Epidemiology

Epidemiology is a branch of medical science which investigates and describes the causes and spread of disease and develops the means for prevention or control. The word is derived from the Greek words meaning 'about',  meaning 'population' and  meaning 'study'. It is a essential medical science that focuses on the distribution and determinants of disease frequency in the human population. Epidemiologists may study many different illnesses, often focusing on major infectious diseases such as influenza or cholera.

Fields
Epidemiologists can be separated into two groups—research and clinical.

Research Epidemiology
Research epidemiologists conduct research in an effort to eradicate or control infectious diseases. Many work on illnesses that affect the entire body, such as AIDS or typhus, while others focus on localized infections such as those of the brain, lungs, or digestive tract. Research epidemiologists work at colleges and universities, schools of public health, medical schools, and independent research firms. For example, Federal Government agencies, such as the U.S. Department of Defense, may contract with a research firm to evaluate the incidence of malaria in certain parts of the world. Other research epidemiologists may work as college and university faculty and are counted as postsecondary teachers.

Clinical Epidemiology
Clinical epidemiologists work primarily in consulting roles at hospitals, informing the medical staff of infectious outbreaks and providing containment solutions. These epidemiologists sometimes are referred to as infection control professionals, and some of them are also physicians. Clinical epidemiologists who are not also physicians often collaborate with physicians to find ways to contain outbreaks of diseases. In addition to traditional duties of studying and controlling diseases, clinical epidemiologists also may be required to develop standards and guidelines for the treatment and control of communicable diseases. Some clinical epidemiologists may work in outpatient settings.

Types of disease

 * Main Article: Disease