA Test (Prepared in Khouzestan, Iran) and Commercial ELISA Kit in the Diagnosis of Human Hydatidosis

Abstract

Background: As an ancient zoonosis, cystic echinococcosis still is prevalent among livestock worldwide. Early diagnosis is of utmost clinical importance. Objectives: Herein, we compared the efficacy of ELISA with native antigen B and a commercial ELISA kit to detect human hydatidosis in Khuzestan province, southwestern Iran. Methods: The current study consisted of 90 serum samples, including 50 samples obtained from hydatid-affected patients approved by surgery, 20 samples from patients affected by other diseases (having anti-Toxoplasma antibody, giardiasis, hepatitis, etc.), and 20 serum samples from healthy individuals. Native antigen B was prepared from sheep-isolated hydatid cysts. Checkerboard procedure was performed to determine the optimum dilution of antigen, serum and conjugate. Commercial ELISA was done using Vircell indirect immunoenzyme assay to detect anti-hydatidosis IgG. The cut-off point for native ELISA was the sum of two-fold standard deviation and the mean optical density of all negative samples. Results: Using commercial ELISA kit and native ELISA test, 22 out of 90 and 52 out of 90 sera were positive for hydatid-specific IgG, respectively. Compared to the operation, the sensitivity of native and commercial ELISA tests was 100% and 44%, respectively. However, the specificity was not determined due to the lack of surgical information among the heterologous and control groups. In comparison to the commercial ELISA, both tests showed the same sensitivity (97%), while the specificity of native and commercial ELISA was 95% and 96%, respectively. Conclusions: Developing ELISA tests using native antigens would be a reliable method to improve the efficacy of human hydatidosis detection.