Epidemiologic field investigations by the Centers for Disease control and Epidemic Intelligence Service, 1946-87

The epidemiologic field investigation is an important tool used by the Centers for Disease Control (CDC) to provide assistance to State, local, and international public health agencies. The Epidemic Intelligence Service (EIS) of the CDC is an ongoing program that gives physicians and other health professionals opportunities to learn and practice epidemiology. In the period 1946-87, EIS Officers and other professional staff based at CDC headquarters participated in 2,900 epidemiologic field investigations requested by State, local, and international public health agencies. Nearly two-thirds of the investigations involved infectious disease problems, while 13 percent involved noninfectious conditions; for 21.1 percent, the etiology of the problem was unknown when the investigation was initiated. Among the specific subcategories, bacterial causes were the most common, accounting for 864 (29.8 percent) of all investigations. During this 41-year period, an increasing proportion of the field epidemiologic investigations involved public health problems of noninfectious etiology. Trends in the types of investigations done probably represent the influence of such factors as CDC's priorities, organizational structure, and budget; the size of the EIS Program; national health initiatives; and the States' needs and programs.