R-dot-igs Assay for Diagnosing Schistosomiasis Japonica

A fast, specific, sensitive, convenient, and economical rapid-dot-immunogold staining (R-Dot-IGS) assay was used to detect serum antibodies in patients infected with Schistosoma japonicum. The soluble egg antigen of Schistosoma japonicum was added onto microspore membrane. After pre-reacting and blocking, the serum to be detected and sheep anti-human IgG labeled with chloroauric acid were added sequentially. The assay took 15 minutes. For comparison, the dot-immunogold silver staining (Dot-IGSS) and rapid micro-volume Dot-IGSS (RM-DotIGSS) assay were also performed. The positive rate to detect the serum of schistosomiasis japonica by the R-Dot-IGS, Dot-IGSS and RM-Dot-IGSS assay was 98%, 98% and 100%, respectively. Samples from 50 healthy controls, 10 cases of clonorchiasis, and 10 cases of paragonimiasis showed negative reactions except for one case of clonorchiasis with RM-Dot-IGSS assay. Compared with Dot-IGSS and RM-Dot-IGSS, R-Dot-IGS assay has similar sensitivity and specificity, but the latter is quicker, simpler, and cheaper. Therefore, R-Dot-IGS is strongly recommended for rapid diagnosis of schistosomiasis japonica both in epidemiological study and in the clinic. SOUTHEAST ASIAN J TROP MED PUBLIC HEALTH 80 Vol 36 No. 1 January 2005 being 3 mg/ml. It was diluted to 150 μg/ml before use. Serum. Sera from 55 schistosomiasis japonica patients with stool positive for Schistosoma japonicum were provided by Institute of Parasitic Diseases of Jiangxi Province. Control sera were from 50 blood donors provided by Xuzhou Red Cross Blood Service, Jiangsu Province, 10 cases of clonorchiasis patients living in Pizhou city, Jiangsu Province, and 10 cases of paragonimiasis provided by Institute of Parasitic diseases, Zejiang Academy of Medicine. Sheep anti-human IgG labeled with chloroauric acid (GSAHIgG). The sheep anti-human IgG was provided by SIND-American Biotechnology Co. The colloidal gold was 5 nm in diameter. The sheep anti-human IgG was labeled in our laboratory according to Slot’s method (Slot and Genuze, 1985) and kept preserved at -20oC. Blocking solution. The solution was 0.02 mol/l TBS pH 8.2 containing 1% bovine serum albumin (BSA).