Global Surveillance for Meningococcal Disease

The word “surveillance” probably first referred to close supervision of individuals exposed to an infectious disease and their close contacts (1 ). Currently, though, surveillance refers more frequently to the ongoing accumulation of data so that it can be used for decision-making. A surveillance system includes collection, analysis, and dissemination of data. Surveillance can be used to evaluate trends in disease, to identify outbreaks, to test hypotheses, to evaluate existing programs, and to plan for new programs. Surveillance is the single most important tool for identifying infectious diseases that are emerging, are causing serious public health problems, or are diminishing in importance (2 ).