Well, the problem was, that this started way back in December.
And, the time when a person is most contagious, is just before symptoms show up.

What the Chinese province head did, when he heard about the disease is hold a giant buffet. Lots of people in an enclosed environment all eating from the same dishes.

Then, the govern-cement finally decided to quarantine the city. Of course they told the people of the city before they enacted this. So, lots of people left.

Further, this is Chinese New Year, when just about EVERYONE in China wants to go home. And they will beg, borrow and steal to get there.

Chinese twitter is all atwit with people, with symptoms, bragging about how they escaped.

So much for the CDC. The supposedly had a plan.... too bad it failed before it even started.