Watch out for this bacteria! Here's what you need to know to ensure that you and your baby stay healthy.


Add this to the list of odd things you have to do during pregnancy: Heat up your luncheon meat before you eat it. Why? To prevent listeriosis, an illness caused by the Listeria monocytogenes bacterium. When Listeria makes its way to your dinner table via contaminated meat, vegetables, or cheeses, it can make you very sick. Listeriosis is not a common disease -- only 2,500 people in the United States become seriously ill with it each year, according to the Centers for Disease Control (CDC) -- but one in five who get it will die from the illness. Because of changes in their immune systems, pregnant women are about 20 times more likely than other healthy adults to get listeriosis.

Listeriosis can be particularly dangerous for pregnant women and their unborn babies because it can be transmitted to the fetus through the placenta even if the mother is not showing signs of illness. Listeriosis during pregnancy can result in premature delivery, miscarriage, fetal death, and severe illness or death of a newborn from infection.

Watch for flulike symptoms: a sudden onset of fever, chills, muscle aches, and sometimes diarrhea or upset stomach. The severity of the symptoms may vary. If the infection spreads to the nervous system, the symptoms may include headache, stiff neck, confusion, loss of balance, or convulsions. If you think you may have listeriosis, contact your doctor immediately. A blood test can determine whether your symptoms are caused by listeriosis. If you have it, your doctor will prescribe antibiotics.

The best way to prevent listeriosis is to avoid or use extra caution with foods that might be contaminated with the Listeria bacteria. The U.S. Department of Agriculture (USDA) and the FDA provide the following advice for pregnant women:

  • Do not eat hot dogs, luncheonmeats, or deli meats unless they are heated until steaming hot.
  • Do not eat soft cheeses such as Camembert, feta, Brie, blue-veined cheeses, and Mexican-style cheeses such as queso blanco fresco. The following can be safely consumed: hard cheeses, semisoft cheeses such as pasteurized processed cheese slices and spreads, mozzarella, cream cheese, and cottage cheese.
  • Do not eat refrigerated pí¢té or meat spreads. Canned or shelf-stable pí¢té and meat spreads are safe to eat.
  • Do not eat refrigerated smoked seafood unless it is an ingredient in a cooked dish such as a casserole. Examples of refrigerated smoked seafood include salmon, trout, whitefish, cod, tuna, and mackerel. These are most often labeled as "Nova-style," "lox," "kippered," "smoked," or "jerky." Canned fish such as salmon and tuna or shelf-stable smoked seafood may be safely eaten.
  • Do not drink raw (unpasteurized) milk or juice. Do not eat foods that contain unpasteurized ingredients.
  • Thoroughly wash all fresh fruits and vegetables before eating.
  • Because Listeria can grow even at refrigeration temperatures of 40 degrees or below, use all perishable items that are precooked or ready-to-eat as soon as possible and clean your refrigerator on a regular basis.

Originally published in You & Your Baby: Pregnancy.

All content on this Web site, including medical opinion and any other health-related information, is for informational purposes only and should not be considered to be a specific diagnosis or treatment plan for any individual situation. Use of this site and the information contained herein does not create a doctor-patient relationship. Always seek the direct advice of your own doctor in connection with any questions or issues you may have regarding your own health or the health of others.

Parents Magazine