Public health officials rely on health providers, laboratories, and other public health personnel to report the occurrence of notifiable diseases to state and local health departments. Without such data, monitoring trends or evaluating the effectiveness of intervention activities would be difficult.

The Council of State and Territorial Epidemiologists (CSTE) has recommended that state health departments report cases of selected diseases (Table_1) to CDC's National Notifiable Diseases Surveillance System (NNDSS). However, the usefulness of such data has been limited by the lack of uniform case definitions for public health surveillance (1). Without explicit criteria for identifying cases, state health departments and individual practitioners have used various criteria for case reporting. This document, prepared in cooperation with the CSTE, provides uniform criteria for reporting purposes. States that wish to improve the specificity of reporting may find the definitions helpful. As uniform case definitions are adopted, the incidence of reported diseases in different geographic areas may be more meaningfully compared.