Usage and Data Collection Patterns for a Novel Web-Based Foodborne-Disease Surveillance System
Wethington, Holly, Bartlett, Paul, Journal of Environmental Health
This paper discusses the traditional system of foodborne-illness surveillance and provides a justification for increased syndromic surveillance of foodborne illness. An innovative method of Web-based reporting of foodborne illnesses is described, and data collected from the Web site are compared with data collected by the traditional telephone-based system.
An estimated 76 million illnesses, over 325,000 hospitalizations, and over 5,000 deaths occur annually from foodborne illnesses (Mead et al., 1999). It has been estimated that foodborne illness costs the United States $23 billion dollars annually (Hedberg, MacDonald, & Shapiro, 1994, as cited in Jones & Gerber, 2001). This figure includes medical costs, time off work, and more.
Pregnant women, the elderly, infants and children, immunocompromised persons, and the undernourished are especially vulnerable (Doyle, Beuchat, & Montville 1997; Kaferstein, Motarjemi, & Bettcher, 1997). With a larger proportion of society reaching senior age and a larger sector living longer in an immunocompromised state, the overall percentage of those falling into a high-risk group is growing.
The current national system of surveillance for foodborne and waterborne diseases, CDC's Foodborne Disease Outbreak Surveillance System, began in 1966 to collect and evaluate data regarding foodborne-disease outbreaks, with an outbreak defined as the presence of two or more cases of a similar illness resulting from the consumption of a common food (Olsen, MacKinnon, Goulding, Bean, & Slutsker, 2000). In this system, state and local health departments have the main responsibility for locating and investigating foodborne-disease outbreaks (Olsen et al.).
Obtaining Reports of Foodborne Illness
Data for the Foodborne Disease Outbreak Surveillance System originate from state, local, and territorial health departments, and possibly from federal agencies or other sources (Olsen et al., 2000). Many local health departments use a standard CDC form, and CDC evaluates the collected data to determine whether a specific food vehicle and etiologic agent have been confirmed for an outbreak (Olsen et al.).
While under-reporting is a major hindrance to the surveillance of foodborne illnesses, the slow speed of the system is an equally important problem when foodborne outbreaks can easily begin and end within several days (Mead et al., 1999). One state health department survey found that the mean time from symptom onset and completion of the case investigation form by the local health department was 35 days (Michigan Department of Community Health, unpublished data).
Currently, data collected through notification and laboratory confirmation represent only the tip of the iceberg of foodborne illnesses (Kaferstein, Motarjemi, & Bettcher, 1997). While a small percentage of cases are being examined at the county or state level, many more are not being reported. The burden-of-illness pyramid designed by CDC displays a passive system that focuses primarily on reports with laboratory confirmation. Reports of foodborne illness without laboratory confirmation, often called "foodborne complaints" rather than "cases," have traditionally been viewed as having marginal epidemiologic value when not associated with a particular outbreak supported by laboratory confirmation. This paper will refer to these reports as syndromic since there is no associated laboratory information. Viewed by many as "low-grade ore" that rarely yields important nuggets of information, foodborne-disease reports without laboratory confirmation are not useful to most health departments that do not have an efficient method for analyzing these reports to identify any commonalities that might define a time-space cluster worthy of further investigation.
If an individual seeks medical attention, an unbroken chain of events must occur for the individual, non-outbreak-related foodborne-disease report to meet the case definition and be counted as an official case of a specific foodborne disease. …