The vision of Public Health included defining the Substance of Public Health as organized community efforts aimed at the prevention of disease and promotion of health. It links many disciplines and rests upon the scientific core of Epidemiology. Epidemiology is “the study of the distribution and determinants of diseases and injuries in human populations. (Mausner and Kramer – Epidemiology and Introductory Text, W.B. Saunders Company, 2^nd Edition 1985).