The US Department of Agriculture's Food Safety and Inspection Service (FSIS) and the US Food and Drug Administration (FDA) have conducted a study to better understand the risks associated with certain foods prepared in retail delicatessens.
The risk assessment was conducted in order to help minimize the public health burden of listeriosis.
FSIS and FDA have also developed recommendations for changes in current practices that may improve the safety of those products.
The study was designed to apply to a range of deli establishments, from small independent operations to the deli departments in large supermarkets and is based on observations of deli employees' work routines; concentrations of Listeria monocytogenes on incoming products and in the deli environment; simulations of the bacteria's transmission, such as from slicer to food; and dose-response modeling.
The key findings of the study recommend certain measures including ideal storage temperature, adding growth inhibitors, avoiding cross contamination, and preventing contamination of incoming product.
According to the study, if all refrigerated, ready-to-eat foods are stored at 41 degrees Fahrenheit or below about nine of 100 cases of listeriosis caused by contaminated deli products could be prevented.
The study suggests that if all deli products that support Listeria monocytogenes growth were reformulated to include growth inhibitor, about 96 of 100 cases of listeriosis could be prevented. In addtion, cross contamination can be eliminated by proper cleaning and personal hygiene.
If the current levels of Listeria monocytogenes in ready-to-eat foods received by the retail deli from processing establishments were reduced by half, 22 of every 100 cases of listeriosis could be prevented. Continued efforts to prevent low levels of Listeria contamination during processing reduces the risk from these products and other ready-to-eat foods that can be subsequently cross contaminated in the retail establishments.
USDA Under Secretary for Food Safety Dr. Elisabeth Hagen said that the risk assessment will be a tremendous asset in the agency's efforts to reduce the 1,600 illnesses and 260 deaths attributed to this pathogen annually.
"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," Hagen added.
Listeriosis primarily affects older adults, pregnant women, newborns and adults with weakened immune systems. Listeriosis is rare, but its fatality rate is very high (i.e., about 16%, compared with 0.5% for either Salmonella or E. coli O157:H7).
