Thanks for your advice, everyone... I probably shouldn't keep reading all the CDC and medical articles about norovirus, but they all say that people can excrete the virus for 2 weeks, and it can live on surfaces for "weeks"... Lysol and other cleaners don't kill it, btw.. only bleach or hydrogen peroxide.

I guess we'll take the chance. I'll make sure my parents bleach everything, and I'll probably bring some peroxide wipes with me (yes, I'm that scared: I bought a container of them on amazon).