This document serves as a brief summary of steps in an outbreak investigation, as well as important terminology. All of the examples relate back to a Salmonella Typhimurium outbreak in peanut paste (and other peanut products). The document also includes links to websites that provide further information on epidemiology and foodborne illness outbreak investigations. Epidemiology is the scientific method used to investigate, analyze and prevent or control diseases in a population. It is helpful to remember that epidemiology is different from the practice of medicine. If a person comes down with the flu, a doctor would examine them and recommend treatment. An epidemiologist would get involved if entire groups of people got sick, and they would want to know more: how people got sick, why people got sick, when people got sick, etc.

Stephen B. Thacker CDC Library collection