Recent listeria outbreaks have affected pizza and ice cream.If you are a Texan who lived through the dark days of the Great Blue Bell Recall of 2015, you know what Listeria is. In case you are new in town or need a refresher, Listeria is the type of bacteria responsible for the removal of our beloved Blue Bell ice cream from grocery store shelves. It caused disease in ten people and the death of three.

Blue Bell has been back on grocery store shelves for a while, but Listeria is a crafty bacteria, and it continues to pop up in unexpected places places. Most recently you might have purchased a frozen pizza contaminated by the bug. Just last week, some soft raw milk cheese was recalled because of Listeria contamination. The month before it might have been in your package of grated cheese.

It seems to be everywhere. But what exactly is Listeria and how concerned should we be about it?

Listeria monocytogenes, as it is formally known, is the bacteria responsible for the disease Listeriosis. Listeriosis is almost always caused by the consumption of contaminated food. According to the CDC, the common culprits are soft cheese, processed meats like hot dogs and cold cuts, raw sprouts, melons, and smoke seafood.

Fun Fact: Listeria, like the mouthwash Listerine, was named for Joseph Lister who introduced sterilization of instruments prior to surgery.

Most people are not affected by Listeria, but it poses a significant risk to  pregnant women, infants, the elderly, and those with a compromised immune system. The disease can cause fever, headache, stiff neck, muscle aches, confusion, and loss of balance in those it affects. Pregnant women are not usually directly affected, but the disease can cause premature birth, stillbirth, or severe infection in the newborn.

For this reason, it is important to take precautions if you fall into one of these risk categories. The CDC recommends the following:

  • Avoid unpasteurized dairy products, particularly milk and soft cheeses. Mexican-style soft cheeses can pose a risk for Listeria even if made from pasteurized milk.
  • Be sure to heat processed meats such as deli meat and hot dogs until they are steaming.
  • Refrigerate food within two hours of preparing and use or discard it within three or four days.
  • Avoid cross-contamination on kitchen surfaces and utensils, and separate risky foods in the refrigerator.
  • Keep your refrigerator at (or below) 40°F and your freezer at 0°F. A separate thermometer offers a more reliable measure than the one built into your refrigerator.

Finally, if you develop symptoms that are associated with Listeria within two months of eating one of the risky foods, or something that has been recalled (like one of those frozen pizzas), contact your doctor.

In general, Listeria doesn’t pose a great risk for most people. For those who fall in the high risk category, a few simple precautions can help you protect yourself from the bacteria and its effects.


Image credit: pedrosala / Adobe Stock