The Mouse Model as a Tool for Histological, Immunological and Parasitological Studies of Trypanosoma cruzi Infection

The global expansion of Chagas disease is due to the constant migration of individuals from endemic countries with incidence of vector and nonvector transmission of Trypanosoma cruzi. The disease is present in its various stages: chronological characteristic signs and symptoms of the infection and its mechanism of immune system and cell and tissue damage. The first stage, which lasts 90 days approximately, is diagnosed by direct methods (blood smears stained with Giemsa, fresh and xenodiagnosis). The indeterminate-chronic stage is asymptomatic, but the growth and intracellular binary multiplication of the trypomastigotes continue promoting cell lysis and allowing parasites to infect other cells, with preferential tropism to organs producing mega syndromes such as cardiomyopathy, myocarditis, meningoencephalitis, megaesophagus and megacolon. Inadvertently, this process is repeated for several years leading to Chagas disease. The mouse inoculation allows checking the parasitemia in vivo and the development of the disease in short time (signs, behavior and tropism), histopathological alterations and detection of antibodies in serum. These parameters may vary when using different strains of T. cruzi from different geographical areas; Triatoma species due to their genetic variability are influenced by the environment, nutrition, reservoirs and habitat. The murine model ECA CD-1 has the ability to replicate human findings of Chagas disease.