National Notifiable Diseases Surveillance System (NNDSS)
In partnership with the Council of State and Territorial Epidemiologists (CSTE), the Epidemiology Program Office of CDC operates NNDSS. The primary purpose of the system is to provide weekly provisional information about the occurrence of diseases defined as notifiable by CSTE. The system also provides summary data on an annual basis. State epidemiologists report cases of notifiable diseases to the Epidemiology Program Office, which tabulates and publishes these data in the Morbidity and Mortality Weekly Report (MMWR) and the Summary of Notifiable Diseases, United States (entitled Annual Summary before 1985). Notifiable disease surveillance is conducted by public health practitioners at local, State, and national levels to support disease prevention and control activities.
Notifiable disease reports are received from health departments in the 50 States, 5 territories, New York City, and the District of Columbia. Policies for reporting disease cases may vary by disease or reporting jurisdiction, depending on case status classification (i.e., confirmed, probable, suspect). CSTE and CDC annually re-review the status of national infectious disease surveillance and recommend additions or deletions to the list of nationally notifiable diseases on the basis of the need to respond to emerging priorities. Reporting nationally notifiable diseases to CDC is voluntary. Reporting is currently mandated by law or regulation only at the local or State level. Thus the list of diseases that are considered notifiable varies slightly among the States. The degree of completeness of reporting is influenced by the diagnostic facilities available; the control measures in effect; public awareness of a disease; and the interests, resources, and priorities of State and local officials responsible for disease control and public health surveillance. Factors such as changes in case definition for public health surveillance, introduction of new diagnostic tests, or discovery of new disease entities can cause changes in disease reporting that are independent of the true incidence of disease.
For further information, contact
Chief, Surveillance System Branch
Division of Public Health Surveillance and Informatics
Epidemiology Program Office
Centers for Disease Control and Prevention
4770 Buford Highway, MS–K74
Atlanta, GA 30341–3717
www.cdc.gov/epo/dphsi/phs.htm
www.cdc.gov/epo/dphsi/nndsshis.htm
