Coronavirus-Update #27: "Handy-Apps können eine Perspektive bieten" | NDR Podcast

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s 93 percent of Germans are in favor of restrictions, i.e. distance regulation and staying at home, according to a survey by infratest dimap on the trend in Germany, Germans are divided on setting up a cell phone app. 47 percent say they would use them and 45 have concerns about data protection. These are the reports from yesterday, today is Friday April 3, 2020. My name is Anja Martini and I am a science journalist at ndr info and we talk. to professor christian drosten, head of virology, every day at the Charité Berlin, hello Mr. Thorsten, hello, I remember at the beginning of the

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we talked very briefly about applications in China and South Korea that evaluate movement data. of mobile phone users to find possible infected people.

At that time you said that it was probably difficult in Germany and I agree with you, now this situation has changed, which means that now we are talking about applications that work anonymously via Bluetooth and. which are carried out on a voluntary basis and there is already an initial study from Oxford in which scientists from all over Europe have worked on this study. Read, what do you think? Yes, this is a study from Christa Fraser's group, one of the best. in the logic modeler calculate that the enemy is simply moving much faster, where more information is coming in than was actually known until recently, so it is simply that the scientific literature is providing more and more data that can also be evaluated to be able to later introduce it into said models.

And the beginning of this study is actually made from the observation that there are more and more real descriptions of transmission pairs in the literature and therefore we can better determine the generation time of this infection, i.e. how long does it last? It takes symptoms to symptoms or infection to infection. One is about generation time, the other is about the length of the series from one infection to another and what is really needed is the length of the series, but it is all relatively difficult to determine exactly and that is why they can at least generate a good coin over the generation time and then they can be derived again from the literature and this is how it starts here: 40 transmission pairs are evaluated from the literature and this is used to feed a pre-existing mathematical model to derive certain parameters and derive certain parts of the entire transmission activity, so the zero transfer number, which here has been recalculated with two, which is a relatively low value if you look at what other analyzes have found previously, succumbed to this , in part it can be approximately two and a half and it puts two more exactly.

Now, of course, we have the opportunity to decompose these transmissions into proportions, so the first question asked here of this mathematical model is how high is the proportion of presymptomatic transmissions of symptomatic transmissions, but also of environmental transmissions and of asymptomatic transmissions, that is, asymptomatic means a carrier who never shows symptoms and presymptomatic means, of course, that it is transmitted before the carrier has symptoms, but this carrier can still be found. later because then you develop symptoms and it is important of course you can still identify contact patients later, it is a consideration that is included later in the post, but first of all, these values ​​that arise are pre-symptomatic 0, 9, so a ratio of 0.9 to 2 then for which is value zero transmission of two symptoms a ratio of 0.8 and then environmental transmission 0.2 symptomatic transmission 0.1 so if you add these four values ​​you get 2 again.

Yes, if you look at the numbers first. We realize that generally the proportion of presymptomatic transmission is 46 percent of the total transmission activity, which is a value that we recently discussed a few days ago in another working group of another paper, so the person It transmits to those infected even before they are sick. It is stored in front of the symptoms in the transmitter. These are, of course, average values ​​that are averaged across many transmitters and then analyzed in a mathematical model. This is memorable because here we have two things you need to think about. about This actually comes from the 0 value of 2.

First of all, it's apparently a good message because if we have a level of 2, then we have less transmissions that we have to reduce to reduce it to zero below 1 and thus bring the value 0 to 2. epidemic until it stops, but if we now realize that since 46 percent of all this transmission activity takes place before the symptoms, of course it will be very difficult to reduce these transmissions because you can only really isolate symptomatic patients and all these considerations are now fueled by an interesting calculation that wants to know what can really be done with certain interventions, that is, with measures to recognize an identified person, how long it takes to recognize and how many people already infected have infected during this time. because 46 of the transmissions occur before the appearance of symptoms and because it still takes some time until after the appearance of symptoms a diagnosis is made and then contacts can be identified and it plays a very important role here, i.e. this calculated generation time. of the infection that actually tells us even if it is isolated immediately when symptoms begin.

If you take someone out who is symptomatic from the transmission situation, then you have not only infected people, but you have also infected people after they have been infected. By the time the first patient has symptoms, he is already infected again and possibly has already infected people again and is just starting to do so. So it gets to the beginning of its infectivity and it's just starting to infect people again and we actually observe. something like that in the study of the Munich persecution case and it surprised us, but now there is basically quantitative evidence of the whole thing, also backed up with numbers and data that this really happens and now in this study a very interesting calculation is made about the possibilities of intervention and what the study really shows is that simple case identification and contact tracing is too late.

Because it all depends on just recognizing a symptomatic patient and it really depends on the last day. the fact that a symptomatic patient has no symptoms for a whole period of time before they are tested and then the test comes and then the chain of reporting begins, then the health department has to come and ask who they had contact with, then these contacts are identified at some point and it all takes so much time that, according to these latest calculations, most of the time is needed to get the patients out. In other words, what is calculated here is also formally very correct and very solid according to the latest figures.

What is calculated is that this can be done from a certain point in the epidemic with specific diagnoses, case tracking and isolation of contacts. You cannot stop this epidemic, that is no longer possible and what, of course, can be done to stop said epidemic is that you simply do a lockdown, then you no longer have to continue with the cases, then everyone is at home and, of course you can do a combination of Take Measures where you say there's a lockdown which is a little bit softer and includes something like a ban on gatherings, something like that is open at the moment, exactly more case prosecution measures, but also that and now there are calculations here that say there are certain efficiencies here.

You can reduce transmission rates by a certain factor, but the measures always only go so far. Efficiency and these limited efficiencies are taken into account here and then you come to the conclusion that this combination of measures can't really stop you, so you do something else. Something else is taken into account and that would be the passage of time that is achieved. when you use an app like this and here you think of a hypothetical app and this app can record these symptoms at the onset of the symptoms, then you just type on your cell phone: Now I have symptoms So check that and then the app says Okay, I already sent your data to the laboratory, which means that the app can already register for laboratory diagnosis and in principle you can receive a diagnosis immediately, so the app solves the diagnosis process and then of course the information about it . the diagnosis comes out if positive with 1 and at that point the app can start tracking who you were with and what other cell phones, so of course it can also tell how long you were in contact and so on, so that's exactly it what these

apps

are supposed to do, then track over time who you were in contact with, which operator of another cell phone, and then these operators of the other cell phone are informed that they were in the infectious state at the time they a patient comes into contact with this patient, this means that the spread of the virus is really too fast for scientists working without an app and if you had an app you could follow the spread of the virus faster.

That is the question that is being asked. asked here This study, what would it be like if we had this speed and we could also store it with parameters in a mathematical model and then you did it, then you assumed okay, if you have an application like that, how long is it? take for example Until the diagnosis comes, how long does it take from diagnosis to information about possible contacts and information you have to stay home now So in principle what does the health department do So in principle, that's what the health department does. The department's work is in parts of this application transfer and the issue is an information effort that the health department is doing and all these parameters have been entered into the model and are can briefly say if the epidemics developed as they did at the beginning where with This time the speed would be something like this: 1.60 percent of case identifications are successfully defended through the application.

It must be made clear that perhaps if 60 percent of the population participated, they would install said application and then. again, about 60 percent of those told they must stay home would actually do so. Stay home, then you could reduce it to zero below 1. That's amazing and now there are some restrictions on that. The spread is now faster, especially in Europe, than at the beginning in Hahn. This is undoubtedly due to several reasons: demographic density, population behavior, but also the degree of progression of the infection, which, of course, makes it even more difficult. that actually a higher degree of cooperation from the population is needed but exactly more than 70 percent but it is achievable so it is an achievable goal to simply bridge this inevitable delay in reporting activity by using such applications and communicate the essential information that you were in contact with an infected person.

You should now get tested to communicate this essential information and the time you spend there. Earnings that would actually bring in much more or almost the same as a real lock according to this mathematical model and then there are some. Chain effects and some game options. One possibility, for example, could be said in a high incidence situation. In a place where there is a very dense epidemic or at a time where there is a wave of infections, it could. We'll even bring more speed to the entire system by saying we're going to leave this test story now, we're going to reschedule it from now on and we're going to say no more, if I check I have symptoms, then the app doesn't tell me, okay?

We've already registered him at the lab to get tested, so the app says "Okay", now we see him as positive. Exactly everyone who is symptomatic is now defined as positive. Without a test, this is, of course, an intervention measure in which this criterion is tightened and then Of course, and this is an interesting consequence effect, then, of course, all of this person's contacts in the last few days with this infected person are immediately defined as real contacts. Therefore, the condition is not established first: the laboratory test must first be positive and then this. The app goes to all the contacts and says, be careful, watch out for symptoms, but that happens immediately and of course then you can make the stricter criteria again for these contacts, so if you give me one now, I'll do it.

I have. I had symptoms, so they warned me and now I had symptoms too. The app no ​​longer said please go get a lab test, but then it said again that we now have to consider you positive and you should go home. quarantine So that means you even have the possibility of aintervention, for example by health authorities, changing the reaction of said application for a limited time or place, which would actually be an intervention measure similar to what you sometimes hear in public. At the moment, it is argued that such lockdown measures are increased and reduced again as part of a long epidemic that must somehow be managed and overcome, and that is just a game of thought that is stimulated here in this article.

You could also use the sensitivity of such a thing. Just modify the application and then you have the option to make said intervention measure sometimes stronger and sometimes weaker and of course you should say that you could also combine said application for example through others. General circumstances that reduce the transmission of infection, such as the use of masks, are of course not included here because we do not all know exactly how much the use of masks could reduce overall transmission activity if everyone wore a mask . There are no numerical estimates, but there are. It is conceivable that this combination of a mask when everyone in society wears it has an effect, that this effect adds to such a finely controlled application and I think that is a real perspective on this.

At the moment, of course, there is already some desperation in the debate in society about how to get out of these measures and what we do next, and I must say that I am really fascinated by the idea that an app like this could be used, especially if a lot of people participated. An instrument would have to achieve a completely different degree of precision in control and could say that normal life can continue, there is no general lockdown, companies can function, schools can teach, everything can work, but not for everyone at all. moment, but at some point there will be a time when you have this message on your mobile phone: please go into quarantine at home if you could show it now and the employer would say well, that's right, at home. quarantine this week, so I think it's a very interesting way of thinking, at least one that you can't say no to.

If the Chancellor said yes, they would say yes and about 47 percent of Germans so far would say yes, as would such an app because it is also anonymous in Germany, so we will wait and see what happens in the coming days and weeks in terms of the application. There is another study that we have to analyze and it is about a medicine that we already have. We talked about, namely, chloroquine, an anti-malarial drug that has now developed resistance and is therefore not used as often anymore, and we talked about a study that I still remember very well in France and they criticized the design a bit of the studio at that time.

There is a new study that comes from China. What do you say about this study? So, of course, chloroquine is still under discussion and it is actually the case. At the time there was a small study from France that I clearly criticized for its design and in the end I said that you cannot learn from this study. Now we don't know if it works or not because it's just the basic design of this study. So it wasn't even possible to say it. exactly if the time of infection was the same in the study group compared to the control group and now we have a more recent study from China that has also been published and is based on 62 patients in total, so that is always the case Another very, very small study, but this time at least they were randomized and distributed into two groups according to a random generator when the patient was admitted and these are mainly mild cases that are positive by PCR, that is, confirmed by laboratory and that they have initial signs of infection on the CT scan.

So you can already see in the lungs that something is happening and that is also normal, even in mild cases at the beginning, you can see something relatively early on the CT scan on the CT scan. and they have no contraindicating factors. the administration of chloroquine, then when you say 'They are not allowed to have a bath queen, so they do not have retinal diseases, or heart rhythm diseases, or liver or kidney diseases. You can see where chloroquine has it all. that has side effects, that is, in these organs, that is really, they are serious side effects and they have.

Then you treat one part with queen bleach and another part that you haven't treated and what you find is that the pneumonia in the untreated group contracts better in 17 out of 31 cases after a week and the lungs show signs of inflammation and that's a combination like cough and then, but also CT scan improved in 25 out of 31 in the treatment group, so that's enough to say it's a relevant difference. The pneumonia improved more quickly in the treatment group, which is very encouraging now. Of course, it must be said that it is not exactly known whether this study is a bit small or whether the groups are really composed.

The same because here it is also the same again, we have that effect again, we have a larger number of people in the obstruction weighing group Patients with fever and also a slightly larger number of patients with cough at the beginning and that is not This is not It necessarily means that the chloroquine group is a group that has worse initial conditions, but that can also mean (and this study unfortunately now doesn't say exactly how). The other study may also mean that chloroquine patients are simply a little ahead of their time. Of course, we found that this is not the case here and in fact I wonder why this is not recorded because we know it from patients, so we will still wait here for larger studies.

So we can't say based on this. study that Eurogreen is at least a partial solution. Based on these studies we can say that if chloroquine is a solution, then it is a weak solution. That's clear, so there's not much to be gained by plocking Vienna, but that could be it. You win something. Interestingly, this is the case for mild and therefore also early patients, so the early administration of such a drug has been investigated here and this could also be innovative for them. In the future, we should also consider it. other drugs a little bit earlier in clinical trials and not waiting so much until patients practically have to go to the intensive care unit, but just having to realize that patients with this disease are almost all mild in the first week.

I know that in the second week they can get worse and now you have the opportunity in the first week to do something to prevent that, even if these preventive measures can have side effects, that is the big dilemma in these clinical studies. So you have to give something. At a time when the patient says why, I actually feel very good when we talk about the issue of protection, so now we are talking about medications, about vaccines, we are talking about not going out, but there are a lot of people also wondering: We can always do more, for example, we can do something for our immune system and strengthen it, maybe vitamin C, vitamin D.

Do you have an idea? Go for a run, of course. It's always good to have a good immune system and of course it's always good physically to be fit and it's certainly not the case that you get infected while running in the park just because you pass other people so you certainly shouldn't worry about go out and go for a run. I think I can recommend it, but that's it. It's also about taking some things, some vitamins, there may be scientific evidence about that here and there, but that's not my area of ​​research. I'm not familiar with it at all and I've never heard of it having a revolutionary effect anywhere.

So in the context of an ongoing infection epidemic, one could say that we specifically recommend what one can say is that one should stay. away from people who could be infected and that would be in a situation like we now have a contact ban, you have to think about it for yourself, which is all the people you meet, for example while shopping or something like that, and there is this standard in the US that says six-week sessions, meaning six feet of distance and six seconds of contact duration. You should take it as a standard to maintain this minimum distance and not be close to someone for too long.

Good way to think when you move in normal public if you follow this hypothesis that you are directly infected by someone and you want to stay away from them today is Friday, let's take a look at this week there was some news about the corona virus that surprised you, you It bothered you or maybe you were happy, so that's it. I have so many different impressions coming to me, so what worries me more and more and also stresses me out is when I see the consequences that these current lockdown measures have. Of course, starting with the economy, with what is happening to small businesses in particular, that is absolutely terrible and of course we have to get out of these measures, there are studies that I see such as the one on the cell phone application that really are glimmers of hope and they are also mental models in which you can say yes, now we have to think positively about the fact that we are all together.

Let's go in this direction and think about smarter measures that can actually be implemented and that, by the way, can also be transferred to poor countries where confinement doesn't work like that but everyone still has a mobile phone in their pocket. Of course, we have to think about it and set an example, but there are other aspects in which I can do it. I just shake my head, since we actually already know quite a bit, but the same misinformation is spread over and over again. For example, I just read again in an American newspaper that 30 percent of PCR diagnoses are false negatives and exactly this report came from China. a few weeks ago and we know exactly why the PCR diagnosis of the throat is normal after the first week it is no longer positive, we already know exactly that and why it spreads.

Such simple knowledge is not better, especially in times like these, when the newspapers are completely occupied with such content and why such information is given again in the middle of such an epidemic and, by the way, it does not only come from the newspapers, but it also reaches out to doctors who simply don't know this, who haven't faced it, who then have this experience themselves, 30 percent can only be diagnosed based on feelings, but they don't even know that with a blood smear throat in patients admitted late to the hospital, Also in the wrong group. That often perplexes me and there are many other impressions.

Yesterday, for example, on a television program there was a compilation of children who contacted their grandparents through videos and said how much they missed them. That, of course, moved them. In our case it is also the same at home and yes, they are just impressions that I always turn into myself to think, okay, now we have to think about the future, we have to visualize and discuss things like this, like this with the applications of the mobile phone and all that. You can do and achieve anything with it, Mr. Thorsten, thank you very much for today and I wish you a great weekend.

As always, you can find this

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at lunchtime on ard audi or thek y. at ndr.de / corona

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and next to the interviews with christian drosten you will also find the scripts and source references have fun reading the ceiling my name is on the martini and I thank you for listening have a good weekend and we will see you soon on corona virus updates a ndr info podcast