Case Report: Severe and Complicated Cynomolgi Malaria in a Rhesus Macaque Resulted in Similar Histopathological Changes as Those Seen in Human Malaria.

Histopathological data collected from patients with severe malaria have been instrumental for studying malaria pathogenesis. Animal models of malaria are critical to complement such studies. Here, the histopathological changes observed in a rhesus macaque with severe and complicated Plasmodium cynomolgi malaria are reported. The animal presented with thrombocytopenia, severe anemia, and hyperparasitemia during the acute infection. The macaque was given subcurative antimalarial treatment, fluid support, and a blood transfusion to treat the clinical complications, but at the time of transfusion, kidney function was compromised. These interventions did not restore kidney function, and the animal was euthanized due to irreversible renal failure. Gross pathological and histological examinations revealed that the lungs, kidneys, liver, spleen, and bone marrow exhibited abnormalities similar to those described in patients with malaria. Overall, this case report illustrates the similarities in the pathophysiological complications that can occur in human malaria and cynomolgi malaria in rhesus macaques.