Immunodiagnosis of clonorchiasis by enzyme-linked immunosorbent assay

The present study applied the indirect enzyme-linked immunosorbent assay (ELISA) technique in the immunodiagnosis of clonorchiasis. Antigen used in this study was extracted from adult worms of Clonorchis sinensis obtained from cats. 132 patients with clonorchiasis, 100 healthy persons and 14 patients with other parasitic infections were studied. Mean O.D. ratio with standard deviation of clonorchiasis was 1.41 +/- 0.21 with 0.95 +/- 0.13 of healthy persons. Results revealed 90.2% to 95.5% of sensitivity and 84% to 99% specificity dependent on the two cut off values of O.D. ratio, i.e. 1.10 and 1.20. Antibody titers derived from O.D. ratio highly correlated with direct titration (Y = 0.0303 +/- 1.1766 X, r = 0.8945). Cross reactions of other parasite infections to clonorchiasis were observed in patients with angiostrongyliasis and schistosomiasis.