Lisa Desjardins:

Meantime, the virus is striking at business and the global tourism industry.

In France, the doors of the famed Louvre museum in Paris remained closed for a second day over fears of spreading the virus in its often-packed hallways. The economic blow may be far wider. The Organization for Economic Cooperation and Development warned, the coronavirus outbreak could cut global growth in half and threatens to plunge several countries into a recession.

Despite the economic warnings, Wall Street roared back today, on hopes that central banks will act to boost growth. The Dow Jones industrial average gained nearly 1,300 points, 5 percent, to close at 26703. The Nasdaq rose 384 points, and the S&P 500 was up 136.

Now let's take a closer look at some of the latest health concerns about the outbreak in the United States and the efforts to contain its spread.

Dr. Sheri Fink is covering this for The New York Times and joins me now.

Thank you for joining us. I know you have been going without sleep on this story.

And I want to ask you, first of all, to help us understand the growing health concerns. Something we seem to be understanding about this virus is that it can infect, but then go undetected, show no symptoms for days.

So, given that, how well do we really understand how far it has spread, including especially in Washington state, where it seems to be the biggest concern right now?