Objective: To establish a simple and fast diagnostic assay for schistosomiasis.
Methods: Based on the immunochromatographic technique and the principle of indirect assay of ELISA, using soluble egg antigen (SEA) of Schistosoma japonicum and mouse anti-human monoclonal antibody labelled with red latex as color developing agents, a latex immunochromatographic assay (DLIA) was developed. Serum samples from 69 schistosomiasis patients were detected by DLIA. Tested were also 264 sera from healthy people, 15 sera from clonorchiasis patients, 8 sera from patients with angiostrongyliasis cantonensis, 11 sera from patients with intestinal nematode infection and 19 sera from paragonimiasis patients. ELISA was used as a parallel control.
Results: The sensitivity for detecting schistosomiasis antibodies with DLIA and ELISA was 94.2% (65/69) and 95.7% (66/69), respectively (chi2=0.15, P>0.05). The specificity in examining healthy persons was 97.4% (257/264) and 94.7% (250/264), respectively (chi2=2.43, P>0.05). No cross reaction was found with the sera of clonorchiasis, intestinal nematode infection and angiostrongyliasis. The cross reaction rate with paragonimiasis of the two assays was 42.1% (8/19) and 47.4% (9/19), respectively (chi2=0.11, P>0.05).
Conclusion: DLIA is a simple, fast, sensitive and specific assay for the diagnosis of schistosomiasis.