Okay so today at lunch I went and washed my hands, but touched to door knobs after that. Well, I grabbed my water bottle and my whole hand touched the part that my mouth does to drink, and it was the same hand I used to open the doors with. What are my chances of contracting norovirus from this? Also, many people had touched the knob before me, so if there were virus particles on there wouldn't someone else have already picked them up?