Why Do We Still Not Have Enough COVID-19 Tests?

IRA FLATOW: This is Science Friday. I’m Ira Flatow. Just a note, due to the need for social distancing this week, we won’t be taking calls during this edition of Science Friday, which was pre-recorded earlier in the week. One of the biggest issues in the US when it comes to the COVID-19 pandemic is testing, getting more tests produced, and the struggle to get one if you need it.

But what exactly is the science and technology behind those PCR tests? How do they work? Maggie Koerth is here to fill us in on that story and other COVID headlines from this week. She is senior science reporter for FiveThirtyEight.com, based in Minneapolis. Welcome to Science Friday. Welcome back.

MAGGIE KOERTH: Thank you so much for having me.

IRA FLATOW: Let’s talk about this coronavirus. It’s made up of RNA. And that is what the tests are analyzing. Can you give us a little thumbnail on that?

MAGGIE KOERTH: Yeah, so the tests are all– it turns out, the ones that we’ve been using for the past few weeks at any rate, are all based around the same technology. That’s true here. It’s true in other countries. And basically, what’s going on is that a medical professional sticks a swab way, way, way, way up the back of your nose. And then they take that biological gunk, in technical terms, and they first have to isolate viral material, the RNA, out of that goo– separating it off from mucus, random cells.

And RNA is sort of like– you can imagine, it is like half of a ladder. So if DNA is like a twisted ladder, RNA is sort of like that split in half. And so the first thing that they have to do is turn RNA into DNA. That’s called reverse transcription. And it’s something that can be done with what amounts to science kits that researchers buy from scientific supply companies.

They do that, and then the next step is something called polymerase chain reaction, which is a long-established technology and method used for multiplying the numbers of DNA fragments that you have, so that you have enough that you can actually study. And a big part of what makes the test that we have from the CDC different from the ones that they’re using with the World Health Organization is what specific fragments of the virus that causes COVID-19 that they’re looking for when they do this replication step. That’s actually the thing that makes it different. It’s not different technology. It’s not a different methodology. It’s just looking for these different sort of fingerprints of the virus.

IRA FLATOW: And so I can see with so many steps and so many different swabs, the vials, everything else, if you have a shortage, if you have a blockage someplace, that could stop creating the tests altogether, right?

MAGGIE KOERTH: Right. So it turns out that what is actually slowing down our testing in the US at this point isn’t really anything that has to do with the technology itself. It has to do with supplies of all the things that you need for the technology. And that includes everything from the nasal swabs to the chemicals that are used to do the reverse transcription and the PCR, to just health care workers to run these tests.

IRA FLATOW: How come South Korea was able to do a quarter of a million people so quickly? And they had the drive-through testing stations. What is taking us so long to catch up there?

MAGGIE KOERTH: Honestly, it sounds like the biggest thing is that we haven’t had a serious outbreak, a serious pandemic affect us since the 1960s. So South Korea had a brush with a cousin virus of COVID, MERS– M-E-R-S– back in 2015. And it wasn’t a huge outbreak there, but it was enough to put the fear of God into the leaders of that country. And they started having plans ready to go. They started having these chemicals in strong supply. And they were ready when this hit.

IRA FLATOW: Well, there has been talk about developing a home test kit. Would this also tax the supply if we had these things?

MAGGIE KOERTH: It depends on what kinds of kits ended up being used. There are a lot of different kinds of ways that you can do tests for viruses. Some of them are based on these reverse transcription and PCR setups. But if you’re doing something at home, it would be unlikely to be based around that, since most of us don’t have the technical equipment at our houses.

But one of the things that we know about tests that are very fast done in doctor’s offices for things like the flu, is that they have a higher percentage of things like false positives, false negatives. So that’s something that, if you have a home kit, test kit, you’re probably going to have a little bit more of a risk of. It’s all about trade-offs.

IRA FLATOW: I get you. We initially heard that the coronavirus struck older people. But there’s interesting news in California. Half of the cases are in younger people?

MAGGIE KOERTH: That seems to be the case. Yeah, that’s what their governor is saying. It ends up being really interesting. I mean, we look at nationwide cases. You’re still talking about a very lopsided hockey stick sort of pattern, where the older you are, the more likely you are to have had symptoms, to have been hospitalized, to have died. But there are a lot of younger people who seem to be getting this too.

IRA FLATOW: And there has been a back-and-forth about whether you should take ibuprofen to treat the COVID-19 symptoms. What’s the latest on that debate?

MAGGIE KOERTH: So this is one of these things that I think is interesting about a national emergency news situation, is that you kind of get into that sort of fog of war place, where it’s hard to understand what’s really happening because you’re so busy living right in the middle of it. And that’s definitely an issue with this pandemic. You know, there have been some of these small studies that have prompted big responses by the media and by the public, and then they turn out to not be as reliable as we sort of first thought.

So last week, the French health minister had announced that people diagnosed with COVID-19 should avoid ibuprofen. That was based apparently on four young people who had developed more severe symptoms after they’d taken it. And it’s not a totally unreasonable idea. The British Medical Journal noted that there have been at least two large trials in the past that provided some evidence supporting the idea that ibuprofen can exacerbate other kinds of respiratory illnesses. But right now, other researchers are saying there’s not really any evidence that SARS-CoV-2 is doing that with ibuprofen.

So even the World Health Organization– which several media outlets had cited as saying you should avoid ibuprofen– is now saying they never said that and they’re, in fact, consider ibuprofen to be safe for COVID patients.

IRA FLATOW: We’ve been hearing stories about some of the companies that make one thing. They’re stepping up to make something to help combat this epidemic. And one of those, you know, is hand sanitizer, which is in short supply. There’s a story that some distilleries– they make alcohol, right? They’re stepping up to make hand sanitizers.

MAGGIE KOERTH: Well, yeah. You know, ethanol is the basic ingredient needed for hand sanitizers. And a lot of distilleries are sort of realizing, hey, we have a lot of this. And the distilleries, as a couple of trade publications I’ve read have pointed out, are not particularly losing money right now. So they’re trying to find ways to give back to the community. And the reports that I’ve read about this, a lot of these different distilleries all around the country are kind of looking at this as a charity thing. And they’re either donating the supplies of the hand sanitizer that they’re making to local hospitals, or providing it as a pay-what-you-can sort of system.

What’s interesting about this to me is that it’s not a completely simple process for them. You know, they have all this ethanol, but it has to be denatured. So they have to kind of add some chemicals to make it unfit for human consumption, which isn’t something they’re used to doing. And they also had to get a hold of these other key ingredients like glycerin and hydrogen peroxide, and even just the plastic containers to hold the stuff that they don’t normally have on hand.

IRA FLATOW: So they have to spend money to sort of retool a bit?

MAGGIE KOERTH: A little bit, yeah.

IRA FLATOW: Yeah. And that always costs money, and that always takes some time. There are all different types of drugs being named as potential treatments, even if their effectiveness is not confirmed. But that hasn’t stopped people from trying to get these drugs, right? And they’re creating shortages, aren’t they?

MAGGIE KOERTH: Right. I mean, this is another thing where you kind of get some of that fog of war stuff happening, where there was a French study, involved less than 30 people. And it suggested that this one common malaria treatment might be effective against the novel coronavirus, which then led President Trump to tout the drug as a likely miracle cure. And then, you know, all of a sudden, you have people kind of making a run on this drug at pharmacies.

And what has sort of happened is that even though there’s not really much evidence at all to support the idea of using this, you have the public stockpiling it. And some of that stockpiling apparently is being done by doctors themselves, who are writing prescriptions for themselves and family members and buying up everything that the pharmacies have in stock– which is a really big problem because besides treating malaria, this drug is also used as a treatment for lupus. So cutting off the supply to lupus patients could mean even more people with these chronic illnesses that make them more susceptible to COVID-19.

IRA FLATOW: Yeah. And if people start experimenting on themselves with drugs, who knows what some of these side effects would be?

MAGGIE KOERTH: Right. I mean, there’s also the sort of problem where chemistry can sound like it’s the same thing and not be the same thing at all. And there was one case in Arizona where a man died because he had tracked down a similar sounding chemical compound to the one from that French study. But what he had found was instead, a industrial chemical used to clean parasites out of fish tanks.

IRA FLATOW: People are desperate. They do desperate things in desperate times.

MAGGIE KOERTH: Fear is a hell of a motivator.

IRA FLATOW: We’re going to talk more actually about debunking some of these treatments right after the break. So people can hang around. But I’m glad you stuck around, Maggie, to talk about these really interesting topics. Thank you for taking time to be with us again, as usual.

MAGGIE KOERTH: Yeah. Thank you for having me.

IRA FLATOW: Maggie Koerth, the senior science reporter for FiveThirtyEight.com, based in Minneapolis.

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