How To Track And Stop The Spread Of The Coronavirus Outbreak

17:15 minutes

people in china on a subway train. everyone is wearing medical masks
Civilians wear surgical masks in the subway in Shanghai, China. Taken in January 2020. Credit: Robert Wei via Shutterstock

This week, the World Health Organization declared that the coronavirus outbreak—which began in Wuhan, China—is a public health emergency of international concern. Nearly 10,000 cases have been confirmed worldwide, as of Friday, January 31, 2pm Eastern. Chinese scientists sequenced the genome of the virus from some of the patients who were infected early on in the outbreak. Virologist Kristian Andersen discusses how the genetics of the virus can provide clues to how it is transmitted and may be used for diagnostic tests and vaccines. Plus, infectious disease specialist Michael Osterholm talks about the effectiveness of quarantines and what types of measures could be put in place to halt the spread of the pathogen.

Editor’s Note 1/31/2020: The case numbers of coronavirus has been updated as of 2:20pm Eastern, from 8,000 to nearly 10,000. 

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Segment Guests

Kristian Andersen

Kristian Andersen is an associate professor of Immunology and Microbiology at the Scripps Research Institute in La Jolla, California.

Michael Osterholm

Michael Osterholm is Director of the Center for Infectious Disease Research and Policy (CIDRAP) at the University of Minnesota in Minneapolis, Minnesota.

Segment Transcript

IRA FLATOW: This is Science Friday. I’m Ira Flatow. The World Health Organization has declared the coronavirus outbreak that began in Wuhan China. Now it’s a public health emergency of international concern. There have been nearly 10,000 confirmed cases worldwide. There are cases popping up outside of China. The first case of human-to-human transmission in the US has been reported.

So how do you fight a new virus like this one besides quarantine? Chinese researchers have sequenced its gene using this research. Can we piece together clues to how this new virus might spread, and possibly design a vaccine? Dr. Anthony Fauci, the director of NIH’s National Institute of Allergy and Infectious Diseases says, “Research into a vaccine is underway and may be ready for human trials in as little as three months.” What do you think? I don’t know. That’s what I want to ask my guests. Let me introduce them.

Kristian Andersen is an infectious disease researcher, associate professor of immunology and microbiology at Scripps Research Institute in La Jolla, California. Welcome to Science Friday.

KRISTIAN ANDERSEN: Hi, Ira. Thanks for having me.

IRA FLATOW: Nice to have you. Dr. Michael Osterholm is director of the Center for Infectious Disease Research and Policy, University of Minnesota in Minneapolis. Welcome back to Science Friday, Michael.


IRA FLATOW: Let’s talk about it. Kristian, you worked on analyzing the genomes of viruses to understand transmission. How do you use the genetic sequence we have to estimate the transmission?

KRISTIAN ANDERSEN: Yes. So we work on genomic sequences that are a sequence of the virus itself from patient samples. And we all rely on publicly available data, so all the data being produced by Chinese researchers and the CDC. And essentially what we’re looking for are small differences in the genomes between different cases. So if you have patient one and patient two, chances are that there are slight differences in the genome of this particular virus. And we could then use that information to connect exactly how these virus are spread and how they’re related. And therefore understanding the patient networks. And that allows us to look at things like what are the reservoirs, how many introductions have we had into the human population. How is the virus actually transmitting? And what is the timing of all these events?

IRA FLATOW: So have you been able to make progress then with this virus?

KRISTIAN ANDERSEN: . Yes so some of the earlier questions we were quite interested in was understanding what is the level of human-to-human transmission versus, for example, repeated spillovers from the animal reservoir. And what the data quite clearly shows is that it’s a single event. So this is something that happened also getting from this data sort of mid-November to mid-December. So this virus jumped into the human population presumably from some sort of intermediate host. So we think the reservoirs are bats. But there’s probably some other host involved. And then from that host into the human population.

IRA FLATOW: And now we see that there has been a secondary infection in the US. Someone who has the virus infected someone else. Do you learn something about transmission in this case?

KRISTIAN ANDERSEN: Yeah. So I think especially very early on, there was sort of the belief that the level of human-to-human transmission was probably pretty low because most cases were linked to this one market in Wuhan. So the belief was that probably the human-to-human transmission is limited. But what the sequencing really shows is that probably from day one, this is really something that has been sustained human-to-human. So having secondary transmissions outside of China is probably what we would expect. I think a very important question here is that how many of these are we actually going to see.

IRA FLATOW: And so you would expect to see more of this. Of course one would be an outlier, right?

KRISTIAN ANDERSEN: Correct, yes. We would expect to see more.

IRA FLATOW: Michael, what’s your reaction to this?

MICHAEL OSTERHOLM: Well, first of all, I think the geneticist that I have worked on this virus have done an amazing job in a very short period of time. And I congratulate Dr. Andersen and his colleagues. And I think his conclusion about its very recent appearance is right on the mark. Epidemiologically looking at how disease is spread, this has been nothing short of a remarkable experience. I’ve worked on both SARS and MERS outbreaks of another coronavirus infections where we really saw a much more reduced human-to-human transmission with occasionally a super spreader, or someone who would spread it to a lot of people.

What we’re seeing here is really much more akin to what we would see with influenza virus transmission. It’s very dynamic. We know we have multiple generations of transmission in China. And in fact now we have clusters of outbreaks in places like the Guangdong province that they don’t even trace back to Wuhan anymore. They’re that far removed. And it’s now in all 33 provinces and administrative districts of China. It’s now in over 20 countries. This is almost what you would have expected to see if you went back and looked at 2009 H1N1 influenza transmission when that pandemic strain emerged. So this is what has us very concerned, is the dynamics here.

The case numbers, Ira, that you mentioned and we talk about really represent just a small fragment of the number of cases in large part because the number of test kits and the availability to access testing in China is extremely limited right now. They’re working on that. They’re doing everything they can to increase that. But we have estimates now based on our studies from inside of China– one that just came out this morning from University of Hong Kong that at least 75 to 100,000 people alone are infected in Wuhan this week. So you can see that this is a very, very dynamic situation, and frankly one that I think the only way I see this going is that the whole world will potentially look like China over the next 6 to 12 months.

IRA FLATOW: That’s alarming. I don’t mean that you’re trying to be an alarmist. But that’s an alarming prediction.

MICHAEL OSTERHOLM: Well, it’s what we’re seeing. And again we come back to the dynamics of the transmission. And it matches up. I have to tell you. We have many sources on the ground in China. And today we actually are seeing emergency rooms that are so overwhelmed that they’re not taking any additional patients into the emergency rooms.

People are not even able to access health care. It’s that major of a health issue. So this is something that, again, none of us would necessarily have anticipated with a coronavirus infection that something might act like an influenza virus. I think the key thing though, however, is not just how much is it transmitting, but how serious is the illness. And while the data are still yet really being collected in a way that is most meaningful early in an outbreak, right now the case fatality rate that we see into the well collected data sets is about 2%.

Now compare that to about 0.1% for seasonal flu in a bad flu year here in the United States. So that’s almost 20 times higher. Now will that continue? We don’t know. But where we have this virus transmitted, we know we’re going to have a lot of serious illness. You also mentioned just the case numbers, but today they also reported just in China 1,527 people are in critical condition in hospitals, which will surely contribute to those death numbers over the days ahead,

IRA FLATOW: Dr. Andersen, do you share this fear?

KRISTIAN ANDERSEN: Yeah. Yeah. I definitely share something. I think talking about case fatality rates, which in my opinion, really can’t sort of accurately be estimated at this stage– I think it’s a little too early. But I totally agree that the number of severe cases, especially is pretty high. It’s about 15% or so of all cases seem to be severe. The sort of uncertainty we have here, too, is that we don’t actually know what is classified as a severe case. Right? So there could be many different levels of severity that might be classified as such. But if you look at just the number of deaths, for example, which is about 200, and the number of recovered patients, which is also about 200, presumably there’s still a lot of patients in the hospital. And that’s based on those kinds of things. And I think it’s too early to try and estimate the case fatality rate.


KRISTIAN ANDERSEN: Although I do absolutely agree with Michael. It’s probably going to be in the lower single digits.

IRA FLATOW: All right. Let’s talk about how we can attack this. Dr. Anthony Fauci of NIH, I said before, says a vaccine may be ready for human trials in about three months. Michael, is that overly optimistic, do you think?

MICHAEL OSTERHOLM: Well, I don’t think it’s overly optimistic. I think that Tony is right on that such a vaccine will be in trials. But let’s just be realistic. I think the fact that we will have a vaccine that will somehow impact this outbreak is a smaller chance than us relocating the Grand Canyon to Minnesota. When we look at all of these outbreaks we’ve had over the years– SARS. We have MERS, Zika.

I can go through the whole laundry list. And I chair five of the working groups at the WHO right now on the vaccine road– our research and development roadmaps. And we have vaccines. But to get them licensed, to get them approved, to get manufacturing plant capacity, to get someone to actually buy them takes years and years.

An Ebola vaccine even took years after the outbreak. But more importantly, it had a great deal of work done beforehand because the biodefense industry and the governments of the US and Canada invested a great deal in Ebola vaccine because of the concern about a bioterrorism agent. We haven’t seen a similar investment. And remember we’ve known about coronaviruses and the need for vaccines dating back to 2003. And we haven’t had one. So I think that this vaccine work is absolutely critical. We need to bring it to completion as quickly as we can. But we can’t at all assure the public that it’s going to have any impact in the immediate days or months ahead.

IRA FLATOW: But Ebola was contained eventually. Are there lessons we can learn about now that we– because we are fighting this that we can use for the coronavirus?

MICHAEL OSTERHOLM: Not really, in the sense that it’s now a very different transmission agent. The Ebola virus was transmitted with body fluid contact. Where this is just breathing somebody else’s air nearby. One thing we did learn was that when there was an attempt to quarantine people early on in the outbreak in the major cities and keep them basically in a one given neighborhood, that backfired immediately and people stopped doing any kind of quarantining. I think we have some lessons to learn from China.

I would be one to say that I think that the major lock-down that was done on 65 million people in the Hubei Province where Wuhan is located actually backfired because we know, for example, that when the announcement that this was going to happen took place, it didn’t take place for almost 36 hours after they announced it. And at least five million people left Wuhan and went to wherever in China, which was just like inventing a viral machine gun to spread it around the country.

IRA FLATOW: I see. I see. Kristian, former FDA commissioner Scott Gottlieb writes in The Wall Street Journal that there is a reliable, fast, and cheap PCR-based test made by Roche that could be ramped up. Right now you have to send the samples to the CDC. They do the test. And by that time, it could be hours, days, whatever to get a result. Do you think that if we had a faster method of diagnosing the disease in people, it would be helpful?

KRISTIAN ANDERSEN: So yeah, definitely. I mean fast diagnosis is absolutely critical here. So we can isolate patients that are known to have the infection. I think that first of all these diagnostics were made based on these first sequences that were released from Chinese investigators and made exceptionally rapidly. Now these types of tests are fast. I mean, I assume most labs in China by now we’ll have these up and running. And one can expect some sort of assault from that within, I would say, four to six hours or so.

So I think as the capacity on that is being ramped up, yes, in this country it’s for now only the CDC, but I’m sure that the different state labs and so on are also getting geared up to actually run these PCRs. So I think that they’re definitely critical so. Again, we can come in with the isolation.

IRA FLATOW: Yeah. OK. So let’s say you have these. You have these tests, and you use them diagnostically. And you find out that people are infected here in the States– just hypothetically. Are the hospitals ready to deal with a flood of patients that might come in, even just people who are worried about whether they have it or not? Kristian?

KRISTIAN ANDERSEN: Yeah. So this is always a good question where flu epidemics, flu outbreaks happen every year. Right? And then the hospitals are able to deal with this. And I totally agree with Michael that a lot of this looks like flu. It really depends on how many cases we are going to see. For sure in China right now, there’s– in Wuhan and other places, there’s too many patients for capacity. And it was the same thing that we saw in West Africa, for example, in the DRC, too, during the Ebola outbreaks. So it’s definitely a real concern, is that are we ready with this.

IRA FLATOW: Michael, do you agree that we’re just not prepared for this?

MICHAEL OSTERHOLM: We’re not. And I think the important message here is that we as a country have a health care system today that in many ways is hanging on by a string. The emergency rooms, even in a moderate flu season, let alone a severe one are severely challenged– the number of beds that are available. We have and have been doing surveys looking at the availability of protective equipment for health care workers. And hospitals are not able today to afford to stockpile this equipment. They hopefully will get it on a just-in-time delivery basis. Well, now when everybody wants it, manufacturers are in no position to provide it like it is.

One of the big challenges right now in Wuhan and other parts of China is health care workers are actually being made to work in the absence of any available protective equipment because they’ve run out. And so we do need really to have our health care systems in this country really dust off the book and look at this very carefully for the future.

IRA FLATOW: I’m Ira Flatow. This is Science Friday from WNYC Studios, talking about the outbreak of the coronavirus with Kristian Andersen and Michael Osterholm. And Michael, whenever you talk about– I think dusting off their equipment is a euphemism for spending money and expanding their facilities.

MICHAEL OSTERHOLM: Yeah. In this case, I said dusting off the playbook, meaning that–

IRA FLATOW: Oh, I see.

MICHAEL OSTERHOLM: –the hospitals actually have preparedness documents that have been worked on over the years. And they all want to do the right thing. But when the number of patients outstrip the number of beds, you don’t have adequate number of health care workers. You don’t have protective equipment, which a very difficult situation becomes even more difficult. And that’s, I think, what we’re worried about right now. And a number of groups are trying to address this. But it, depending on how soon this might arrive here in any meaningful way, is going to depend in part how prepared we are.

IRA FLATOW: Well, one last question. When do we know we’ve reached the tipping point where things are getting bad in this country? What are the signs? And the cases are what? Michael, what would we look for?

MICHAEL OSTERHOLM: I say this jokingly, and it’s not meant to be disrespectful. But maybe when China Airlines refuses to fly to the United States, we know that we hit a problem here. I think that at this point, it’s really going to be a matter of filing our emergency rooms and outpatient clinics to see where we’re at, and just how many beds are available in any one given community. That’s when we’ll know.

KRISTIAN ANDERSEN: Kristian? Yeah. And I think like one of the key things to look out for is that how many transmissions do we have outside China, not just in the United States, but also in Europe and other places where the virus is being imported– right– by the travelers. And the question is, how many cases does that actually lead to? Is it a very small number of cases so we can hope to stop the virus? Is it going to be a large number of cases?

And I should say just because I agree with the whole, like the vaccine is too far out, but one thing that is critically important I could see that could influence this is the repurposing of pre-existing drugs– the drugs that we already have that fully approve other indications that might actually come in and be helpful in this particular outbreak.

IRA FLATOW: Such as?

KRISTIAN ANDERSEN: This could be influenza drugs, drugs that have been developed for other viruses, just general antivirals, for example. Remdesivir is one of the ones out there that will presumably go into clinical trials as part of this outbreak.

IRA FLATOW: Thank you, gentlemen, for informing us. Kristian Andersen, Infectious Disease Researcher, Associate Professor of Immunology and Microbiology at Scripps Research Institute in La Jolla. Michael Osterholm, Director of the Center for Infectious Disease Research and Policy, University of Minnesota in Minneapolis. Thank you all for being very informative for us today.



IRA FLATOW: You’re welcome.

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