Investigating the emergence of the Brazilian porcupinepox poxvirus in wild Brazilian porcupines (Coendou longicaudatus)

Brazilian porcupinepox virus (BPoPV) has been associated with fatal infections in free-ranging Brazilian porcupines (Coendou longicaudatus), raising concerns regarding its epidemiology and conservation impact. This study comprehensively investigates BPoPV infection, pathology, and mortality in a free-living population from the Federal District, Brazil. Between 2021 and 2024, 30 porcupines submitted for postmortem examination were evaluated using gross and histopathology, PCR, epidermal morphometric analysis, and transmission electron microscopy. BPoPV infection was detected in 70% of animals (21/30), including all ten fatal cases and eleven individuals that died from unrelated traumatic injuries. Six PCR-positive animals without gross lesions showed significant epidermal thickening on microscopy, revealing a previously unrecognized subclinical infection. Fatal cases consistently exhibited severe proliferative and degenerative cutaneous lesions, intracytoplasmic inclusions, marked dermal inflammation, and visceral involvement, particularly interstitial pneumonia, esophageal pustules, and lymphoid depletion, suggesting systemic dissemination. Ultrastructural analysis confirmed abundant poxvirus-like particles within keratinocytes. Traumatic injuries, mainly dog attacks and electrocution, represented the most frequent noninfectious cause of death. These findings demonstrate a high frequency of clinical and subclinical BPoPV infection, identify the virus as a major infectious threat, and provide essential baseline data to support wildlife disease surveillance and conservation strategies for C. longicaudatus.