Schistosoma mansoni is a multicellular trematodes that has a complex antigenic structure that elicit different types of immune reactions. The earliest one of those antigen is the stage specific cercarial elastase antigen which is secreted during initial skin penetration to facilitate their entry. In this study we showed that the immune response to this enzyme which could be detected by ELISA technique was mainly IgM and appeared as early as day 6 post exposure. The reactivity increased to the maximum by the sixth week and diminished to the control level by the tenth week. reexposure studies and quantitative ELISA revealed that cercarial elastase is a useful tool for the determination of the intensity of cercarial exposure |
