For some National Notifiable Diseases Surveillance System (NNDSS) conditions, health departments use a surveillance system specialized for that disease. Jurisdictions use specialized systems when projects require substantial information that is not meaningful for other conditions, a small team within the health department manages all data for that disease, or the CDC program provides an interface for entry into a CDC-maintained system. Regardless of how CDC receives the data, CDC incorporates data from all these sources into the statistics published weekly and annually in the Morbidity and Mortality Weekly Report and in other surveillance reports.
With modern standards-based, integrated surveillance information systems and electronic data transmissions, separate data systems are becoming less common. One objective of the NNDSS Modernization Initiative is to reduce the need for health departments to maintain separate disease-specific data systems.