Abdel r omran biography of albert einstein

A term in demography

In demography and medical geography, epidemiological transition is a theory which "describes changing population patterns in terms of fertility, life expectancy, mortality, and leading causes of death."^[1] For example, a phase of development marked by a sudden increase in population growth rates brought by improved food security and innovations in public health and medicine, can be followed by a re-leveling of population growth due to subsequent declines in fertility rates.

Such a transition can account for the replacement of infectious diseases by chronic diseases over time due to increased life span as a result of improved health care and disease prevention.^[2][3] This theory was originally posited by Abdel Omran in 1971.^[4][5]

Theory

Omran divided the epidemiological transition of mortality into three phases, in the last of which chronic diseases replace infection as the