Myocarditis - Chaga's disease
The arrow points to a myocyte containing numerous amastigote forms of Trypanosoma cruzi in this Latin American case of Chaga’s myocarditis.
Chaga’s disease (American trypanosomiasis) due to T. cruzi is an important cause of myocarditis in almost all Latin-American countries. About 80% of infected patients have myocardial involvement. Skeletal muscles are also parasitized. Myocarditis is severe in a small proportion of these patients. Parasitization of myofibers presents a distinct histopathologic feature. The accompanying infiltrate is composed of neutrophils, lymphocytes, macrophages, and eosinophils. The patients who survive the acute illness face the possibility of development, even decades later, of an immune-mediated chronic lymphocytic myocarditis and progressive heart failure. Cardiac transplantation is an option in such cases and early results give no indication of recurrent Chaga’s disease of the heart.
Contributed by Dr. Roberto Miranda.