Public Health Surveillance

The term surveillance, derived from the French word meaning “to watch over,” may be defined as a system providing close observation of all aspects of the occurrence and distribution of a given disease through the systematic collection, tabulation, analysis, and dissemination of all relevant data pertaining to that disease.(1) The preferred term is public health surveillance, which emphasizes the focus of surveillance as discussed in this chapter to develop data that results in a public health preventive act ion. This distinguishes public health surveillance from other types of surveillance.(2) Although the methodology of surveillance is basically descriptive, its function is more than merely collective and archival. Surveillance must be dynamic, current, purposeful, and result in a public health action. This action frequently results in the establishment of a new or the reinforcement of an existing public health policy. It is fundamental for the prompt and effective control and prevention of disease. Traditionally, surveillance was first applied to the acute communicable diseases in the mid-1800s.(3) Since then, surveillance methodologies have been utilized to cover a many infectious diseases,(1) a wide variety of non-infectious diseases, and other health-related events such as environmental hazards, potential bioterrorism events injuries, vaccinations, the distribution of biological products, and health-care delivery.