Old and new approaches to epidemiology
Schematic diagram contrasting old and new approaches to epidemiology. Old static triangle labeled at its three points with: environment, agent, host. New triangle-shaped diagram, with interactive vector arrows pointing among all points, has labels: between environment and agent, are longevity and infectivity, distribution and transport, altered selective pressures; between agent and host, are tissue tropisms, pathogenicity, immune response, and host specificity; and between host and environment are nutrition, hygiene, treatment, and housing
Ecosystem Change and Public Health:.A Global Perspective, Chapter by Mark L. Wilson, pg. 286 fig. 10.1