Listeria Linked to Contaminated Deli Meat Slicers, Says New Report


Listeria causes the third highest number of foodborne illness deaths in the United States. People become infected with this infection by eating contaminated food.

Listeriosis is a serious infection and a vital public health problem in North America — caused by the bacterium Listeria monocytogenes.

Listeriosis symptoms sometimes include nausea, diarrhea, muscle aches, and fever. If the infection spreads to the nervous system, symptoms may include confusion, loss of balance, a stiff neck, headaches, or convulsions.  Listeria can also be fatal.

New report about Listeria infections

Each year, close to 255 people die from a listeria infection. The most common way people are infected with listeria is by eating unpasteurized milk products and improperly processed deli meats.

According to the U.S. Centers for Disease Control and Prevention (CDC), listeriosis “primarily affects older adults, pregnant women, newborns, and adults with weakened immune systems.” People without these risk factors can also be affected.

A new report published in the April 1 issue of the CDC’s journal, Morbidity and Mortality Weekly Report, advises that deli meats are a major source of Listeriosis illnesses. In addition, meats sliced and packaged at retail delis are the major source of Listeriosis cases and deaths attributed to deli meats.

The U.S.D.A. reports that approximately 83 percent of listeria cases and deaths in the U.S. are associated with deli meats sliced at retail.

Additionally, the CDC states, “Mechanical slicers pose cross-contamination risks in delis and are an important source of listeria cross-contamination. Reducing listeria contamination of sliced meats in delis will likely reduce listeria illnesses and outbreaks.”

The CDC’s Environmental Health Specialists Network studied how often retail deli slicers were fully cleaned — that is, disassembled, cleaned, and sanitized — “at the Food and Drug Administration (FDA) Food Code specified minimum frequency of every four hours.” The organization also examined and interviewed a group of deli and staff people with relation to when and how often meat slicers are cleaned.

Deli chain interviews

Managers and staff at 298 randomly selected delis across the U.S. were interviewed about their daily safety activities. The interviewers noted they contacted about 700 deli managers in New York City, Tennessee, Minnesota, Rhode Island, New York, and California. Forty-three percent of the managers agreed to take part of the survey.

The results of survey found that “approximately half of delis fully cleaned their slicers less often than the FDA’s specified minimum frequency of every four hours.”

The CDC researchers explain the number of delis that did not follow the food-safety requirements of cleaning their meat slicers may be larger than what was reported in the survey.

They suggest that many of the deli workers and management may be telling the investigators what they want to hear, in order to make their deli look better than it actually is — when in fact, the delis did not adhere to the required food-safety guidelines.

However, the investigators did find that larger deli chains were more likely to hold fast to the 4-hour rule than independent establishments.  Surprisingly, busier delis were actually more likely to be very particular about cleaning the slicer than delis with a smaller customer base.

Checking on your local deli

Here are some tips that may help in checking whether your local deli is doing a good job in protecting you and your family from contracting listeria from their meat slicer.

  • Does your deli have a written slicer-cleaning policy in place?
  • Does your deli have a higher turnover of meat products each day?
  • Does your deli have more deli workers per shift?
  • Ask whether the deli workers and management have a food safety-training program.
  • Are there multiple slicers? Having more slicers increases the chances they were cleaned regularly.
  • Workers that say their slicers are “easy to clean” also raised cleaning rates.


Precautions you could take

If you want to be cautious and avoid a listeria infection — especially if you or someone you know is pregnant, or has a weak immune system — you may want to take the advice from the Mayo Clinic Staff.

Take additional precautions with these types of foods:

  • Be cautious of hot dogs, luncheon meats, and deli meats. Avoid hot dogs, luncheon meats, and deli meats unless they’re reheated until steaming hot. Keep fluid from hot dog packages away from other foods, utensils, and food preparation surfaces. Wash your hands after handling hot dogs, luncheon meats, or deli meats.
  • Don’t eat refrigerated pates or meat spreads. Canned or shelf-stable pates and meat spreads are acceptable.
  • Don’t eat refrigerated smoked seafood. These products may be labeled as kippered, lox, jerky, or nova style. One exception to this guideline is if you’re using these products in a casserole or other cooked dish. Shelf-stable or canned smoked seafood is acceptable.
  • Be cautious of Mexican-style cheeses and soft cheeses. Don’t eat soft cheeses, like feta, Brie, Camembert, blue cheese, or Mexican-style cheeses — such as queso blanco and queso fresco — unless you’re sure they were made using pasteurized milk.

Simple guidelines to avoid a listeria infection

Try to keep your surroundings and objects you use clean.

Always wash your hands thoroughly with warm, soapy water before and after handling or preparing food. In addition, after you cook, use hot, soapy water to wash the cutting board, utensils, and food preparation surfaces.

You should also clean raw vegetables under plenty of running water with a vegetable brush or scrub brush. Also, you want to scrub raw vegetables.

Make sure you thoroughly cook your food. Using a food thermometer helps to make sure your egg dishes, poultry, and meats are cooked to a safe temperature.

The Mayo Clinic adds that listeria bacteria can survive refrigeration and even freezing. People who are at higher risk of serious infections should avoid eating the types of food most likely to contain listeria bacteria.

Implications of public health practices

The CDC recommends in order to help prevent the spread of listeria, deli owners, management, and workers must ensure that deli slicers are cleaned at least every 4 hours.  Additionally, as a foodborne illness prevention measure, “states and localities should require deli manager training and certification, as specified in the FDA Food Code.”

It’s also recommended that delis should be required to have written slicer-cleaning policies. Because independent and smaller delis are shown to clean their meat slicers less often, prevention efforts should focus on these types of establishments.

Mechanical slicers pose cross-contamination risks in delis — they are an important source of listeria cross-contamination. Good slicer cleaning practices can reduce this foodborne illness risk and save lives.

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George Zapo, CPH
George Zapo, CPH is certified in Public Health Promotion & Education. George focuses on writing informative articles promoting healthy behavior and lifestyles. Read more of George's articles at his website: