Hey,
I think its really unlikely that you could get it from this. Although apparently viruses can survive for weeks, clothes are not the ideal location for them to reproduce so there wouldn't be many of them in the first place. And also, they would have to have moved onto the chair, to the clothes, to the hamper, to the other clothes into his nose, and even if they did get that far, they'd still have to get past his immune system (or yours if that's what you're worried about). And that's assuming that it is a virus, which it may not be as no-one else has had it. (It could have been food poisoning or something.)

I would probably be panicking like you are, just at the thought, but as someone who is detached from the situation I would say don't worry! I would say it would be practically impossible for you to get something from this!