Pathological and Molecular Characterization of Avipoxvirus Infection in Burhinus oedicnemus in the Canary Islands

Abstract

Avian poxvirus was diagnosed in eight wild Stone-curlews (Burhinus oedicnemus) from the Canary Islands, based on a combination of pathological and molecular analysis. Affected birds exhibited lesions consistent with poxvirus infection; three of four with mild lesions (≤2 on pelvic limbs, excluding phalanges) were successfully rehabilitated and released, while four with moderate (≤2 on phalanges) to severe lesions (≥3 on phalanges) potentially faced impaired mobility, increased predation risk, and reduced foraging efficiency. Histopathology of six individuals revealed Bollinger bodies, characteristic of Avipoxvirus infection, and molecular analysis confirmed the presence of viral DNA in six cases. Three genetically distinct viral variants were identified, each associated with different phylogenetic clades and subclades, suggesting substantial viral diversity within this host species. Co-infection with Aspergillus fumigatus was also detected in six of the eight birds, confirmed by molecular analysis in either skin lesions or lung tissue. To our knowledge, this represents the first report of A. fumigatus co-infection in Stone-curlews with Avipoxvirus. Additionally, one individual presented a tumor-like lesion, expanding the known pathological manifestations of the disease. These findings provide new insights into avian pox and highlight the importance of considering fungal co-infections in the differential diagnosis, given their potential to exacerbate disease severity.