Surveillance is a key tool for public health decision making in all countries. Photo credit:WHOPublic health surveillance is the continuous and systematic collection, orderly consolidation and evaluation of pertinent data with prompt dissemination of results to those who need to know, particularly those who are in a position to take action. 

Effective disease control programmes rely on effective surveillance and response systems. Strengthening disease surveillance capacity makes countries better identify disease prevention priorities, plan for the best possible health of their populations, sensitize beneficiaries, focus evidence based interventions that work and monitor the trends to show impact as well as to detect issues to address. 

Surveillance should be a common public service using similar structures, processes and resources, while recognizing that different diseases may have specialized surveillance needs and exploiting opportunities for synergy when carrying out core functions (detection, confirmation, analysis, response) and support functions (training, supervision, communications, resource management).