Background & History
Foodborne illnesses are caused by ingesting bacteria, fungi, parasites, viruses, toxins, or other harmful substances in contaminated food. Knowing the cost of foodborne illness helps policymakers assess risks, focus policy, and prioritize spending. Some of the first economic estimates of the cost of foodborne illness were provided by ERS.
- conduct economic analysis of the benefits of improved food safety,
- refine estimation methodologies, and
- provide updated estimates of the cost of illness for selected foodborne pathogens.
History of ERS Cost Estimates
ERS researchers conducted some of the earliest studies on the economic cost of foodborne illness and have since updated and expanded this research, using improved estimation methods and better data. Each set of ERS estimates has worked to incorporate better information on disease incidence, and more detailed data on the health consequences of foodborne illness and advances in the economic methodologies for valuing health outcomes.
ERS published its first comprehensive cost estimates for 16 foodborne bacterial pathogens in 1989 in the American Journal of Agricultural Economics (see Roberts, Tanya, "Human Illness Costs of Foodborne Bacteria," American Journal of Agricultural Economics, 71(2):468-74, May 1989). These initial estimates reflected the limited information then available about the incidence of foodborne illness. They also used cost-of-illness (COI) methodology to tally expenditures on medical care and lost wages resulting from nonfatal illnesses and premature deaths.
In 1996, ERS updated the cost estimates for:
- six bacterial pathogens (Campylobacter, Clostridium perfringens, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella, and Staphylococcus aureus) in a report, Bacterial Foodborne Disease: Medical Costs and Productivity Losses; and
- one foodborne parasite (toxoplasma gondii): see "ERS Updates U.S. Foodborne Disease Costs for Seven Pathogens".
ERS continued to use the COI methodology for nonfatal illnesses but adopted two different health valuation methodologies for premature deaths: the individualized human capital approach and the willingness-to-pay (WTP) approach.
In 1999 a Salmonella cost estimate was prepared in collaboration with Centers for Disease Control and Prevention’s (CDC) FoodNet Foodborne Diseases Active Surveillance Network. The estimate used new sources of data on medical costs and productivity losses, including FoodNet surveillance data and a large commercial medical claims database. See "Salmonella Cost Estimates Updated Using FoodNet Data".
In 2000, ERS used new CDC disease incidence estimates by Paul S. Mead and co-authors (see "Food-Related Illness and Death in the United States," Emerging Infectious Diseases) to update the cost of illness estimates for four pathogens (Campylobacter, Salmonella, E. coli O157:H7 (now termed STEC O157), and Listeria monocytogenes). The COI methodology was used for nonfatal illnesses, and the WTP approach was used for premature deaths. See "Food Safety Efforts Accelerate in the 1990’s".
In 2003, ERS introduced the Foodborne Illness Cost Calculator, an interactive online version of the updated ERS cost estimates for selected foodborne pathogens. The Cost Calculator initially included the Salmonella cost estimate, and later added the 2005 STEC O157 estimate. The Cost Calculator provided detailed information about the assumptions underlying each estimate and allowed users to make alternative assumptions and re-estimate the costs.
In 2005, the cost estimate for STEC O157 was updated in collaboration with FoodNet, using FoodNet surveillance data and a case-control study of STEC O157 patients. Unlike other estimates which valued lives lost, this research estimated reduced life expectancy and valued each year of lost life by annuitizing the value of statistical life (VSL) estimate. This report provides a detailed description of the methods used for the STEC O157 cost of illness. See "Economic cost of illness due to Escherichia coli O157 infections in the United States".
In 2014, ERS replaced the Cost Calculator with the new Cost Estimates of Foodborne Illnesses data product. This data product added cost estimates for 11 pathogens to those already included in the ERS Cost Calculator, based on research published by Hoffmann and coauthors (see Hoffmann, Sandra, Michael B. Batz, and J. Glenn Morris, Jr., "Annual Cost of Illness and Quality-Adjusted Life Year Losses in the United States Due to 14 Foodborne Pathogens," Journal of Food Protection 75(7):1291-1302, January 2012). The 2014 estimates are based on CDC’s 2011 foodborne disease incidence estimates by Elaine Scallan and co-authors (see "Food-Related Illness Acquired in the United States—Major Pathogens" in Emerging Infectious Diseases). The current set of estimates on the ERS Cost Estimates of Foodborne Illnesses data product are updated to 2018 dollars for inflation and income growth (following the methods set out in documentation on the data product website).
The documentation section of the Cost Estimates of Foodborne Illnesses data product provides a full explanation of the methods used. These estimates follow U.S. Environmental Protection Agency guidance on the use of the VSL and do not annuitize the VSL. The rationale for this shift in method is described in Making Sense of Recent Cost-of-Illness Estimates. A companion report, Economic Burden of Major Foodborne Illnesses Acquired in the United States, provides pathogen-specific graphics and disease descriptions designed to help inform food safety education efforts. The documentation section also includes instructions for updating estimates annually for price inflation and real income growth.