May 14, 2014
The U.S. Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC) and USDA’s Food Safety and Inspection Service (FSIS) have posted a recording of their most recent webinar on progress toward attributing foodborne illnesses to food sources.
The webinar, titled “Are Outbreak Illnesses Representative of Sporadic Illnesses?,” was presented on January 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 features an analysis of data collected by CDC’s Foodborne Diseases Active Surveillance Network (FoodNet), and compares the characteristics of illnesses associated with outbreaks with those that are not linked to outbreaks. The results of the analysis suggest that:
- For Campylobacter, Listeria monocytogenes, and E. coli O157, outbreak illnesses are similar to sporadic illnesses with respect to patients’ illness severity, gender and age.
- For 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.
- Because FoodNet data includes only a small portion of reported U.S. illnesses, the number of outbreaks and illnesses available for analysis was limited. For example, there were fewer Campylobacter illnesses 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 are important because they indicate that, with the exception of Salmonella illnesses among children 0 to 3 years old, it may be appropriate to use outbreak data to estimate which foods may be associated with sporadic illnesses in the population. FDA and its partners are exploring the practical applications of these findings when attributing foodborne illnesses to food sources.