The US Department of Agriculture's Food Safety and Inspection Service and the Food and Drug Administration collaborated on the study which focuses on Listeria monocytogenes. The Atlanta-based Centers for Disease Control and Prevention estimates that infections with Lm cause about 1,600 illnesses, 1,500 hospitalizations and 260 deaths in the United States each year. Listeriosis is rare, but its fatality rate is very high. The study provides a scientific evaluation of the risk of listeriosis associated with consumption of meats, cheeses and other ready-to-eat foods prepared in retail delis. It also examines interventions that limit the survival, growth or transmission of the bacteria that causes listeriosis.
Among the major findings:
• At least nine of every 100 cases of listeriosis caused by contaminated deli products could be prevented if all refrigerated, ready-to-eat foods are stored at 41 degrees Fahrenheit or below.
• 96 of every 100 cases of listeriosis caused by contaminated deli products could be prevented if all deli products that support Lm growth were reformulated to include growth inhibitor. The study found that while this finding is significant, the actual benefit may be smaller in part because the amount of growth inhibitor used may not be effective throughout the shelf life of a food, and it can affect the flavor.
• Cross contamination dramatically increases the predicted risk of listeriosis, according to the study. Slicers are a particular challenge, however the study shows proper cleaning and personal hygiene can make a difference.
• 22 of every 100 cases of listeriosis caused by contaminated deli products could be prevented if current levels of Lm in ready-to-eat foods received by the retail deli from processing establishments were reduced by half. The study suggests that continued efforts to prevent low levels of Lm contamination during processing, even on products that do not support growth of the pathogen, reduces the risk from these products and other ready-to-eat foods that can be subsequently cross-contaminated in the retail delicatessens.
"The risk assessment will be a tremendous asset in our efforts to reduce the 1,600 illnesses and 260 deaths attributed to this pathogen annually," said USDA Under Secretary for Food Safety Dr. Elisabeth Hagen. "Essential information has been gained from these findings, including the fact that once Lm enters a retail environment, it has the potential to spread due to cross contamination. This assessment highlights the importance of our work to prevent Lm from entering the retail environment in the first place, and provides a significant tool towards this effort to protect consumers and prevent foodborne illness."