Listeria is the name of a bacteria found in soil and water and some animals, including poultry and cattle. It can be present in raw milk and foods made from raw milk. It can also live in food processing plants and contaminate a variety of processed meats.
Listeria is unlike many other germs because it can grow even in the cold temperature of the refrigerator. Listeria is killed by cooking and pasteurization.
- Keep Refrigerated Foods Cold
- Clean Refrigerator Regularly
- Clean Hands and Kitchen Surfaces Often
If you eat food contaminated with bacteria called Listeria, you could get so sick that you have to be hospitalized. And for certain vulnerable people, the illness could be fatal.
Unlike most bacteria, Listeria germs can grow and spread in the refrigerator. So if you unknowingly refrigerate Listeria-contaminated food, the germs could contaminate your refrigerator and spread to other foods there and increase the likelihood that you and your family will become sick.
Those most at risk for listeriosis—the illness caused by Listeria monocytogenes—include pregnant women, older adults and people with compromised immune systems and certain chronic medical conditions (such as HIV/AIDS, cancer, diabetes, kidney disease, and transplant patients). In pregnant women, listeriosis can cause miscarriage, stillbirth, and serious illness or death in newborn babies.
Recently, a multi-state outbreak of listeriosis tied to contaminated cantaloupes has caused illnesses and deaths. Listeria has also been linked to a variety of ready-to-eat foods, including unpasteurized milk and dairy products, Mexican-style or soft cheeses made with unpasteurized milk, processed deli meats, hot dogs, smoked seafood and store-prepared deli-salads.
Donald Zink, Ph.D, senior science advisor at FDA’s Center for Food Safety and Applied Nutrition, says FDA is aware of cases of foodborne illness caused by bacteria that can live in the kitchen and spread to foods.
Consumers are advised to wash all fruits and vegetables under running water just before eating, cutting or cooking, even if you plan to peel the produce first. Scrub firm produce such as melons and cucumbers with a clean produce brush.
To further protect yourself and your family from Listeria, follow these steps:
Keep Refrigerated Foods Cold
Chilling food properly is an important way of reducing risk of Listeria infection. Although Listeria can grow at refrigeration temperatures, it grows more slowly at refrigerator temperatures of 40 degrees F or less.
- Keep your refrigerator at 40 degrees F or lower and the freezer at 0 degrees F or lower.
- Wrap or cover foods with a sheet of plastic wrap or foil or put foods in plastic bags or clean covered containers before you place them in the refrigerator. Make certain foods do not leak juices onto other foods.
- Place an appliance thermometer, such as a refrigerator thermometer, in the refrigerator, and check the temperature periodically. Adjust the refrigerator temperature control, if necessary, to keep foods as cold as possible without causing them to freeze. Place a second thermometer in the freezer to check the temperature there.
- Use precooked and ready-to-eat foods as soon as you can. The longer they are stored in the refrigerator, the more chance Listeria has to grow.
“If you have leftovers in your refrigerator, it’s best to throw them out after three days, just to be sure,” says Zink. “It’s better to be safe than sorry.”
Clean Refrigerator Regularly
Listeria can contaminate other food through spills in the refrigerator.
- Clean up all spills in your refrigerator right away—especially juices from hot dog and lunch meat packages, raw meat, and raw poultry. Consider using paper towels to avoid transferring germs from a cloth towel.
- Clean the inside walls and shelves of your refrigerator with warm water and liquid soap, then rinse. As an added measure of caution, you can sanitize your refrigerator monthly using the same procedures described below for kitchen surfaces.
Clean Hands and Kitchen Surfaces Often
Listeria can spread from one surface to another.
- Thoroughly wash food preparation surfaces with warm, soapy water. As an added precaution you should sanitize clean surfaces by using any of the kitchen surface sanitizer products available from grocery stores, being careful to follow label directions.
You can make your own sanitizer by combining 1 teaspoon of unscented bleach to one 1 quart of water, flooding the surface and letting it stand for 10 minutes. Then rinse with clean water. Let surfaces air dry or pat them dry with fresh paper towels. Bleach solutions get less effective with time, so discard unused portions daily.
- A cutting board should be washed with warm, soapy water after each use. Nonporous acrylic, plastic, or glass boards can be washed in a dishwasher.
- Dish cloths, towels and cloth grocery bags should be washed often in the hot cycle of your washing machine.
- It’s also important, to wash hands with warm water and soap for at least 20 seconds before and after handling food.
|Incubation Period||3-70 days|
|Symptoms||Fever, stiff neck, confusion, weakness, vomiting, sometimes preceded by diarrhea|
|Duration of Illness||Days to weeks|
|Who’s at Risk?||
|What Do I Do?||If you are very ill with fever or stiff neck, consult your doctor immediately. Antibiotics given promptly can cure the infection and, in pregnant women, can prevent infection of the fetus.|
|How Do I Prevent It?||
Listeriosis (Listeria infection) – CDC
Listeria – FoodSafety.gov