Ancient Leprosy in America: Pre-Columbian Evidence
Decades before the arrival of Europeans,leprosy ravaged the Americas.Groundbreaking research reveals that the bacterium Mycobacterium lepromatosis, causing this devastating disease, was present in North and South America a millennium ago, challenging the long-held belief that the disease arrived with colonizers. Scientists analyzed ancient DNA, uncovering evidence of the rapid spread of this neglected disease among indigenous populations. This study rewrites leprosy’s history with help of advanced genetic techniques, identifying new lineages and an ancestral branch of the primarykeyword that predates European contact, suggesting a vast diversification of the secondarykeyword on the continent. The findings, published in science, have implications for understanding contemporary infectious diseases. News Directory 3 reported on this crucial finding. Discover what’s next as researchers delve into identifying potential animal reservoirs.
Leprosy in Americas Predates Colonization, Study Finds
Leprosy, long thought to have been introduced to the Americas by European colonizers, may have a much deeper history on the continent. A new study indicates that Mycobacterium lepromatosis,a bacterium responsible for leprosy,was present in the Americas at least 1,000 years ago.
The research,conducted by scientists from the Institut Pasteur,CNRS,and the University of Colorado,suggests that this form of leprosy,a neglected disease,was endemic among Indigenous populations centuries before European contact. The findings were published in Science.
The study,led by scientists from the Laboratory of Microbial paleogenomics at the Institut Pasteur and the university of Colorado,analyzed DNA from nearly 800 samples.These included ancient human remains from archaeological excavations and recent clinical cases showing leprosy symptoms. the results confirm that M. lepromatosis was widespread in North and South america well before European colonization.
Dr. Maria Lopopolo, the study’s first author and researcher at the Institut Pasteur, said the discovery transforms the understanding of leprosy’s history in America, showing it was endemic among Indigenous populations before European arrival.
Using advanced genetic techniques, the team reconstructed genomes of M. lepromatosis from ancient individuals found in Canada and Argentina. Despite the geographical distance, these ancient strains, dating back approximately 1,000 years, were genetically close, suggesting a rapid spread of the pathogen across the continent within a few centuries.
Scientists also identified new lineages, including an ancestral branch that diverged from the rest of the known species’ diversity over 9,000 years ago but continues to infect humans in North America today. This suggests an ancient and long-lasting diversification on the continent.
Analyses suggest that strains found in red squirrels in the UK in 2016 are part of an American lineage introduced to the British Isles in the 19th century, highlighting the pathogen’s ability to cross continents through human or commercial exchanges.
According to Nicolás Rascovan, the lead author of the study and head of the Laboratory of Microbial Paleogenomics at the Institut Pasteur, the study illustrates how ancient and modern DNA can rewrite the history of a human pathogen and help better understand the epidemiology of contemporary infectious diseases.He added that the research allows them to hypothesize that there might be unknown animal reservoirs.
The project involved close collaboration with Indigenous communities, who participated in decisions regarding the use of ancestral remains and the interpretation of results. Ancient DNA and remaining materials were returned when requested, and the generated data was shared via ethical platforms designed to meet the specific expectations of Indigenous communities.
What’s next
Further research will focus on identifying potential animal reservoirs and understanding the full extent of Mycobacterium lepromatosis diversity in the Americas and globally, which could lead to better strategies for managing and preventing the spread of leprosy.