Geographies of twenty-first-century disease

The theory of epidemiological transition is derived from the earlier developed theory of demographic transition, which describes the shift from a situation of simultaneously high birth and death rates to the opposite—very low birth rates combined with low death rates. A. R. Omran emphasized that patterns of illness vary depending on geographical location and time period, and only marginally referenced the changing age structure of populations due to decreasing mortality. Pison draws attention to the interesting case of Senegal, a low AIDS prevalence country, where the mortality of children fell in the 1970s and 1980s, then plateaued in the 1990s, and started falling again at the beginning of the twenty-first century. The most commonly held view derived from the concept of epidemiological transition links changes in patterns of health and disease with the modernization of society. The double burden of disease is also pervasive in Asia.