The Kroger Co. of Cincinnati, OH, announced Thursday, Oct. 15, that its retail grocery stores would withdraw from sale unrefrigerated caramel apples that have been pierced with dipping sticks due to new scientific evidence that the product, if left unrefrigerated, may present a health risk. According to the U.S. Centers for Disease Control and Prevention (CDC), 35 people in 12 states were sickened between October 2014 and January 2015 in a Listeria outbreak linked to commercial produced, prepackaged caramel apples. Of these, 34 people were hospitalized and Listeriosis contributed to at least three of seven deaths reported. Although no recent illnesses have been reported in connection with these products, Kroger stated that the decision was made out of an abundance of caution after reviewing a study published online by the American Society of Microbiology. The study, by Kathleen Glass, Ph.D., of the University of Wisconsin-Madison and four colleagues, showed that the average population of Listeria monocytogenes on caramel apples with sticks increased 1,000 fold if they were 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. While dipping apples in hot caramel kills off a lot of the surface bacteria, Glass noted that, “… those that still survived were the ones that were able to grow. If someone ate those apples fresh, they probably would not get sick. But because caramel-dipped apples are typically set out at room temperature for multiple days, maybe up to two weeks, it is enough time for the bacteria to grow.” She recommended that consumers look for refrigerated caramel apples or eat them fresh and that caramel apple manufacturers might consider thoroughly disinfecting apples before dipping them in caramel, add growth inhibitors to the caramel coating or apple wax, or use better temperature-time controls to inhibit the growth of L. monocytogenes. “After reviewing the study, we have decided to voluntarily withdraw unrefrigerated caramel apples from our stores,” said Dr. Payton Pruett, Kroger’s vice president of food safety. “While we believe the potential health risk is minimal, we are acting out of an abundance of caution on behalf of our customers.” The company stated that its stores have pulled these products from shelves and distribution centers and disposed of them. These stores include Kroger, City Market, Dillons, Food 4 Less, Fred Meyer, Fry’s, Harris Teeter, Jay C, King Soopers, QFC, Ralphs and Smith’s. Pruett added that the company is open to carrying these products again in the future and will work with suppliers to reduce the risk of bacterial growth. Kroger, one of the world’s largest retailers, employs nearly 400,000 people in 2,623 supermarkets and multi-department stores in 34 states and the District of Columbia.  The company also operates 781 convenience stores, 327 fine jewelry stores, 1,350 supermarket fuel centers and 37 food processing plants in the U.S. (To sign up for a free subscription to Food Safety News, click here.)