Syndromic surveillance is a public health tool relying on the real time use of information about the health of a population to identify issues of concern and address them before they become epidemics. This tool relies on pooling data from a number of different sources to identify trends and act on them. Anything from bioterrorism to food contamination can be identified more rapidly with the use of syndromic surveillance, allowing public health officials to intervene in a timely and effective fashion.
Public health agencies use this technique to spot clusters of activity associated with particular syndromes. For instance, a public health agency might want to monitor the incidence of flu to identify serious outbreaks as quickly as possible. It would look at reports from hospitals and doctors' offices, checking for an uptick in patients with flu-like syndromes and taking special note of clusters of similar cases. It would also look at data like absenteeism from school and work, traffic patterns, and so forth, under the logic that a rise in flu cases will cause a ripple effect in society.
Syndromic surveillance for food-borne illness has also proved very effective. Historically, outbreaks caused by contaminants in food were sometimes identified long after the fact. With syndromic surveillance, seemingly unconnected cases can be linked with the use of biostatistics. A rise in people with the same symptoms in different health care facilities will be noted and investigators can be sent out to see if an epidemic is unfolding, and take rapid action if it is.
Rather than waiting for reports to come in, syndromic surveillance uses an active pursuit of data. Information of little use in isolation can become more meaningful when combined with material from other places. Syndromic surveillance is used in many nations of the world at various levels, from city-wide public health programs to efforts at national agencies like the Centers for Disease Control and Prevention.
There are some criticisms of syndromic surveillance. Privacy advocates argue that since patients are not given information about such programs and may not be able to opt out, privacy may be violated. Public health workers counter this argument with the point that, historically, public health concerns have been viewed as more important than privacy in epidemics and pandemics. While efforts are taken to conceal the identities of individual cases, collecting public health data is viewed as being of paramount importance in identifying emerging public health threats. If an investigation is launched, patient records may need to be reviewed by investigators to get a complete picture, with the goal of preventing the spread of disease.