The Role of Epidemiology in Building Coherent Systems of Public Health
In most if not all countries of the world Public Health is being built and operated in a piecemeal way. Its various parts are rarely linked to each other by an all-embracing concept and often not by their practice either. The reasons are largely historical. A particular Public Health Service was created when there seemed to be a more or less urgent need. Screening in schools for tooth decay, bad eyesight and other ailments is a typical example. This practice started about one and a half centuries ago. Preventive measures such as hygiene, clean drinking water, sewage systems, and recommendations about nutrition and physical activities are documented from ancient Egypt, China, Greece and Rome but not as parts of a general systematic effort. Immunizations followed in the nineteenth Century after some forerunners; see Sect. 5.1.