Leprosy in Americas Predates Europeans: Shocking New Study Unveils Ancient Bacterial Strain

A groundbreaking study has turned the history of leprosy in the Americas upside down, revealing that this infectious disease was present long before European explorers set foot on these shores. Scientists from the Institut Pasteur in Paris, alongside collaborators from the U.S., have discovered a second bacterial culprit behind leprosy, known as Mycobacterium lepromatosis, which predates the arrival of Europeans by a staggering 1,000 years.

For years, the narrative pinned the spread of leprosy—also called Hansen’s disease—on early European settlers carrying Mycobacterium leprae. But this new finding shatters that theory, proving that an endemic strain was already thriving among Indigenous populations across North and South America. Dr. Maria Lopopolo, a lead researcher, emphasized the paradigm shift, stating that this discovery rewrites our understanding of the disease’s origins in the region.

Using cutting-edge genetic techniques, researchers reconstructed the genomes of this ancient bacterium from remains in Argentina and Canada, uncovering a rapid spread across the continents. This suggests a deep-rooted presence that challenges everything we thought we knew. The study, which analyzed over 800 DNA samples from ancient and modern cases, also hints at potential unknown animal reservoirs—a mystery yet to be unraveled.

What’s clear is that leprosy’s story in the Americas is far more complex and ancient than previously imagined. As we continue to dig into the past, we’re not just uncovering pathogens; we’re rewriting human history itself.