Information is a prerequisite for public health, but it may be perceived more as a curse than a blessing if the expanding base of available information cannot easily be put to use for a specific purpose. Virtually all essential public health services depend on ready access to information about what is known about a particular public health problem and who is doing what in a particular community. For example, diagnosing the cause of an outbreak (such as the recent release of nerve gas in the Tokyo subway system) and identifying effective interventions requires a fast, targeted review of the research literature, identification of available resources and experts, and application of what is known generally to the features of a particular situation. Practitioners in both the public and private sectors as well as managers of health care organizations need efficient access to the latest disease and disability prevention guidelines and ways to apply them to their patients and populations. Consumers also need help in comprehending the public health literature, not only to obtain information relevant to their individual needs, but also to sort fact from fiction, and to identify local support services that can help them take effective action.
Sophisticated tools for displaying and manipulating data are also important in public health, especially for essential services that depend on seeing a pattern in rare events or applying what is known generally to a small region or subpopulation. For instance, the recent Hantavirus outbreak was diagnosed through a CDC medical examiner surveillance database, which showed a clustering of similar deaths among young people in the Four Corners area of the Southwest United States. In situations such as food poisoning, environmental contamination, and water-borne illness, geographic displays of data can visibly target the likely source of widespread incidents and, by identifying what is available in and near the source area, promote efficient deployment of resources. Modeling and simulation techniques can extend the usefulness of available data by extrapolating what is known about one geographic area or one population to others for which primary data are not available. In addition, specially-designed displays can make information about public health problems and resources meaningful to those outside of the field of public health. This can be critical for policymakers, who need to make increasingly difficult decisions about public health capacity in times of tightening budgets and "downsized" government.