A long-held narrative about leprosy has been debunked, as a new study reveals that a form of the disease was present in the Americas before European contact. Researchers analyzed ancient DNA from 389 individuals who lived in the Americas before European arrival and found evidence of the bacterium M. lepromatosis.
Contrary to popular belief, Europeans did not introduce leprosy to the Americas. Instead, scientists have discovered that this pathogen has been branching out and evolving in the region for nearly 10,000 years. The study also revealed that most modern cases of M. lepromatosis are caused by strains that originated from ancient times.
Researchers teamed up with Indigenous communities to analyze DNA samples from people who lived in the Americas before European contact. They found evidence of M. lepromatosis in remains from individuals near the Alaska-Canada border and in Argentina, dating back around 1000 years ago. The bacteria’s genomes varied slightly, suggesting distinct strains separated by around 12,000 kilometres.
The study suggests that at least two distinct lineages of M. lepromatosis are still infecting people in North America today, alongside the M. leprae strains introduced by Europeans. The findings also shed light on a pressing public health issue: leprosy is re-emerging in parts of the world and rising antimicrobial resistance could make it harder to treat.
Overall, this study forces a rethinking of the disease’s history and highlights the need for increased surveillance and global mapping of bacterial strains.
Source: https://www.newscientist.com/article/2482399-leprosy-was-in-the-americas-long-before-the-arrival-of-europeans