CARAMEL apples have been linked to four deaths in the US, sparking a call for Americans to stop eating the pre-packaged treats.
They are believed to be the source of a serious listeriosis outbreak affecting at least 28 people in 10 states.
Patients aged between seven and 92 are in hospital and of the five deaths so far, four were caused by listeriosis.
The infection develops after eating food contaminated with the listeria bacteria, and can cause fever, vomiting, seizures, meningitis and death.
Most of the cases, which started on 17 October, occurred in New Mexico, Missouri, Arizona, Texas and Minnesota.
There have been two cases reported in Wisconsin and one each in California, North Carolina, Utah and Washington.
Pregnant women are among those affected, although no miscarriages have been reported, and some of the children taken ill have developed potentially deadly meningitis.
A spokesperson for the US Centers for Disease Control and Prevention (CDC) said: "Although limited information is currently available about the specific brand consumed, the finding that most of the ill people reported consuming these apples suggests that these Listeria infections are likely related to commercially produced, prepackaged caramel apples."
Investigators are urgently working to trace the brand involved and identify the source of contamination.
Caramel apples, which are similar to toffee apples but with a softer coating, are sold widely throughout America and frequently eaten during winter.
But now the CDC is urging people throw away any pre-packaged caramel apples until they have more information on the cause of the outbreak, wrapping them well so animals do not eat them.
Some of the apples may still be on sale in shops, the agency warned, and could have a shelf life of a month or more.