They should wash their own hands frequently, use disposable towels, change diapers in a special place, wash toys frequently, and assign food service to a single person. These infection-control policies have been shown to work in hospitals and nursing homes as well as day care centers, so don't be afraid to insist that they become the norm. This is called cross-contamination. While the bacteria in the meats is killed when cooked thoroughly, the bacteria could taint the rest of your meal. To prevent making you and your family sick, be sure to thoroughly wash counter tops, cutting boards, and utensils in hot, soapy water between the different steps in meal preparation.
Germs can also thrive in sponges and towels.
Consider using paper towels to clean kitchen surfaces. Be sure to change hand and dish towels daily and launder them in hot water.