BERMAN: Breaking overnight, the State Department issued its highest- level warning, advising Americans against travel to China because of the coronavirus outbreak. The warning follows the first reported person-to-person transmission of the virus here in the United States. I want to bring in CNN's chief medical correspondent, Dr. Sanjay Gupta. Sanjay, how concerning is this new case, this person-to-person transmission here?</s>DR. SANJAY GUPTA, CNN CHIEF MEDICAL CORRESPONDENT: Well, there's no question it's concerning. There's now evidence of spread within the United States. That never happened during the SARS epidemic. So just to keep that in context. But also, this person who now has it, to whom it was spread, is the spouse of one of the people who -- who was known to have this infection. So they had close contact when the person was symptomatic. So it's a little less concerning for wider spread. I think the risk to the general population still remains pretty low. The United States now is among the list of six countries where we do have evidence of spread. China, obviously, but you can see the list of other countries there. And it's because of the spread in other countries that the World Health Organization took this step yesterday, John, of declaring this is a public health emergency of international concern. That's -- that's something -- you know, these declarations sort of were in response to the SARS epidemic, and they've only happened a few times throughout history now. You know, back 2009, the H1N1, Ebola. You can see the list there. But this public health emergency now sort of gives a signal to countries. END
U.S. State Department Advises Against Travel to China.