Implementing the concepts of William Farr: the contributions of Alexander D. Langmuir to Public Health Surveillance and Communications.

Among Alexander Langmuir's many accomplishments in public health and epidemiology, his contributions to public health surveillance were pivotal. Langmuir credited William Farr with founding the modem concepts of surveillance in the nineteenth century (1). However, it was Langmuir who built on his own introduction to public health practice in the Westchester County (New York) Health Department to orchestrate a paradigm shift in the application of these concepts to populations and to appropriate action in public health. In the 1950s, while he was serving as chief epidemiologist at the Communicable Disease Center (now known as the Centers for Disease Control and Prevention (CDC)) in Atlanta, Georgia, Langmuir applied the term "disease surveillance" to the careful monitoring of disease in a population (2). The basic elements of data collection, analysis, and dissemination were fundamental to Langmuir's concept of surveillance, as was the responsibility to use the data for public health practice-information for action. In the early 1950s, the first applications of these elements in disease surveillance were initiated to chart the decline of malaria, smallpox, yellow fever, and other diseases in local geographic areas for the purpose of monitoring prevention and control programs. In this paper, we describe chronologically Langmuir's contributions to the development of disease surveillance, with special emphasis on the use of the Morbidity and Mortality Weekly Report (MMWR) to communicate these data to those who need to know. We then describe the evolution of his concepts during the two decades following his retirement from CDC in