Glossary of Foodborne Surveillance Terminology
Epidemiology Terminology

Endemic ~ the constant presence of a disease or infectious agent within a given geographic area, or the usual prevalence of a given disease within such an area

Epidemic Curve ~ a histogram that shows the course of an outbreak or epidemic by plotting the number of cases of a disease according to time of onset

Epidemiologic Triad ~ the traditional model of infectious disease causation, which has three components: an external agent, a susceptible host agent, and an environment that brings the host and agent together so that disease occurs.

Host ~ a person or other living organism that is susceptible to an infectious agent under natural conditions.

Agent ~ a factor that is essential for a disease. Examples of agents include microorganisms, chemical substances, forms of radiation, and, in the case of injury, physical force. Agents can cause a health problem by either by being introduced, being present in excess, or being present at deficient levels.

Environment ~ an extrinsic factor, such as geology, climate, insects, sanitation, or health services, that affects an agent and the opportunity for exposure.

Foodborne Illness ~ the result of eating food contaminated with bacteria (or their toxins) or other pathogens such as parasites or viruses. The illnesses range from upset stomach to more serious symptoms, including diarrhea, fever, vomiting, abdominal cramps, and dehydration