As late as the 1970s, conventional wisdom in epidemiology held that communicable diseases were on their way out as the predominant contributor to the world's morbidity profile, and were being replaced by noncommunicable diseases (NCDs) comprising degenerative diseases such as diabetes, circulatory disorders and cancers, and by accidents. Except for the developing countries, most of the rest of the world was already experiencing this so-called “epidemiological transition” from the terrible epoch of famines and pestilence that lasted from the dawn of mankind to the middle of this millenium, followed by the age of epidemics that culminated with the influenza pandemics of the earlier part of this century, to the prevailing situation since the 70s where diseases largely due to changed lifestyles — lack of exercise, high-fat diet, smoking and other substance abuses — predominate.
