Colorado State University Extension
SafeFood Rapid Response Network
Go to Table of Contents for this issue
Listeria Risk Assessment Report Emphasizes Keeping Foods Cold
Edited by: Mary Schroeder, M.S., R.D. & Pat Kendall, Ph.D., R.D., Colorado State - Winter 2004
This October, the Food and Drug Administration (FDA) released its final draft of a comprehensive Risk Assessment Report on Listeria monocytogenes (Lm). The report represents an important milestone in defining the relationship between foodborne listeriosis and human health. In the report, the FDA identified the risk of Lm associated with 23 types of ready-to-eat foods, including seafood, produce, meats, dairy products and deli-type salads. It also identified five factors important in developing action plans to further reduce the risk of listeriosis. These factors include:
- amount and frequency of consumption of a ready-to-eat food
- frequency and levels of Lm in a ready-to-eat food
- potential of the food to support the growth of Lm
- refrigerated storage temperature
- duration of refrigerated storage before consumption.
Two of these factors relate to refrigerated storage. Because L. monocytogenes grows at refrigerator temperatures above 40ºF, the report advises all consumers to store ready-to-eat foods at 40ºF or lower, and to consume perishable and ready-to-eat foods as soon as possible. Another factor relates to the potential for a food to support the growth of Lm. In response to this factor, products are beginning to be reformulated to no longer support the growth of the Lm.
Special Recommendations for High-Risk Individuals:Although listeriosis is rare, it is potentially life threatening when illness occurs. According to the CDC, Lm causes ~2,500 serious illnesses and ~500 deaths each year. Those at increased risk include persons with weakened immune systems, such as the elderly and chronically ill persons. In addition listeriosis in pregnant women can result in miscarriage, fetal death and severe illness or death of a newborn infant. For those at high risk for listeriosis, the CDC makes the following special recommendations:
- Do not eat hot dogs and luncheon meats, unless they are reheated until steaming hot.
- Do not eat soft cheeses such as Feta, Brie and Camembert cheese, blue-veined cheese, queso fresco and Panela unless it is labeled as made with pasteurized milk.
- Do not eat refrigerated pates or meat spreads. Canned or shelf-stable pates and meat spreads may be eaten.
- Do not eat refrigerated smoked seafood, unless it is contained in a cooked dish, such as a casserole. Refrigerated smoked seafood, such as salmon, trout, whitefish, cod, tuna, or mackerel, is most often labeled as "nova-style," "lox," "kippered," "smoked," or "jerky."
- Do not drink raw (unpasteurized) milk or eat foods that contain unpasteurized milk. Of note, the recommendation not to eat soft cheese unless it is labeled as made with pasteurized milk reflects a change from previous consumer advice for at-risk consumers not to eat soft cheeses at all. Newer data about the contamination of cheese indicates that the risk is not in all soft cheeses, but specifically in cheese made from unpasteurized milk. This reflects the efforts of the dairy industry and FDA over the past several years to develop effective programs to control Listeria monocytogenes in soft cheeses.
The risk assessment is available on the FDA website at, FDA Web Site, Food Safety Web Site and Food Risk Clearinghouse.
Source:- FDA News. October 21, 2003. Risk Assessment Reinforces That Keeping Ready-To-Eat Foods Cold May be the Key to Reducing Listeriosis. FDA Web Site
