Nearly two dozen people have been sickened with listeria, and one has died, according to the Centers for Disease Control and Prevention, which said the source of the outbreak has not been identified.
Of those sickened, 22 people were hospitalized and one person died, the CDC said.
Those who have fallen ill reside in 10 U.S. states, but the majority of them live in or traveled to Florida about a month before they got sick, according to the CDC.
Symptoms usually start within two weeks after someone eats food contaminated with listeria. People can experience fever, muscle aches, headaches, loss of balance and other symptoms.
While the CDC has not identified the specific food item that might be spreading the deadly bacteria, foods that are often culprits for listeria outbreaks are soft cheese, raw sprouts, melons, lunch meats, pâtés, hot dogs, smoked fish and unpasteurized milk.
People at higher risk from a listeria infection include older people, people with weakened immune systems or chronic diseases, pregnant women and newborns.
Pregnant women with listeria typically experience only fever and other flu-like symptoms, like fatigue and muscle aches, but an infection can lead to miscarriage, stillbirth, premature delivery or complications after the baby is born.
The CDC is urging health care providers to report listeriosis illnesses to their health department. Those experiencing symptoms of listeria should write down as much as they can remember about what they ate the month before they got sick, the CDC said.