Researchers have suggested that leprosy might have been transmitted to humans during the Middle Ages by squirrels. They examined bones from red squirrels and human remains from archaeological sites in Winchester, southern England, finding a close link between the bacterium responsible for leprosy in both cases, as reported by the BBC.
Leprosy, a chronic and contagious disease affecting the skin, nerves, and mucous membranes, hasn’t been reported in the UK for 70 years but remains endemic in many other countries. While it’s commonly believed that armadillos can transmit the disease to humans, there has never been a documented case of human-to-human transmission, and experts suggest the risk is extremely low. Nonetheless, some current red squirrels in the UK are carriers of leprosy.
This discovery marks the first time the host for leprosy during the Middle Ages has been identified as an animal. Dr. Sarah Inskip from the University of Leicester, a co-author of the study, expressed surprise at finding leprosy in modern squirrels and noted the significance of uncovering its presence in medieval times. She remarked, “It really challenges the prevailing notion that leprosy was exclusively a human disease.”
The exact direction of transmission between squirrels and humans during the Middle Ages remains unclear. However, the discovery of a common strain suggests a previously unrecognized route of transmission between humans and animals during that time period, potentially involving HIV, according to the researchers.