Public health surveillance is the continuous, systematic collection, analysis and interpretation of health-related data. Disease surveillance data:
- serves as an early warning system for impending outbreaks that could become public health emergencies;
- enables monitoring and evaluation of the impact of an intervention, helps track progress towards specified goals; and
- monitors and clarifies the epidemiology of health problems, guiding priority-setting and planning and evaluation public health policy and strategies.
Humanitarian emergencies increase the risk of transmission of infectious diseases and other health conditions such as severe malnutrition. An effective disease surveillance system is essential to detecting disease outbreaks quickly before they spread, cost lives and become difficult to control. Effective surveillance can improve disease outbreak detection in emergency settings, such as in countries in conflict or following a natural disaster.