Eggs are having their turn in the glaring spotlight right now for their contribution to foodborne illnesses. But according to a study the Centers for Disease Control and Prevention released earlier this month, the foods that caused the greatest number of illnesses in 2007 were processed foods with multiple ingredients. Hummus served at a single event—the Taste of Chicago—spread salmonella-based illness among 802 people, while frozen pot pies served salmonella-related sickness to 401 people and caused 3 deaths in 37 states.
“About half of those outbreaks where a food vehicle was identified were due to single commodities,” such as finfish, poultry or beef, said Dana Cole, a doctoral epidemiologist with the CDC’s FoodNet and Outbreak Surveillance Team. “But when you count up the illnesses, there were more due to the complex commodities than the single commodities. There are a variety of reasons.”
For example, multi-ingredient foods are commonly served at large venues, like wedding or festivals, where temperature control and handling may be less than ideal, and large numbers of people eat it. “It may have initially been a single contaminated ingredient, but now it’s integrated into the entire food vehicle,” Cole said. In the case of pot pies, or other processed foods distributed across multiple states, “you just have an opportunity to distribute [a pathogen] more widely,” she added.
Cole said she had no data on whether organic processing would prevent such contamination. “It’s not a variable that we collect; we can’t identify that in our database, so we can’t analyze it.” According to the Organic Trade Association, a single study in 2004 found a lower incidence of another pathogen, E. coli, in fresh produce from organic farms than from conventional growers, but more data is needed to draw any broad conclusions.
“Most foodborne disease outbreaks can be prevented,” Cole said. “The food preparers must be diligent about the preparation process–making sure they cook things thoroughly and, if they’re going to transport it, make sure they keep it at the proper temperature, and wash their hands frequently to prevent cross-contamination.”