ዶክፋን ፋርማ አካዳሚ

1. Epidemiological transition

Abdel Omran (1971) described the shift in the pattern of disease and death that comes with modernisation. He named three ages:

• Age of pestilence and famine: life expectancy 20 to 40 years; infections, malnutrition and childbirth deaths dominate; mortality high and fluctuating.
• Age of receding pandemics: improved nutrition, sanitation and medicine; epidemics become less frequent; life expectancy about 30 to 50 years and rising.
• Age of degenerative and man-made diseases: heart disease, cancer, diabetes, injuries; life expectancy above 50 years.

Later authors added further stages: an age of delayed degenerative diseases (cardiovascular deaths postponed to older ages) and an age of re-emerging infections, obesity and inactivity. Countries follow different pathways: the classical (Western) model; the accelerated model (Japan); and the protracted-polarised or delayed model of low- and middle-income countries, where infections and chronic diseases exist at the same time and the poor suffer most. This is the double burden of disease.

2. Demographic transition

The demographic transition describes the movement from high birth and death rates to low ones.

Key measures: crude birth rate (CBR), crude death rate (CDR), total fertility rate, life expectancy, the dependency ratio (people aged 0 to 14 and 65 and over per 100 people aged 15 to 64) and the age pyramid. A country with a high share of young people has a wide-based pyramid; when fertility falls, the working-age group becomes relatively large and a demographic dividend is possible, but only if there are jobs, education and good health. Ethiopia’s total fertility rate fell from above 7 in 1990 to about 4 in 2019, and its population is young, with a very large number of adolescents who will need services and jobs.

3. Nutrition transition

Barry Popkin described changes in diet and activity as societies develop: from hunter-gatherer diets, through famine, to a stage of receding famine and then to diets high in fat, sugar and processed foods with low physical activity and rising obesity and chronic disease, and finally a stage of behaviour change. Low- and middle-income countries now show a double burden of malnutrition: stunting, wasting and micronutrient deficiency alongside overweight and obesity, even in the same household. Ultra-processed foods, sugar-sweetened drinks, urban living and less walking drive the change.

4. Urbanisation

More than half of the world’s people now live in cities, and Africa is urbanising faster than any other region. Cities offer jobs, schools and clinics (the ‘urban advantage’), but rapid growth creates slums with crowded housing, poor water and sanitation, air pollution, injuries, violence, stress, and unhealthy food environments. The poor in cities may have worse health than rural neighbours because they live in informal settlements, pay for water and cannot use services.

• Communicable diseases: TB, cholera, measles, dengue and urban malaria (Anopheles stephensi) spread more easily in crowded areas.
• Non-communicable diseases: less physical activity, processed food, tobacco, alcohol.
• Injuries: road crashes, burns, fires, occupational injuries.
• Mental health: stress, isolation, unemployment.

Addis Ababa’s HIV prevalence (about 1.2 percent) is higher than the national average (about 0.8 percent) The Reporter 2026. Healthy city policies, safe water, sanitation, urban planning for walking and cycling, and strong primary care in informal settlements are key public health tools.

5. The health transition

The health transition (Frenk and colleagues, 1991) combines two parts: the epidemiological transition (changes in disease patterns) and the health-care transition (the way society organises its response: from hospital-based acute care toward long-term, prevention-oriented and community-based care). It also includes changes in knowledge, technology, financing and demand.