Recent developments in the field of Chagas' disease.

Chagas' disease is an endemic human trypanosomiasis produced by Trypanosoma cruzi, which is usually transmitted by blood-sucking triatomid bugs. This article reports recent developments in research on Chagas' disease and outlines some of the basic investigations that have immediate practical application or that contribute to our knowledge of the parasite and its relationship with the vertebrate host.Much progress has been made recently in the development of techniques for characterization of T. cruzi strains, e.g., isoenzyme electrophoresis and analysis of kinetoplast DNA, and in research on the biochemistry of the parasite. Studies on membrane components have detected a number of distinct surface glycoproteins which may be important in the interaction between parasite and host cells. New methods of investigating ultrastructural membrane components are also being developed.There is a great need for an animal model in which T. cruzi induces a chronic infection resembling the human disease. Recent work has shown that the rabbit could be a suitable model; monkeys, dogs, and mice are also susceptible to T. cruzi but may not be useful as a model of the disease in man.A number of serological tests are available for the diagnosis of Chagas' disease, e.g., complement-fixation test, immunofluorescence, ELISA haemagglutination, direct agglutination. However, both tests and reagents need to be standardized and active reference centres are necessary to help improve the reliability of the reactions in the different endemic areas.