An integrated approach to communicable disease surveillance.

Effective communicable disease control relies on effective response systems and effective response systems rely on effective disease surveillance. A functional surveillance system is essential in providing information for action on priority communicable diseases; it is a crucial instrument for public health decision-making in all countries. Surveillance data provide information, which can be used, for priority setting, policy decisions, planning, implementation, resource mobilization and allocation, and prediction and early detection of epidemics. A surveillance system can also be used for monitoring, evaluation and improvement of disease prevention and control programs. Disease surveillance is thus a critical component of the health system since it provides essential information for optimal health care delivery and a costeffective health strategy.