Trypanosoma cruzi, the causative agent of Chagas disease, is a zoonotic, vector-borne parasite with a wide host range. While natural infections have been documented in both wild and captive nonhuman primates, there are no reports of treatment.2-6 An 11-year-old, captive-bred, male De Brazza’s monkey (Cercopithecus neglectus) presented with weight loss, despite normal appetite in August, 2018. Physical exam findings under anesthesia included pale mucous membranes and thin body condition. Two-view chest and abdominal radiographs and abdominal ultrasound were unremarkable. A complete blood count (CBC) revealed a normal leukogram and non-regenerative anemia (17%), and a biochemistry panel revealed severe hypoglycemia (26 mg/dl) in the face of low insulin (<7.5 µU/ml). The monkey was treated with supportive care and had an uncomplicated anesthetic recovery. Many trypanosomes were seen on a blood smear, and a blood sample was polymerase chain reaction (PCR) positive for T. cruzi. Strain typing revealed parasite discrete typing unit TcIV. The monkey was treated with benznidazole (Exeltis USA, Inc., Florham Park, NJ, USA) 25 mg PO, BID for 60 days with no obvious negative effects. Blood was initially obtained daily, then weekly, then monthly through voluntary blood collection to monitor CBC, biochemistry panel, cardiac troponin, quantitative PCR, and serology; obtaining voluntary blood samples was instrumental in monitoring his response to treatment. Over several months, serology demonstrated a rise in immunoglobulin G and a decrease in immunoglobulin M, and qPCR showed a decrease. Mild hypoglycemia persisted for several months, which has been documented in other species infected with trypanosomes.1,7 The monkey recovered with no apparent lasting effects.
The authors thank the primate department and veterinary staff at the Birmingham Zoo for their dedication to providing the best possible care for all animals in their care, and Lisa Auckland for molecular diagnostics.
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