Health, Safety, and Nutrition for the Young Child 9th Edition by Lynn Marotz

Exercise 17

The health department recently investigated an outbreak of food poisoning at a local school. The children had been served a menu that included tacos, tossed lettuce salad, fresh melon cubes, and milk. Chris, the head cook, had forgotten to put the ground beef in the refrigerator to defrost a few days earlier, so she allowed it to thaw on the counter overnight. After dividing the partially thawed raw ground beef with her bare hands, she continued preparations for lunch and chopped the ingredients for a tossed salad. She then diced the melon into cubes for the fruit salad with the same knife that had been used to open the packages of ground beef,
How could this outbreak have been prevented