I'm pretty sure that my daughter and I currently have Rotavirus and contracted it at a baby shower where there are a lot of children who were touching all over the food.  Unbeknownst to me, until later, that one of the families there had just gotten over a stomach bug.   The real problem is people's ignorance about the contagious period and that these parents aren't placing importance on their children washing their hands, and/or ensuring that their children are washing their hands.  That's one thing that my daughter has definitely been taught to do, and I make sure that she always washes her hands properly.