A 2.25-y-old male pigtailed macaque (Macaca nemestrina) was experimentally irradiated and received a bone marrow transplant. After
transplantation and engraftment, the macaque had unexpected recurring
pancytopenia and dependent
edema of the prepuce, scrotum, and legs. The diagnostic work-up included a blood smear, which revealed a trypomastigote consistent with Trypanosoma cruzi, the causative agent of
Chagas disease (CD). We initially hypothesized that the macaque had acquired the
infection when it lived in Georgia. However, because the animal had received multiple
blood transfusions, all blood donors were screened for CD. One male pigtailed macaque blood donor, which was previously housed in Louisiana, was positive for T. cruzi
antibodies via serology. Due to the low prevalence of
infection in Georgia, the
blood transfusion was hypothesized to be the source of T. cruzi
infection. The transfusion was confirmed as the mechanism of transmission when screening of archived serum revealed seroconversion after
blood transfusion from the seropositive blood donor. The macaque made a full clinical recovery, and further follow-up including thoracic radiography, echocardiography, and gross necropsy did not show any abnormalities associated with CD. Other animals that received
blood transfusions from the positive blood donor were tested, and one additional pigtailed macaque on the same research protocol was positive for T. cruzi. Although CD has been reported to occur in many nonhuman primate species, especially pigtailed macaques, the transmission of CD via
blood transfusion in nonhuman primates has not been reported previously.