What is Listeria infection? How common is Listeria in ice cream?

Listeriosis is a serious infection usually caused by eating food contaminated with the bacterium Listeria monocytogenes. An estimated 1600 people get listeriosis each year, and about 260 die.

The disease, caused by eating food contaminated with listeria, primarily affects older adults, pregnant women, newborns and adults with weakened immune systems, according to the US Centers for Disease Control and Prevention.

The infection is most likely to sicken pregnant women and their newborns, adults aged 65 or older, and people with weakened immune systems.

How common is Listeria in ice cream?

The Centers for Disease Control and Prevention is investigating a listeria outbreak linked to Big Olaf Creamery brand ice cream. The outbreak has resulted in at least one death and 22 illness.

Big Olaf ice cream is sold only in Florida.