Listeriosis is a serious infection caused by the bacterium Listeria monocytogenes. Listeriosis can cause severe illness in newborns, pregnant women, the elderly, and anyone with a weakened immune system. Illness can range from fever and diarrhea to infections resulting in brain damage or death. Healthy adults and children can get infected with Listeria, but they rarely become seriously ill. Listeria is commonly found in the environment in soil and water and on plant material. Listeria has also been found in raw foods, such as uncooked meats and vegetables, as well as in foods that become contaminated after processing, such as soft cheeses and cold cuts at the deli counter. In addition, unpasteurized (raw) milk and foods made from unpasteurized milk may contain Listeria.
In the United States, an estimated 2,500 persons become seriously ill with listeriosis each year; of these, about 92 percent are hospitalized and 20 percent die. Persons at increased risk of serious infection are: pregnant women, newborns, the elderly, and persons with weakened immune systems, including persons with cancer, diabetes, kidney disease, or AIDS, and those who take prescription steroid medications. Pregnant women are about 20 times more likely than other healthy adults to get listeriosis. Although infected pregnant women may only experience a mild, flu-like illness, infections during pregnancy can lead to miscarriage, stillbirth, premature delivery, or infection of the newborn.
What can a person do to prevent listeriosis?
Recommendations for persons at high risk, such as pregnant women and persons with weakened immune systems:
- Do not eat hot dogs, luncheon meats, or deli meats, unless they are reheated until steaming hot.
- Avoid getting fluid from hot dog packages on other foods, utensils, and food preparation surfaces, and wash hands after handling hot dogs, luncheon meats, and deli meats.
- Do not eat soft cheeses such as feta, Brie, and Camembert, blue-veined cheeses, or Mexican-style cheeses such as queso blanco, queso fresco, and Panela, unless they have labels that clearly state they are made from pasteurized milk.
- Do not eat refrigerated pâtés or meat spreads. Canned or shelf-stable pâtés 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." The fish is found in the refrigerator section or sold at deli counters of grocery stores and delicatessens. Canned or shelf-stable smoked seafood may be eaten.
General recommendations to avoid foodborne illness:
- Thoroughly cook raw food from animal sources, such as beef, pork, or poultry.
- Wash raw vegetables thoroughly before eating.
- Keep uncooked meats separate from vegetables and from cooked foods and ready-to-eat foods.
- Avoid unpasteurized (raw) milk or foods made from unpasteurized milk.
- Wash hands, knives, and cutting boards after handling uncooked foods.
- Consume perishable and ready-to-eat foods as soon as possible.