New research overturns long-held beliefs about leprosy in the Americas, demonstrating its presence well before European explorers arrived.
At a Glance
- A new species, Mycobacterium lepromatosis, responsible for leprosy in the Americas, predates European contact.
- The study challenges the notion that Europeans introduced leprosy to the continent.
- DNA analysis reveals Mycobacterium lepromatosis existed 1,000 years ago in the Americas.
- Research points to possible unknown animal vectors as carriers of the disease.
- The findings emerged from an international collaboration, led by the Institut Pasteur, Paris.
New Discoveries in Leprosy
Researchers have revealed the existence of Mycobacterium lepromatosis, alongside Mycobacterium leprae, as a cause of leprosy in the Americas before European explorers set foot in the New World. Genetic sequencing of ancient skeletal remains from Argentina and Canada shows the bacteria were endemic, challenging the theory that Europeans first brought the disease to the continent. The Institute Pasteur, in conjunction with the French National Centre for Scientific Research and the University of Colorado, spearheaded this groundbreaking research.
Unexpectedly, DNA samples from ancient and recent contexts highlight that Mycobacterium lepromatosis was widespread across North and South America well before European contact. Researchers studied over 800 DNA samples, showcasing the bacterium’s rapid spread. Analysis from Canada to Argentina reveals that the pathogens spread across the continent, supporting the idea of a naturally occurring disease among Indigenous populations.
Questioning Established History
This new evidence poses significant questions about leprosy’s history in the Americas. Findings suggest Indigenous populations had the disease long before European arrival. The research, utilizing advanced genetic techniques to reconstruct genomes, disputes the belief that European settlers were responsible for introducing the disease. Results indicate unknown animal vectors or reservoirs might have played a role in spreading Mycobacterium lepromatosis.
Dr. Maria Lopopolo remarked, “This discovery transforms our understanding of the history of leprosy in America. It shows that a form of the disease was already endemic among Indigenous populations well before the Europeans arrived.”
The study examined over 400 modern cases from countries like Mexico and Brazil. Most bacterial strains matched those from ancient samples, suggesting the ancient lineage’s persistence today. A rare strain found in a North American patient indicates multiple lineages may exist.
Impacts and Implications
The international collaboration between scientists and Indigenous communities underscores the importance of ethical research practices in uncovering historical truths. The profound impact of these findings reshapes our understanding of infectious diseases’ epidemiology, offering lessons for current pathogen studies.
The potential involvement of unknown animals as carriers introduces layers of complexity in tracing the pathogen’s origins. Dr. Nicolás Rascovan notes, “clearly illustrates how ancient and modern DNA can rewrite the history of a human pathogen and help us better understand the epidemiology of contemporary infectious diseases.”
The study highlights the necessity for continued research into human diseases’ ancient pathways and evolving interactions with hosts. As genetic studies unfold, they allow greater clarity, challenging preconceived notions of diseases’ histories.
