Listeriosis

Listeria is a bacteria found in soil and water. (Read about "Microorganisms") It has been found in a variety of raw foods, such as uncooked meats and vegetables, as well as in processed foods that haven't been processed properly. In some people, eating or drinking a product contaminated with listeria results in a dangerous condition called listeriosis. According to the Centers for Disease Control and Prevention (CDC), an estimated 2,500 Americans become seriously ill with listeriosis each year. Of these, around 500 die.

A person with listeriosis usually has fever, muscle aches and sometimes gastrointestinal symptoms such as nausea or diarrhea. (Read about "Diarrhea") If infection spreads to the nervous system (Read about "Nervous System"), symptoms such as headache, stiff neck, confusion, loss of balance or convulsions (Read about "Seizures") can occur.

The biggest risk is to pregnant women and their babies. According to CDC, pregnant women are about 20 times more likely than other healthy adults to get listeriosis. Infected pregnant women may experience only a mild, flu-like illness; however, infection during pregnancy can lead to premature delivery (Read about "Preterm Labor"), infection of the newborn or even stillbirth. If a pregnant woman has symptoms such as fever or stiff neck, she should see her doctor at once. (Read about "Healthy Pregnancy")

In addition to pregnant women, the Food and Drug Administration (FDA) says people whose immune systems (Read about "The Immune System") are weakened by AIDS, cancer or kidney disease are more at risk, as are the elderly. (Read about "HIV / AIDS" "Cancer: What It Is" "Kidney Disease")

Where it comes from

Vegetables can become contaminated with listeria from the soil or from manure used as fertilizer. Foods of animal origin such as meats and dairy products can also get contaminated. CDC says it's important to be aware of the risk of listeria from:

• uncooked or undercooked meats and vegetables
• processed foods that may have become contaminated after processing, such as soft cheeses and cold cuts
• foods that haven't been properly pasteurized during manufacture
• unpasteurized (raw) milk or foods made from unpasteurized milk

Reducing the risk

To reduce the risk for listeriosis, CDC has these recommendations:

• Thoroughly cook all food from animal sources such as beef, pork or poultry and cook left-over foods or ready-to-eat foods until steaming hot before use
• Wash raw vegetables thoroughly before eating
• Keep uncooked meats separate from vegetables and from cooked foods and ready-to-eat foods
• Avoid raw (unpasteurized) milk or foods made from raw milk
• Wash hands, knives and cutting boards after handling uncooked foods.
• Avoid soft cheeses such as feta, Brie, Camembert, blue-veined, and Mexican-style cheese.

Because pregnant women, older adults and people with weakened immune systems are at higher risk for listeriosis, CDC recommends the following measures for those persons:

• Do not eat hot dogs and luncheon meats, unless they are reheated until steaming hot.
• Avoid cross-contaminating other foods, utensils and food preparation surfaces with fluid from hot dog packages and wash hands after handling hot dogs.
• Do not eat soft cheeses such as Feta, Brie and Camembert cheeses, blue-veined cheeses and Mexican-style cheeses such as "queso blanco fresco." Cheeses that may be eaten include hard cheeses, semi-soft cheeses such as mozzarella, pasteurized processed cheeses such as slices and spreads, cream cheese and cottage cheese.
• 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.

When infection occurs during pregnancy, CDC says that antibiotics given promptly to the pregnant woman can often prevent infection of the fetus or newborn. If you suspect a problem, contact your doctor at once.

Related Information:

    Food Safety

    Digestive System

    Antibiotics