By Stephen Beech & Rom Preston-Ellis Red squirrels spread a deadly disease to people in medieval England, reveals new research. Evidence from archaeological sites in Winchester, Hampshire, shows that the nut-loving rodents once served as an important host for Mycobacterium leprae strains that causes leprosy in humans. Study senior author Professor Verena Schuenemann said: “With our genetic analysis we were able to identify red squirrels as the first ancient animal host of leprosy. “The medieval red squirrel strain we recovered is more closely related to medieval human strains from the same cit…