Overview

Epidemiology is the branch of medicine that deals with the investigation of the causes, distribution, and control of disease in the general population, rather than at the level of individual cases. Over the past 50 years there have been significant changes in disease patterns throughout the world. Epidemiology uses statistics not only to explain present disease patterns but also to help predict how they may change in the future. The explosion in the world's population that has taken place in the last half century and the vast environmental and lifestyle changes experienced worldwide have created significant shifts in the causes of mortality as well as in morbidity, the rate of incidence of diseases. The development and more widespread use of vaccines to prevent infectious diseases and of antibiotics (antibacterial drugs) also have had an important impact on morbidity and mortality. This essay...