Mark Jorgensen (2:29)

You know, the size, the size of it is just, they're just huge. I mean, to think that this thing actually floats is just, it's just amazing.

Wendy Zuckerman (2:38)

18 decks, four pools and all you can eat buffets. Mark and his wife Jerry climbed Aboard. And from there, they were off on a two week adventure across parts of Asia.

Mark Jorgensen (2:50)

My favorite stops were Hong Kong and Taiwan. Hong Kong is just an amazing city and it's just so vibrant and so much going on.

Wendy Zuckerman (2:59)

And this cruise ship, maybe you've heard of it.

Mark Jorgensen (3:02)

Well, it's called the Diamond Princess.

Wendy Zuckerman (3:04)

Yeah, that Diamond Princess. Unbeknownst to Mark, he was on board what would become an infamous cruise ship. A major hotspot for the coronavirus. The Diamond Princess ended up becoming this accidental experiment. And Mark an accidental guinea pig. His experience would give scientists some crucial information on how this virus can spread silently. By the way, you're listening to science verses and I'm your host, Wendy Zuckerman for back to Mark. In the early days of that cruise, Mark never thought this virus would become something he'd have to worry about. When him and his wife boarded the ship towards the end of January, there was news of the outbreak in Wuhan. But Mark was like, whatever my mindset,

Mark Jorgensen (3:57)

I was like, why is everybody freaking out about this? In fact, I actually, I actually wrote a Facebook post where I kind of said, what's the big deal with this coronavirus? I mean, it doesn't seem to be that big of a deal. Why is everybody making such a fuss about it? As it turns out, karma has a sense of humor, and that one came back to bite me.

Wendy Zuckerman (4:18)

So then take me to the moment where it then starts to. Karma starts to bite.

Mark Jorgensen (4:25)

When they announced over the intercom that there was a man who got on the ship and was not feeling well. Then a couple days later, he went and got checked out and he was tested positive for coronavirus.

Wendy Zuckerman (4:39)

Mark and his wife Jerry, found this out the night before they were supposed to leave the cruise, which meant an extra day on the ship so that the Japanese government could see if anyone else was sick. And to the couple, at first, this seemed like kind of a bonus.

Mark Jorgensen (4:55)

We were actually kind of, okay, we could stay longer, right? So we just, we just enjoyed ourselves and went to the gym and got lunch. And so it was just another, like another day at sea. And then that's when. That's when the big hammer dropped was that night at dinner. Because during dinner, they announced that they had found 10 people that tested positive. And that's the point at which the Japanese ministry of health said, okay, this, no one's getting off the ship and you're going to stay quarantined on the ship for 14 days. These dining rooms are massive, and there's hundreds of people in them and noisy, busy, environment. But when this was announced, all that just stopped. It was just dead quiet. And there were a few gasps and everyone just looking at each other said, are you kidding me? And that was the big moment.

Wendy Zuckerman (6:04)

Everyone was told to stay in their rooms. No more big group meals, no more gym. And the Japanese government started doing tests of people aboard, including Mark and Jerry. And when their test results came back, it turned out that Jerry was actually positive. But Mark's test was negative, which seemed a bit odd to him.

Mark Jorgensen (6:24)

We've been interacting and sleeping next to each other and, and sharing spoons and straws and whatever. I mean, we were not practicing any social distancing at all.

Wendy Zuckerman (6:34)

We didn't even know what social distancing was back then.

Mark Jorgensen (6:37)

No. Didn't even know the term. No.

Wendy Zuckerman (6:39)

Because Geri tested positive. She was taken to a quarantine facility back on land. She was feeling kind of crummy, but her symptoms never became serious. Mark, though, as someone who tested negative, he couldn't go with her. He stayed on the ship. A day later, the US government arranged for the US citizens and residents stuck on board to fly back to the states. And this whole evacuation was kind of a mess. Mark was put on this cramped bus for a few hours. Eventually, they boarded this cargo plane that would fly them all back home. But then just after the plane took

Mark Jorgensen (7:14)

off, they found out that about a dozen people became symptomatic. And they took everyone who was showing symptoms and they sat them in a little screened off area. There was just a curtain between them and everyone else.

Wendy Zuckerman (7:27)

Mark was sitting up the front a little further away from the sick passengers, but he could still hear them coughing. And since this was a cargo plane, it wasn't designed for passengers. Everyone on the flight, 170 people, were sharing two porta potties.

Mark Jorgensen (7:43)

And they were just disgusting. They just reeked. And I mean, you can imagine the full portal. I did have to use it once and it was one of the most disgusting experiences of my life. And they were just. Oh, because, because it's. They're like filled up to just like six inches below you, you know, it's not like it's. Oh, feel like something to jump up and grab you. Anyways, so that. And the people in the back, you can smell it from the back. There's people throwing up from the smell. Oh, yeah, that was. That was just awful.

Wendy Zuckerman (8:20)

Mark and some of the other passengers were eventually taken to Travis Air Force Base in California, where the US government told them they had to stay in quarantine before they could go home. And it was at this point that Mark and the rest of the passengers were tested again for the virus.

Mark Jorgensen (8:37)

I get a knock on the door, there's two people there all decked out in their gear and two doctors. And they said, yeah, we've got your test results back and you are positive and pack your bags and you're going to the hospital.

Wendy Zuckerman (8:52)

So after all that, Mark was now infected. And here's what's kind of bizarre though. Mark didn't feel sick. In fact, he felt perfectly fine. Did you have any, any, any symptoms at all? Fever, little, little cough?

Mark Jorgensen (9:11)

No, I had no symptoms at all.

Wendy Zuckerman (9:13)

Like, were you expecting symptoms to come at some point?

Mark Jorgensen (9:17)

I, I kind of was, yeah. I thought at some point I'll start to feel this. So I just kind of waiting for that, waiting for those symptoms to come. They just, they just never did. Weird. Very.

Wendy Zuckerman (9:29)

So it's almost two months ago and you've never had symptoms?

Mark Jorgensen (9:34)

I've never had symptoms.

Wendy Zuckerman (9:37)

So Mark cleared the infection. He eventually tested negative and got out of quarantine. And this means that if he never got tested, he would have never known that he was infected. Which makes him think, I do believe

Mark Jorgensen (9:51)

that there's many more people that have had it than we know. But that's what they've got to figure out, isn't it, is how many are asymptomatic.

Wendy Zuckerman (10:01)

So how many people out there are like Mark, They've gotten infected with this virus but never had any symptoms. New reports are coming out suggesting that maybe a whole lot of people are like this large number of Americans could be walking around with coronavirus and not even know it.

Mark Jorgensen (10:20)

The, the state's antibody testing program showed nearly one in four people in New York City tested positive for COVID 19 antibodies.

Wendy Zuckerman (10:27)

How many asymptomatic cases are out there and how could they spread it? That's what we're going to dive into today. And the stakes are high. If there are a bunch of people like Mark walking around not knowing they're sick, does that mean we've got a swarm of silent spreaders on our hands? When it comes to this coronavirus, there's a lot of weird, very. But then there's science. Science versus silent spreaders is coming up just after the break.

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Wendy Zuckerman (12:59)

Welcome back. Today on the show Silent Spreaders. How many people who get infected with this virus don't show any symptoms? And this question really matters because we're learning that some people can spread this virus even when they don't feel sick. They have the virus in their nose and throat and they can be shedding it. So we really need to know how common it is to be asymptomatic. Because when we hear big numbers in the news suggesting that one in four New Yorkers have had this, it sounds like heaps of people must be walking around with no symptoms. But is that right? So these numbers are coming from a new kind of testing that's being rolled out in the US and other parts of the world and it's getting a lot of buzz. Antibody testing.

Mateusz Plonkinski (13:50)

Antibody test. Antibody test.

Wendy Zuckerman (13:51)

Antibody testing. Antibody testing. These tests are looking for, you guessed it, antibodies. We've talked about them on the show before. These are proteins from our immune system. And having antibodies are a Sign that your body has at one point been exposed to the virus. So can these antibody tests help us nail down how many people got this virus without getting sick? To find out, we called up Vivek Nurumbai, a doctor at Mass General Hospital in Boston who specialises in how viruses affect our immune system.

Dr. Vivek Nambiar (14:28)

Hello.

Wendy Zuckerman (14:29)

Hi. You're a much wanted expert in this current climate.

Dr. Vivek Nambiar (14:34)

Oh, I don't think anyone's an expert

Wendy Zuckerman (14:36)

really, but we're all trying. Vivek told us that these antibody tests, they're not perfect. But a bigger issue when it comes to using them to know how many people are asymptomatic is that these tests, they can't tell you that on their own. You need to actually ask the people you're testing, have you been feeling sick? And in some studies, like the big one we're hearing about from the New York State government, they're not actually asking people that question. One of the few studies we have on this comes from Vivek's team.

Dr. Vivek Nambiar (15:08)

We wanted to get a first glimpse of what was going on and I'm happy to tell you a little bit about the results.

Wendy Zuckerman (15:13)

Vivec's team just finished this study and it's still going through peer review. And here's what his team did. They went to a small city just outside of Boston called Chelsea, which had been hit really hard by this disease.

Dr. Vivek Nambiar (15:27)

Chelsea was bearing a huge brunt of the COVID epidemic. We knew that because in the hospital we were seeing dozens of patients coming in with COVID 19. So because of that, we went to Chelsea and we decided to test 200 people walking down the street on a Tuesday and Wednesday afternoon and see if they had antibodies.

Wendy Zuckerman (15:44)

To measure antibodies, Vivec's team uses a little finger prick blood test, kind of how you measure for blood sugar levels. And then they ask the people, in the last four weeks, have you had symptoms like coughing, shortness of breath? And here's what Vivec's team found. 63 people in his study had antibodies to this virus. And how many had no symptoms?

Dr. Vivek Nambiar (16:10)

So of the people who are antibody positive, 40% had no symptoms whatsoever. So they'd had no symptoms in the last four weeks.

Wendy Zuckerman (16:17)

Oh, wow. So in Vivek's study, 25 people, or around 40% of those with antibodies, said they didn't have symptoms. But don't hang your hat on that 40%, because Vivek's study was small and it's preliminary. Plus another early study out of France found a totally different number, that less than 20% of the people who had antibodies said they never had symptoms. So why are these numbers so different? Well, we're just so early in this. We basically haven't studied enough people with these antibody tests to get a handle on how many people are truly asymptomatic.

Dr. Vivek Nambiar (17:00)

I don't know. I really don't.

Mark Jorgensen (17:02)

I think I'd be.

Dr. Vivek Nambiar (17:03)

I'd be, you know, I'd be disingenuous if I said that I know the correct answer here.

Wendy Zuckerman (17:09)

Vivek says that eventually these antibody tests might help us get to the bottom of this asymptomatic question. But for now, we need to look elsewhere. We need to go on an adventure back to that Diamond Princess cruise ship, the ship that Mark was on, because this cruise ship gives us some of the best information about asymptomatic people. Yes. I tell you, there hasn't been a ship this important to science since the HMS Beagle. While passengers were going through quite the ordeal on this ship, scientists were all watching this from afar.

Mateusz Plonkinski (17:50)

A colleague told me to check the news and specifically related to the Japan cruise ship. And a day later, I was on my way to Japan.

Wendy Zuckerman (18:02)

This is Mateusz Plonkinski. He's an epidemiologist with the CDC and he was deployed as part of the CDC's cruise ship response team. Yeah, the CDC sent this team over to help get the Americans back home. But it quickly became clear that this ship gave scientists an unusual opportunity. There were more than 3,000 passengers and crew on that ship with nothing to do but get tested for coronavirus and answer questions about their symptoms. And that is what happened. Basically, all the passengers on that ship were tested for coronavirus, whether they were sick or not, including Mark, who we heard from at the beginning of the show.

Mateusz Plonkinski (18:41)

It was definitely one of the first settings in which we had done universal testing regardless of symptoms.

Wendy Zuckerman (18:48)

Now, it turned out that more than 700 people would be positive. So how many of those had no symptoms?

Mateusz Plonkinski (18:55)

Around half the people that they were coming back with positive tests were asymptomatic at the time of the test.

Mark Jorgensen (19:02)

Half? Yes.

Wendy Zuckerman (19:05)

That's quite high.

Mateusz Plonkinski (19:06)

Yeah, it is high. So I think at the time it was definitely a surprising finding.

Wendy Zuckerman (19:12)

But Mattea says that this 50%, it isn't ship shape and in fact, it can be deceiving.

Mateusz Plonkinski (19:19)

But the thing to understand is that there's multiple reasons for having a positive test while asymptomatic.

Wendy Zuckerman (19:27)

So, for example, Matteus says that people can start to feel sick after the test was done, so they're not actually Asymptomatic, they're what's called pre symptomatic.

Mateusz Plonkinski (19:37)

And you're not showing symptoms at the time, but you will eventually develop symptoms.

Wendy Zuckerman (19:43)

This is a big issue with a lot of the studies that you might have heard about, including one out of Iceland that got a ton of attention. The kind of testing that they're doing in these studies is seeing if someone has pieces of the virus in their body at the moment they're getting tested. And the problem with this is that if you find bits of virus, you could be catching someone at the beginning or end of their illness. You don't know. And if you've got someone at the beginning, they could still go on to get symptoms later. So that means you need to follow people after they've been tested to see if they eventually get sick. And many studies, they don't do this. But Matthias's team did. After the cruise ship travelers were brought back to the States, his team went back and asked them a bunch of questions like soon after you were tested, did you have symptoms? So we started with around 50% who seemed to be asymptomatic. Where did we land?

Mateusz Plonkinski (20:47)

When we administered this questionnaire and actually asked really detailed questions about what symptoms passengers had experienced on board the ship, it turned out that only around 20% were truly asymptomatic while on board the ship.

Wendy Zuckerman (21:01)

So that drops the number from 50 to 20%. A pretty big drop. And while Matthias's study just looked at the Americans on the Diamond Princess cruise, other researchers used models to expand this out to the other passengers from other countries. And they got similar figures estimating that now 18% were truly asymptomatic.

Mateusz Plonkinski (21:22)

Based on the studies where we've done universal testing, it does look like the majority of of individuals will develop some symptoms.

Wendy Zuckerman (21:30)

So for now, the evidence suggests that most people who get this virus will go on to get symptoms. And the best study we have, this Diamond Princess study, suggests that the number of people who won't is maybe 20%. A caveat here is that a lot of people on that cruise ship were older folks, the cruise loving crowd. Which means that we don't know if this 20% figure applies across the board. It's possible that the younger, not so cruise loving crowd could be more likely to be asymptomatic. And there is another wrinkle to this story. Research is starting to pop up to suggest that while some asymptomatic people may feel fine, they might not be perfectly healthy. Doctors are noticing that when hospitals actually scan these people's lungs, sometimes they don't look quite normal. Vivek, who we heard from earlier, said, for example, doctors are finding this when people come into the hospital for something else, like, say, a broken arm.

Dr. Vivek Nambiar (22:33)

And so you happen to get a

Mark Jorgensen (22:35)

chest X ray as part of that

Dr. Vivek Nambiar (22:36)

workup and you see, hold on, there's something going on. They've got pneumonia in their lungs, but they're telling me they've got no senses whatsoever.

Wendy Zuckerman (22:42)

A few small studies have found this kind of thing. Like One study of 18 asymptomatic patients found seven of them had gunk in their lungs. So that means even when people don't feel sick, the virus still might be causing trouble in their bodies. Alright, so what does this all mean for us now? Well, we are still learning a lot. This virus has thrown us a real curveball with this asymptomatic thing. But that doesn't mean we can't take a swing here. Since we know that people can spread this virus even when they don't feel sick, and we think that it's not rare for asymptomatic people to be wandering around, it means that it is going to be harder to control this virus. And it makes some fundamental stuff that we've been talking about on this show for a while even more important. We need to make sure that people can get tested. We need to make sure that we're tracking down everyone who has this and the people they come in contact with. But with all the unknowns here, one thing is for sure, this virus is going to keep being a huge pain in the ass for a while yet. And now, time for a little bit ncvc.

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Pharmaceutical Advertiser (24:13)

NCVC for short.

Wendy Zuckerman (24:16)

Today, what happens when a computer tries to make the perfect pop song? What does it sound like? Well, to find out, here's what a team of nerds from Australia did. First, they taught a computer algorithm what pop music was by feeding it samples of songs from this very cheesy but very wonderful European pop music competition called Eurovision. Then the team taught the computer what lyrics are by giving it a bunch of words from pop songs. Finally, for a bit of a homespun sound, they added into the mix some Aussie noises like koalas. Yeah, this is what a koala can sound like. The algorithm took those koala sounds and and turned it into this jam. And then lyrics were added which transformed the koala noises and made a brand new song. And humans did intervene a bit. They made sure that the words were in an order that made sense. But here's what came out. The world is beautiful. It felt bad, right? And this is all part of a machine learning song competition. So you could actually vote for this song. We'll put a link to the entire higher song and to the competition in our show notes. That's Science versus.

Michelle Dang (26:09)

Hello.

Wendy Zuckerman (26:09)

Hey, Michelle Dang, producer at Science versus.

Michelle Dang (26:12)

Hi, Wendy.

Wendy Zuckerman (26:13)

How many citations in this week's episode?

Michelle Dang (26:16)

I gotta check. Hold on. All right, all right, all right, all right. We have 80 citations.

Wendy Zuckerman (26:24)

80 citations. And if people want to see these citations, where should they go?

Michelle Dang (26:29)

They can check out the link in our show notes. Great. Okay. Awesome.

Wendy Zuckerman (26:39)

This episode was produced by Michelle Dang with help from me, Wendy Zuckerman, Laura Morris, Rose Rimler, Meryl Horn, and Sidhuja Srinivasan. We're edited by Blythe Terrell with help from Kate and Kenny. Fact checking by Lexi Krupp. Mix and sound design by Peter Leonard. Music written by Peter Leonard, Marcus Bergala, Emma Munger and Bobby Lord. A huge thanks to all the researchers we got in touch with for this episode, including Professor Gerardo Chal, Dr. Natalie Dean, Dr. Sandra Utenbogard, and Carolyn Pegram. A special thanks to the Zuckerman family and Joseph Labelle Wilson. I'm Wendy Zuckerman. I'll catch you next time. I Short dramas Infinitos Paraver cuando quieras rapidos faciles. Hey you.

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