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This fact sheet answers frequently asked questions about Listeriosis.

Listeriosis is a serious infection caused by a bacteria called Listeria monocytogenes.

The basics

What is Listeriosis?

You get the infection by consuming food contaminated with the bacteria. The disease is most serious in pregnant women, newborns, the elderly, and people with weakened immune systems.

How is it spread?

Listeria exists in nature in both water and soil. Listeriosis spreads by eating food contaminated with Listeria. It spreads from person to person through sexual contact. It can also pass from mother to child during pregnancy or childbirth.

Some healthy people may not get sick from eating contaminated food. People at increased risk for infection may get listeriosis after eating food contaminated with even a few bacteria.

Who is at greater risk of getting seriously ill from Listeriosis?

People with compromised immune systems such as:

  • People with HIV/AIDS
  • People with cancer, diabetes, or kidney disease
  • People with weakened immune systems due to other causes
  • People who take steroid medications
  • The elderly
  • Pregnant women are about 20 times more likely than other healthy adults to get Listeriosis. About one-third of Listeriosis cases occur during pregnancy and lead to miscarriages and stillbirths.

Healthy adults and children can get Listeria, but serious illness is rare.


What are the symptoms?

Symptoms can include fever, muscle aches, and gastrointestinal symptoms such as nausea or diarrhea. If infection spreads to the nervous system symptoms can include:

  • headache
  • stiff neck
  • confusion
  • loss of balance
  • convulsions

Infected pregnant women may not experience any symptoms or experience only a mild, flu-like illness; however, infections during pregnancy can lead to premature delivery, infection of the newborn, or even stillbirth.


How can I reduce my risk of getting Listeria?

General recommendations:

  • Thoroughly cook raw meat, such as beef, pork, or poultry
  • Wash raw vegetables thoroughly before eating
  • Keep uncooked meats separate from vegetables, cooked foods, and ready-to-eat foods
  • Avoid unpasteurized milk or foods made from unpasteurized milk
  • Wash hands, knives, and cutting boards after handling uncooked foods

Recommendations for high risk people include:

  • Avoid soft cheeses such as feta, Brie, Camembert, blue-veined, and Mexican-style cheese
  • Cook leftover foods or ready-to-eat foods, until steaming hot before eating. Pregnant women and immunosuppressed people may choose to avoid deli meats and cheeses or reheat cold cuts before eating


How is it treated?

Several types of antibiotics are effective against Listeria. When infection occurs during pregnancy, antibiotics given promptly to the pregnant woman can often prevent infection of the fetus or newborn. Even with prompt treatment with antibiotics, some infections result in death, particularly in the elderly and in persons with other serious medical problems.

What should I do if I’ve eaten food recalled because of contamination with Listeria?

The risk of an individual developing Listeria infection after consumption of a contaminated product is very small. If you have eaten a contaminated product and have no symptoms, you do not need testing or treatment, even if you are in a high-risk group. If you are in a high-risk group, have eaten the contaminated product, and get a fever or signs of serious illness within two months, you should contact your health care provider.

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