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Thread: Disease and pandemics thread (because it's science)

  1. #1681
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    It has occurred to me from my last post that a vortex filter, like Dyson uses, is likely to be better than a mesh. When you force air through a funnel, it starts to spin and particles are flung outwards where they can be caught. Rather than random micro passages, a matrix of small well formed funnels might filter much better for particles and if the particles are water droplets, they will stick to hydrophilic surfaces, ie damp surfaces, or some types of fibre.. I have not checked the patent library but such a filter might be many times more effective than simple felted fibres. And easily mass produced.
    sicut vis videre esto
    When we realize that patterns don't exist in the universe, they are a template that we hold to the universe to make sense of it, it all makes a lot more sense.
    Originally Posted by Ken G

  2. #1682
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    Quote Originally Posted by grant hutchison View Post
    After the CDC pushed out its advice about home-made cloth masks, there was a little burst of discussion in the health press and mainstream media about how "everyone" had been asking the wrong question. It wasn't about whether masks protected the wearer from infection, it was about stopping the infected wearer transmitting the disease.
    Writing the above discussion about airborne and respirable droplets made me wonder if cloth masks might not just be a recipe for converting short-range large droplets to smaller long-lived droplets and droplet nuclei--that is, if cloth mask use might not be an aerosol-generating procedure.
    That is certainly a disturbing possibility, but there's not much data to confirm or refute it. The study you mention did not look at that, indeed it stated "We do not know whether masks shorten the travel distance of droplets during coughing." And although I can certainly picture big drops getting pushed through a mask and then breaking into smaller aerosols as they are expelled, which would certainly be bad for masks, I also tend to think that if they are doing it in South Korea, how bad can it be? If all those people were creating tiny aerosols with their masks, wouldn't there be lots of contagion floating around, and wouldn't they not be having such resounding success?

    On the question of that particular study, there are a lot of problems with it that I can see without even being a medical professional-- just someone who understands quantitative data to some extent. First of all, as you mentioned, it was tiny-- there were only 4 subjects, and often there were only two results that were quantified (the others are tagged "ND", which is odd because if there was not enough sample to get a reading, that is surely in itself a significant outcome). Second, the way they get their average loads was a bit odd, I would have looked at the mean factor by which the mask reduced the load, and then averaged-- they averaged the loads first! That was a strange thing to do with data that has a wide spread (and is probably logarithmic-- when does anyone average raw logs together, that's insane), and did you look at their table of data? The statistics are very low, but the table of data seems to lead to quite a different conclusion from what they said. I'm going to assume a "log copy" means the log base 10 of the number of copies, so we should subtract the log copies they get with and without masks to test the significance of the mask. There are only two patients that did not have "ND" results from their cotton masks (whatever that means), and they had reductions of 1.11 and 1.16 compared to the average "control" (averaging the two before-and-after no mask result). Those are factors of 13 and 14 relative to no mask (which doesn't seem surprising that having a mask would significantly reduce the spatter). Oddly, the results for the surgical masks (these are not N95 for those not reading the study) were 0.12 and 0.37, or factors of 1.3 and 2.3 (for such small reductions, it might be better to say reductions of about 25% and 60%). So if such small statistics could be trusted, I would tend to conclude that surgical cloth masks are of essentially no value, but the (presumably cheaper) cotton masks are much more effective, and might significantly reduce R0.

    Part of what is happening here could be that again a different question is being focused on. First, the focus was on whether or not masks protect the wearer, rather than the broader issue of what is the effect on R0. Here, the focus is claimed to be about transmission, so R0, but the conclusions of the study seem more attuned to the question of whether an individual standing close to someone with a cough can feel safe if the coughing person is wearing a cloth mask. If their viral load is only reduced by a factor of 10 compared to being coughed directly on, then no, I would not feel much satisfaction from their wearing a mask. But if everyone is wearing a mask, then R0 is certainly going to be reduced if all viral loads are reduced by a factor of 10 at close range (and who knows what happens at longer range-- perhaps an even greater reduction, although perhaps there are tiny aerosols being created, a rather important difference that we don't seem to have any studies about at all).

    But I will confess to some uncertainty about the unit being used. I think it must be an exponent, because it calls itself a "log copy", and if it was a linear unit then it would be surprisingly low and surprisingly consistent between patients. But if it is a log base 10, it is odd that the spread in patients is so large-- factors like 100,000 in variance. Maybe it's a log base e, but that would mean the surgical masks really do nothing, and the cotton masks are still much better than nothing.
    (And it would be nice to see a comparison with a well-applied elbow, which seems unlikely to transmit many droplets.)
    Yes, it's too bad they didn't put the "elbow" into their study, but note that even if they did, it's not a fair comparison. One key advantage of wearing a mask is that you have it on when you cough-- there's no problem with not getting the elbow up in time (which of course happens quite often when coughs are sudden and violent).

    So I'm not at all sure where that study gets its conclusions from. My own conclusions from their data are:
    1) they should not average raw log data, that's a very silly thing to do because it does not properly weight the trials. The factor reductions are much more consistent.
    2) their statistics are too low to be of much use, especially given those strange "ND" results. For me, this data has the quality of something that I might expect for a high school science project.
    3) their conclusions are opposite what their data say. If one could trust that data, it says that cloth masks are much better than nothing, and significantly better than surgical masks.
    4) the only conclusion they draw that seems valid is that they found a strange tendency for the outside of the mask to be more infected than the inside, which they attribute to currents that carry particles around the mask and deposit on the outside (though it could also be that particles tend to be driven all the way through the mask and end up on the other side, which actually seems more likely to me). So the only thing I take away from that study is that a coughing person should treat their entire masks as contaminated, not just the inside layer. So if they pull the mask down to talk or take the mask off from the outside, they should regard their hands as contaminated as well. On the issue of whether wearing cotton masks is protective of others, this study seems to get support that it does, and it also cites another study that also concluded that (although that other study concluded surgical masks are also of value, which they could not corroborate).

    In my opinion, the fact that I reach such a different conclusion from their own data suggests the article was also not well refereed-- the referee should make sure the conclusions actually stem from the data. So I think you only point to this study because there is such a dearth of good information, and that's exactly what I find so puzzling-- I mean, how hard was it really to do this study, and why aren't better ones being done with a hundred patients? I realize we can't be talking about patients in the ICU, but surely there are plenty of people around who are coughing. Why are we always a month behind this disease? It's time to get some good information and get out ahead of it.
    Last edited by Ken G; 2020-Apr-10 at 05:46 PM.

  3. #1683
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    Quote Originally Posted by profloater View Post
    Well the “experiment “ enters a crucial phase. Sweden sees a rise in deaths, Norway has just closed the long border. Sweden is either now in big trouble or in a flattened death toll rise spiral. As you predicted Sweden has locked down.
    I didn't know that, but I'm not surprised. Every time anyone said "Sweden is trying a different approach" I thought, looks like the exact same approach to me-- just taking them longer to see the noses on their faces. Why wasn't it obvious to everyone that Sweden was going to have to lockdown, and just do it when it could have saved more lives than waiting, the way New Zealand did? Why wasn't it obvious that a potentially airborne disease requires immediate social distance warnings, back in February? There are two diseases going on-- COVID-19, and wishful thinking.

    Now the plan is, get the cases down and relax the requirements. The problem is, no one is really able to get their cases down (everyone thinks China is lying)-- instead, what happens is the cases merely level off, so it's very important they not get high in the first place. Too late for the US, sadly. Maybe the cases come down in a month or so, but what seems to happen instead is there are pockets of superspreading that keeps the cases level. I'm guessing, it's because some people still refuse to accept the wise approach, so everyone just has to hunker down for a year.
    Last edited by Ken G; 2020-Apr-10 at 05:52 PM.

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    Several news items I've seen in the last couple of days. Unfortunately I can't find the links apart from one. So take as rumour for now.

    One study is discussing the specifics of the COVID-19 virus and the configuration of the rna. Their conclusion is that the COVID-19 virus is a mutated version of a previous human virus. So not from bat's or pangolin.

    Another study finds that ventilators are doing more harm than good to Covid-19 patients. They're suggesting simple oxygen masks, because patients blood oxygen levels are so low they should be dead, but they're not.

    The last item is behind a paywall on the Financial Times site. The headline suggests that of the 17 Covid-19 tests they're (uk govt.) developing, none actually work.

    I am searching my history for the other links but virtually every item contains the keywords : virus, human oxygen etc. Hard slog on a phone screen.
    Also, apologies if some of those items are on this site.
    Last edited by headrush; 2020-Apr-10 at 05:39 PM. Reason: Clarification)

  5. #1685
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    Quote Originally Posted by Ken G View Post
    I didn't know that, but I'm not surprised. Every time anyone said "Sweden is trying a different approach" I thought, looks like the exact same approach to me-- just taking them longer to see the noses on their faces. Why wasn't it obvious to everyone that Sweden was going to have to lockdown, and just do it when it could have saved more lives than waiting, the way New Zealand did? Why wasn't it obvious that a potentially airborne disease requires immediate social distance warnings, back in February? There are two diseases going on-- COVID-19, and wishful thinking.

    Now the plan is, get the cases down and relax the requirements. The problem is, no one is really able to get their cases down-- instead, what happens is the cases merely level off, so it's very important they not get high in the first place. Too late for the US, sadly.
    Well, playing devil advocate, it could be wait until the cases reach a trigger, then lock down, as a specific plan. That plan hopes for some immunity. It probably goes on to relax, lock, relax and so on. How do the early lock down advocates plan to get through till a vaccine?
    sicut vis videre esto
    When we realize that patterns don't exist in the universe, they are a template that we hold to the universe to make sense of it, it all makes a lot more sense.
    Originally Posted by Ken G

  6. #1686
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    The BBC carried the news that no antibody tests work, yet. And hints that young people will be allowed to move around, and work, while we old folks stay at home, to shop on line!
    sicut vis videre esto
    When we realize that patterns don't exist in the universe, they are a template that we hold to the universe to make sense of it, it all makes a lot more sense.
    Originally Posted by Ken G

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    Re infection rate in India:

    Yesterday, we conducted 16002 tests. Only 0.2% cases tested positive. On the basis of the samples collected, the infection rate is not high; Rapid diagnostics kits have also been sanctioned: Lav Agrawal, Jt Secy Ministry of Health
    From Ani-news.

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    Looking at the case curves, I am starting to think the "SIR" model is making some importantly wrong assumptions. The SIR model has s be the fraction of susceptible people, i the fraction of infected people, and r the fraction of recovered. Of course s+i+r=1. The key equation assumes that each of these classes involves identical people behaving as per their class, and the transmission is scale invariant, so there are infection and recovery rate coefficients A and B that don't depend on s, i, or r. Then the equation one gets is
    di/dt = Ais - Bi
    on grounds that you need binary encounters between the i and s subgroups to get new i members, and the i members are resolving at a fixed rate B. The key parameter is R0 = A/B, and the result that connects those who never got it (s) from those who have recovered (r) is
    s=e^[-R0*r]
    and since i --> 0 eventually, in the asymptotic limit we have r =1 - e^[-R0 * r] as the number of resolved cases after the epidemic is over. An important feature of this model is that the final r is not 1, but for typical R0 ~ 2, it is something like half. The model is so crude one cannot conclude much more than that from it.

    Of course what one really wants to know is not the final r, but rather, the final r*D, where D is the death fraction. But assuming D does not depend on r (which is only true if the health care system is not overwhelmed), you can know D independently, so r ends up being the key statistic anyway. When D is ~1%, as may be true for COVID-19, one cannot tolerate a final r that is like half, so R0 has to be attacked directly. Hence, lockdowns.

    This also means that the SIR model is no good at all for what we have. It's only good for tracking what happens if you don't do anything, since then you can treat R0 as a fixed parameter. What we actually have is a situation where R0 receives feedback from i, because when you have a lot of cases, you take action that reduces R0. There's no easy way to model how R0 responds to our actions, so we have no choice but to use trial and error. We just do stuff, and watch the resulting case rate, and if we don't like what we have, we do more. So the key thing we need to know is not R0, but rather, what is the time lag between what we do, and when it shows up in the case rate. That is controlled by the B parameter, it has nothing to do with R0 because it doesn't depend on the A parameter at all. The A parameter is the inverse of the timescale for cases to resolve, which seems like about 3 weeks from infection to resolution. So we lockdown, and look at what happens to the case load 3 weeks later. Herd immunity plays no role because it's not high enough and that's not what controls the case curve-- we can rewrite all our equations with r=0, which simplifies them a lot because then s=1-i and the equation is
    di/dt = (A-B)i - iAi
    (I write it that way in case i is a vector and A a matrix). Also, we can't control B, so we should define a new time coordinate, call it x=Bt, and the equation with low levels of herd immunity is
    di/dx = [R0 - 1] i - i[R0]i
    But here's the real point-- the SIR equation is designed to treat situations where both r and i are quite high. That would be a catastrophic situation for COVID-19 unless there is huge asymptomatic numbers. Assuming that is not the case, we should also assume i << 1, and the equation becomes
    di/dx = [R0 - 1] i
    which has a very simple exponential growth solution if R0 is constant. But it isn't constant, that's the whole point of the new way of thinking about this equation that I am espousing. We should instead think of R0 is a function of i (and probably a 3-week lagged function of i, but let's leave that out for now). The simplest way to make R0 depend on i is to say R0 should be made to drop as i rises, so let's say R0 = R(i0 - i) where i0 is a hypothetical level of infection that is so bad everyone makes it their entire priority to prevent any contagion whatsoever.

    This model has two interesting benchmarks for infection levels. One is i_max - 1/R, which is the infection level that stays fixed (and might be somewhat like what we are seeing in almost all western nations right now), and half that is the level where the infection rate is the inflection point. I would argue this model is better for what we are seeing, because the inflection and peaks are not coming at points of very high i, which is what you get in the "SIR" approach. But note the key difference-- in this model, once i gets to the constant level, it stays there-- it does not drop like in the SIR model.

  9. #1689
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    Quite a few media reports emerging about the data Iceland is producing. They've apparently tested 10% of their population - a figure far higher than any other country.

    The chief officer of their testing efforts said Iceland's randomized tests showed that between 0.3%-0.8% of Iceland's population is infected with the respiratory illness, that about 50% of those who test positive for the virus are asymptomatic when they are tested, and that since mid-March the frequency of the virus among Iceland's general population who are not at the greatest risk those who do not have underlying health conditions or signs and symptoms of COVID-19 has either stayed stable or been decreasing.

    They haven't yet been able to determine how many asymptomatic infections, once confirmed, will later go on to develop symptoms, though.

  10. #1690
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    As I understand it, neither the Imperial nor Oxford models look like that. The mobility of people and ratio of super spreaders are both in the model.(referring to KenG post above)
    sicut vis videre esto
    When we realize that patterns don't exist in the universe, they are a template that we hold to the universe to make sense of it, it all makes a lot more sense.
    Originally Posted by Ken G

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    Here's an interesting ramification of that model. In order to make it match an SIR-type model when the infection rate is much lower than the untolerable level i_max, the R I used must equal R0 / i_max. If we use that, and also rescale the infected fraction i to be I = i / i_max, so we express the infected fraction as a fraction of what we regard as intolerable, then the equation becomes
    dI/dx = (R0 - 1)I - R0 I^2
    which is exactly the same as the SIR equation in the limit of negligible herd immunity, except that here it applies to i/i_max rather than i itself. This is a very important difference, because the reason the SIR approach never leads to a constant infection level is that the peak is always due to the appearance of herd immunity, and that also always presages a downtrend and the end of the epidemic. It also means a very high infected fraction overall. But if the intolerable i_max is much less than 1, as it is now, then once the equation uses i/i_max instead of just i, it not only reaches its peak when i = i_max * (R0 - 1)/R0, it reaches that peak when the herd immunity is very low and so there is no reason for a downtrend. Hence, this model levels off to a constant infected fraction, not just a temporary peak. It sustains i = i_max * (R0 - 1)/R0 for a long time. The R0 is the same as the SIR R0 that comes with the disease prior to any societal intervention (because when i << i_max, there is no societal intervention, due to wishful thinking), so we already know what that is for COVID-19, it is something in the neighborhood of 2. Thus this model predicts that i will level off and stay fairly fixed at about half whatever the society regards as intolerable, which peaks out at what breaks its healthcare system, but could be lower for nations with a willingness to sacrifice personal freedom or have an ability to maintain an economy under draconian conditions. So the simple model predicts that COVID-19 dooms all nations to suffer roughly half the infection level that they would regard as intolerable, and that level of infection will remain fairly constant until there is either a vaccine, or herd immunity appears (and I suspect the former will come first, but either one is probably a year or more).

    This simple model also tells us that we can wait for each nation to reach a constant level of currently infected fraction, and that will tell us what the intolerable level is regarded to be for that nation-- we basically just double the cases per day that they actually have. I would imagine the intolerable fraction is based on how that nation weighs the importance of health vs. personal freedom. The model is only as good as its unverified assumptions, but it is certainly better than SIR, which is clearly inapplicable to a world of variable rolling lockdowns and extremely low herd immunity since SIR always gives that low immunity implies exponentially growing case rates, and has no way to include feedback into the R0 parameter.
    Last edited by Ken G; 2020-Apr-10 at 10:59 PM.

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    Quote Originally Posted by profloater View Post
    As I understand it, neither the Imperial nor Oxford models look like that. The mobility of people and ratio of super spreaders are both in the model.
    The issue is not how you name the variables, it is in how you build in their dependence on the infected fraction. I'm unconvinced by the Oxford model because it only applies when herd immunity is an important factor, which is the flaw in the SIR approach as well. I don't see any evidence that is a good assumption at all. The model I'm describing is very simplistic, but it builds in a feedback between infected fraction and societal limitations on the infection rate, and its salient feature is that it leads us to expect that once the cases per day reaches its peak, it does not drop-- it just stays constant. It's too soon to tell if this is a good prediction, but so far it seems pretty valid.
    Last edited by Ken G; 2020-Apr-10 at 10:59 PM.

  13. #1693
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    Quote Originally Posted by Ken G View Post
    The issue is not how you name the variables, it is in how you build in their dependence on the infected fraction. I already reject the Oxford model because it only applies when herd immunity is an important factor, which is the flaw in the SIR approach as well. I don't see any evidence that is a good assumption at all. The model I'm describing is very simplistic, but it builds in a feedback between infected fraction and societal limitations on the infection rate, and its salient feature is that it leads us to expect that once the cases per day reaches its peak, it does not drop-- it just stays constant. It's too soon to tell if this is a good prediction, but so far it seems pretty valid.
    Headline overnight here, social distancing might be indefinite, I think that is what you are concluding too.
    sicut vis videre esto
    When we realize that patterns don't exist in the universe, they are a template that we hold to the universe to make sense of it, it all makes a lot more sense.
    Originally Posted by Ken G

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    Quote Originally Posted by profloater View Post
    Well, playing devil advocate, it could be wait until the cases reach a trigger, then lock down, as a specific plan. That plan hopes for some immunity. It probably goes on to relax, lock, relax and so on. How do the early lock down advocates plan to get through till a vaccine?
    That is indeed the problem, but forget herd immunity. Unless there is a huge rate of asymptomatic cases, herd immunity equals disaster and is nothing to plan for!

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    Quote Originally Posted by profloater View Post
    Headline overnight here, social distancing might be indefinite, I think that is what you are concluding too.
    Oh definitely, what should be permanent is everything that is easy. It's easy to wash hands, it's easy to wear masks (assuming that is found to help), and it is easy to keep 6 feet apart and avoid nonessential activities that involve crowds. Bad news for the entertainment industry, but they will need to find socially distanced alternatives. I don't think lockdowns are temporary, the only question is what should they look like-- how restrictive do they need to be to keep the case level tolerable (and I'm thinking tolerable is going to be high-- about half what we would regard as very intolerable, and probably pretty much the same as we are seeing right now). Of course, medical advances might allow us to tolerate a higher level, so I think better treatments are going to be key-- ventilators just aren't the solution, they never really were.

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    Quote Originally Posted by Selfsim View Post
    The chief officer of their testing efforts said Iceland's randomized tests showed that between 0.3%-0.8% of Iceland's population is infected with the respiratory illness, that about 50% of those who test positive for the virus are asymptomatic when they are tested, and that since mid-March the frequency of the virus among Iceland's general population who are not at the greatest risk – those who do not have underlying health conditions or signs and symptoms of COVID-19 – has either stayed stable or been decreasing.

    They haven't yet been able to determine how many asymptomatic infections, once confirmed, will later go on to develop symptoms, though.
    That's a key question, but at least someone is finally starting to put the pieces together by using testing that is not symptom based. This does seem to support the unfortunate conclusion I've already been using, that cases that never get reported to a doctor are not a dominant majority of all cases. But what I don't know is, when they count the cases in a country, do they only count positive tests, or are they also including situations where it was obvious from the symptoms and no tests were needed? In other words, when someone calls in and is told to self-quarantine because they have suspicious symptoms, and they resolve on their own without being tested, how does that get counted? That might be a place where the case numbers are higher and the death rate lower than what is getting reported, and might mean we are getting some herd immunity, but I don't know if it's enough to validate models whose peaks are ruled by herd immunity (as I believe applies to all the models being widely quoted, like the SIR model and the Oxford model). Is it possible, for example, that exploded pockets like New York City had so many people self-quarantine with symptoms that never led to hospitalization that there is now significant immunity in NYC? To know that, we need the Iceland data to tell us not only how many asymptomatic people later got a more serious illness, we also need to know how many symptomatic people would not have been counted as COVID-19 cases if they were in, for example, the USA.
    Last edited by Ken G; 2020-Apr-10 at 11:04 PM.

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    Quote Originally Posted by Ken G View Post
    That is indeed the problem, but forget herd immunity. Unless there is a huge rate of asymptomatic cases, herd immunity equals disaster and is nothing to plan for!
    I think I agree .. the infected asymptomatic phenomenon is one to watch closely I think, (see Iceland).
    Italy (Lombardy - the hardest hit region), seems to be alone(?) in saying they think they may have a 'large portion of the population (Lombardy) showing signs of immunity' - but that may just be apparent.
    Iceland's case of asymptomatic infections is at least backed up by good 'hard' test data.

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    Quote Originally Posted by Ken G View Post
    But what I don't know is, when they count the cases in a country, do they only count positive tests, or are they also including situations where it was obvious from the symptoms and no tests were needed? In other words, when someone calls in and is told to self-quarantine because they have suspicious symptoms, and they resolve on their own without being tested, how does that get counted?
    I think that the reporting is not consistent about this everywhere. I think some of the official numbers include what are termed "presumptive cases", cases where someone has a respiratory illness that is probably coronavirus, but no test is performed. That can be especially likely if someone dies; there are places where a hospital may assume that someone died from the novel coronavirus, but does not want to use what limited testing is available, since there are living patients that are a higher priority. So I think those show up in some counts. But in other regions, those same situations may get excluded from official counts.
    Conserve energy. Commute with the Hamiltonian.

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    There could be herd immunity in local pockets, but only ones that have been devastated by the disease. It seems to require something like a few people out of every 1000 to die, which are like wartime casualties.

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    Quote Originally Posted by Grey View Post
    I think that the reporting is not consistent about this everywhere. I think some of the official numbers include what are termed "presumptive cases", cases where someone has a respiratory illness that is probably coronavirus, but no test is performed. That can be especially likely if someone dies; there are places where a hospital may assume that someone died from the novel coronavirus, but does not want to use what limited testing is available, since there are living patients that are a higher priority. So I think those show up in some counts. But in other regions, those same situations may get excluded from official counts.
    It certainly makes it difficult to get useful numbers for the various models!

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    I note that pneumonia is a regular killer, typically cited in many more deaths than we see now as shocking when citing Covid19. My sample of one is a friend who was very ill in Thailand, all the signs of this virus, untreated he survived. Now he is fine but no test available to check his status. We have old people homes with a proportion dead. What does the proportion tell us? The survivors are either lucky to avoid infection or now post mild infection. (It’s not fair for me to call it mild if they don’t die, but statistics are brutal nowadays)
    sicut vis videre esto
    When we realize that patterns don't exist in the universe, they are a template that we hold to the universe to make sense of it, it all makes a lot more sense.
    Originally Posted by Ken G

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    Quote Originally Posted by profloater View Post
    I note that pneumonia is a regular killer, typically cited in many more deaths than we see now as shocking when citing Covid19. My sample of one is a friend who was very ill in Thailand, all the signs of this virus, untreated he survived. Now he is fine but no test available to check his status. We have old people homes with a proportion dead. What does the proportion tell us? The survivors are either lucky to avoid infection or now post mild infection. (It’s not fair for me to call it mild if they don’t die, but statistics are brutal nowadays)
    Malaria:
    In 2018 there were 228 million cases of malaria worldwide resulting in an estimated 405,000 deaths. Approximately 93% of the cases and 94% of deaths occurred in Africa
    .. now there's a brutal statistic!

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    Quote Originally Posted by Selfsim View Post
    Malaria:
    .. now there's a brutal statistic!
    Agreed, and Ebola has hurt the Congo terribly; we got rid of smallpox, the top killer. Malaria keeps evading the ingenious countermeasures, and is moving northwards with climate change too. I am afraid we have been too complacent.
    sicut vis videre esto
    When we realize that patterns don't exist in the universe, they are a template that we hold to the universe to make sense of it, it all makes a lot more sense.
    Originally Posted by Ken G

  24. #1704
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    Is there Unacast type data https://www.unacast.com/covid19/soci...ing-scoreboard for social distancing in Europe?

  25. #1705
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    One problem is that the current COVID-19 tests seem to have a high rate of false negatives.
    Information about American English usage here. Floating point issues? Please read this before posting.

    How do things fly? This explains it all.

    Actually they can't: "Heavier-than-air flying machines are impossible." - Lord Kelvin, president, Royal Society, 1895.



  26. #1706
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    Quote Originally Posted by tashirosgt View Post
    Is there Unacast type data https://www.unacast.com/covid19/soci...ing-scoreboard for social distancing in Europe?
    Google's COVID-19 Community Mobility Reports give you fairly granular data from all around the world.

    Grant Hutchison

  27. #1707
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    It appears that the UK is still shadowing Italy by 14 days.
    IMG_20200322_120847.jpg
    Latest figures UK :

    Screenshot_20200411-213339.png

    Latest figures Italy

    Screenshot_20200411-213433.png

    I've selected the points 14 days apart.

    It looks like the UK death total will almost double in the next 14 days.

  28. #1708
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    Yes, it seems to lowest order, every nation is experiencing the same things, just some a bit later. The normal course is, they look at others and think "we're glad that's not us", and then two or three weeks later it is them-- at least in pockets (why there are such local explosions is still unclear, it might be that isolated errors are the problem and could conceivably be avoided with testing and oversight like they do in South Korea, coupled with selective lockdowns). It's still not clear what happens in the long run, however. I think many people in the US still expect some kind of "SIR model" curve, which peaks and then drops significantly once herd immunity appears. It doesn't seem to have sunk in that this is not at all the course we are on, we are on the course that prevents herd immunity, and so the curve never drops-- you just decide what you can tolerate and what version of "normalcy" can sustain that. I think people are going to be very surprised to learn how little like "normal" that is actually going to look. For example, I predict that no major sport will be able to sustain a normal season until Fall 2021. I would suggest they consider substantial rule changes to allow more socially distanced versions of their games, along with completely new stadium policies. Waiting for the curve to drop, then going back to normal, doesn't seem responsive to the way this virus actually works. What would make me wrong is if there is a huge fraction of asymptomatic cases, and increased testing shows there is actually some herd immunity building. I doubt it, I predict that when tests are more available, we will simply find that you get lots of cases if you try to do much that is "normal."
    Last edited by Ken G; 2020-Apr-11 at 11:11 PM.

  29. #1709
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    Quote Originally Posted by Ken G View Post
    I didn't know that, but I'm not surprised. Every time anyone said "Sweden is trying a different approach" I thought, looks like the exact same approach to me-- just taking them longer to see the noses on their faces. Why wasn't it obvious to everyone that Sweden was going to have to lockdown, and just do it when it could have saved more lives than waiting, the way New Zealand did? Why wasn't it obvious that a potentially airborne disease requires immediate social distance warnings, back in February? There are two diseases going on-- COVID-19, and wishful thinking.

    Now the plan is, get the cases down and relax the requirements. The problem is, no one is really able to get their cases down (everyone thinks China is lying)-- instead, what happens is the cases merely level off, so it's very important they not get high in the first place. Too late for the US, sadly. Maybe the cases come down in a month or so, but what seems to happen instead is there are pockets of superspreading that keeps the cases level. I'm guessing, it's because some people still refuse to accept the wise approach, so everyone just has to hunker down for a year.
    Sweden is an important blip on the radar, so if you don't mind a graph (rates)....

    Sweden to Apr 10.jpg

    Their CFR continues to rise almost in spite of the decline in their death rate. But there are still < 10,000 cases, so more time is needed to determine the wisdom of their plan to fight this battle, though I agree with your concern with their strategy.

    [Added: For clarity, those rates are the rates from day to day changes. For instance, the "Death Rate" is from the no. of deaths increasing by 77 (793 deaths to 870 deaths) from the 9th to the 10th, which is a 9.7% increase (over the deaths for the 9th) in the no. of deaths.]
    Last edited by George; 2020-Apr-11 at 11:43 PM.
    We know time flies, we just can't see its wings.

  30. #1710
    Join Date
    Oct 2005
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    Here's something else. In my state there is a nursing home that now has over 70 cases of COVID-19, in mid April. Not late February or early March, mid April. We've known COVID-19 is a very serious threat to nursing homes for about three months by now. Of course they will have dozens of deaths in that nursing home, three months after that horse left its barn. Now for me, this tells me we have one of two things going on. Either we have total incompetence at that nursing home, or we have a complete failure to understand and communicate effective measures for preventing the spread of this disease. I would tend to blame all the wrong information that has followed this disease from the start. Yes it would be nice to have plentiful cheap testing, but surely at a nursing home, every policy should be based around the central assumption that anyone might have the disease, and act accordingly. Knowing someone has it shouldn't really change the behavior that much from assuming they might. Why are there different protocols once someone tests positive? By now,we should realize, in a nursing home above all, that everyone should already be assumed to be potentially positive, and we should have long since moved on to what you do when dealing with a potentially positive case. And there's the rub-- what should you do? What are people being told to do that actually works, and what do governments need to do to make that possible? It isn't build more ventilators, because ventilators appear to be the most expensive, most invasive, and least effective possible solution.
    Last edited by Ken G; 2020-Apr-11 at 11:52 PM.

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