Five people have died and 21 more have been hospitalized after they were infected with listeria linked to prepackaged caramel apples, the Centers for Disease Control and Prevention said Friday.

In all, 28 people in 10 states were infected in October and November by the bacterium, which causes listeriosis, a life-threatening illness. The CDC is urging consumers not to eat “commercially produced, prepackaged caramel apples” while it investigates the outbreak. No illnesses have been linked to uncoated apples or caramel candy, or caramel apples that are not prepackaged, the agency said.

Listeria can live in food processing plants and can grow even in cold temperatures, such as those in refrigerators. It is killed by cooking and pasteurization. It is also found in soil and water and in animals such as poultry and cattle, and can be present in raw milk or food made from raw milk.

Minnesota health officials have determined that two people died and two others were sickened in the fall after eating contaminated prepackaged caramel apples, according to the Associated Press. The four were between 59 and 90 years old.

The CDC said nine of the illnesses across the nation occurred in pregnant women or newborns. The disease particularly affects older adults, pregnant women, newborns and people with weakened immune systems. Three people have come down with meningitis.

The other states where infections have been found are: Arizona (4), California (1), Missouri (5), New Mexico (5), North Carolina (1), Texas (4), Utah (1), Washington (1) and Wisconsin (2).