It looks like the apple, and not the caramel, is getting the blame for the deadly multistate outbreak of Listeriosis linked to caramel apples that occurred late last year. The outbreak sickened 35 people in 12 states, requiring hospitalization for all but one victim. Seven of the sickened people died. Canada also reported an additional case genetically related to the U.S. outbreak. Variety of caramel applesThe Listeria outbreak was first thought to be limited to commercially produced, pre-packaged caramel apples, but according to the federal Centers for Disease Control and Prevention (CDC), at least three people who had eaten only whole or sliced green apples before getting sick were victims of the outbreak. Its role as the common supplier to companies making caramel apples led investigators to a Bakersfield, CA, apple processing plant owned and operated by Bidart Bros. Environmental sampling discovered two strains of Listeria monocytogenes inside the apple processing plant, which were matched to apples collected from retailers. Caramel apple producers, including Happy Apple, California Snack Foods, and Merb’s Candies, were among the first to recall products. While the onset of the outbreak illnesses ran from Oct. 17, 2014, to Jan. 6, 2015, it was not until nearly the end of that period that Bidart Bros. was identified as the common supplier to the caramel processors. It was also on Jan. 6, 2015, that Bidart Bros. recalled its entire 2014 crop of Gala and Granny Smith apples. The company stated that its final shipment was on Dec. 2, 2014. The raw apple cases and the strains found inside the plant both point to the apples as the source of the Listeria, but the order in which these events were first reported may have left people confused. At last month’s Interagency Food Safety Analytics Collaboration (IFSAC) public meeting on attribution estimates for foodborne disease outbreaks, a participant from the University of Minnesota wanted to know if the “candy apple” outbreak would be attributed to the apples or “tossed off as a complex food.” The question related to the fact that in its analysis of all foodborne illness outbreaks that occurred between 1998 and 2012, IFSAC excluded those attributed to foods with multiple ingredients to which the specific ingredient was never identified as the source of the pathogen. “In that case,” responded CDC’s Dr. Dana Cole, “we were fortunate to isolate the contaminate ingredient and that will be classified as a simple food outbreak.” Her response seemed to indicate the single ingredient identified as the source of last fall’s Listeria outbreak was the apple, not the caramel. Overall, IFSAC found that fruit was the source of 50 percent of the Listeria cases, but this was extrapolated from one out of 24 Listeria outbreaks where 147 people were sickened by cantaloupe in 2011. The partnership between CDC, the Department of Agriculture’s Food Safety and Inspection Service, and the Food and Drug Administration warned that its confidence in its Listeria estimates was not very high because of the small number of outbreaks included from the study period.