Blueprint for a national public health surveillance system for the 21st century.

This article lays out a blueprint for public health surveillance and assessment for the year 2000 and beyond. The blueprint defines the roles of local, state, and national public health agencies and partners in the medical care system in conducting surveillance and assessment activities. It proposes a new over-arching National Public Health Surveillance System to be the conceptual framework for all public health surveillance and assessment activities into the 21st century.