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Listeriosis Overview and Prevention

What is listeriosis and what are the symptoms?

Listeriosis is an infectious disease caused by a group of bacteria called Listeria. Listeria can cause a variety of symptoms depending on the person and the part of the body affected. People infected with Listeria can develop fever and diarrhea, but this type of Listeria infection is rarely diagnosed. Pregnant women typically experience a fever and flu-like symptoms. In people other than pregnant women, symptoms can include fever, muscle aches, headache, stiff neck, confusion, and loss of balance. Symptoms typically start within 1 to 4 weeks after being exposed, but have been reported to start as early as the same day as exposure or as long as 70 days after exposure.

Who is at risk?

Most people with listeriosis are in one of three high risk groups: pregnant women and their newborns, older adults (aged 65 and older), and people with weakened immune systems. Other people can get infected with Listeria, but they rarely become seriously ill.

How serious is it?

Listeria can cause severe disease and even death. Most people infected with Listeria need hospital care and antibiotic treatment. Older adults and people with weakened immune systems can develop severe infections in the brain or bloodstream. Listeriosis during pregnancy can cause premature delivery, miscarriage, stillbirth, or infection of the newborn.

How does it spread?

Listeria live in soil and water. People become infected with Listeria when they eat contaminated foods. The bacteria may be passed from mother to the fetus during pregnancy or directly to the newborn at the time of birth.

How can I prevent Listeria infections?

Listeria hides in some foods making them more risky to eat, such as raw milk, soft cheeses, cold deli meats and hot dogs, raw sprouts, and smoked seafood. Avoid these foods if you are in a high-risk group.

Wash your hands before and after handling, preparing, or eating foods, and wash fresh produce thoroughly with clean water before eating.

Practice food safety: Avoid cross-contamination in the kitchen, cook foods thoroughly, and store foods properly by keeping raw meats away from fresh produce and other ready-to-eat foods.

Avoid unpasteurized or raw dairy products and, if unsure, look for the word pasteurized on the label.