Definition of Epidemiology


Epidemiology directly impacts public health policy. In an effort to prevent flu pandemics, epidemiologists track the flu and determine which strains go into flu vaccines.


Epidemiologists may specialize in a particular disease like diabetes or focus on a broader topic like environmental health. Epidemiology also has applications in fields such as economics.


Epidemiology requires an advanced degree of at least a Master's and sometimes a PhD.


Epidemiology has a long history dating back to Hippocrates who is believed to have been the first to relate cause and effect to disease. Today, sophisticated mathematical models and statistics are used to prove cause and effect.

Professional Standards

The work of epidemiologists must pass the Bradford-Hill Criteria checklist which requires data to be consistent and verifiable.

Famous Ties

The phrase "Typhoid Mary" is a historical example of epidemiology in action. A sanitary engineer was able to identify a maid, Mary Mallon, as a typhoid carrier even though she never had typhoid herself. The phrase now refers to someone who is contagious.

Fun Fact

In 1954, epidemiology uncovered the link between smoking and lung cancer. Epidemiology is the study of health and disease in a population with an emphasis on establishing cause and effect. It looks at how disease manifests and spreads in populations at risk to determine effective prevention and treatment. Epidemiology differs from other medical fields in that the focus is on the group, not the individual.