State and federal officials have ended their investigation into an outbreak of infections caused by Listeria monocytogenes found in Big Olaf Ice Cream. The CDC declared the outbreak over on Nov. 2.

The Centers for Disease Control and Prevention reports there were 28 patients across 11 states. Of those patients, 27 were hospitalized, one died and one pregnant woman miscarried.

Sick people’s samples were collected from Jan. 24, 2021, to Aug. 19, 2022. Patients’ ages ranged from less than 1 to 92 years old. The last known illness onset was June 24, 2022.

Big Olaf Creamery of Sarasota, FL, recalled all of its ice creams on July 13. Its facilities were closed down by the Florida Department of Health with the assistance of the Florida Department of Agriculture & Consumer Services.

Florida officials found 16 of 17 flavors of Big Olaf ice cream were contaminated with Listeria monocytogenes. They also found the pathogen in production equipment at the company’s factory.

The state department of agriculture performed whole genome sequencing on samples collected from the finished product and equipment and they matched samples from outbreak patients.

Complete distribution details were not available for the ice cream, but most of it was sold at retail in Florida. Some were served to consumers in restaurants and in senior homes, as well as one location in Fredericksburg, OH, according to the FDA. Some sick people reported traveling to Florida and eating ice cream before becoming ill.

States with patients were: Colorado with 1, Florida with 14, Georgia with 1, Illinois with 1, Kansas with 1, Nebraska with 1, Massachusetts with 2, Minnesota with 1, New Jersey with 1, New York with 4, and Pennsylvania with 1.

about Listeria infections
Food contaminated with Listeria monocytogenes may not look or smell spoiled but can still cause serious and sometimes life-threatening infections. Anyone who has developed symptoms of Listeria infection should seek medical treatment and tell their doctors about possible Listeria exposure.

Also, anyone who has eaten any suspect products should monitor themselves for symptoms during the following weeks because it can take up to 70 days after exposure to Listeria for symptoms of listeriosis to develop. 

Symptoms of Listeria infection can include vomiting, nausea, persistent fever, muscle aches, severe headache, and neck stiffness. Specific laboratory tests are required to diagnose Listeria infections, which can mimic other illnesses. 

Pregnant women, the elderly, young children, and people such as cancer patients who have weakened immune systems are particularly at risk of serious illnesses, life-threatening infections, and other complications. Although infected pregnant women may experience only mild, flu-like symptoms, their infections can lead to premature delivery, infection of the newborn, or even stillbirth.