What is listeriosis?

Listeriosis is an illness caused by eating foods contaminated with a kind of bacteria, often found in soil and water, called Listeria monocytogenes. Bacteria are too small to be seen without a microscope.

Most people do not get listeriosis. However, pregnant women and newborns, older adults, and people with weakened immune systems caused by cancer treatments, AIDS, diabetes, kidney disease, etc., are at risk for becoming seriously ill from eating foods that contain Listeria monocytogenes.

According to the Centers for Disease Control and Prevention (CDC), an estimated 1,100 people in the United States report serious illness from listeriosis each year. Of those reporting, approximately 25% die as a result of the illness.

How do you know if you have listeriosis?

Listeriosis has flu-like symptoms, such as fever and chills. Sometimes people have an upset stomach, but not always. If the infection spreads to the nervous system, symptoms such as headache, stiff neck, confusion, loss of balance, or convulsions can occur.

While infected pregnant women may experience only mild, flu-like illness, the mother's illness can be transmitted to the fetus through the placenta. This can lead to miscarriage, stillbirth, or serious health problems for her newborn child.

It takes an average of 3 weeks for someone to become ill. If you are an at-risk individual and/or have symptoms that concern you, consult your physician. Listeriosis can be treated with antibiotics.

How does Listeria monocytogenes get into food?

Animals can carry Listeria monocytogenes in their intestines without becoming sick. As a result, the bacteria may be spread to meat and dairy products. Listeria monocytogenes is killed by cooking or by other heating methods, such as pasteurization, used to produce ready-to-eat foods.

However, ready-to-eat food can become contaminated after processing within the processing plant or along the route from the plant to your plate.

Outbreaks of listeriosis are associated with ready-to-eat foods such as hot dogs, luncheon meats, cold cuts, fermented or dry sausage, and other deli-style meat and poultry. In the home, Listeria monocytogenes is destroyed if ready-to-eat foods are reheated to steaming hot.

What at-risk consumers can do to prevent listeriosis and other foodborne illness?

People at risk for listeriosis and their family members or individuals preparing food for them should:

• Reheat until steaming hot the following types of ready-to-eat foods: hot dogs, luncheon meats, cold cuts, fermented and dry sausage, and other deli-style meat and poultry products. Thoroughly reheating food can help kill any bacteria that might be present. If you cannot reheat these foods, do not eat them.
• Wash hands with hot, soapy water after handling these types of ready-to-eat foods. (Wash for at least 20 seconds.) Also wash cutting boards, dishes, and utensils. Thorough washing helps eliminate any bacteria that might get on your hands or other surfaces from food before it is reheated.
• Don't eat soft cheeses such as feta, Brie, Camembert, blue-veined or Mexican-style cheese. You can eat hard cheeses, processed cheeses, cream cheese, cottage cheese, and yogurt.
• Do not drink raw, unpasteurized milk or eat foods made from it, such as unpasteurized cheese.
• Observe all expiration dates for perishable items that are precooked or ready-to-eat.

How all consumers can prevent listeriosis and other foodborne illness

All consumers should follow the four simple steps to food safety promoted by the food safety education program called Fight BAC!^TM

Clean: Wash hands and surfaces often with hot, soapy water. Because Listeria monocytogenes can slowly grow at refrigerator temperatures, always use hot, soapy water to clean up liquid that spills in the refrigerator -- including spills from packages of luncheon meats and hot dogs. Always wash hands, cutting boards, dishes, and utensils with hot, soapy water after they come in contact with raw food.

Separate: Don't cross-contaminate. Ready-to-eat foods and raw meat, poultry, and seafood can contain dangerous bacteria. As a result, keep these foods separate from vegetables, fruits, breads, and other foods that are already prepared for eating.

Cook: Cook to safe temperatures. If you are at risk for listeriosis, reheat luncheon meats, cold cuts, and other deli-style meat and poultry until they are steaming hot.

Chill: Refrigerate or freeze perishables, including ready-to-eat foods, within 2 hours.

What to do if you have food that is recalled because of Listeria monocytogenes

Do not eat any food that is recalled and ordered off grocery store shelves. Return recalled food to the place where you bought it.

The Federal Government plays a critical role in food safety

The U.S. Department of Agriculture's Food Safety and Inspection Service (FSIS) is responsible for inspecting plants that slaughter and/or process meat, poultry, and egg products. The Food and Drug Administration (FDA) oversees the safety of most other foods. Neither agency permits Listeria monocytogenes on cooked, ready-to-eat food. This is called "zero tolerance." As a result, Federal agencies are working with industry to identify and correct potential problem areas.

In addition, FSIS now requires plants that slaughter and process meat and poultry to use a process called the Pathogen Reduction and Hazard Analysis and Critical Control Point (HACCP) system to reduce dangerous bacteria on food. The system requires the food production industry to identify critical points where food may become contaminated and to take the necessary steps to prevent contamination.

FSIS plays an active role in investigations with CDC and FDA if a food production problem or an illness outbreak is identified that involves meat, poultry, or egg products. If necessary, the Agency prevents these food products from going to grocery stores, restaurants, and other food service operations; can stop a plant from operating; and works with producers to recall food that has already gone to store shelves or homes.