The Interagency Food Safety Analytics Collaboration (IFSAC) released a report titled “Foodborne illness source attribution estimates for 2013 for Salmonella, Escherichia coli O157, Listeria monocytogenes, and Campylobacter using multi-year outbreak surveillance data, United States.” The authors used outbreak data to update previous analyses to estimate which foods are responsible for illness related to four foodborne pathogens. CDC estimates that, together, these four pathogens cause 1.9 million cases of foodborne illness in the United States each year.
The analysis builds on a method developed by IFSAC in 2015 to estimate foodborne illness source attribution, which is the process of estimating the most common food sources responsible for specific foodborne illnesses. IFSAC described this method and the estimates for the year 2012 in a report and at a public meeting. The estimates for 2013 were derived using the same method as the 2012 estimates with a few modifications.
For the report, IFSAC analyzed data from just over 1,000 foodborne disease outbreaks that occurred from 1998 through 2013 to assess which categories of foods were most responsible for making people sick with Salmonella, E. coli O157, Listeria monocytogenes, and Campylobacter. The method gives the greatest weight to the most recent five years of outbreak data (2009–2013) and IFSAC experts divided implicated foods into 17 categories for the analysis. The pathogens were chosen because of the frequency or severity of the illnesses they cause, and because targeted interventions can have a significant impact in reducing them. The report noted that:
- Salmonella illnesses came from a wide variety of foods.
- E. coli O157 illnesses were most often linked to Vegetable Row Crops (such as leafy greens) and Beef.
- Listeria monocytogenes illnesses were most often linked to Fruits and Dairy products.
- Non-Dairy Campylobacter illnesses were most often linked to Chicken.
- An attribution percentage for Dairy was not included in this analysis because, among other reasons, most foodborne Campylobacter outbreaks were associated with unpasteurized milk, which is not widely consumed, and likely over-represents Dairy as a source of Campylobacter illness.
- Removing Dairy outbreaks from the estimates highlights important sources of illness from widely consumed foods, such as Chicken.
The full findings are contained within the report. The updated estimates combined with other data may help shape agency priorities and support the development of regulations and performance standards and measures, among other activities. As more data become available and methods evolve, attribution estimates may improve. Updates to these estimates will enhance IFSAC’s efforts to inform and engage stakeholders, and further their ability to assess whether prevention measures are working.
IFSAC was created in 2011 by three federal agencies—the Centers for Disease Control and Prevention (CDC), the U.S. Food and Drug Administration (FDA), and the U.S. Department of Agriculture’s Food Safety and Inspection Service (USDA-FSIS)—to improve coordination of federal food safety analytic efforts and address cross-cutting priorities for food safety data collection, analysis, and use. The current focus of IFSAC’s activities is foodborne illness source attribution, defined as the process of estimating the most common food sources responsible for specific foodborne illnesses. For more information on IFSAC projects visit IFSAC's Project page or email IFSAC at IFSAC@fda.hhs.gov.