Public health surveillance is the ongoing, systematic collection, analysis and interpretation of data that is then disseminated to those responsible for preventing diseases and other health conditions. The data allow managers to respond quickly to a population's health needs. This information is also essential for ministries of health, ministries of finance, and donors to monitor how well people are served. Surveillance enables decision makers to lead and manage effectively.
Public health surveillance provides real-time, early warning information to decision makers about health problems that need to be addressed in a particular population. It is a critical tool to prevent outbreaks of diseases and develop appropriate, rapid responses when diseases begin to spread. Training and equipping health workers in developing countries with the skills and technology for surveillance are an absolute necessity in today's world.
A few examples are as follows:
Sentinel surveillance systems consist of a sample of health facilities or laboratories in selected locations that report all cases of a certain condition to indicate trends in the entire population. Sample reporting is a good way to use limited
Resources to monitor suspected health problems. Examples include networks of health providers reporting cases of
Influenza or a laboratory-based system reporting cases of certain bacterial infections among children.
Household surveys can be used to monitor diseases if the surveys are consistent and repeated periodically, say every
three to five years. The surveys are population-based; that is, they select a random sample of household's representative of
the whole population. Examples include demographic and health surveys in developing countries and the behavioral risk factor surveillance system in the United States.
Laboratory-based surveillance is used to detect and monitor infectious diseases. For example, for food-borne diseases such as salmonella, the use of a central laboratory to identify specific strains of bacteria allows more rapid and complete identification of disease outbreaks than a system that relies on reporting of syndromes from clinics. In the United States, the Centers for disease Control and Prevention maintain PulseNet, an Internet based network of laboratories that uses standard methods for identifying and reporting the genetic makeup of disease-causing agents. PulseNet is also active in Canada and Europe and is expanding in Asia and the Pacific and Latin America.
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