The vector defecates on the host's skin when it feeds, and the metacyclic trypomastigotes enter the host's bloodstream, most often by being rubbed into the bite. The local inflammation caused by the entry of T. cruzi is called chagoma. Chagoma of the eye, Romana' sign, is seen in most of patients diagnosed as recently infected. The chronic or permanent stage of the disease likely involves an enlarged heart, due to antibody-antigen conflicts.