Medieval pet squirrels suffered from leprosy

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When Kathleen Walker Meikle, a historian at the University of Basel in Switzerland, thinks about the Middle Ages, she thinks about squirrels, not religious conquests or Viking raids. To be more precise, it's a red squirrel with a tan back, white belly, and tufted ears. For hundreds of years, society's elite have kept red squirrels as pets by sewing them into luxurious floor-length cloaks, holding them in their laps, and fashioning them into golden collars adorned with pearls. Because human life was closely intertwined with that of red squirrels, One of the most cursed diseases in history There may have been repeated passages between our species and theirs, according to new research contributed by Walker Meikle.

Unpleasant questions about medieval squirrels first surfaced about 10 years ago, after another group of researchers accidentally discovered three populations of red squirrels. Scotlandtwo different british isles-He had strange characteristics, including swollen lips, a warty nose, and thick, crusty skin on his ears. A search for microbial DNA in some of the squirrel's tissues revealed that the squirrels had leprosy. “What's going on inside a red squirrel?” Colorado State University microbiologist John Spencer recalled thinking. For a long time, scientists believed that leprosy only infected humans, but Until the 1970sDaniel Romero-Alvarez, an infectious disease ecologist and epidemiologist at Ecuador's International University SEK, told me that the bacteria that causes armadillos was also starting to be discovered. But that was in the Americas. In Europe, it was established that leprosy had essentially disappeared. around 16th century. The most plausible explanation for the presence of the pathogen in modern squirrels, Spencer said, is that the strain has been infiltrating the rodent's body unnoticed for hundreds of years.

Bacterial genomes extracted from several infected British squirrels These sequences were very similar to other sequences previously extracted from medieval human remains. The next step was to prove that medieval squirrels also carried the bacterium, Verena Schuenemann, a paleogeneticist at the University of Zurich in Switzerland and one of the authors of the new study, told me. told. If the microbes were genetically similar to microbes found in medieval people, this would indicate that leprosy likely moved back and forth between rodents and humans on a regular basis.

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Working with archaeologist Sarah Inskip of the University of Leicester, Schuenemann set out to discover British sites containing both human and squirrel remains. They focused on the medieval city of Winchester, once famous for its fur-obsessed market patrons and large leper sanitariums. After analyzing dozens of samples taken from around Winchester, the research team was able to extract just four leprosy genomes. Three of them were from humans and one was from a small squirrel foot bone. But they turned out to be sufficient. All four samples date from the High Middle Ages and are the oldest cases of leprosy ever detected in non-human animals, Inskip said. The genomes also all bud from the same branch of the leprosy family tree and share sufficient genetic similarity, strongly indicating that medieval humans and squirrels were exchanging disease-causing insects. said Schuenemann.

Still, Schuenemann wasn't sure exactly how that would happen, given that leprosy transmission generally requires close contact over a long period of time. So, hoping to fill her void, she contacted Mr. Walker Meikle. widely studied medieval pets.

Walker Meikle already had the exact kind of evidence Schuenemann and others were looking for. Medieval artwork depicting people cradling animals, a document describing a woman taking her animals for a walk, and finances detailing the purchase of rodent-sized flashy accessories and enclosures for the animals. Accounts, etc. Walker Meikle told me it's the kind of thing people today might buy for their pet dogs. At the time, squirrels were so popular that the 13th-century archbishop who, despite years of pleading, could not get the nuns in her district to stop doting on them. I found a description of the suffering of They essentially resemble small pet dogs, she said. The processing of fur would also have provided ample opportunity for dissemination. From the High Middle Ages to the Late Middle Ages, squirrel fur was the most popular fur used for trimming and lining clothing, and clothing made from squirrel fur is now considered as high fashion as a Prada bag. Schuenemann said. In just one year of the 14th century, the British royal family Approximately 80,000 pieces of squirrel belly skin. Because contact between squirrels and humans was so intimate, Inskip said leprosy likely passed back and forth between squirrels and humans throughout most of the medieval period.

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However, the team's study says nothing about the origins of leprosy, which infected humans at least several thousand years ago. It is also not possible to prove whether leprosy first entered humans or whether it was introduced by red squirrels. Romero-Alvarez said it further dispels the idea that leprosy is only a human problem. Armadillos may have acquired leprosy from humans relatively recently, after Europeans imported the pathogen into South America. The scaly mammal is now “giving it back to humans,” Spencer told me. especiallyApparently part of South America Southern United Statessome communities hunt animals for food or keep them as pets.

Although most of the spread of leprosy is still due to human-to-human transmission, it remains rare overall. But Professor Romero Álvarez pointed out that the mere presence of the bacterium in another species means that we and other organisms can be infected by it, making the disease even more difficult to control. “Everyone believes that leprosy is gone,” Claudio Guedes Salgado, an immunologist at Brazil's Federal University of Pará, told me. “But we have more lepers than the world thinks.” The barrier between species is porous. And once a pathogen gets in, it's impossible to completely reverse that jump.