Effective disease surveillance and response capabilities are critical to robust public health systems and overall global health security. Early detection and response initiatives promote the containment or control of an outbreak which may avert regional epidemics or a global pandemic. According to the World Health Organization (WHO), core functions of these systems include: surveillance strategy and coordination, early warning systems; case detection, testing and confirmation; epidemiological data analysis and reporting; epidemic preparedness and effective control measures in response to an outbreak.

Public health departments also run ongoing programs to prevent, control and treat remerging infectious diseases and persistent epidemics. These include tuberculosis, multidrug-resistant tuberculosis (MDR-TB) and HIV/AIDS.