Fatal acute Chagas disease in a chimpanzee

Chagas disease (CD) or American trypanosomiasis is caused by a hemoflagellate protozoan, Trypanosoma cruzi. This organism has been isolated from more than 100 mammalian species and several insect vectors demonstrating a wide host distribution and low host specificity.

A 23-year-old male chimpanzee died acutely and a complete necropsy was performed to evaluate gross and microscopic pathologic changes. After observation of trypanosomal amastigotes in the myocardium, PCR and immunohistochemistry was employed to confirm the diagnosis of T. cruzi.

Gross findings were consistent with mild congestive heart failure. Microscopic findings included multifocal myocardial necrosis associated with severe lymphocytic to mixed inflammatory infiltrates, edema, and mild chronic interstitial fibrosis. Multifocal intracytoplasmic amastigotes morphologically consistent with T. cruzi were observed in cardiac myofibers. Trypanosoma cruzi was confirmed by PCR and immunohistochemistry.

We report, to the best of our knowledge, the first fatal spontaneous case of T. cruzi infection in a chimpanzee.