Leprosy in the Americas Before Columbus

For centuries, leprosy—now known as Hansen's disease—has carried the stigma of being a medieval scourge brought to the Americas by European colonizers. But new research disrupts that narrative. Long before ships from Spain or Portugal cast anchor in the New World, a form of leprosy had already taken hold among Indigenous populations of the Americas.

From this type of sample, ancient DNA techniques enable the reconstruction of human and pathogen genomes from the past. In the back, a Wiphala flag representing Indigenous communities of South America. Credit: Nicolas Rascovan, Institut Pasteur

A recent study published in Science¹, led by Maria Lopopolo and a broad consortium of archaeologists, microbiologists, Indigenous collaborators, and paleogenomic experts, presents compelling genetic evidence that Mycobacterium lepromatosis, a lesser-known cousin of M. leprae, was present across the American continent more than a millennium ago.