Ch. 2 The Epidemiologic Transition Health threats facing each stage of the Demographic Transition – developed by epidemiologist Abdel Omran in 1971

Let’s Begin with drawing our four stages of the Demographic Transition – but this time we title it Epidemiologic Transition Stage 1 – Pestilence and Famine Infectious and parasitic diseases are the main causes of human deaths along with animal/human attacks. Thomas Malthus called these “natural checks” on population growth. Most violent Stage 1 epidemic was the Black Plague (bubonic plague)

Epidemiologic Transition Stage 2 – Receding Pandemics Pandemics begin receding due to improved sanitation, nutrition and medicine during the Industrial Revolution. BUT this is not what Stage 2 countries start as…Cholera became a virulent epidemic in urban areas (due to contaminated drinking water) and not until Dr. John Snow used his on GIS to map outbreaks and solve the issue. However, construction of water and sewage systems helped to eliminate this type of pandemic. https://youtu.be/M7CeZXJ4DgM

Epidemiologic Transition Stage 3 – Degenerative Diseases Characterized by a decrease in deaths from infectious diseases and increase in chronic disorders associated with aging. Most important chronic disorders are cardiovascular disease (heart attacks) and cancer. Unlike Stage 2 diseases still found in most Sub-Saharan Africa and South Asia, there are very low rates of caner primarily due to lower life expectancy.

Epidemiologic Transition Stage 4 – Delayed Degenerative Diseases Omran’s work was extended by Jay olshansky and Brian Ault into a stage 4. The same degenerative diseases linger – cardiovascular disease and cancer BUT life expectancy of older people is extended through medical advances. These medical advances and improving health behaviors create population living longer…but obesity is however on the rise in stage 4 countries.