Surveillance for the Expanded Programme on Immunization

Abstract

Surveillance is the foundation of public health practice. This review examines the experience of surveillance in the Expanded Programme on Immunization (EPI). Surveillance systems include routine reporting, sentinel surveillance, and community-based reporting. Data from ongoing surveillance should be linked with those from supervision, health facility assessments, population surveys, and outbreak investigations to provide information for programme planning, implementation, evaluation, and modification. Evaluation of surveillance systems should assess the extent to which data are used for policy-making and programme improvement, and the simplicity, accuracy, completeness, timeliness and cost of the data. The surveillance of vaccine-preventable diseases has evolved as programmes mature, to monitor progress towards disease control targets. The establishment of goals to reduce measles cases by 90%, eliminate neonatal tetanus, and eradicate poliomyelitis has put increased emphasis on the need for effective disease surveillance. This opportunity should be taken to promote strengthening of national routine systems for disease surveillance, to make them effective instruments for prevention and control of diseases of public health importance.

PIP: Public health programs and activities are based on surveillance. The WHO Expanded Programme on Immunization (EPI) has designed and used different surveillance methods to improve disease control. It uses various methods of data collection. Routine reporting includes immunization coverage and cases of EPI target diseases (measles, neonatal tetanus, and poliomyelitis). Surveillance through sentinel sites and community-based reporting are other methods of data collection. Immunization programs should like their ongoing surveillance data with data supervision of immunization practices, health facility assessments, population surveys, and outbreak investigations. Program managers and other public health decision makers should use surveillance data to determine public health priorities, to decide on appropriate immunization schedules and strategies, to target populations at high risk, to implement immunization programs, and to evaluate program effectiveness. The US Centers for Disease Control have developed guidelines for evaluating surveillance systems. Surveillance system evaluations should examine the degree to which public health officials use data for policy-making and program improvement. They should also consider the timeliness, completeness, simplicity, accuracy, and cost of surveillance data. Public health decision makers should strengthen existing routine systems for surveillance of infectious diseases instead of instituting parallel systems for EPI target diseases. The district level should manage these systems. Countries with immunization coverage of infants greater than 80% should concentrate on areas and population groups with increased risk of disease. This high-risk approach is needed to eradicate the wild poliovirus. EPI's goals of reducing measles cases by 90%, eliminating neonatal tetanus, and eradicating poliomyelitis offer countries an opportunity to allocate resources to improve disease surveillance so as to achieve an effective disease surveillance system.