Chagas' heart disease: experimental models.

An experimental model embodies an evaluation procedure that helps the investigator to choose between possible alternatives. In this paper, consideration is given to a variety of aspects related to the host-parasite relationship in Trypanosoma cruzi infection and disease. Although several animal species have been used, there is still a lack of consistent experimental studies. A few examples of investigations mainly in dogs, monkeys, and rabbits are briefly described, showing the diversity of methodological approaches and, therefore, the difficulty experienced in comparing results and interpretations. Emphasis was given to the need for a suitable model presenting all possible stage of the infection as seen in man, as well as the functional and organic disorders commonly seen in this disease. The alterations of the autonomic nervous system involving the heart and other organs in Chagas' disease was stressed.