Comparative study on rapid dot-immunogold staining and two immunogold silver staining assays 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-Dot-IGSS) 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.