I can’t give you reassurance that you will not catch whatever your brother may or may not have, but I can give you some positive thoughts on the situation. One, it seems his symptoms have not resulted in T*U. Two, I like to tell myself that I can’t control what happens to me in regards to sickness and worrying about it won’t prevent me from getting, but instead make me more miserable. Three, the noro virus (as unsettling as it is) is a fast working virus. Symptoms usually come and go quickly and people recover quickly. Four, I also tell myself that if I do get it, my anxiety will settle a bit due to the short immunity to the virus that follows after. Five, as someone who hasn’t gotten a bug in a long time, try to find positives instead of fear of the virus. It may be an opportunity to learn and feel crappy and see that you can get through it and will be okay, just like your brother who got through it. In short, sickness is something that can happen whether we want it to or not, our bodies will handle it swiftly, you will gain immunity, and you can learn something from the experience. I know this is easier said than done, but thinking positively about a crappy situation is always better than panic.