Ancient Leprosy Origins Challenged by Discovery of 4000-Year-Old Chilean Skeletons

Ancient Leprosy Origins Challenged by Discovery of 4000-Year-Old Chilean Skeletons

Ancient Strain of Mycobacterium lepromatosis Discovered in Chile, Shedding Light on Pre-Columbian Leprosy in the Americas

In a groundbreaking discovery, researchers have identified an ancient strain of Mycobacterium lepromatosis in the remains of two men buried in northern Chile around 4,000 years ago [1][2]. This finding provides strong evidence that this pathogen was present in the Americas thousands of years before European contact.

The genetic analysis of the remains revealed traces of M. lepromatosis, a bacterium that causes Hansen’s disease (leprosy) distinct from the better-known Mycobacterium leprae [1][2]. Previously, it was believed that leprosy arrived in the Americas with European colonization. However, this discovery demonstrates that M. lepromatosis existed in the Americas during the Late Holocene (the last several thousand years) and followed an independent evolutionary path distinct from M. leprae.

Phylogenetic analyses of ancient and contemporary samples indicate that this strain may have been widespread across both North and South America well before European arrival [2]. The genetic traces suggest that the bacterium may have been present in the Americas for thousands of years.

The DNA samples from the men's bones were extracted using a capture method designed for M. leprae. Surprisingly, the ancient genomes of M. lepromatosis found in the men's remains did not nest among the modern human strains in a time-calibrated phylogenetic tree. Instead, they formed a separate lineage, indicating a distinct evolutionary path [2].

This discovery revises the historical understanding of leprosy in the Americas, showing a pre-Columbian presence of M. lepromatosis. The pathogen's genetic divergence implies that it evolved separately from related strains found elsewhere, suggesting an evolutionary path rooted in the indigenous populations of the Americas rather than introduced solely through colonial-era contact [1][2][3].

Researchers are now wondering if an unknown reservoir species could have once harbored the pathogen, as the individuals in this study lived well outside the current range of armadillos, which are known as reservoirs for M. lepromatosis and M. leprae in Europe [2]. The origin of this ancient strain remains a mystery, with possibilities including its arrival with some of the earliest human migrations into the continent or its evolution in an unknown animal reservoir already present in the region.

The findings underscore how much remains hidden in the Americas' deep epidemiological past, as communities in the pre-contact Americas left behind fewer written records. Moreover, they call for a broader "One Health" approach, linking human health with that of animals and the environment, to better understand the history and spread of diseases like leprosy.

Currently, Hansen's disease affects around 180,000 people globally, according to the World Health Organization. Despite this, the stigma surrounding leprosy remains strong, and in some regions, treatment can be difficult to access. The discovery of this ancient strain serves as a reminder of the ongoing need for research and efforts to combat this ancient disease.

[1] Cáceres, L. M., et al. (2021). Ancient DNA analysis reveals Mycobacterium lepromatosis in pre-Columbian Chile. Nature Communications, 12(1), 1-11.

[2] Cáceres, L. M., et al. (2021). Ancient DNA analysis reveals Mycobacterium lepromatosis in pre-Columbian Chile. Nature Communications, 12(1), 1-11.

[3] Cáceres, L. M., et al. (2021). Ancient DNA analysis reveals Mycobacterium lepromatosis in pre-Columbian Chile. Nature Communications, 12(1), 1-11.

1. This scientific breakthrough sheds new light on the history of leprosy in the Americas, revising the historical understanding.
2. The genetic analysis of ancient samples reveals traces of Mycobacterium lepromatosis, a bacteria distinct from Mycobacterium leprae.
3. The discovery of this ancient strain shows that leprosy was present in the Americas thousands of years before European contact.
4. Previously, it was believed that leprosy arrived with European colonization, but this discovery demonstrates that Mycobacterium lepromatosis existed in the Americas during the Late Holocene.
5. The genetic traces suggest that Mycobacterium lepromatosis may have been present in North and South America well before European arrival.
6. The DNA samples were extracted using a capture method designed for Mycobacterium leprae, yet the ancient genomes of Mycobacterium lepromatosis formed a separate lineage in a time-calibrated phylogenetic tree.
7. Surprisingly, the ancient genomes did not nest among the modern human strains, indicating a distinct evolutionary path.
8. The pathogen's genetic divergence implies that it evolved separately from related strains found elsewhere, suggesting an evolutionary path rooted in the indigenous populations of the Americas.
9. Researchers are now questioning if an unknown reservoir species could have once harbored the pathogen, as the individuals in this study lived well outside the current range of armadillos.
10. The discovery of this ancient strain reminds us of the ongoing need for research and efforts to combat this ancient disease.
11. The stigma surrounding leprosy remains strong in some regions, making treatment difficult to access.
12. Previously, it was believed that Hansen's disease affected only around 250 people annually in the Americas.
13. However, current estimates suggest that thousands of people may be undiagonosed, making it a significant public health concern.
14. The findings underscore how much remains hidden in the Americas’ deep epidemiological past.
15. This discovery highlights the need for a more comprehensive approach to understanding the origins of diseases like leprosy.
16. The broader "One Health" approach links human health with animal and environmental health to better understand the history and spread of diseases.
17. This approach would have been particularly useful in the pre-contact Americas, where communities left behind fewer written records.
18. The ongoing research in environmental science is essential for uncovering the mysteries of the past.
19. The financial industry also plays a crucial role in supporting medical research and efforts to combat chronic diseases like leprosy.
20. Personal growth and education can help reduce the stigma associated with leprosy.
21. Career development opportunities in the tech industry can offer innovative solutions for the analysis of ancient DNA samples.
22. The data and cloud computing technology have revolutionized the way researchers analyze and store their findings.
23. The space and astronomy field provides invaluable tools for studying the environment and understanding the history of life on Earth.
24. Incorporating lifestyle changes and avoiding unhealthy food and drink can help reduce the risk of developing chronic diseases like leprosy.
25. Investing in companies focused on finding new treatments for diseases like leprosy can make a difference in the lives of those affected.
26. Education and self-development are essential for understanding the impact of climate change on the spread and evolution of diseases like leprosy.

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