Angiostrongylus cantonensis infection in a captive non-human primate (Varecia variegata) from the southeastern United States.

Angiostrongylus cantonensis is a nematode of public health relevance that parasitizes lungs of rodents and can cause eosinophilic meningoencephalitis in humans. In this study we report a case of meningoencephalitis due to A. cantonensis infection in a geriatric, male black-and-white ruffed lemur (Varecia variegata) at a zoological facility in Atlanta, Georgia, southeastern United States of America. In December 2022, the animal presented with a history of acute hindlimb lameness that progressed to right hindlimb paresis and paralysis with loss of pain sensation. Radiographs revealed possible decrease in intervertebral joint space and spondylosis deformans at vertebrae C7-T1, T8-T10, and Cd 2-4. Euthanasia was elected due to the poor prognosis of the intervertebral disease. To investigate potential additional causes for the neurological manifestation exhibited by the animal, fragments of organs and tissues (i.e., eye, spinal cord, peripheral nerves, and brain) were fixed in 10 % neutral buffered formalin and processed and embedded in paraffin. Hematoxylin and eosin-stained slides were assessed for histological changes. Scrolls of the cerebellum were also processed for genomic DNA extraction followed by PCR and sequencing. The histological evaluation revealed lesions compatible with migration or presence of larval nematodes in nervous and ocular tissues. The parasitism by A. cantonensis was molecularly confirmed (GenBank: PQ783804) in cerebellum samples, supporting the evidence of the infection in a non-human primate kept in the Atlanta Zoo, Georgia. While the lemur had intervertebral disease that could have caused neurological manifestations, the presence of A. cantonensis could have contribute to the overall clinical presentation.