Mycobacterium leprae
Red squirrels ("Sciurus vulgaris"), a threatened species in Great Britain, were found to carry leprosy in November 2016. It has been suggested that the trade in red squirrel fur, highly prized in the medieval period and intensively traded, may have been responsible for the leprosy epidemic in medieval Europe. A pre-Norman-era skull excavated in Hoxne, Suffolk, in 2017 was found to carry DNA from a strain of "Mycobacterium leprae," which closely matched the strain carried by modern red squirrels on Brownsea Island, UK.