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Listeriosis and Food Safety Tips

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.
Symptoms of Listeriosis are flu-like, 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.

Pregnant women may experience only mild, flu-like illness, but 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 heating ready-to-eat foods to 165 degrees F or pasteurizing raw milk or milk products.

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 165 degrees F.

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

  • Reheat ready-to-eat foods such as hot dogs, luncheon meats, cold cuts, fermented and dry sausage and other deli-style meat and poultry products until steaming hot (160-165 degrees F.) 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.