See a lot of them this time of year – caramel apples, but there’s concern they may breed listeria if they’re not refrigerated. The problem starts when you jab the stick into them. It releases a little bit of juice that gets trapped under the layer of caramel creating an environment that can facilitate the growth of listeria. A listeria outbreak in the U.S. last year was traced back to this. Thirty-five people became ill, three died.