Trypanosoma cruzi and experimental Chagas' disease: characterization of a stock isolated from a patient with associated digestive and cardiac form. 
A new Trypanosoma cruzi stock isolated from a patient in the chronic phase of Chagas' disease with the digestive and cardiac form of the disease was characterized by experimental infection in isogenic, susceptible, A/Sn strain mice.  Parasitemia curves showed up to 1.7 x 10(6) parasites/ml and no mortality was observed up to 300 days post infection.  Specific IgM was found in mice in the acute phase up to 40 days and also in the chronic phase.  IgG antibodies were detected in the acute and chronic phase.  Histopathology examination demonstrated myotropism to the digestive tract muscle layers and to the heart.