Acute chagasic cardiopathy produced by a strain of Trypanosoma cruzi (type I) in an experimental model.

We have carried out a study of the tissular tropism of the strain Y of T. cruzi considering that the different strains of T. cruzi show a great instability in their pathogenic properties with the aim of proving that the classifications of his parasite based in its tissular tropism are not reliable given that these characteristics are subject to change as can be seen by comparing our results with those of other authors. In our study, the Y. strain of T. cruzi shows a strong pancytotropic action, specially with marked cardiotropic aspects. The lack of affectation in the lymphatic ganglion and the small proportion of spleen lesions (8%) as well as the absence of pseudocysts at this level is surprising in a strain which was described as eminently reticulotropic. Our data show that this strain produces cardiac pseudocysts without lesions of the parasitized muscle fiber. The above mentioned data evidence that the biological behavior of a strain and specially its tissular tropism are susceptible to present variations with time.