Long considered a disease brought to the Americas by European colonizers, leprosy may actually have a much older history on the American continent. Scientists from the Institut Pasteur, the CNRS, and the University of Colorado (U.S.), in collaboration with various institutions in America and Europe, reveal that a recently identified second species of bacteria responsible for leprosy, Mycobacterium lepromatosis, has been infecting humans in the Americas for at least 1,000 years, several centuries before the Europeans arrived. These findings are published in the journal Science. Leprosy: A Scientific Understanding Leprosy is a neglected disease, mainly caused by the bacterium Mycobacterium leprae, affecting thousands of people worldwide: approximately 200,000 new cases of leprosy are reported each year. Although M. leprae remains
