The past, present, and future of public health surveillance.

This paper provides a review of the past, present, and future of public health surveillance-the ongoing systematic collection, analysis, interpretation, and dissemination of health data for the planning, implementation, and evaluation of public health action. Public health surveillance dates back to the first recorded epidemic in 3180 B.C. in Egypt. Hippocrates (460 B.C.-370 B.C.) coined the terms endemic and epidemic, John Graunt (1620-1674) introduced systematic data analysis, Samuel Pepys (1633-1703) started epidemic field investigation, William Farr (1807-1883) founded the modern concept of surveillance, John Snow (1813-1858) linked data to intervention, and Alexander Langmuir (1910-1993) gave the first comprehensive definition of surveillance. Current theories, principles, and practice of public health surveillance are summarized. A number of surveillance dichotomies, such as epidemiologic surveillance versus public health surveillance, are described. Some future scenarios are presented, while current activities that can affect the future are summarized: exploring new frontiers; enhancing computer technology; improving epidemic investigations; improving data collection, analysis, dissemination, and use; building on lessons from the past; building capacity; enhancing global surveillance. It is concluded that learning from the past, reflecting on the present, and planning for the future can further enhance public health surveillance.