by Dr. Threvia West, Maternal-Fetal Medicine Specialist

Listeria infections (known as listeriosis) are rare. When they do happen, they usually affect pregnant women in their last trimester, newborns and people whose immunity is weakened by diseases such as cancer or HIV. People who have had various types of transplants are also more at risk for listeria infection.

Listeria infections are caused by the bacterium Listeria monocytogenes, which can spread through soil and water. A person also can ingest these bacteria by eating certain foods, such as deli meats and cold cuts, soft-ripened cheese, milk, undercooked chicken, uncooked hot dogs, shellfish and coleslaw made from contaminated cabbage. Many cases of infection, though, don't have an identifiable source.

Infections caused by Listeria include gastroenteritis (vomiting and diarrhea, also called the "stomach flu"), bacteremia (bacterial infection in the blood), meningitis, pneumonia, osteomyelitis (infection in the bone) and endocarditis.


Listeria infections may cause symptoms such as fever, vomiting, diarrhea, lethargy, difficulty breathing and poor feeding. Pregnant women who develop listeriosis may only have mild flu-like symptoms, but they are at risk for premature delivery, miscarriage and stillbirth.

People who have weakened immune systems are at particular risk for developing the more serious illnesses from listeriosis, including pneumonia, meningitis and sepsis. 

Fortunately, cases of listeriosis are relatively uncommon. The earlier listeriosis is detected and treated, the better, since it can cause serious and life-threatening infection. And particularly if you are pregnant or in one of the other high-risk groups, avoiding certain foods and drinks can reduce your risk of getting this infection.

Treating listeriosis

Listeriosis is usually treated with antibiotics in the hospital through an intravenous catheter (IV) through a vein. Treatment lasts for about 10 days, but that can vary depending on the body's ability to fight off the infection.

In healthy people with gastroenteritis due to Listeria, symptoms often last only two days and they recover completely.

Preventing listeriosis

There are no vaccines against the bacteria that cause listeriosis. But there are some food safety precautions you can take to help prevent listeriosis:

  1. Always cook food (especially meat and eggs) thoroughly to the proper internal temperature.
  2. Wash fruits and vegetables well before eating.
  3. Only drink pasteurized milk, and make sure that milk is refrigerated at the appropriate temperature, which is below 40°F (4°C).
  4. Avoid foods made from unpasteurized milk.
  5. If you're in a high-risk group, avoid soft cheeses such as feta, Brie, Camembert, blue-veined cheeses, and Mexican-style cheeses (like queso fresco).
  6. Reheat precooked, prepackaged foods — such as deli meats or hot dogs — to steaming hot temperatures, especially if you're pregnant.
  7. Carefully wash hands and utensils after handling raw foods.

-- Dr. Threvia West is a Maternal-Fetal Medicine Specialist with Maternal-Fetal Medicine Center, 4704 Ambassador Caffery Pkwy., Suite 302, Lafayette and the Women’s & Children’s Center, 1811 Rees St., Breaux Bridge. Call 337-443-6870 today for an appointment or to learn more.