Surveillance of foodborne disease .1. Purposes and types of surveillance systems and networks

This is the first part of a four-part series on foodborne disease surveillance. Although these articles are primarily built on expertise gained within North America, the substance is of value to any community or country wishing to initiate or improve its surveillance system. Foodborne disease surveillance is necessary for preventing further spread of foodborne disease and includes identifying and controlling outbreaks at the time they are occurring; gathering data on incidence of these diseases and prevalence of their etiologic agents, vehicles, and reservoirs; identifying factors that led to the outbreaks; providing a data bank for HACCP systems and risk assessments; estimating health and economic impacts of foodborne diseases; and providing information upon which to base rational food safety program goals and priorities. Reports of outbreaks by local health agencies to regional and, then, national agencies responsible for disease surveillance, laboratory isolations of certain foodborne pathogens from human beings, sentinel community studies, and hazard surveillance are the types of foodborne disease surveillance activities that are used to varying extents in Canada and the U.S. In recent years, some national surveillance reports have been collated internationally in Europe and Latin America. Surveillance at local, state/provincial, national, and international levels must be coordinated for effective and rapid transfer of data. Computer software can assist investigation and management of the information submitted through surveillance networks. Information summarized on individual reports usually includes (a) location of the event, (b) clinical data, (c) epidemiologic data, (d) laboratory findings, and (e) results of on-site investigations. Each outbreak report should be subjected to critical review before classifying it into the various categories of surveillance data. Such a review would also be useful when comparing surveillance data from different places and intervals. Highlights of individual reports are tabulated as line listings that are the direct sources of surveillance data, which are the subject of the second and third parts of this series.