We have become accustomed to ready-to-eat meats because they are convenient and available. But we can’t just assume that the luncheon meats, hot dogs, bologna, or pepperoni in our refrigerators are safe just because the expiration date is current. There is a lurking killer called listeria monocytogenes that can contaminate these and similar products.

LM is a bacterium commonly found in soil and water, which can cause a serious, even life-threatening, illness called listeriosis.

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

According to the Centers for Disease Control and Prevention, roughly 2,000 people in the United States report serious illness from listeriosis each year. Of those reported, about 25 percent die as a result of the illness. There were 2,493 cases of LM contamination in 1998, resulting in 499 deaths.

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 may take up to eight weeks for someone to become ill. If you are an at-risk individual or have symptoms that concern you, consult your physician. Listeriosis is successfully treated with antibiotics.

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 can be destroyed if ready-to-eat foods are reheated to steaming hot.

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 they are steaming hot. If you cannot reheat these foods, do not eat them.

. Avoid raw, unpasteurized milk and foods made from it.

. Avoid soft cheeses such as feta, Brie, Camembert, or blue-veined varieties.

All consumers should follow four simple steps to food safety:

. Clean: Wash hands and surfaces often with hot, soapy water. Because LM bacteria can slowly grow at refrigerator temperatures, always use hot soapy water to clean up spills in the refrigerator.

Always wash hands, cutting boards, dishes and utensils with hot, soapy water after they come in contact with raw food or ready-to-eat food that requires additional heating.

. 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 two hours.

Following these steps will substantially reduce or eliminate your risk of LM contamination.

Consumer Forum is a collaboration of the Bangor Daily News and Northeast COMBAT/The Maine Center for the Public Interest, Maine’s membership-funded nonprofit consumer organization. For help or to request individual or business membership information write: Consumer Forum, Bangor Daily News, PO Box 1329, Bangor 04402-1329.