SCHISTOSOMIASIS - PRENATAL INDUCTION OF TOLERANCE TO ANTIGENS

THE pattern of pathology seen in human schistosomiasis has been compared with the infection experience, or lack of it, in the progenitors of a population1. It often, happens that populations new to an endemic area experience the disease in an acuter form than does the indigenous population1-5. To a great extent these early disease symptoms as well as the lator pathology are immunologically specific phenomena of hypersensitivity. For example, the granulomatous lesion arising about the schistosome egg in the host tissues6 is a manifestation of delayed hypersensitivity7 that may be reduced by immunosuppressive drugs8 or thymectomy9. © 1969 Nature Publishing Group.