Recent scientific research conducted in Winchester, England, has uncovered evidence suggesting that leprosy may have been transmitted between humans and red squirrels during the medieval period. The study, led by Dr. Sarah Inskip at the University of Leicester, involved genetic analysis of bone samples from both humans and red squirrels. Results published in Current Biology show a close genetic match in the strains of Mycobacterium leprae, the bacteria responsible for causing leprosy, found in samples from both species.

This discovery challenges the previously held belief that leprosy was primarily spread among humans and certain other animals like armadillos. The research highlights the potential role of the medieval fur trade and the historical practice of keeping squirrels as pets, which may have facilitated this interspecies transmission. Winchester, a significant medieval trade center with a leper hospital, provided an ideal setting for this study due to the availability of both squirrel and human remains.

While modern red squirrels in the UK have been found to carry strains of the leprosy bacteria, Dr. Inskip emphasized that the risk of contracting leprosy from squirrels today is extremely low, as the disease is not highly contagious and requires prolonged contact for transmission.

The findings are particularly relevant in the context of current global health challenges posed by zoonotic diseases. Understanding the historical transmission of infections like leprosy could offer insights into managing diseases that can be spread from animals to humans. Currently, leprosy affects approximately 208,000 people worldwide, predominantly in Asia and Africa, despite being treatable with antibiotics.

The culmination of this research not only contributes to our understanding of medieval health and diseases but also to the broader implications of human interaction with wildlife and the potential risks involved.