Surveillance is the ongoing systematic collection, analysis, and interpretation of outcome specific data for use in planning, implementing and evaluating public health policies and practices. A communicable disease surveillance system serves two key functions; early warning of potential threats to public health and programme monitoring functions which may be disease specific or multi-disease in nature. (WHO 2006)
Modern disease surveillance systems in-country are essential and augmented by both formal global networks and the informal rapid exchange of information through social media, telecommunications, and other interchanges.
The WHO has developed a guide to monitoring and evaluating disease surveillance systems, available online. In their guide, they note:
As the momentum to scale up the global response to communicable diseases increases, public health practitioners need to constantly review their performance in detecting and responding to communicable diseases. At the same time, they should account for the planned activities, policies and resources to a variety of stakeholders.
The staff working at different levels of surveillance need to report accurate data in a timely manner to the next higher level to ensure timely and effective responses to contain communicable disease outbreaks. They may be required to report on progress to partners and donors, but most importantly, surveillance information should be used locally to address and resolve problems related to control of communicable diseases and to strengthen evolving programmes.
Monitoring and evaluation are keys to establishing and maintaining effective and efficient surveillance and response systems.