Listeriosis is an illness caused by the bacterium Listeria monocytogenes. People typically get sick with listeriosis by eating food that is contaminated with the bacteria. While anyone can get listeriosis, certain groups are most at risk from this disease. This includes pregnant women, older adults, newborns and individuals with weakened immune systems. A Listeria infection during pregnancy can have serious outcomes including fetal loss, preterm labor, or illness or death in newborn babies. Listeriosis is a rare, but serious disease. In Vermont, less than one Listeria monocytogenes infection per year is reported to the Vermont Department of Health.


Most people who are diagnosed with listeriosis have an “invasive” infection, where the bacteria spreads beyond the gastrointestinal system and into the person’s bloodstream or central nervous system. It can take up to 70 days for symptoms to appear after being exposed to the bacteria, though most people become sick within a month. Symptoms of listeriosis include fever, headache, stiff neck, confusion and muscle aches. Pregnant women infected with listeriosis may only have non-specific symptoms, such as fever, muscle aches and fatigue.


Listeria monocytogenes has been found in a variety of foods including raw milk, soft cheeses, sprouts, deli meats, hot dogs and uncooked meats and vegetables. Unlike most bacteria, Listeria monocytogenes can even grow on some foods when stored properly in a refrigerator. It is important to handle, wash and store foods properly in order to reduce the risk of contracting listeriosis.

For more information on listeriosis, visit the CDC website.

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