A comparison was made of a new serological method, thin layer immunoassay (TIA), and an established method, enzyme-linked immunosorbent assay (ELISA), in the detection and quantification of antibodies in clonorchiasis. Saline extract of lyophilized Clonorchis sinensis adult worm was used as antigen, and TIA by the method of Elwing et al. (1976) and ELISA by Voller et al. (1974) were performed. Using sera from known clonorchiasis cases, 100 percent of the sera tested were positive by TIA and 88.3 percent by ELISA. TIA produced false positive results in 14 out of 36 cases, which were 10 amoebiasis cases, 16 paragonimiasis cases and 10 healthy controls. ELISA, however, produced a small number of false positives, 7 out of 55 cases. There was correlation between immunoglobulin G level in sera and ELISA value (correlation coefficient, 0.69), whereas no correlation between immunoglobulin G level and TIA result. The performance of TIA and ELISA was not correlated in the results using homologous antigen.
