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Testing for Coronavirus: The Who, What and Where

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Published on April 9, 2020

Key Takeaways

Who should get tested for coronavirus (COVID-19)? What tests are available? Where can people get tested? 

Renowned expert in molecular diagnostics Dr. Susan Leclair walks through the process and accuracy of PCR-based tests and other fast-tracked methods available to diagnose coronavirus.

Dr. Leclair also explains who should get tested and why the virus may not be detected in the early stages of infection. Watch now to find out more.

 [Due to extreme load on our website and Zoom platform, viewers may experience a time delay between the audio and video of the interview - please note the transcript can be read below.]

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Transcript | Testing for Coronavirus: The Who, What and Where

Please remember the opinions expressed on Patient Power are not necessarily the views of our sponsors, contributors, partners or Patient Power. Our discussions are not a substitute for seeking medical advice or care from your own doctor. That’s how you’ll get care that’s most appropriate for you.

Recorded on March 30, 2020

Esther Schorr:

Hi there. This is Esther Schorr from Patient Power, and today is March 30, 2020. I certainly know that this is a very trying time for all of us. We're all experiencing globally a pandemic. A virus that is causing a lot of people a lot of fear, and there's a lot of illness. But there's also a lot of information that's being shared between physicians all over the world and researchers to try to get us to a point where this can be managed.

I know that those of you who are watching this are some of the folks who will be perhaps a bit more concerned about the potential for catching this virus, because we're a community of cancer patients and care partners. That is a community that is more at risk for complications from the virus.

We have been doing a series of programs to try to answer some very specific questions for your condition in this context of this virus, but today I have a very special person that's with us. Who is our blood test 101 guru and one of our favorite people to interview, Dr. Susan Leclair. Hi, Susan, how are you?

Dr. Leclair:

I'm fine, Esther, how are you?

Esther Schorr:

Very good, very good. For those of you who don't know, Dr. Leclair, she is a retired chancellor professor from the Department of Medical Laboratory Science at the University of Massachusetts. She's been a lab professional for many, many years, and she is a super specialist in clinical hematology and oncology.

We're just so glad to have a few minutes of your expertise to help us understand a really big topic right now related to the coronavirus, and that's testing. There are a lot of questions about certainly the availability of testing, but even before that, which we can't really cover here about the availability. There are just a lot of questions about what the test is? What it's going to tell our medical teams? What do you do? What are our medical teams going to do with those results?

Can we just start with a few basics? Can you tell us, Susan, what tests are currently being done when they're available?

Dr. Leclair:

Okay. The best test. The gold standard is called a reverse transcriptase, PCR. In essence, and it's a long test, so it's going to take a little while to explain. You take a specimen, you encourage it by the use of stimulants and primers as they're called to undergo replication. That is you cause one strand of RNA to translate itself backwards. That's the reverse into what its DNA should look like.

Then you multiply the DNA, so you're forcing this to replicate for as long as you can. Then you test to see if the DNA that you have caused to amplify is sometimes called the amplicon, has got the particular chemistry that you're looking for.

It's an extraordinarily sensitive test. Many of you have had these or a straight PCR done before, because you've had genetic testing, and you've had some of the FISH testing that you've done. Gets a separation, then you go through the PCR process to find whether or not something is positive, negative—in some instances, how many of them you might have.

Some kind of quantity is discussed. So obviously if you start off with a lot, you're going to get more as a product than if you started off with one or two. It's a long complicated procedure. That's the best one. It's the one no one wants.

Esther Schorr:

Because?

Dr. Leclair:

Because you're nervous and you're upset and you want—for many of you, you're Americans, you want it now, because everything else has been now. I want you to think about those genetic tests that you've had for your disease and how—yes, I understand you wanted them now when it was a question of are you in remission or are you not? I think you probably would have preferred waiting a little while and getting the most sensitive answer, then some shortcuts.

Esther Schorr:

That's the goal. You're talking about the gold standard for testing for the coronavirus presence in somebody's body?

Dr. Leclair:

Yeah. Usually since you get this disease by droplet nuclei spread—and if you want we can talk a little bit about that—it means that you're breathing it in, or it means that it's landed on your hands and you have, as we all do, touched our face, touched our nose, mouth, eyes. You have in essence inoculated yourself with this virus, which is always a depressing thing to know. It's exactly by the way, the same way you catch a cold.

Esther Schorr:

So inoculate, you mean you've actually given yourself the virus? 

Dr. Leclair:

Yes, you can blame other people if you want, but in the back of your head there has to be an asterisk that says not entirely because you’ve done it. What you've done when you've taken your hand and you've rubbed your eye is that you've put the virus in your tear ducts.

Well, so what? When you cry, what happens to your nose? The excess tears go down in your nose. Your eyes will in a sense cause tearing that brings that virus down into the nasal passage, or you rubbed your nose and so now you're breathing it into the nasal passages.

The place it's going to land first is kind of like in the sinus area, the nasal pharyngeal area. Think sinuses, it's kind of an easy way to remember it. Then over time you blow your nose—or you don't—and there's post-nasal drip. It goes from there all the way down into your lungs. It has to pass the throat. Let's take an oral pharyngeal swab way in the back as well. So we double the chances of getting a good answer.

Esther Schorr:

How exactly is this test done?

Dr. Leclair:

Well, the specimen collection, which is now what's being done in the drive-through sites. If there's a test that's going on there it's for strep and for a couple of others, because all it's doing there is the collection.

You have to have somebody—it's not the world's easiest test—shove a swab up your nose, they can't touch the top of the inside of the nose. They can't touch the sides. They have to go straight in, kind of like not really scraping, but across the bottom plate of the nose as you're going in this way.

Then you have to—I think everybody's seen it on the news—you have to get to that moment when you're not sure whether you're going to gag, sneeze or just faint. As though you get that kind of funny—because that's swabbing right up here, and it's not a place you usually swab—those nerves are a little bit confused.

Stop here and say if you don't feel that level of discomfort that the swab didn't get to where it needed to be and you should say to somebody, and I know that all of you have become your own patient advocates. You have to say to somebody, "No. Can you do that again, because I don't think you got all the way back to the nasal pharyngeal area." Same thing as with a throat swab.

My husband, a microbiologist, frequently used to use me—I think it was getting even I'm not sure—as the dummy model when he was showing students how to do this. The bottom line is, it's shorthand. I don't want to tongue swab, or a teeth swab, or a hard pallet swab. Again, if you don't get that swab all the way to the back where you cough and gag, it didn't get to where it needed to be. Rule number one on this, make sure your specimen is the best it can possibly get.

Esther Schorr:

If I understood all that correctly, now that I'm feeling like I want to gag. When you are tested, there are two swabs that need to be done—one in your nasal passage and the other is a mouth, in your throat. Okay.

Dr. Leclair:

We won't know enough yet, because this is happening relatively fast, and some countries are more communicative about details than others. That we don't know whether just the oral pharynx swab will be good enough or just the nasal swab, we're going to keep both of them going until there's proof that we don't need one of them.

Esther Schorr:

Dr. Leclair, we've been talking about how the test is conducted. How the specimens are collected. Is there anything else that an individual person who is getting tested for the coronavirus that they can do to make sure that it's done right the first time?

Dr. Leclair:

This is going to sound really odd, but it's probably the most important thing that you can do, and I don't mean to be disrespectful of any of the people who are collecting the specimens. But the number one complaint I am hearing from my colleagues across the country is that the specimens are incompletely or not at all labeled.

I will use me as an example. My name is Leclair. Yes. However, there are four different ways to spell that, and I almost always get things misspelled addressed to me that way. My name is not S. Leclair, because that could be Steven, or Sam or Susan. It can't even be Susan J. Leclair, because it happens the three miles away from me is this Susan J. Leclair, who lives in the same city that I do. It must be my name, my address, my physician's name, because who am I going to report this thing to?

All of the other, there's an accession number that goes on those. Federal law, common sense tells you that if I get 12 or 200 samples into the laboratory, and I pick one bag up, and there's nothing on that case, I have to throw it away.

Esther Schorr:

Yeah.

Dr. Leclair:

If something comes up and it's Smith S. I have to throw it away, and then what ends up happening is of course everybody says, "It's the lab's fault for losing the specimen." I didn't lose it. It was a heartrending decision. I had to give it and throw it away.

Well, yes, people are going to be tired. They're going to be standing in the sun or the rain. You want to look to make sure that that swab is labeled completely and if it isn't, you want to stop the person. They're exhausted, they're overwhelmed and say, "Could you finish labeling that please?" Because that way the answer gets to you.

Esther Schorr:

What is the difference between what you just described and the kind of like you mentioned the drive-through testing? There's drive-through testing that seems to go pretty quickly when they do it. Is that not that gold standard, or are they doing that, and it is a rapid test of some sort? Is there a quick test and a gold standard test?

Dr. Leclair:

There are machinery issues. When you pick up the specimen, let's say you picked it up on April 1st. Sounds good. Your specimen was collected at 9:30 in the morning ,and I know this is going to sound overly detailed, but there's actually a point to it. At 9:30 in the morning, the specimen gets collected. It's going to have to be packaged so that it can be transferred.

Now it can be transferred to a hospital down the block or your hospital or whatever setting it is in a parking lot, may have to package these and send them to another state. All of a sudden now we're adding mail time, transport time to this.

When it gets to the place, typically hospitals are used to doing a relatively small number of these. The plate itself that you get can maybe go up to 12 for a run-through. If I take 12 specimens and I put them into this test procedure and kind of like baking a cake. Once I close the door and I begin the procedure, I can't go back in and say, "Well let me do a 13th, or let me put in another tray." That thing has to go through an entire amount of time by itself.

What are those times? Well, let's say I'm going to do 12 people at a time. It's going to take me between an hour and two hours to get everything set up, make sure the instrument's working right, do all of that stuff. Then it's going to take another maybe two hours for the first stage.

There are essentially five stages in this whole thing. Then I'm going to have to put it into something that maybe will allow it to be quantified. Now here's a point where if you're not interested in quantification, maybe I can play here, but if you want the cake fully cooked, then I can't ,and that can sometimes go up to six hours.

Esther Schorr:

Is there such a thing as a—I know there are rapid strep tests. Where they do a swab, you wait 15 minutes and they say, "Yes or no." You have strep, or you don't have strep. Does that test exist for the coronavirus yet?

Dr. Leclair:

There is one test that I know of that yesterday was allowed by the FDA. It is not an approved test. So here your own nervous system is going to come into play. The FDA has said, "People want this fast. This is a way of answering people's needs. I'm not going to say it's approved, because it hasn't gone through the full procedure, but I'm going to say in an emergency, yeah, if you want to use it, you can."

Esther Schorr:

Okay, so that's fair. That leads into when you do something fast.

Dr. Leclair:

Yeah.

Esther Schorr:

Does the accuracy come into question? I guess where I'm going with this is what determines whether the test shows a positive or a negative? Are there a lot of false positives or false negatives? Can you explain a little bit about that piece of it?

Dr. Leclair:

As everyone I think instinctively knows, you want it done right, or you want it done fast. It's an unfair statement. I don't want the company suing me on this one, but yes whenever you make shortcuts, like one of the shortcuts is that the rapid tests do not quantify. They just don't.

One of the other shortcuts, obviously, is the amount of time that these proteins, the RNA and the DNA, get to be able to replicate and to become more and more and more. The shorter that time, maybe the less sensitive this test is. You might have to go back and get another one, because you might be falsely negative, because it didn't have enough time.

Esther Schorr:

It's kind of like the cake didn't bake kind of...

Dr. Leclair:

...right, all the way through.

Esther Schorr:

Oh, okay.

Dr. Leclair:

Now, the world, I think knows that you can take a chocolate cake that's not baked entirely all the way through, and we call it molten lava, and you have a dessert success. Then there are other times it just falls flat.

Esther Schorr:

Right, but in this particular case, I'd be more worried than ending up with a molten lava cake. In this case, I guess where we'd need some clarification is, let's say I came in contact with someone who had the virus. How many days do I have to wait before I can get a test that will tell me whether I've caught it or not? 

Dr. Leclair:

Nothing is easy in biology. It would be much easier if this was just chemistry, because sodium always does the exact same thing all the time.

Somebody was in a grocery store ,and then someone sneezed six feet away from you. Maybe you got one virus, or somebody was walking down the aisle of the grocery store and was getting very close to you, because you have to get by each other. So it was well within the too close distance, and they sneezed directly on you.

Okay, I got one here or I got a face full. One of the things that will determine how quickly you get signs and symptoms is how much of an inoculum did you get? No, that's just the way that's going to happen. Did this person who sneezed at you, let's say the heavy sneeze—the one that went all over the place—did this person just get the virus himself and is therefore sneezing not a huge amount of them to you? Or did this person get to go to the store, because they might as well get all this stuff now before they go to bed? Well, you got to get a different inoculum that way too. Maybe I would say three to four days after that you might be able to come up with something that's positive. The longer you can wait the better, and I understand nervous systems don't do that.

Esther Schorr:

Right. If I'm understanding it correctly, it's kind of like the virus, it takes time to grow. Whether it's in the first person who sneezed on you where they are in their continuum of their process of having the virus that will affect how much of the virus you might get at a given time. Then it's going to take time for the virus to grow within you. Okay.

It gets pretty complicated. Maybe what would help is to explain the idea that these tests, as I understand it are kind of a snapshot of what's happening in an individual related to their contracting the virus. What is that versus what happens next?

Dr. Leclair:

That's so important. I will tell you a family story that parallels this, and this might help with the next paragraph. My father-in-law had diabetes and well didn't exactly adhere to the diet. In the old days, he would then realize, "Oh, next week I have a doctor's appointment, and I'm going to have a fasting blood sugar." He would not eat for two or three days.

He would get to that doctor's appointment, and he would sail through it, because he had done whatever was necessary for him to do. Then, of course, came the test, the A1C which evaluates what your blood sugar was over the last three months. I believe the term is busted at this point, because he could no longer cheat on that.

In the same sense, this COVID virus test that we are looking at is looking at a blood sugar test, a single point in time. You do not have it today at this point. Does that mean you will not get it? Absolutely not. Does it mean that you don't have it? Well, at this moment in time you do not have it, or you do not have it for long enough to cause the test to turn positive.

Let's say I went to the grocery store today. I got sneezed upon, and in the process for some reason I really rubbed my eyes, and I got a good inoculum in there. If you tested me, then I'd be negative. No, you've got to wait for a little while for the viruses to accommodate themselves to you, find some cells that they can enter, and then allow themselves to grow so that they can cause some kind of damage.

The common cold is something you typically get three days or so before you actually get signs and symptoms. If you wake up one morning feeling kind of clogged and you think, "Oh, my God, I've got a cold." I wouldn't blame the person sleeping next to you. I would however go back two or three or four days and say, "Where was I? Did I touch my face, or nose, or eyes? And then who can I blame from that group," because they're the ones who gave it to you.

Esther Schorr:

Okay, so by that logic then, what is the rationale for testing people with no symptoms?

Dr. Leclair:

I think you almost answered that question yourself. That's the problem. There is no rationale for it ,and there's maybe a little bit later when we have some time, I want to do some numbers on what danger testing people who shouldn't be tested can do—not only for the individuals and their co-habitors, but also for the general population. It makes the numbers really skewed. So we need to talk about that, but that will be later.

The answer is, "Wait until you have the symptoms." Now I understand that the symptoms are somewhat common to the flu. We are still in the flu season. They're somewhat common to strep throat, and that's always in season, but there are those different signs. Most of the time, the strep throat is not going to give you a headache. It's going to give you the, "This hurts so bad I'm never going to swallow again. "It's not going to give you much of a cough either. The flu isn't going to give you that much of a cough. There are nuances to this. This is not black and white.

Esther Schorr:

Right. If I start to not feel well, at what point should I as a patient or as a care partner, say “I have enough indication that something is going wrong?” What is that point? What should I be looking for? For me to advocate and say “Doctor, I think I need to be tested?”

Dr. Leclair:

Right. Fever, 101 or over. All overaching pain. Someone once described it as a few weeks ago actually. How I think of it is once, because so much has happened. The kind of aches you feel after a very strenuous and you've not been used to it exercise session, now, it's just that really hard to move around ache.

You're going to feel fatigue that is unusual. You went to bed not feeling this. You got a good night's sleep, and now the next morning you can barely get out of bed. It's that dramatic of fatigue. The fever, the coughing I've been told is not—now, there's a lot of people out there that are on a cardiac med called lisinopril (Prinivil, Qbrelis or Zestril), and they cough all day long. That's not that kind of cough.

It's a dry cough, but it's a you don't cough for four or five hours, and then you cough not quite constantly, but a lot for a half an hour or 45 minutes. It's like you can't catch your breath. You can't stop the coughing. When you get two or three of those, I would say that I need to talk to somebody about this.

Esther Schorr:

Okay. That's very helpful, and I assume from what we've been hearing is the first call you make is to your hematologist-oncologist, and you say, "This is what's going on, do I need to be tested?"

Dr. Leclair:

Right.

Esther Schorr:

Right?

Dr. Leclair:

Right.

Esther Schorr:

Okay. One other area that I'd like to cover, at least in this first chapter, because I have a feeling there's so much here that we could cover we're going to need another chapter. There's one area that it seems to be some confusion—the difference between detecting a virus.

Dr. Leclair:

Yep.

Esther Schorr:

And detecting the antibodies to a virus.

Dr. Leclair:

Yes.

Esther Schorr:

Can you help kind of sort that out?

Dr. Leclair:

Well, the good part is I know most of your listeners. I know some of these terms are going to be familiar to them, because they've been very interested in their immune system over time. Let's use the common cold as a model.

On Friday, you went somewhere, and you got the virus. Nothing happens until Monday morning when you wake up, and you're feeling that little crankiness that says, "I got a cold." The whining sets in and the morbid thoughts, and you get worse for three days. Then you stay at that level for another maybe three or four days.

Now you've been miserable for a week. All of a sudden, usually day eight, sometimes a little bit longer, you slightly begin to feel like you've turned the corner. Something has happened. It's not as bad as it was. You actually can breathe through the night without 12 different decongestants, whatever it happens to be.

That moment when you felt the turn was because you have made sufficient amount of IgM, which is your first antibody. That antibody has now made enough of itself to actually cause a decrease in the amount of viruses that are available. It's winning.

It was losing before, because, of course, it was starting from nothing and going this way where the virus was already here. It's that moment in eight days when the IgM outnumbers, outranks the viruses that you begin to feel better. IgM does that, and then its exhausts itself within about two weeks. You have this wonderful splurge of IgM, and that's what's making you feel better. So by the end of maybe 14 days, you don't have that cold anymore.

Esther Schorr:

Is that similar with this virus with the way your antibodies? So the antibodies say the antibody, that's a different test. That's not what's being tested for. Oh, okay.

Dr. Leclair:

Part of what the understanding on this is somewhere around there IgM, another name I know a lot of people are familiar with, begins also to be made, and that's a memory antibody. The problem is that different viruses cause different lengths of memories. You caught a cold, sadly. You caught a cold in January.

Yeah, you still have IgM antibody. You can't catch that cold until June. Then in six months, that IgM has dissipated, and it just goes away. Yes, protection for that common cold that you got in January. Yes. Is it protective? While technically, yes, could I use it for anybody else? Only until June, because then it's going to dissipate.

Esther Schorr:

I take it that's where a vaccine comes in. 

Dr. Leclair:

Yes. Yes. These are all—this is the problem with this is this is a tapestry. You can't just pull one thread, it connects to everything. For those of you who have the flu, you got about a year's worth of internal IgM protection.

What we want is what we get from pertussis. You got a whooping cough when you were 10, okay. You probably are going to have protective antibodies for maybe 20 years. Now that's a protection antibody that can do very well as an antibody that we give you to handle the next time you get confronted with pertussis. 

We don't know. We actually have no real idea yet if the antibodies that you make are, as the term goes, as you have heard Dr. Fauci call it a lot, if these are protective antibodies. We know that can make you better, that's good. Will it protect you in the future? That we don't know.

Esther Schorr:

That's why if you get the virus once now at the moment, medical science doesn't have the answer to whether you can get it again. Okay.

Dr. Leclair:

We're seeing some funny stuff out of it, because okay everybody said that the Wuhan method of quarantining, and all the rest seems you've been highly effective. Now that people are beginning to go out and stop the isolation and interact, people who had COVID got better, one would assume with antibody production, are now testing positive.

Now, is that because they never really got rid of the virus in the first place, or is that because they went out and got themselves reinoculated and got it again? Nobody knows.

Esther Schorr:

We're kind of in the middle of a research project all of us together.

Dr. Leclair:

Yeah. Without informed consent, without all that other stuff. 

Esther Schorr:

We're in a big clinical trial here. To wrap up chapter one, let me see if I can sum up. What I heard was, there is now testing going on.

Dr. Leclair:

Yep.

Esther Schorr:

The government is trying to get that out to as many people as possible, but right now the people who really need to be tested first are ones who have already shown some symptoms.

Dr. Leclair:

Right.

Esther Schorr:

Because we know at some point then they're going to need some support. They may need treatment.

Dr. Leclair:

Right.

Esther Schorr:

There's no reason if you have no symptoms to try to go get tested. Is that accurate? 

Dr. Leclair:

Yes, there are actually more reasons for you not to get tested.

Esther Schorr:

Not to get tested. Okay. Then the other big takeaway I got from this is that once you get the virus and you seem to get over it, at the moment, we don't know whether you can get the virus again. The best thing to do is continue to be...

Dr. Leclair:

...on guard.

Esther Schorr:

Vigilant, just be on guard until there is a vaccine that's generally available, because this is still in our atmosphere, it is in our population. We need to continue to be vigilant and careful.

Dr. Leclair:

I think the best thing everybody needs to be able to say at the end of this whenever this end of this happens, is to look back and go, "Boy, I really overreacted, in isolation longer. I was a little more concerned about things than I needed to be. Oh, wasn't that too bad."

Esther Schorr:

That would be great. So what if we could all do that? So what would be your parting words here, Susan, in this Dr. Leclair? What would be your parting words then, Dr. Leclair, to everybody who's watching this? There are some knowns, and there are some big unknowns. What would you tell the audience now?

Dr. Leclair:

I have gotten this down to four rules. Because there's a lot of stuff out there that—there's just a lot of stuff up there. The first rule is, if you want to know anything about the science, listen to NIH. If you're an American, listen to NIH and CDC and essentially nobody else—your neighbor, neighbors, ex-girlfriend don't count. You'll listen to NIH or CDC, no one else.

If you want to know about stuff that's happening as a citizen, you want to listen to your governor, or your mayor, or the town leadership, or however that happens. Those are the only people who know about closures, and when to go grocery shopping, and how many people in your neighborhood have got what? They're the only ones who know that stuff. Again, don't listen to your neighbor, unless your neighbor happens to be your mayor.

Now in other countries, you'll listen to your ministry of health, and you'll listen to the World Health Organization. The mayors and stuff are the same. The burden of this is on the communities, and that's who you should listen to.

The third rule, to people have an underlying disorder of any kind whatsoever, you want to talk to either your PCP and/or and your hem-oncology staff, whether it's the nurse practitioner that you talk to, or the physician himself, or the pharmacist that they suggested that you talk to or the nutritionist. That team knows you better than you know you in some circumstances.

Those are the people you want to listen to, and you want to seriously consider what they're going to say—no gargling with bleach. The real answers will—oh yes, there are many people who want to do that. You want to pay attention to them. I think above and beyond all of that, people panic when they lose control.

You are in control of your life. You decide, "Am I going to go to the grocery store today? Am I going to go in the morning or in the evening? Am I going to go out for a walk? Am I going to do it in the rain and in the cold so it's likely, I'm also going to get a weakened immune system from that? Are we going to stay in the house?"

You decide whether you want to kiss your spouse at night or hug your grandchildren before, because they came over to visit. There are holidays coming up. You decide, "Are you going to have a virtual holiday, or are you going to have maybe one or two people?"

You decide. You are in control of your life. You need to take that control back. Don't let a virus, itty-bitty thing, don't let a virus take that away from you.

Esther Schorr:

Dr. Leclair, thank you for always your wit and always your wisdom on these things. Certainly you've made it clear this is an evolving global problem that there are a lot of great minds working on right now. Hopefully over the next few weeks and months, we'll have more clarity on how this can become something that can be managed well. But the bottom line is don't panic, be in control.

Thank you. Like we always like to say, knowledge can be the best medicine of all.

Please remember the opinions expressed on Patient Power are not necessarily the views of our sponsors, contributors, partners or Patient Power. Our discussions are not a substitute for seeking medical advice or care from your own doctor. That’s how you’ll get care that’s most appropriate for you.
 
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