Interagency Food Safety Analytics Collaboration Releases New Report on Sources of Foodborne Illnesses

Interagency Food Safety Analytics Collaboration Releases New Report
on Sources of Foodborne Illnesses

The Interagency Food Safety Analytics Collaboration (IFSAC) has released a report on updated foodborne illness source attribution estimates using multi-year outbreak surveillance data. The authors used outbreak data to produce new estimates for foods responsible for foodborne illnesses caused by four pathogens in 2016. CDC estimates that, together, these four pathogens (Salmonella, Escherichia coli O157, Listeria monocytogenes, and Campylobacter) cause 1.9 million foodborne illnesses in the United States each year. The analysis uses a method developed [PDF - 12 pages] by IFSAC to estimate foodborne illness source attribution, which is the process of estimating the degree to which specific foods and food categories are responsible for foodborne illnesses.  IFSAC also posted estimates for 2014 and 2015 on its website, reflecting IFSAC’s goal to provide annual updates of these estimates using data from the most recently available outbreak data. For the 2016 report [PDF - 14 pages], IFSAC analyzed data from just over 1,000 foodborne disease outbreaks that occurred from 1998 through 2016 to assess which categories of foods were most responsible for Salmonella, E. coli O157, Listeria monocytogenes, and Campylobacter infections. IFSAC chose the pathogens because of the frequency or severity of the illnesses they cause, and because targeted interventions can have a major impact in reducing them. The implicated foods were divided into 17 categories for the analysis. The method gives the greatest weight to the most recent 5 years of outbreak data (2012–2016). Of note in the 2016 report is the following: 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 Dairy products and Fruits. Dairy and Fruits remain the top two categories with the highest estimated attribution percentages, but the difference between the two categories is not statistically significant. There was an increase in the estimated attribution of Listeria illnesses to Vegetable Row Crops from 3.4% in 2013 to 12.5 % in 2016 due to the impact of a large multistate outbreak in 2015 linked to prepackaged lettuce. Campylobacter illnesses were most often linked to Chicken after removing Dairy outbreaks from the estimates. Most foodborne Campylobacter outbreaks were associated with unpasteurized milk, which is not widely consumed, and those outbreaks likely over-represent Dairy as a source of Campylobacter. For 2016, Chicken had a significantly higher estimated attribution percentage than the other non-Dairy food categories. The adjusted Chicken percentage increased from 9.5% to 30.3% after removing Dairy. The updated estimates combined with other data might 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 is a collaboration among the Centers for Disease Control and Prevention, the U.S. Department of Agriculture’s Food Safety and Inspection Service, and the U.S. Food and Drug Administration. The collaboration works to improve coordination of federal food safety analytic efforts and address cross-cutting priorities for food safety data collection, analysis, and use. For more information on IFSAC, please visit the collaboration's website or email IFSAC at IFSAC@fda.hhs.gov.