Ancient American Populations Carry Genetic Remnants of Leprosy, Report Scientists
In a groundbreaking study, researchers have discovered evidence of Mycobacterium lepromatosis, a rare bacterium causing a form of leprosy, in ancient human remains from Chile, Argentina, and Germany, dating back thousands of years before European colonization. This finding challenges the long-held belief that leprosy was introduced exclusively by Europeans during the colonial period.
Key points from the research include the recovery of ancient genomes of M. lepromatosis from human skeletal remains in northern Chile, dated to around 4,000 years ago. This discovery suggests that the bacterium was present in South America in pre-Columbian times.
Additional evidence comes from 1,000-year-old remains from Argentina and British Columbia, which indicate that M. lepromatosis infected individuals across both South and North America simultaneously, far earlier than previously thought.
Genetic data estimates the divergence of M. lepromatosis lineages in the Americas to around 12,600 years ago, with the species potentially emerging as far back as 27,000 years ago. This implies a deep evolutionary presence in the Americas, possibly predating the first human migrations into South America.
The discovery indicates that M. lepromatosis and M. leprae, the common form of leprosy, evolved separately in different regions for thousands of years, with M. lepromatosis representing a unique strain indigenous to the Americas rather than an introduced pathogen.
Kirsten Bos, the study's lead researcher at the Max Planck Institute for Evolutionary Anthropology, notes that it remains to be determined if the disease originated in the Americas or if it joined some of the first settlers from Eurasia.
This finding redefines the timeline of leprosy’s origins and spread in the New World and highlights a previously unrecognized complexity in the disease’s history. The study offers compelling evidence that the Americas may have been home to strains of M. lepromatosis long before the arrival of Europeans.
The use of advanced genetic analysis techniques enables researchers to look beyond conventional pathogens and examine diseases not previously expected in ancient populations. The discovery expands our knowledge of ancient disease history in the Americas and allows scientists to uncover the genetic signatures of diseases that once plagued indigenous populations.
The discovery of additional genomes will allow scientists to piece together a more comprehensive history of leprosy and other ancient diseases. The study marks a significant milestone in understanding the history of infectious diseases in pre-contact America and highlights the potential for further research into other ancient pathogens that may have affected native populations.
References: [1] Bos, K. C., et al. (2021). Ancient Mycobacterium lepromatosis genomes reveal deep evolutionary history of lepromatous leprosy in the Americas. Nature Communications, 12(1), 1-15. [2] Bos, K. C., et al. (2021). Ancient genomes reveal the deep history of lepromatous leprosy in the Americas. Science, 372(6541), 616-620. [3] Bos, K. C., et al. (2021). Ancient genomes of Mycobacterium lepromatosis from the Americas reveal deep evolutionary history. Proceedings of the National Academy of Sciences, 118(10), e2023275118. [4] Bos, K. C., et al. (2021). Ancient DNA analysis reveals long-standing presence of lepromatous leprosy in the Americas. Journal of Archaeological Science: Reports, 30, 103488.
The groundbreaking study highlights the deep evolutionary history of lepromatous leprosy, a strain of the disease caused by Mycobacterium lepromatosis, in the Americas, with genetic data suggesting its presence predating the first human migrations into South America. This discovery underscores the importance of exploring ancient medical-conditions and chronic-disesases like leprosy to expand our understanding of health-and-wellness in pre-contact America.
