New Study Reveals Leprosy Was Present in Chile 4,000 Years Ago
A recent study has uncovered evidence that leprosy was circulating in Chile around 4,000 years ago, indicating that the disease reached the Americas much earlier than previously believed. This groundbreaking research, conducted by a team of scientists from Germany, Argentina, and Chile, challenges the conventional notion that leprosy was introduced to the region by European colonizers in the 16th century.
The researchers conducted a thorough analysis of ancient bones and teeth, using DNA fragments extracted from two human skeletons to identify the presence of the Mycobacterium lepromatosis pathogen – the less common bacterium responsible for causing leprosy.
Anthropologist DarÃo Ramirez from the National University of Córdoba in Argentina commented on the findings, stating, “We were initially skeptical, as leprosy is typically associated with the colonial era, but further examination of the DNA confirmed the presence of the lepromatosis strain.”
Exploring the History of Leprosy
While M. lepromatosis is a relatively newly identified bacterium, with Mycobacterium leprae being the more prevalent strain linked to leprosy, researchers have traced the latter back thousands of years across Eurasia. This historical data has led experts to believe that leprosy was brought to the Americas from Europe.
Recent studies have also detected traces of M. lepromatosis in ancient remains from Canada and Argentina, dating back over a thousand years prior to the arrival of European settlers. The discovery in Chile pushes the timeline back even further, prompting a reevaluation of the disease’s history.

Uncovering Ancient Diseases
Anthropologist Kirsten Bos from the Max Planck Institute for Evolutionary Anthropology emphasized the significance of ancient DNA analysis in shedding light on diseases with a long history in the Americas. Advanced techniques allow researchers to investigate unexpected pathogens and expand our understanding of disease transmission and evolution.
By examining more genomes from archaeological sites and clinical samples, experts hope to unravel the complex history of leprosy and other ancient diseases. The discovery in Chile highlights the importance of looking beyond conventional narratives and exploring new avenues of research.
Anthropologist Rodrigo Nores from the National University of Córdoba noted, “This study reveals that leprosy was present in Chile 4,000 years ago, opening doors for further investigations in different contexts.”
The findings of this research have been published in Nature Ecology & Evolution.