Researchers are revisiting the timeline of when infectious diseases, especially leprosy, first emerged in America, suggesting these bacterial strains existed long before European explorers set foot on the continent.
A study conducted in collaboration with a US university revealed a second strain of bacteria related to leprosy, which challenges the long-held belief that the only significant source was Mycobacterium leprae, introduced by early settlers.
This new finding raises questions about the prevailing narrative, indicating that leprosy may have already affected Indigenous populations prior to European contact.
The bacterial strain, Mycobacterium repromatosis, was first identified in a Mexican patient back in 2008 and later spotted in a red squirrel from the British Isles in 2016. Dr. Maria Lopopolo, a key researcher from the Institute Pasteur in Paris, stated that this discovery alters our understanding of leprosy’s history, suggesting it was endemic among Indigenous peoples before Europeans arrived.
Utilizing advanced genetic techniques, scientists reconstructed the genomes from ancient samples found in Argentina and Canada, revealing a close genetic relationship between strains from different regions, indicating that this bacterium spread swiftly across the continent.
This study highlights not just past infections but opens up discussions about potential unknown reservoirs in animals, showing that the journey of this pathogen might be more complex than previously thought. As Nicholas Lascovan from the Pasteur Institute noted, there’s still much to uncover about the diversity and global migratory patterns of this bacterium.
The CDC notes that leprosy, though treatable with antibiotics, can impact nerves, skin, and eyes, with approximately 225 cases reported in the U.S. and about 250,000 cases worldwide.
