COVID-19 Numbers Are Rising. But How Are Those Numbers Counted?
This story is part of Science Friday’s coverage on the novel coronavirus, the agent of the disease COVID-19. Listen to experts discuss the spread, outbreak response, and treatment.
This week, the death toll attributed to the new coronavirus outbreak passed 2,000 people. And while that number is solid, many of the other numbers involved with this disease, including the total number infected and the degree of transmissibility of the virus, change from day to day. Those shifting numbers are in part due to changes in how countries, such as China, are diagnosing patients and defining who is “infected.”
It can be difficult to know what information deserves attention, especially when information on possible transmission routes and timelines for vaccine development shift constantly. Helen Branswell, senior reporter on infection diseases at STAT, joins Ira for an update on COVID-19 and a conversation about evaluating medical information in the midst of a developing story.
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Helen Branswell is a senior writer covering infectious diseases at STAT in Boston, Massachusetts.
IRA FLATOW: This is Science Friday. I’m Ira Flatow. A bit later in the hour, a look at some newly unearthed Neanderthal bones. And we ponder whether synthetic diamonds could be genuine and fake at the same time.
But first, this week, the death toll from the new coronavirus outbreak passed 2,000. And while that number is good for now, many of the other numbers we’re hearing, how many cases, how fast is it spreading, and those numbers seem to change day to day.
And joining me now to help sort out the shifting status of COVID-19 is Helen Branswell, a senior reporter covering infectious disease and public health for STAT in Boston. She joins us via Skype. Welcome to Science Friday.
HELEN BRANSWELL: Hi, Ira. Thanks for having me.
IRA FLATOW: Cases keep going up all the time.
HELEN BRANSWELL: Yes, they are going up, and they’re coming from different parts of the world as well. It’s not just China anymore.
IRA FLATOW: Where, for example?
HELEN BRANSWELL: Well, very interestingly, cases have spiked in South Korea. They started out the week with 30 cases. They ended the week with 204. The virus seems to be spreading in a religious community there and spreading very nicely. As well, Iran on Wednesday announced that it had found two cases and people who had already died. And by today, that was 18 cases, four deaths. And Iran has actually exported two cases, one to Canada and one to Lebanon. So that’s a new hotspot.
IRA FLATOW: So are we seeing more cases because there’s better diagnosis of the disease? We’re just catching more of it as it spreads?
HELEN BRANSWELL: Well, certainly more testing will find more cases– that’s true. And more countries are coming online with the ability to be able to test. But I think we’re seeing more cases because there are more cases.
IRA FLATOW: Yeah. Yeah, and I was interested to see a report this week from the Chinese, their centers for disease control, that stool samples had tested positive for live virus in it.
HELEN BRANSWELL: I didn’t see that one. Was it live virus?
IRA FLATOW: Yeah.
HELEN BRANSWELL: That would be interesting. OK, I’ve seen PCR viral fragments, which would be interesting, but live virus is different.
IRA FLATOW: Well, I mean, I may be having it wrong. I know there are viruses, but you’re saying, maybe they’re not live viruses.
HELEN BRANSWELL: I don’t know. Your information may be better than mine. But it would be important to know because, obviously, if it’s viral particles, that doesn’t necessarily mean it’s potentially infectious. If it’s live virus that can be cultured, then conceivably, you could have a sort of fecal oral route, although this is a respiratory virus.
And people don’t typically get too near other people’s stools. So it seems much more likely that coughing and sneezing and maybe touching contaminated surfaces and then touching our faces is going to be more the route that one would get infected by.
IRA FLATOW: Yeah. People are also very interested in the estimates of how easily the disease is transmitted or how often it leads to death in infected persons. But those numbers are very dependent on the initial estimates of how many people are infected, correct?
HELEN BRANSWELL: Yeah. Yeah, we still don’t really have a good picture of that. I mean, we know as of today that about 77,000 people have been confirmed to have had the virus. But it’s likely that there are lots of people that have had infection and haven’t been detected. Because in a lot of places, the protocol requires you, or has required in the past, person to have had pneumonia before they would even get tested. And so that would automatically rule out anybody who has mild infection and maybe just has what looks like a common cold.
IRA FLATOW: Are there reports– I’ve heard there are reports of people who have the virus, but don’t show any symptoms of it.
HELEN BRANSWELL: Yeah, there have been several small case studies that report on that a few people who seemed to be completely symptom free, and yet, still have about the same amount of virus in their upper respiratory tract as people who have symptoms, which is worrying because, obviously, it could mean that they could be contributing to the spread.
IRA FLATOW: Are the numbers that the Chinese are giving us, are they dependable numbers? Because they seem to be changing dramatically back and forth.
HELEN BRANSWELL: Yeah, so initially, they were only releasing lab confirmed cases and acknowledging to the World Health Organization that they had a bit of a problem dealing with a backlog of cases.
And then at a point last week, they said, all right, we’re going to include cases that have a CT scan evidence of pneumonia and symptoms of the disease. And if the people live in Hubei province, which is where the epicenter of the outbreak is, but these people haven’t had a positive test.
And so after that happened, the numbers spiked up. One day, they reported 15,000 cases. And then this week, they said, OK, we’re going back to the old way of testing. We’re not going to use a clinical diagnosis. It’s only lab confirmed cases. And the cases plunged. The other night, they reported fewer than 400 cases, which is the first time in weeks that it’s been in triple digits.
Are they reliable? I don’t think anybody thinks they’re catching all of the cases. Because as I mentioned before, it’s pretty clear from the cases that have come out of China, that there’s a lot of mild infection, and it’s very hard to find mild infection when you’re responding to an outbreak like this. So that’s probably being missed. That’s as much as I can tell you.
IRA FLATOW: Yeah. Do we know how easy it is to catch the virus from one person to another?
HELEN BRANSWELL: It seems pretty transmissible. There’ve been different estimates of the reproductive number. They R not, as your listeners probably know, the number of people each person is likely to infect, if anything, is below one. An outbreak can’t sustain itself, and anything above two, things get kind of brisk.
The R not for this has been estimated at something like 2, 2 and 1/2 to almost 5, which is a pretty brisk level of transmission. It just sounds like people– that this virus is very efficient at spreading from person to person.
IRA FLATOW: There was a report out of a company in Texas this week that claims to have invented a vaccine for this. Have you seen that report?
HELEN BRANSWELL: I haven’t seen that one. There have been others. There’s certainly a lab in Hong Kong announced two or three weeks ago that they probably– that they thought they had a vaccine. But I mean, when anybody is talking about a vaccine at this point, they’re talking about a prototype, or effectively, a recipe for a vaccine. They’re not actually talking about something you or I could get.
IRA FLATOW: Why do you say that? Do you mean because it takes a lot more time, once you get the recipe, to then go out and test it and get it to the market?
HELEN BRANSWELL: Yeah, exactly. I mean, you have to make sure that your idea actually works. You have to test it in animals. And in fact, right now, there’s not even an established animal model for this disease yet, so that has to be done before you could do the animal testing. You have to test it in people to see if it’s safe, and then you have to test it in more people to see if it works.
And then you have to make it, and it’s not like you can commandeer company X’s vaccine production line to make a vaccine. You have to figure out where it’s going to be produced. And all of that takes time. People don’t like to hear that.
But earlier this week, Sanofi, which is a major vaccine manufacturer, said that they were going to try to make a coronavirus vaccine. And they estimated that if they could get it done in three to four years, that that would be about as fast as was possible. I think that’s probably a more realistic timeline than people like to hear.
IRA FLATOW: That’s what you heard– we the federal government say they could have one within a year.
HELEN BRANSWELL: Well, I’ve heard Dr.– I was actually moderating a panel last week that Dr. Anthony Fauci, who was the head of the National Institute for Allergy and Infectious Diseases, he was on it. And his Institute is partnering with a biotech company to produce a vaccine. And he believes they could have a prototype within sort of 16 weeks of the start of the work, so maybe, at this point, two and a half months from now or something.
But then you still have to test it. And he was saying he thought that they might be able to do phase one testing in people and have results sort of by the end of the year. But they don’t actually have anybody to make that vaccine yet.
IRA FLATOW: Why is that? Because there’s no money to be made in the vaccine? Drug companies want to make billions on something they make and that that’s not the scale we’re talking about?
HELEN BRANSWELL: Well, here’s the thing. No one knows what’s going to happen with this virus. It looks right now like it’s going to be bad, and we’re going to be dealing with it for a while, in which case, there would be a market for a vaccine. But there have been so many instances in the past couple of decades where a new virus emerged. The world demanded a vaccine immediately. And all the major manufacturers stepped forward and tried to make a vaccine.
You can think about West Nile virus arriving in the United States or chikungunya or Ebola, the big Ebola outbreak. That did lead to a vaccine, but that one had been in the works for about 15 years before that. Zika, a few years ago, people wanted a vaccine. And then the threat seemed to dissipate. And with it went the market.
Vaccine manufacturers are companies. They have to make a profit. And it’s time and again, they have tried to make vaccines for these kinds of emerging threats, only to lose time, money, opportunity costs, and not end up with a product. So this time around, they’ve been more cautious about getting into it.
IRA FLATOW: So it’s a question of number of deaths before we see so much.
HELEN BRANSWELL: I think it’s more about sort of a sense of certainty that this is established, that it’s establishing itself and going to be around and a problem that people are going to want addressed. China has been trying to contain it at the source– put it out within China. They’ve taken these extraordinary steps to quarantine cities, where tens of billions of people there.
IRA FLATOW: Yeah, we’ve been following that. And–
HELEN BRANSWELL: Right. And if they were to manage to do that, then the demand for a vaccine would go away. It seems, frankly, hard to believe, with 77,000 cases globally, that that could be done. But this–
IRA FLATOW: Well, Helen, we’ll pick it up when we can later on. Thank you for taking the time to be with us.
HELEN BRANSWELL: OK. Thank you.
IRA FLATOW: Helen Branswell, a senior reporter at STAT in Boston.