I observed a great number of medical face masks on customers in the supermarket yesterday.
They likely purchased them in early January. When many folks realized this China flu was heading this way.
That is a possibility.
But there has been a local campaign here to donate all excess PPE to local hospitals.
There is also an effort by local crafters to sew cloth masks.
Last week, no one was wearing a mask. This week, many people are wearing medical masks.
You can interpret that as you like. I will do the same.