Abstract
BACKGROUND: The model of epidemiologic transitions has served as a guiding framework for understanding relationships between patterns of human health and disease and economic development for the past several decades. However, epidemiologic transition theory is infrequently employed in epidemiology. OBJECTIVE: Moving beyond Omran's original formulation, we discuss critiques and modifications of the theory of epidemiologic transitions and highlight some of the ways in which incorporating epidemiologic transition theory can benefit theory and practice in epidemiology. DESIGN: We focus on two broad contemporary trends in human health that epidemiologic transition theory is useful for conceptualizing: the increased incidence of chronic inflammatory diseases (CIDs), such as allergic and autoimmune diseases, and the emergence and reemergence of infectious disease. RESULTS: Situating these trends within epidemiologic transition theory, we explain the rise in CIDs with the hygiene hypothesis and the rise in emerging and reemerging infections with the concept of a third epidemiologic transition. CONCLUSIONS: Contextualizing these trends within epidemiologic transition theory reveals implications for clinical practice, global health policies, and future research within epidemiology.