I hate when something like this finds it's way to the US because Americans are the worst at not staying home when they are sick. We can be so sick we can hardly walk but we can still drag ourselves out to shop and have fun. It's almost like some badge of honor, "look how sick I am and I'm still able to hang out with you guys."
I wish we were more like the Japanese and would wear masks out in public when we are sick.
Once, I had a customer walk into my office, cough in my face and then tell me proudly that he had just been released from the hospital that morning. I almost punched him.