Section for the Study of Child Growth and Development and Disease Patterns in Primitive Cultures, National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland 20014
Small populations living in marked isolation as hunters and gatherers, fisherfolk, or primitive hoe and digging-stick agriculturists, or plying isolated routes apart from major settled populations as migratory herders, often present medical problems that are unique or unusual. These groups are never large, but their importance to medicine may be disproportionately large because, for a number of reasons, they present unique situations of promise to investigations aimed at elucidations of the etiology, pathogenesis, ecology, or epidemiology of disease. These reasons lie in these peoples' close association with the flora and fauna, ectoparasites, and toxins of their geographically restricted territory; their lack of travel outside this territory, often in a lifetime; their high degree of inbreeding; and their customs, diets, and social patterns, which may result in a particular expression of a disease or a strange epidemiologic pattern. Thus, it is among such isolated groups that restricted populations with unusually high or unusually low incidence of certain diseases are to be found.