Reference Work Entry

Encyclopedia of Public Health

pp 101-104


  • Hristina VlajinacAffiliated withInstitute of Epidemiology, School of Medicine, University of Belgrade




A cause of a disease can be defined as an event, condition, or characteristic that plays an essential role in producing an occurrence of the disease (Rothman 1986).

The most important aim of epidemiology is to identify the causes and the risk factors of a disease, and to improve public health by reducing or eliminating exposure to these factors.

Basic Characteristics

Epidemiological – Ecological Models

A disease is a result of the interaction of host factors and the environment. Several models have been developed in order to depict the ways in which these interactions influence the occurrence of the disease: the triangle, the wheel, and the web of causation.

The triangle – This model consists of three components, agent, host, and environment, which are in a kind of dynamic equilibrium. Change in any of these components will alter an existing equilibrium and increase or decrease the frequency of the disease. This model has been the most frequently app ...

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