RENEE MONTAGNE, HOST:
And there are very few confirmed cases of coronavirus in the U.S. right now. Still, the White House has declared a public health emergency. That means travel to and from China is being sharply restricted. American citizens are being told to avoid going there. Those who are returning to the state might end up in quarantine. And noncitizens who've recently visited China will not be allowed to enter the U.S.
NPR science correspondent Richard Harris is with us. Welcome.
RICHARD HARRIS, BYLINE: Good morning, Renee.
MONTAGNE: Thank you. So growing numbers of cases of this coronavirus around the world. That we know, not many deaths, especially when you compare it to the annual flu. But bring us up to date on the latest.
HARRIS: Right. There are now something like 10,000 reported cases. And every time you turn around, that number grows. Most are in China, but the disease has popped up sporadically in more than a dozen countries now. Here in the United States, we have seven reported cases. As a result of all of these developments, both the World Health Organization and now the U.S. government have declared these public health emergencies.
MONTAGNE: What exactly does that mean?
HARRIS: Well, first and foremost, the U.S. government is adding a significant travel restriction for people attempting to return from China. Health and Human Services Secretary Alex Azar announced those restrictions at a White House briefing yesterday.
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ALEX AZAR: Any U.S. citizen returning to the United States who have been in Hubei province in the previous 14 days will be subject to up to 14 days of mandatory quarantine.
HARRIS: Americans or permanent residents and their immediate families who are returning from other parts of China will be screened carefully at one of seven airports and monitored closely for 14 days. And most other travel of non-Americans coming from China will be just banned. Also, and you remember those 195 people who returned on a charter flight from Wuhan earlier this week. Well, they are now in official quarantine in a military base in Riverside County, Calif.
MONTAGNE: And quarantine is a big word. It sounds like an extreme step. How often does the government impose that?
HARRIS: Well, the federal government hasn't imposed a quarantine for, like, 50 years. That was back in the days when they were trying to put an end to smallpox. Local health officials have the power to quarantine, and they have used it on a small scale. But this is a big step for the federal government. I should mention that other nations, including France and the U.K. and Australia, have been quarantining their citizens returning from these coronavirus hotspots.
MONTAGNE: OK, but why use quarantines when we've had just seven cases so far in the United States and public health officials keep telling us that the general public is not at risk?
HARRIS: This is the, really, only chance we have to nip this epidemic in the bud. Once it gets a foothold outside of China, there's really no telling how big it will become. So thus far, it seems to be much less deadly than other nasty viruses like SARS and Ebola. But, you know, it does spread through the air, and we already get enough grief from the annual flu, which typically kills tens of thousands of Americans every year. Nobody wants a second disease like that to take hold.
MONTAGNE: So you just said that this virus spreads through the air, but how easy is that to do? I mean, what do health officials say about how vulnerable people are?
HARRIS: The short answer is they say we don't know enough. With SARS and Ebola, those viruses don't spread unless the person who has them is actually showing symptoms. And, you know, that made it easier to identify people at risk for spreading the virus. Dr. Anthony Fauci at the National Institutes of Health said we are just now learning about the situation for the new coronavirus.
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ANTHONY FAUCI: It was not clear whether an asymptomatic person could transmit it to someone while they were asymptomatic. Now we know from a recent report from Germany that that is absolutely the case.
HARRIS: So that potentially makes it a lot harder to bottle up. Fauci also said the test the CDC has developed to diagnose people with this disease isn't 100% effective or reliable. So that's another factor that led health officials to push for more aggressive measures such as this quarantine.
MONTAGNE: And, Richard, do you have any idea of how long these measures will be in effect?
HARRIS: No, I don't. They say it's temporary, but it looks like the situation is likely to get worse before it gets better.
MONTAGNE: That's NPR science correspondent Richard Harris. Thanks very much.
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