The Centers for Disease Control and Prevention is recommending "out of an abundance of caution" that U.S. consumers avoid commercially packaged caramel apples, as some of them may have caused an outbreak of food poisoning that's linked to five deaths so far.
As of Dec. 18, an outbreak of the bacteria Listeria monocytogenes has contributed to at least four and possibly five deaths, and has sickened 28 people in 10 states, the CDC said in a notice on its website Friday. The agency has not confirmed the presence of listeria in caramel apples, but many of the people hospitalized have reported eating caramel apples before they got sick.
Listeriosis can cause fever, muscle aches, nausea and diarrhea. It can be particularly harmful or even fatal to children, the elderly and pregnant women. At least three of those recently affected are children.
Read MoreUh-oh: Storm could thwart holiday travel plans
The CDC has not yet ordered a recall on any specific products.
A representative for the CDC told CNBC the agency is still investigating the outbreak with the Food and Drug Administration, and that it has no additional information on the probe aside from what it's posted online.
Concerns over listeria contamination has been cited in several voluntary recalls of food products containing apples in recent years, according to the FDA website. On Dec.10, produce distributor Del Monte Fresh voluntarily recalled several cut-fruit products containing Gala red apples grown in Pennsylvania over such concerns, according to an FDA report.
Apple growers pointed out that such concerns for now involve only commercial caramel apples, but the U.S. Apple Association said it supports the CDC decision.
Read More
"There are no documented cases of foodborne illness from the consumption of whole fresh apples, and listeria has never been associated with whole fresh apples," said the trade group's Wendy Brannen said in an email to CNBC. "We urge consumers to follow the FDA/CDC warning not to eat prepackaged, caramel-coated apples including those with nuts, chocolate, sprinkles, or other toppings and encourage consumers to continue enjoying all other apples and apple products, which remain healthy, flavorful and safe."
For CDC advice to consumers and retailers on the listeria outbreak, click here.