Listeria (Listeriosis)

listeriaListeriosis, a serious infection usually caused by eating food contaminated with the bacterium Listeria monocytogenes, is an important public health problem in the United States. The disease primarily affects older adults, pregnant women, newborns, and adults with weakened immune systems. However, rarely, persons without these risk factors can also be affected. The risk may be reduced by recommendations for safe food preparation, consumption, and storage.

How can I reduce my risk for listeriosis?

The general guidelines recommended  for the prevention of listeriosis are similar to those used to help prevent other foodborne illnesses, such as salmonellosis. In addition, there are specific recommendations for persons at higher risk for listeriosis. Recommendations related to Listeria in melons, including cantaloupes, are also included on this page.

There are some general recommendations on how to prevent an infection with Listeria, and some additional recommendations specifically for  persons who are at higher risk.

General recommendations to prevent an  infection with Listeria:

FDA recommendations for washing and handling food.

  • Rinse raw produce,  such as fruits and vegetables, thoroughly under running tap water before eating, cutting, or cooking. Even if the produce will be peeled, it should  still be washed first.
  • Scrub firm produce,  such as melons and cucumbers, with a clean produce brush.
  • Dry the produce  with a clean cloth or paper towel.
  • Separate uncooked meats  and poultry from vegetables, cooked foods, and ready-to-eat foods.

Keep your kitchen and environment cleaner and safer.

  • Wash hands, knives, countertops, and cutting boards after handling  and preparing uncooked foods.
  • Be aware that Listeria monocytogenes can grow in foods in  the refrigerator. Use an appliance thermometer, such as a refrigerator thermometer, to check the temperature inside your refrigerator. The refrigerator should be 40°F or lower and the freezer 0°F or lower.
  • Clean up all spills in your refrigerator right away–especially juices from hot dog and lunch meat packages, raw meat, and raw poultry.
  • Clean the inside walls and shelves of your refrigerator with hot water and liquid soap, then rinse.

danger zoneCook meat and poultry  thoroughly.

Store foods safely.

  • Use precooked or ready-to-eat food as soon as you can. Do not  store the product in the refrigerator beyond the use-by date; follow USDA  refrigerator storage time guidelines:    
    • Hot Dogs –store opened package no longer than 1 week and unopened package no longer than 2 weeks in the refrigerator.
    • Luncheon and Deli Meat – store factory-sealed, unopened package no longer than 2 weeks. Store opened packages and meat sliced at a local deli no longer than 3 to 5 days in the refrigerator. 
  • Divide leftovers into shallow containers to promote rapid, even  cooling. Cover with airtight lids or enclose in plastic wrap or aluminum foil.  Use leftovers within 3 to 4 days.

Choose safer foods.

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Recommendations for persons at higher risk

 For pregnant women, persons with weakened immune systems, and older adults in addition to the recommendations listed above, include:

Meats

  • Do not eat hot dogs, luncheon meats,  cold cuts, other deli meats (e.g., bologna), or fermented or dry sausages  unless they are heated to an internal temperature of 165°F or until steaming  hot just before serving.
  • Avoid getting fluid from hot dog and  lunch meat packages on other foods, utensils, and food preparation surfaces,  and wash hands after handling hot dogs, luncheon meats, and deli meats.
  • Pay attention to labels. Do not eat refrigerated pâté or meat  spreads from a deli or meat counter or from the refrigerated section of a  store. Foods that do not need refrigeration, like canned or shelf-stable pâté  and meat spreads, are safe to eat. Refrigerate after opening.

Soft Cheeses

  • Do not eat soft cheese such as feta,  queso blanco, queso fresco, brie, Camembert, blue-veined, or panela (queso  panela) unless it is labeled as made with pasteurized milk. Make sure the label  says, "MADE WITH PASTEURIZED MILK."   
    • Be aware that Mexican-style cheeses  made from pasteurized milk, such as queso fresco, likely contaminated during  cheese-making, have caused Listeria infections.

Seafood

  • Do not eat refrigerated smoked  seafood, unless it is contained in a cooked dish, such as a casserole, or  unless it is a canned or shelf-stable product.
  • Refrigerated smoked seafood,  such as salmon, trout, whitefish, cod, tuna, and mackerel, is most often  labeled as "nova-style," "lox," "kippered,"  "smoked," or "jerky."    
    • These fish are typically found in the refrigerator section or sold at seafood and deli counters of grocery stores and  delicatessens.
  •   Canned and shelf stable tuna, salmon, and other fish products are safe to eat.  

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Safety tips for eating melons

Get specific safety information  about the Listeria outbreak in cantaloupes here.

Follow this general FDA advice for melon safety:

  • Consumers and food preparers  should wash their hands with warm water and soap for at least 20 seconds before and after handling any whole melon, such as cantaloupe, watermelon, or honeydew. 
  • Scrub the surface of  melons, such as cantaloupes, with a clean produce brush under running water and dry them with a clean cloth or paper towel before cutting. Be sure that your scrub brush is sanitized after each use, to avoid transferring bacteria between melons.
  • Promptly consume cut melon or refrigerate promptly. Keep your cut melon refrigerated at, or less than 40 degrees F (32-34 degrees F is best), for no more than 7 days. 
  • Discard cut melons left at room temperature for more than 4 hours.

Source: Centers for Disease Control www.cdc.gov