The discovery of Mycobacterium lepromatosis suggests that leprosy existed in the Americas long before European explorers arrived, reshaping the historical understanding of the disease.
Recent research indicates that a species of bacteria has significantly altered the timeline of leprosy’s presence in the Americas. Contrary to previous beliefs that the disease, also known as Hansen’s disease, was introduced by European explorers, findings suggest that leprosy was already endemic among Indigenous populations long before their arrival.
Scientists from the Institut Pasteur in Paris, France, in collaboration with a U.S. university, announced their findings in a news release. They revealed that a second species of bacteria, Mycobacterium lepromatosis, is responsible for leprosy in the Americas. Historically, it was thought that Mycobacterium leprae was the sole cause of the disease and that it was spread by early European settlers.
The revelation of Mycobacterium lepromatosis challenges this long-held belief, as it indicates that this strain of bacteria had been infecting humans for approximately 1,000 years prior to European contact. Dr. Maria Lopopolo, the first author of the study and a researcher at the Laboratory of Microbial Paleogenomics at the Institut Pasteur, emphasized the significance of this discovery.
“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,” Dr. Lopopolo stated in the release.
The study, which involved researchers from the Laboratory of Microbial Paleogenomics at the Institut Pasteur, the French National Center for Scientific Research, and the University of Colorado, began after Mycobacterium lepromatosis was identified in a Mexican patient in 2008 and in red squirrels in the British Isles in 2016.
Using advanced genetic techniques, scientists reconstructed the genomes of Mycobacterium lepromatosis from ancient individuals in Argentina and Canada. Their analysis revealed that the two strains from these different regions were closely related within the Mycobacterium genome family tree, suggesting that the bacteria spread rapidly throughout the continent.
The findings confirm that Mycobacterium lepromatosis had already disseminated across North and South America prior to European exploration. The research team collaborated with Indigenous communities, various international institutions, and archaeologists, studying over 800 DNA samples from ancient human remains and recent medical cases of leprosy.
Nicolás Rascovan, the lead author of the study at the Institut Pasteur, remarked on the implications of their research. “We are just beginning to uncover the diversity and global movements of this recently identified pathogen,” he said. “This study allows us to hypothesize that there might be unknown animal reservoirs.”
The Centers for Disease Control and Prevention (CDC) notes that leprosy can affect the nerves, skin, and eyes of patients, but it is treatable with antibiotics. Currently, there are up to 225 reported cases in the U.S. and approximately 250,000 cases worldwide, according to the CDC.
This groundbreaking study not only reshapes the historical narrative surrounding leprosy in the Americas but also opens new avenues for understanding the disease’s origins and its impact on Indigenous populations.
Source: Original article