UNDATED (WOWO): Kroger grocery stores will no longer sell unrefrigerated caramel apples pierced with dipping sticks because, if left unrefrigerated, they could present a health risk.

35 people in 12 states got sick last fall and winter in a Listeria outbreak linked to commercial produced, prepackaged caramel apples. Most of the victims endedup in the hospital and Listeriosis contributed to at least three of seven deaths. 

Although no recent illnesses have been reported, Kroger says the decision was made out of an abundance of caution after reviewing a new study from the University of Wisconsin. It shows Listeria bacteria chances increasing, big time, if  the apples are stored at room temperature for three days. 

However, Listeria grew more slowly on such apples stored in the refrigerator and not at all on apples without sticks after four weeks of storage.