Last year consumers were made aware of a multi-state outbreak of Listeriosis which caused illness and deaths. Listeria has also been tied to 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, along with some produce.

Unlike most bacteria, Listeria germs can grow and spread in the refrigerator. If Listeria contaminated food is unknowingly put in the refrigerator, the germs could contaminate your refrigerator and spread to other foods to increase the likelihood that your family becomes sick.

One group of people most at risk for Listeriosis (the illness caused by Listeria monocytogenes) is pregnant women. In pregnant women, Listeriosis can cause miscarriage, stillbirth and serious illness or even death of newborn babies. Other groups at risk for Listeriosis include seniors, people with compromised immune systems and those with certain chronic medical conditions, like HIV/AIDS, cancer, diabetes, kidney disease and transplant patients.

So how do you protect yourself from Listeriosis? The first defense is to wash all fruits and vegetables under running water just before eating, cutting or cooking, even if you plan to peel it first. This includes everything from oranges to onions to bananas. Scrub firm products such as melons and cucumbers with a clean produce brush.

Chilling food properly is another important way to reduce the risk of Listeria infection. Although Listeria can grow at refrigeration temperatures, it grows more slowly at 40 degree Fahrenheit or under. Making certain foods do not leak juices onto other foods to avoid cross contamination is another way to protect food. Cover all food or wrap food in plastic wrap or foil before placing it in the refrigerator. Utilize a refrigerator thermometer in the center of the fridge and check periodically. Adjust the temperature control if necessary to keep foods at or below 40 degree Fahrenheit. Use pre-cooked and ready-to-eat foods as soon as you can. The longer they are stored in the fridge, the more chance Listeria has to grow. If you are storing leftovers, they must be consumed or disposed of after three days.

It is also important to clean your refrigerator regularly. Listeria can contaminate other food by spills, especially from meat juices. Use paper towels to avoid transferring germs on a cloth towel. Clean the inside walls and shelves of your refrigerator with warm water and liquid soap, then rinse. You can also sanitize monthly using one teaspoon of unscented bleach to every one quart of water. Put in a spray bottle, spray the surface, let it stand for 10 minutes, wipe with a clean paper towel then let air dry. Remember bleach solutions become less effective with time, so discard unused portions daily.

Last but not least, clean hands and kitchen surfaces often, as Listeria can spread from one surface to another. For proper handwashing techniques see Handwashing 101: Avoid the flu and colds by correctly washing your hands on the Michigan State University Extension website.