Sticky Note


Electron micrograph of a Listeria bacterium in tissue. Credit: CDC/PHIL

What is Listeriosis?   Listeriosis is a foodborne illness usually caused by eating food that is infected with the bacterium Listeria monocytogenes.  Listeria monocytogenes is the infectious agent responsible for the food borne illness Listeriosis. In the United States, an estimated 2,500 persons become seriously ill with listeriosis each year. Of these, 500 die.(1)  Listeriosis a severe invasive infection that has a high-case fatality rate.

Who is at Risk?  The types of population that are at most risk are pregnant women, newborns, the elderly, and people that have a weakened immune system.  Healthy adults and children can contract this disease, but rarely become seriously ill.

Where is Listeria?  Listeria can be found in soil and water.  Animals that carry the bacterium can go unnoticed due to the fact that they do not appear to be ill.  This bacteria can live in food processing plants for years!  Unlike many other germs, Listeria can grow even in the cold of your walk-in cooler or refrigerated reach-ins.

Listeriosis has been listed as one of the pathogen-food combinations that most burden the U.S., taking 2 of the top 10 spots. The two pathogen-food combinations of listeria that hit the top 10 are:

>Deli meats

>Dairy products

> Also raw produce.  Read about the recent outbreak from Cantaloupes at FDA and CDC.

How Is It Killed?  Listeria differs from most bacteria by the fact that it can grow and multiply in refrigerated items. The Listeria bacterium is killed by pasteurization and cooking, but foods can become contaminated after factory cooking and before packaging.  People get this illness from foods that are contaminated. 

 The most common causes of this illness from the food industry would be:

  1. Raw meats.
  2. Unpasteurized dairy products.
  3. Ready-to-eat foods such as deli meats, hot dogs, soft cheeses such as feta and brie.
  4. Refrigerated smoked seafoods such as salmon or tuna, unless contained in a cooked dish, canned or contained in a shelf-stable product.

You should have guidelines and policies in your restaurant to ensure you and your staff are doing all that you can do to help prevent the spread of Listeria.  Here are some guidelines that you can train your staff by:

  • Throw any product out that has passed its expiration date.
  • Cook all raw meat to minimum internal temperatures.  (Refer to Protein Temperature Chart for proper cooking temperatures.)
  • Spills in your frigeration units should be cleaned immediately, especially juices from foods such as hot dogs, luncheon meats, raw meats and poultry.
  • Rinse all raw vegetables under running tap water.
  • Sanitize all materials that have come in contact with raw foods.
  • Make sure that all foods are stored in coolers that will prevent cross contamination.  (See: “6 Tips for Proper Storage").
  • Divide leftovers into shallow containers so that foods are cooled quickly and evenly.  Cover with airtight lids, or enclose with plastic wrap or aluminum foil.  Use all leftovers with 3 to 4 days.

If you and your team follow these simple steps, you can prevent the Listeria bacteria from getting to any of your guests.

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