Identification of Trypanosoma cruzi in human tissues using an immunoperoxidase method: study of acute Chagas disease, congenital form.

: The immunoperoxidase technique using a polyclonal T. cruzi rabbit antiserum was compared with the routine hematoxylin-eosin staining procedure in the study of two cases of congenital Chagas disease. Comparatively, the immunoperoxidase technique gave better results than that using hematoxylin-eosin in identification of T. cruzi. The immunoperoxidase technique detected T. cruzi nests in unsuspected sites like lungs and testes, in which the hematoxylin-eosin stain failed to demonstrate their presence. In the two cases studied there was no evidence of positive immunoperoxidase reaction which could suggest the presence of cross-antigens between T. cruzi and host tissues, in the heart, gastrointestinal tract or other organs. These negative results are discussed.