[Immunologic and parasitologic aspects of Biomphalaria tenagophila infected by Schistosoma mansoni and other Digenea].

The behavior of Biomphalaria tenagophila amoebocytes was studied in infections produced by Schistosoma mansoni and other Digenea. The resistance to superinfection was also verified in mixed infections. Data on amoebocyte phagocytic activity, on the number of amoebocytes in hemolymph, and on amoebocyte tissue reactions were obtained and electrophoretic and immunodiffusion examinations of the hemolymph were carried out. It was concluded that the snails infected with Digenea show resistance to superinfection with S. mansoni. Apparently sporocysts are not destroyed by the action of amoebocytes. An increase in amoebocyte phagocytic activity was discovered in infected snails. Immunoelectrophoresis shows quantitative and qualitative differences in the hemolymph of the infected snails.