The U.S. Department of Agriculture's Food Safety and Inspection Service (FSIS), the U.S. Food and Drug Administration (FDA) and the U.S. Centers for Disease Control and Prevention (CDC) have posted a recording of their most recent webinar, which detailed progress toward attributing foodborne illnesses to food sources. The webinar, “Are Outbreak Illnesses Representative of Sporadic Illnesses?” was presented on Jan. 10, 2014, by the Interagency Food Safety Analytics Collaboration (IFSAC), a tri-agency partnership focused on projects related to attribution of foodborne illnesses.

The presentation featured an analysis of data collected by CDC’s Foodborne Diseases Active Surveillance Network (FoodNet) and compared the characteristics of illnesses associated with outbreaks with those that are not linked to outbreaks. The results of the analysis suggest that:

  • Campylobacter, Listeria monocytogenes and E. coli O157 outbreak illnesses are similar to sporadic illnesses with respect to patients’ illness severity, gender and age.
  • Salmonella outbreak illnesses are similar to sporadic illnesses with respect to illness severity and gender. For age, the percentages of outbreak and sporadic illnesses that occur among older children and adults are also similar. However, the percentage of outbreak illnesses in the youngest age category (0-3 year olds) was substantially lower compared with the other age groups.
  • The number of outbreaks and illnesses available for analysis was limited because FoodNet data includes only a small portion of reported U.S. illnesses. For example, fewer Campylobacter illnesses were associated with outbreaks compared with the other three pathogens in the study, which limits the conclusions that can be drawn from this analysis.

These findings indicate that it may be appropriate to use outbreak data to estimate source attribution for sporadic illnesses for most age groups, IFSAC officials stated. FSIS and its partners are exploring the practical applications of these findings when estimating foodborne illness attribution. To watch the recording, visit the IFSAC web page, and select Webinar #2.