Rapid detection of specific IgG in sera of patients with infection of Sparganum mansoni by dot immuno-gold filtration assay

In this study,a simple and rapid immunoassay was established to detect the specific IgG antibodies in serum of patients with infection of Sparganum mansoni,in which the soluble extract of plerocercoid used as antigen was dotted on nitrocellulose and protein A conjugated with colloidal gold was employed as the probe,and a filtration device with vertical flow was applied to detect the specific IgG antibodies.By using this new immunoassay,it was found that 92%(23/25)of patients with sparganosis showed positive results on the detection of serum IgG,and 2%(2/100)of healthy individuals had false positive results.However,high and partially high percentages of the cross reactions could be demonstrated in sera of patients with paragonimiasis or cysticercosis and in those of patients with clonorchiasis or schistosomiasis,respectively.None of patients with angiostrrangyliasis or tuberculosis showed false positive reaction.In addition,significant correlation existed in the parallel detection of this method of assay with ELISA on 74 serum specimens(K=0.871.P0.001).It is apparent that the dot immune gold filtration assay(DIGFA)used for the detection of specific antibody IgG in sera of patients infection of Sparaganum mansoni appears to be simple,rapid and sensitive with high percentages of positive results,but it also shows higher percentages of cross reaction with sera of patients with paragonimiasis and cysticercosis.Therefore,it would be necessary to undergo differential diagnosis upon the epidemiological information,such as patient custom and behavior patterns.