NOEL KING, HOST:
A new virus appeared in the Chinese city of Wuhan last month. Health authorities say in the last couple of days, they've identified dozens more people who've been infected, and that includes new cases in Beijing and Shenzhen. There are now more than 200 cases in this outbreak. NPR's global health and development correspondent Nurith Aizenman is with me in studio. Thanks for coming in.
NURITH AIZENMAN, BYLINE: Hi, Noel.
KING: What do we know about this virus?
AIZENMAN: Well, we know that it belongs to a family of pathogens called coronaviruses, which can cause respiratory illnesses ranging from a cold to fatal pneumonias. And we know that at least three people who've contracted this new strain have died. But there are still a lot of unanswered questions, including not just how lethal this virus is - you know, how many people have actually died - but where it originally came from and how easily it can spread.
KING: How easily it can spread would seem like a very big question at this point. I know that one early theory was that this outbreak started in a seafood and meat market in Wuhan. Why is that significant?
AIZENMAN: Right. Fresh seafood and meat that people were buying, and at least some people who were infected early on were sellers or buyers in that market. Authorities found traces of the virus there. And so that suggested that people contracted the virus through contact with some as-yet unknown animal there. But there have also been plenty of cases of people who do not seem to have spent time in that market. And, of course, now we're hearing about more and more cases overall, including in these other Chinese cities, and, in fact, several Chinese travelers to Thailand and Japan and, just today, South Korea have also been diagnosed with the virus. And so officials at the World Health Organization say that means, to at least some extent, the virus has been jumping not just from animals to humans but then from one human on to another.
KING: OK. Hence the concern. At this point, 200 cases - that number is, thankfully, still fairly low. How much of a concern is this?
AIZENMAN: Look, this could still turn out to be a fairly contained, pretty mild outbreak. But anytime you have a new virus suddenly jumping from animals to humans and then spreading among humans, that sparks worries because it suggests the virus could be mutating in a way that could be dangerous and could spark a major epidemic or even a global pandemic. And officials are mindful that back in 2002, one recent new coronavirus caused Severe Acute Respiratory Syndrome, or SARS, and another one caused Middle East Respiratory Syndrome, or MERS, and those are both really serious illnesses that infected thousands of people. So that's the nightmare scenario that keeps officials up at night.
KING: Yeah, I can imagine. In China, also, they are approaching the Lunar New Year holiday period, which means people will be traveling a lot. Is that a big concern?
AIZENMAN: Yes. It's a huge holiday. Millions of people are going to be traveling within the country. So if there is a significant transmission of this virus from human to human, that poses a real risk of spread way beyond not just the city of Wuhan but China and beyond.
KING: Nurith, thanks for keeping an eye on this for us.
AIZENMAN: Glad to do it.
KING: NPR's Nurith Aizenman. Transcript provided by NPR, Copyright NPR.