02103nas a2200301   4500000000100000008004100001260004400042653003100086653001100117653002700128653001000155653002300165100001500188700001400203700001500217700002000232700001300252700002100265700001900286700002800305700001200333700001100345245012900356856005500485300000700540520124000547022001401787       2025                            d  bSpringer Science and Business Media LLC10aMycobacterium lepromatosis10aGenome10aRegion of the Americas10aChile10aHansen’s disease1 aRamirez DA1 aSitter TL1 aÖversti S1 aHerrera-Soto MJ1 aPastor N1 aFontana-Silva OE1 aKirkpatrick CL1 aCastelleti-Dellepiane J1 aNores R1 aBos KI00a4,000-year-old Mycobacterium lepromatosis genomes from Chile reveal long establishment of Hansen’s disease in the Americas  uhttps://www.nature.com/articles/s41559-025-02771-y  a133 a<p>Mycobacterium lepromatosis is a recently identified cause of Hansen’s disease, and is associated with the more severe and potentially lethal presentations of diffuse lepromatous leprosy and Lucio’s phenomenon. Detection of this infection has been limited to a small number of individuals, leaving much to be learned about its global distribution and transmissibility. Its discovery in wild rodent populations in the United Kingdom and Ireland also raises questions about its zoonotic potential. Here, we raise further awareness of this disease via analyses of two exceptionally well preserved M. lepromatosis genomes obtained from 4,000-year-old human remains of two adult males from the archaeological sites of El Cerrito and La Herradura in Northern Chile. This formed the basis of genomic comparisons between ancient and modern forms of the pathogen. We demonstrate an unexpected long history of M. lepromatosis in the Americas, which contrasts with the more recent Eurasian history of the closely related Mycobacterium leprae. We offer relevant perspectives on its evolution while providing an incentive for further disease monitoring in both humans and other potential reservoir species in the Americas and elsewhere.</p>
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