Some principles of the immunology of trypanosomiasis.

Although immunological methods have not been used on a wide scale for the study of trypanosomiasis in Africa, there is hope that immunological research will lead to improved methods of diagnosis, methods for the classification of trypanosome strains, better understanding of the epidemiology, epizootiology and pathology of trypanosomiasis, and ultimately the development of methods of immunization against the disease.This paper reviews some of the problems that hinder progress in each of these areas. Such problems include inadequacies in existing methods of obtaining antigens of Trypanosoma vivax, T. congolense, and T. gambiense; the general lack of fundamental information on the nature and properties of trypanosome antigens; and the variability of certain trypanosome antigens in infected animals. Recent progress towards the solution of these problems is summarized, and aspects of the immunology of trypanosomiasis that require further study are discussed. These include the diagnostic value of determinations of IgM globulin levels; the properties of T. vivax and T. congolense antigens; the natural immunity of game animals and certain varieties of cattle to trypanosomiasis; and the possibility of immunizing livestock by exposing drug-treated animals to a continuous low-grade trypanosome challenge.