Adenovirus emergence in a red squirrel (Sciurus vulgaris) in Iberian Peninsula

Adenoviruses (AdV) are pathogens capable of infecting animals and humans leading to a wide spectrum of diseases. They have a widespread geographical dissemination and infect several species, including red squirrels (Sciurus vulgaris). In the Iberian Peninsula, there are no reports of infection of red squirrels by AdV. In this study, we report for the first time the detection of squirrel AdV in a red squirrel trapped in central Portugal. The phylogenetic analysis showed that the sequences obtained for the hexon and the penton base genes were similar to the Korean squirrel AdV strain and strongly divergent from the strains present in red squirrels in Europe. These findings indicate the emergence of a new strain circulating in Europe and raise concerns regarding the conservation of the red squirrel.