Fifty years of epidemiology at the Centers for Disease Control and Prevention: significant and consequential.

The Epidemic Intelligence Service (EIS) was the vision of Alexander Langmuir, who developed a program with a vital mission to address an unmet need in the United States. The Communicable Disease Center, now the Centers for Disease Control and Prevention (CDC; Atlanta, Georgia), and the EIS steadily expanded from focusing on infectious disease to address chronic diseases, health statistics, occupational and environmental health and safety, injury prevention and control, and reproductive health. Langmuir recognized the need for epidemiologists to collaborate with others, initially from the laboratory and later including veterinarians, demographers, statisticians, nutritionists, behavioral and social scientists, industrial hygienists, and sanitarians. These partnerships stimulated the further evolution of the EIS Program to include sophisticated statistical analysis, economics, and the tools of the behavioral and social sciences. A mixture of analytical rigor and practical application characterizes the practice of epidemiology at CDC and in the EIS. Thus, the "significant" in the title of this paper refers to the analytical rigor of the public health approach and the validity of the results, while the "consequential" reflects the practical application of the results, trying to make a difference in health outcomes.