CDC: Deadly listeria outbreak that caused 1 death and 1 pregnancy loss may be linked to tubs of ice cream

• Dozens of people have gotten sick with listeriosis, an infection caused by bacteria in food.
• More than half of those people ate ice cream in the month before they got sick.

The listeria outbreak that sickened 23 people and killed one has been linked to Big Olaf Creamery, an ice cream brand based in Sarasota, Florida, according to the Centers for Disease Control and Prevention.

Most of the people affected by the bacterial illness either lived in Florida or recently traveled there, but the cause of the outbreak was previously unknown.

Symptoms of listeria infection can range from non-specific, flu-like illness to gastrointestinal upset or headache and confusion, depending on whether the bacteria has entered the bloodstream or brain.

CDC officials interviewed 17 of the 23 people affected by the outbreak. Of that group, 14 people said they ate ice cream in the month before they got sick. Six of those people remembered eating Big Olaf Creamery brand ice cream specifically.

While the CDC has not initiated an official recall, Big Olaf Creamery has voluntarily informed retailers and recommended they pull their ice creams from shelves. Public health officials have also urged consumers who have Big Olaf ice cream at home to throw away any remaining product.

Big Olaf Creamery did not immediately respond to Insider's request for comment.

The brand is only sold in Florida, but the outbreak affected people from 10 states

Twelve Florida residents reported illness, as well as two New Yorkers, two people from Massachusetts, and individuals from Colorado, Georgia, Illinois, Kansas, Minnesota, New Jersey, and Pennsylvania. Most of the out-of-staters had visited Florida in the month before they got sick.

Early symptoms of listeria infection — fever, fatigue, and muscle aches — can appear up to 70 days after someone eats food contaminated with Listeria monocytogenes bacteria. The long incubation period makes it especially difficult to determine the cause of listeria outbreaks, food safety attorney Bill Marler told Insider.

Marler is representing the family of the woman who died of listeria infection. She was visiting family in Sarasota when she ate Big Olaf Creamery ice cream, and she died shortly after, Marler told local news outlet WTSP.

The people who got sick had a median age of 72, with ages ranging from less than one to 92 years old.

Listeria is more likely to sicken pregnant people, babies, and the elderly

According to the Food and Drug Administration, listeriosis occurs almost exclusively in people with compromised or altered immune systems. This may include people who are immunocompromised due to medication, illness, or age.

Pregnancy doesn't completely suppress the immune system, but it does put pregnant people at a higher risk of contracting certain infections. Their risk of listeriosis is 10 to 18 times higher than that of other healthy adults, and the infection can lead to complications.

Five of the people sickened in the recent outbreak were pregnant at the time. One person miscarried due to the infection. Other complications could include premature delivery, stillbirth, or serious illness in newborn babies, according to the CDC.