Figure 1.

The major components of a surveillance-response system. Four components are crucial: (i) a minimum database/dataset for data collection and management, (ii) data modelling by either statistical or mathematical models to forecast the future tendency of disease transmission, thereby providing the guidance for intervention, (iii) novel tools to sensitively detect or respond to low-transmission patterns and (re-)emerging pathogens, and (iv) evaluation of the chosen elimination programme. The overall goal will depend on additional indices to provide the threshold of zero transmission and specific parameters depending on specific scenarios (MED = Minimum Essential Database/set, M&E = Monitoring and Evaluation). (This figure was contributed by Dr. Guo-Jing Yang, and Dr. Jing-Fan Xu).