'Silent Spreaders' Speed Coronavirus Transmission A growing body of evidence shows that people without any major signs of illness can spread the coronavirus.

'Silent Spreaders' Speed Coronavirus Transmission

'Silent Spreaders' Speed Coronavirus Transmission

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A growing body of evidence shows that people without any major signs of illness can spread the coronavirus.


As the coronavirus pandemic continues, researchers are learning more about the virus, specifically its transmission, how it spreads and why it seems to be so hard to stop. NPR's Geoff Brumfiel has been talking to scientists in the U.S. and Europe this week, and he joins us. Thank you for being with us, Geoff.


SIMON: And what have you learned?

BRUMFIEL: Well, there's this growing body of evidence that this is really a stealth virus. It can spread before people show any major signs of illness. So I'm going to tell you about one data point that comes from the Netherlands. There was this virologist named Marion Koopmans, and she was trying to track the coronavirus. Like a lot of countries, initially, they were only tracking and testing people who had a history of travel recently. But then there were the number of cases that just sort of popped up. Nobody knew where they came from. So Koopmans and her team from Erasmus Medical Center went to the hospitals where these patients had turned up, and they started testing health care workers and found a lot of them were already infected.

MARION KOOPMANS: We see very rapid, very high levels of virus in the nose and in the throat.

BRUMFIEL: And those high levels of virus mean these healthcare workers could transmit the virus to others, even though they weren't very sick at all. You combine this with some new epidemiological studies, also out this week, that show silent spreaders are a factor, and this virus does have sort of the long, latent time, and this could help explain why it seems to be spreading so quickly.

SIMON: So, Geoff, how do we stop it?

BRUMFIEL: Well, social distancing, just like you and I are doing right now, even from apparently healthy people is one thing we have to start with, and that's why we're doing it. It's really the only way we have to sort of slow things down. But there's this other really important component we need, and that's testing. We need a lot of testing. I spoke to a few epidemiologists yesterday, and they're saying this isn't just about testing people who come to the hospital. Here's Jeffrey Shaman at Columbia University.

JEFFREY SHAMAN: You should be testing as much as possible because that informs people to stay home. If they are themselves infected, and they're mild symptomatic, you tell them, you're staying home for the next 14 days or 21 days. And just do it.

BRUMFIEL: You go, and you test their friends and their family. And if any of them are sick, you say, stay home, too. This is what South Korea did, and it really seems to have helped them slow down the spread of the virus.

SIMON: So can the U.S. do that?

BRUMFIEL: Well, our testing capacity just isn't there right now. Shaman also warned me that we're so far behind, and there are already so many sick people in the country - it's going to be really, really hard to get that testing and tracing up and running, especially as the hospitals begin to fill, which - they're going to very soon.

SIMON: Geoff, this sounds pretty bleak. I'm wondering if there's any encouraging news.

BRUMFIEL: I mean, honestly, we're in for a really terrible month in the U.S. I think the epidemiologists feel like the trajectory is set. But if we work together, we can slow this disease down, we can start to turn this ship. And we have to social distance. It's economically painful. It's psychologically stressful. But we don't really have a choice. I mean, I'll give you a kind of a bright spot, I guess, which is that Koopmans said she's been studying the virus's genetic code. And, despite, a lot of rumors about a second strand or mutations or it getting worse, that's not true. It appears that it's not getting any worse. So I guess, you know, it could be worse.

SIMON: NPR's Geoff Brumfiel. Thanks so much, Geoff.

BRUMFIEL: Thank you.

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