Humans may have caught leprosy from squirrels in medieval times, researchers say.
They studied human and red squirrel bones from archaeological sites in Winchester, southern England, and found they had closely related strains of the bacteria that causes it.
Leprosy is a chronic disease infectious between humans that attacks the skin, nerves and mucous membranes. No-one is thought to have caught it inside the UK for 70 years but it’s still endemic in many parts of the world.
Armadillos carry it and are suspected of passing it on to humans. Some modern red squirrels in the UK also have it, but there has never been a reported case of transmission to humans and experts say the risk is very low.
It’s the first time a medieval animal has been identified as a host for the disease.
“The finding of leprosy in modern squirrels was surprising and then it’s incredible that we found it in the medieval period,” said study co-author Dr Sarah Inskip of the University of Leicester.
“It really goes against the narrative that it was a human disease specifically,” she said.
It’s not clear whether squirrels in medieval times gave humans leprosy or the other way around.
But the shared strain suggests it was circulating between people and animals in the Middle Ages in a way that hadn’t been detected before, the researchers say.
Back then, squirrel fur was used as a fine lining for clothes and some people also had pet squirrels. They were particularly popular with women.