Extended Data Fig. 4: Confirmation of leprosy infection in Zora through histopathology of skin sample and lateral flow test.

a, Lepromatous leprosy, skin with diffuse histiocytic infiltrate in the dermis. The haematoxylin and eosin stain was conducted once; scale bar, 500 μm. b, Lepromatous leprosy, skin, acid-fast bacilli in histiocytes. The inflammatory infiltrate consists predominantly of histiocytes admixed with fewer lymphocytes. Histiocytes show foamy or vacuolated cytoplasm and containing bacteria surrounded by a clear zone. Fite-Faraco stain; scale bar, 20 μm. Fite-Faraco stain was conducted once and was controlled by a positive control slide containing mycobacteria. c, whole blood from Zora (1) and the positive control (2). d, whole blood from a chimpanzee at TNP (Olivia) not infected with M. leprae, used as negative control. C, control lane; T, test lane.