Did she specify how he was sick? You have to remember that non-emets most often refer to things as either a cold, or the flu. Two terms, that is it. So, when someone says they have the flu, I always ask them to specify, for my own peace of mind. With that being said, chances are that he is down with something else, maybe influenza, or maybe he ate something that isn't agreeing with him. Either way, there is no need to panic. Even IF he did have the same sv* again, having his son over won't be an issue as long as the child does not v* near you, and you keep your hands out of your mouth all day. If you do that, it is literally IMPOSSIBLE to contract Noro.

Best of luck, and always remember..."this too shall pass"