New research reveals that a form of leprosy caused by Mycobacterium lepromatosis existed in the Americas over 1,000 years before European colonization, challenging the long-held belief that Europeans introduced the disease. Scientists discovered ancient DNA evidence in samples from Canada and Argentina. While leprosy is largely eradicated in many places, this finding suggests M. lepromatosis, a less-studied leprosy-causing bacteria, may pose a greater threat than previously thought, and its origins and spread are still under investigation. The research highlights the need for further study of this neglected pathogen.

Prepared by Olivia Bennett and reviewed by editorial team.