Story highlights 7 people have died after eating caramel apples possibly infected with listeria

32 people have become infected in 11 states; listeriosis is on the CDC notifiable diseases list

Adults with compromised immune systems, older adults, pregnant women, and infants are most vulnerable

(CNN) A sweet treat has turned potentially deadly for dozens of people in multiple states.

At least seven people have died after eating caramel apples that may have been infected with Listeria monocytogenes

Some 32 people have become infected with the deadly bacterium in 11 states, according to the Centers for Disease Control and Prevention.

Of those people who got sick 31 were hospitalized and seven deaths have been reported. A press release from the Centers for Disease Control and Prevention says that "listeriosis contributed to at least three of these deaths."

The Public Health Agency of Canada has also identified two cases of listeriosis in Canada and the samples show the same DNA fingerprints as the American cases.

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