Infectious processes in ancient populations (5200–100 years BP) from Patagonia, Argentina

Abstract

The study assessed the impact of infectious diseases on ancient hunter- gatherer communities in Southern Patagonia, by examining skeletal lesions in human remains dating from the Middle to Late Holocene period (c.5200–100 years BP). A macroscopic analysis was conducted on 46 adults and eight non-adults (30 males, 15 females, and nine indeterminate) from 50 archaeological sites across the region. The presence, location, type of new bone formation (woven, lamellar, mixed), and distribution of bone lesions was recorded, followed by a differential diagnosis and classification according to the Istanbul Protocol. In addition, the biological sex, age-at-death and regional and temporal location of the affected individuals was evaluated. The results revealed lesions highly indicative of infection in eight individuals (14.8 %), with no discernible differences based on sex or age. Three of these individuals died prior to European-indigenous contact, with six individuals originating from South Tierra del Fuego. Four individuals exhibited lesions strongly indicative of osteomyelitis, while two displayed lesions highly compatible with tuberculosis. These findings suggest recurrent infections among Southern Patagonian hunter-gatherers. Some osteomyelitis-related lesions might have stemmed from previous traumas, potentially necessitating communal assistance for treatment or healing. Moreover, the tuberculous lesions found across multiple skeletal elements (ribs, spine, tibias, femurs, and ulnas) indicate an extra-pulmonary stage of the disease, providing valuable insights into the nature and spread of infections within these ancient populations. These observations highlight the significant impact of infectious diseases on the health and lives of these prehistoric communities in Southern Patagonia.