Ancient Origins of Leprosy in the Americas Discovered

Recent scientific research challenges long-held beliefs about the history of leprosy, an infectious and potentially severe disease. A groundbreaking study indicates that a specific bacteria responsible for leprosy existed in the Americas centuries before European explorers set foot on the continent. This discovery significantly alters the narrative of how and when the disease arrived in the New World.

Uncovering a Second Bacterial Culprit

Scientists from the Institut Pasteur in Paris, in collaboration with a prominent U.S. university, announced that a second bacterial species, in addition to the well-known Mycobacterium leprae, was responsible for leprosy in the Americas. This revelation was shared in a recent press release and underscores the complexity of the disease’s history in the region.

Challenging Previous Assumptions

Traditionally, it was believed that Mycobacterium leprae caused leprosy and that its presence in the Americas was solely due to European explorers and settlers transmitting the disease. However, the identification of Mycobacterium lepromatosis as another causative agent suggests that leprosy was already endemic among indigenous populations long before European contact.

Ancient DNA Evidence Confirms Long-Standing Presence

Researchers have found that Mycobacterium lepromatosis infected humans at least 1,000 years prior to the arrival of Europeans. Dr. Maria Lopopolo, lead author of the study and a researcher at the Laboratory of Microbial Paleogenomics, emphasized the significance of this discovery. She stated, “This fundamentally changes our understanding of leprosy in the Americas. It shows that the disease was already widespread among indigenous communities before Europeans arrived.”

New Cases and Genetic Insights

The study began after the bacteria Mycobacterium lepromatosis was detected in a Mexican patient in 2008 and in red squirrels in the British Isles in 2016. Using advanced genetic sequencing techniques, scientists reconstructed the genomes of the bacteria from ancient human remains in Argentina and Canada. Their findings revealed that both strains are closely related within the bacterial family tree, indicating rapid spread across the continent.

Implications for Human and Animal Health

The research confirms that Mycobacterium lepromatosis was widespread throughout North and South America long before European contact. The team collaborated with indigenous communities, archaeologists, and international institutions to analyze over 800 DNA samples from ancient remains and modern cases showing signs of leprosy. These findings open new questions about the disease’s transmission pathways and potential animal reservoirs.

Potential Animal Reservoirs and Future Research

Lead researcher Nicolás Rascovan highlighted that understanding the disease’s history could reshape our view of human migration and pathogen spread. He mentioned, “We are just beginning to uncover the diversity and global movement of this recently identified pathogen. There could be unknown animal reservoirs contributing to its persistence.”

Leprosy Today and Ongoing Concerns

The Centers for Disease Control and Prevention (CDC) reports that leprosy can affect skin, nerves, and eyes, and is treatable with antibiotics. While relatively rare in the United States, with up to 225 cases annually, the disease remains a global health concern, with approximately 250,000 new cases reported worldwide.

Ethan Cole

I'm Ethan Cole, a tech journalist with a passion for uncovering the stories behind innovation. I write about emerging technologies, startups, and the digital trends shaping our future. Read me on x.com