A Nasty Germ That Can Lurk in Favorite Foods

Recalls of assorted foods and different brands of ice cream over the past few years have put a spotlight on the germ known as listeria.

And though many of these cases happened during manufacturing, the potential for contamination is actually greater for foods after they’ve arrived at supermarkets and other food stores. And one item at particular risk is store-sliced deli meat.

One study that tested samples over 6 months in the deli departments of chain supermarkets in three states found listeria in almost 10 percent of samples.

Even if surfaces that come into contact with food, such as meat slicers, are cleaned thoroughly, listeria can be transferred unintentionally from moist areas where it hides — even floors and drains. And unlike other types of bacteria, it can live and grow at some refrigerator temperatures.

Listeria is a type of bacteria that can cause listeriosis, a serious food-borne infection. An estimated 1,600 Americans get listeriosis each year, and about 260 die. The infection is most likely to sicken pregnant women and their newborns, adults 65 or older, and people with weakened immune systems, according to the U.S. Centers for Disease Control and Prevention.

If you’re healthy, eating contaminated food may cause typical food poisoning symptoms that you’ll recover from. But symptoms of listeriosis include diarrhea, upset stomach, fever, aches and chills, and can take days or even weeks to appear.

If you’re pregnant, it can cause miscarriage, premature labor, and illness or even death in your newborn.

The U.S. Food and Drug Administration recommends that people vulnerable to the infection skip sliced-at-the-store meats or heat them to 165 degrees Fahrenheit.

There are also everyday precautions that everyone should take for many foods — not just deli meat.

The precautions include:

Keeping your refrigerator at 40 degrees Fahrenheit or lower and the freezer at 0 degrees or lower.
Regularly cleaning your fridge with hot water and liquid soap. Clean up spills immediately.
Always storing uncooked meat away from all other foods.
Eating precooked or ready-to-eat food as soon as possible. You can keep factory-sealed pre-packaged deli meat unopened for a maximum of 2 weeks, but don’t keep opened packages and any deli-sliced meat for more than 3 to 5 days.
Thoroughly rinsing all raw produce — even foods you will peel — before eating, cutting or cooking. Use a produce brush to scrub firm produce.
Washing hands, knives, countertops and cutting boards after handling and preparing uncooked foods.
Cooking meat thoroughly, using a cooking thermometer to check doneness.

Keep in mind that you can’t see listeria — it doesn’t show signs of spoilage, so always practice these safety measures.

More information

The CDC has detailed information on listeria.