Exposure to infectious pathogens

Introduction For the entire evolution of our species, we have been exposed to a wide range of infectious agents – parasites, bacteria, and viruses – resulting in a range of diseases. The dental and skeletal evidence for some of these diseases, mostly chronic, is well documented (Aufderheide & Rodriguez-Martin, 1998; Ortner, 2003; Roberts & Manchester, 2005). Current bioarchaeological inquiry emphasizes biocultural perspectives of disease in relation to social, cultural, and environmental contexts and risks for infection, impacts on population, and implications for pathogen – host evolution (Armelagos & Van Gerven, 2003; Buikstra, 2010; Buikstra & Cook, 1980; Larsen & Walker, 2010). This growing record of health in past populations and especially the emphasis on origins and evolution of infectious disease in the biocultural context provides a powerful approach for understanding health determinants and outcomes in the world we live in today. Infection by a pathogen does not always result in disease. The progression from infection to disease depends on agent pathogenicity, transmission route from agent to host, and the strength and nature of the response of the host (Brown et al., 2011; Inhorn & Brown, 1990; Smith & Moss, 1994). Many acute infectious diseases or epidemics result in death of the infected individual soon after microbial attack. These infectious diseases leave no skeletal record, clouding the full picture of disease and its relationship to mortality in past populations. A number of chronic infectious diseases affect osseous tissues in patterned ways. Despite the interpretive drawbacks and sometimes lack of specificity, the study of bone lesions documenting disease provides important perspectives on health in earlier societies and the impacts of particular living circumstances on the human condition.