I am still not seeing as much as I would like about ventilation. One of main things we have learned about the virus is that indoor air exchange is the A-1 vector for transmission. I think of this at work when I go down to the cafeteria and a young woman with gloves has to pick up a sugar packet, a coffee stirrer, and a coffee cover and hand it to me. Then I go back to an isolated office for phone and online meetings while all the air in the building is pumped directly onto me.
This is significant for nursing homes. No everyone is there for the comorbidities we are so attentive to these days. For some, it is dementia, or mobility and balance issues, or Parkinson’s symptoms that prevent independent living. But there they are, now stuck in close quarters with a lot of people with C-Pap machines aerosolising everything. I have an ugly suspicion that it goes less-noticed because it is not easily weaponised by either camp in the national debate. If a governor had said early on that businesses like restaurants could stay open with a few restrictions, so long as they had ventilation systems that met a certain standard – particularly in areas outside of the Northeast cities that were so heavily affected – it would be hard to gin up anger either way. Dan from Madison raised the caution flag that a lot of these systems are now so far back-ordered that no one is getting delivery in months. I’m betting that stuff is harder to switch production to than individual ventilators. So who can capitalise on that one at the Conventions?
I have also not heard much about viral load, which I suggested early on would be important. Next-most-affected after older people are those taking care of them. It can’t be a non-factor, but whether it large or merely worth noting as a possibility would seem of some interest. If I were to guess, the importance of superspreader events would suggest that crowds indoors are an enormous risk.
Bsking just mentioned in the Apples to Apples comments (at Assistant Village Idiot) that America’s high obesity rate as a factor is also neglected. That matters at a couple of levels. Median age has also been mentioned WRT Laos in specific and SE Asia in general. It likely matters.
The advance notice for the Apples to Apples II post is that the regional approach within countries does look like the best way to look at this, and whatever lessons we might extract across countries are often going to come from this.
As some background, I spent 27 years working for a filtration company as a design engineer prior to retiring. My expertise is not in filtration efficiency or airborne particle mechanics, but I couldn’t help picking up some of the information along the way.
The most recent ASHRAE Journal had a small article on the viral efficiencies of higher-than-standard efficiency filters for HVAC systems. It was interesting, but left out huge numbers of things, the primary of which was the test setup’s filter face velocity, which was startlingly low for any commercial HVAC system. Their conclusions were that higher-efficiency filters could remove a substantive number of aerosols (up to 98% – 99%)) which tend to carry the viral particles. What the article didn’t emphasize was that the difference in static pressure between standard-efficiency and higher-efficiency filter elements was very, very large.
This increase in static pressure at nominal operational filter face velocities (as opposed to those in the test setup) means that most HVAC blowers would be unable to move sufficient amounts of air through them to maintain reasonable delta-T across things like A/C coils. To get the same air conditioning effect, the coil-side delta-T would have to go up, and this in turn causes all kinds of problems. “Dan from Madison” can probably address these issues, including mold growth due to lower LAT’s off the coils and other issues.
(As a side note, all of the filter elements tested were also statically charged, which means the first time they encounter air with high RH (near the dew point) they completely lose the charge on the filter media, and drop their efficiency like a rock. I’ve seen this first-hand when testing charged media; as soon as they’re run under real-world conditions, their theoretical efficiencies plummet.)
About the only way to really keep HVAC systems in places like nursing homes relatively biologically “clean” is through sanitization (note that this is not the same as “sterilization”, which is basically impossible). Meticulously cleaning the air ducts of dust build-up, and then sanitizing things like A/C coils and heating coils or elements with high-wavelength UV is one of the few ways to do it. Hospitals (modern ones) do it with dedicated outside air makeup systems, but this is not practical to retrofit to existing buildings in most circumstances.
Sorry about the length of this comment, but this only begins to point out just one of the multitude of potential issues in congregate living centers.
Or we could simply look at the current morbidity statistics and decide that Covid-19 has now become Much Ado About Not Much.
Let’s address more significant health concerns– like protecting people from being hit by lightning. Require everyone to carry her personal lightning conductor at all times?
Then I go back to an isolated office for phone and online meetings while all the air in the building is pumped directly onto me.
This is obviously a major issue and we have been discussing it. I mentioned that my HVAC contractor wanted to sell me a UV system last spring for $700. and I chose not to do it as we live here with few visitors. I was also a bit put off by the hard sell which included two other items for $1400 and high estimates for other services. I will be using a different contractor next time.
nanometers: 1 = 0.000001 millimeter
Because of the way that “obesity” is defined for those studies– via a screening system that is supposed to catch 99-95% of those who are obese, with the associated massively high false positive– it would be much more shocking if it didn’t show up.
It’s as if someone looked at “white hair” in association with mortality.
The recent push for MERV 13 filters has unintended consequences indeed. While they will filter out (I prefer the word trap) the virus, as Blackwing1 rightly states the static pressure is dramatically increased, especially when the filters load up. So even when they are new, you have new stresses on the equipment, and this is multiplied when they load, and the stresses are even worse on older equipment. Lead times on MERV 13 filters are anywhere from 12-24 weeks right now. If someone wants them, we recommend a full years order at once. Oh, by the way, they are about three times as expensive as standard pleats, and you have to change them more often due to the factors mentioned above. That isn’t a big deal for a homeowner with one filter, but it is a very big deal indeed for someone with a commercial facility that requires a full truckload of filters for one change.
We don’t recommend them. If someone wants to do something to put commercial tenants at rest, we highly recommend either a UV or an ionizer solution (we have had health clubs and hotels run the marketing loops of installed ionizers in their lobbies and it really puts people at ease). Availability has improved a bit on these products. We also recommend to commercial clients that they make sure their economizers are working properly to bring in fresh air.
I don’t have a lot of letters behind my name, but I have 30 years of practical, real world experience with HVAC systems of various sizes. I am having a hard time believing that the virus is easily spread by this route.
Very interesting information here thus far. Thanks.
1. I’m curious what sort of air filtration systems planes have, because I would have thought they’d be perfect transmission sites but that doesn’t seem to be the case.
2. It seems clear now that outside events are very low risk, so I don’t see any reason why outdoor sports events for all ages shouldn’t be completely on.
Then I go back to an isolated office for phone and online meetings while all the air in the building is pumped directly onto me.
What percent of air is recirculated (vs. fresh) in your typical office HVAC system?
What Blackwing1 said.
Jay Manifold made a presentation on what his church was doing in terms of ventilation:
https://chicagoboyz.net/archives/63951.html
It seemed to me to be well thought out and not ruinously expensive. It’s probably near the limit of what can be accomplished by retrofitting an already good system.
What nobody knows is if it improves things enough to make a difference. I’m not confidant that there’s even a good way to test it.
You can get an idea of the difference between a good system and one that’s proven to contain airborne bio-contaminants by thinking back to the Ebola outbreak. This is where we learned that out of all the hospital rooms in the country, there were only a hand full that were considered capable of containing it.
The $64 question is what would it take to make a difference? My opinion, reinforced by Blackwing’s information, is that just changing filter type and adding this or that accessory isn’t going to do it. He talked about disinfecting the duct work. There are so many small nooks and crannies in a standard system that I don’t see how you would do it short of heat sterilization. High level clean room systems are built in a very deliberate way to eliminate accumulation of contaminants and are very expensive to match.
The air handling systems in most large buildings already take up a goodly amount of volume. They limit the amount of outside air exchange in the pursuit of energy efficiency to the lowest tolerable minimum. The ducts and machinery are laid out as carefully as a moon rocket because space is money. It’s hard to see how they could be radically changed or much added to make them comply with standards that they were never intended to meet. I fully expect that it will prove impossible to retrofit existing nursing homes with effective systems. Especially as most are cash strapped as it is.
you are wasting your time … there is not a technical (i.e. equipment) soultion to infection … isolation (as in different building) the covid19 sick elderly and the hotspot infection of at risk people goes away … test the nursing home workers with temperature checks and require they minimize exposure to all paitents and the chance of initial infection is further reduced … everyone else can go on living …
I challenge anyone to find a large single room/event gathering of elderly with comorbidities outside of a nursing home … a large gathering of anyone else is as safe as gatherings during normal flu season …
every other corona virus presents as a COLD … that is the disease … covid19 the disease is just a cold (yes a dangerous one for some elderly) …
MCS: “It’s probably near the limit of what can be accomplished by retrofitting an already good system.” And now the rubber hits the road. With today’s technology, and the millions of perfectly fine heating and air conditioning systems that have been already installed, there is only so much that can be done re the virus. As I have mentioned before, those things are:
1) Dilute it (fresh air)
2) Zap it (UV or Ionizers)
3) Trap it (MERV 13 or HEPA filters)
There comes a point where expense gets ridiculous.
It’s easy to forget that outside of a few “anecdotes” that are probably more accurately characterized as rumors, there isn’t any proof that wuflu is transmitted through HVAC systems. It’s also easy to imagine that things like filters and disinfection would move the balance in a favorable direction. On the other hand, I can imagine the possibility that either might cause unforeseen and unfavorable effects down the line.
It doesn’t seem impossible that adding UV disinfection could allow resistant organisms to colonize a system, especially if it was done haphazardly. It doesn’t seem impossible that high efficiency filters could provide a breeding ground for organisms which could then contaminate the whole system when they are changed. The life cycle of the wuflu virus doesn’t make it a candidate but there are a lot of other bugs out there, Legionella is just one.
Then there’s the government. We can’t count on the facts; that we don’t know if this is being transmitted through HVAC systems, that we don’t know what it would take, assuming it was actually happening, to stop it, that there is every likelihood that we would be unable to retrofit existing systems, that measuring the actual ability of a system to reduce the transmission in most places would be impossible, to deter the government from regulating. The present climate doesn’t seem conducive reasoned, thoughtful and informed decision making. As if that was ever common in government.
All of the above, plus ubiquitous quick-turnaround self-testing as outlined in this article that someone here linked to recently:
It’s all so simple really. Everyone knows that all the directions will be followed perfectly. That no one will leave it in too long or not long enough.
Assume the false positive rate is ONLY 1%. That means on average 30-40 million people flooding the health care system for no reason, every single day. How could that cause any problems at all? On average, you’d be one of them three or four times a year. The alternative would be to simply quarantine for two weeks. It isn’t worth my time to figure out haw long it would be before there wouldn’t be anyone left to keep the wheels turning. If you live with anybody else, you’d probably have to isolate if any of them tested positive.
Then there’s the false negatives. People spewing all over, totally convinced that they were negative.
Probably par for the course for Harvard.
3-4 million.
MCS: I think the idea is they’ll be so cheap and easy that if you get a positive one, you can just do another and only if that’s positive would you consider that a “true” positive requiring medical attention. That would beat the false positives down to almost nothing, unless the cause is something systematic that would make the results not independent.
And what reason would there be to believe it was not systematic. The nature of the test says that false negatives could easily come from some mistake in procedure. A false positive is different. There are an unknown number of corona viruses circulating, there is some reason to believe there might be enough commonality to cause false positives.
Just how long would it take to set up production of 350 million tests a day? To be at all useful, it requires very careful quality control of all of the components. It’s not something you can whip up in your kitchen. Where do you find that many vials for the “solution” that must remain sterile and uncontaminated until use or some place to fill them? How do you distribute them?
You know where the cheap pregnancy tests come from, don’t you. I remember reading more than one article that pointed out that they were far less accurate than the slightly more expensive ones that are used in hospitals.
For every problem there is a solution that is simple, neat””and wrong.
For every problem there is a solution that is simple, neat””and wrong.
My professor of health care policy said, “Every system is perfectly designed to get the results it gets.”
MCS: I don’t understand your objections. The concept is to make a quick test that can be done at home that can detect “well enough” people with high viral loads. Seems like an admirable goal that is in principle achievable. My impression is that home pregnancy tests do a great job, and do “well enough” to prevent obgyns from being overwhelmed my people who “feel” pregnant.
Why was this not done months ago?
https://www.bbc.com/news/world-europe-53875370
The concert study, called Restart-19, was created “to investigate the conditions under which such events can be carried out despite the pandemic”, researchers said.
The first of Saturday’s three concerts aimed to simulate an event before the pandemic, with no safety measures in place. The second involved greater hygiene and some social distancing, while the third involved half the numbers and each person standing 1.5m apart.
You don’t administer 350 million pregnancy tests every day to people that have no reason to believe they might be pregnant. When the consequences of a missed diagnosis are important because of proposed drug or radiation exposure the stakes go up, and the better test is used, otherwise the truth generally becomes known soon enough.
If a vaccine becomes available in time to matter, I expect great consternation and recriminations in the media (especially if Trump is in office) when it is made clear that there will still be a delay of weeks or, more likely, months before enough doses can be prepared and packaged for everybody. This packaging has to take place under the same conditions and at the same facilities where this fantasy $1 test would be packaged. I don’t know if preparations are being made now to increase this, I hope so. It is still limited. Anybody who thinks 350 million of anything isn’t much should start counting quietly to themselves and come back when they get to 350,000,000.
No, if positive retest immediately. 30k to 40k. Retest, 300-400. The test it not used for medical treatment, it is used for self-evaluation for limiting contact. Symptoms and the CDC $100 test is used for medical diagnosis. The home 15-minute test is used to tell you if you are likely a contact risk. Say, three positives in a row and you get the diagnostic test.
False negative, you don’t need to retest, but you can at the cost of $1. The risk of contact is no higher than if you just said, I feel OK, I’m going to work/school/etc. today and you do. If you have an actual infection rate of 5%, you are testing for 16 million real positives and false negatives on say 160k. Better to daily self-test self and alert with true positives the 15,840,000 detected and trusting them to avoid contacts.
I doubt that any test for viral infection is 99% sensitive or accurate, but in the 90’s is possible. Even if it were 80% that would still drastically allow for reducing contact spreading while allowing normal activities for the vast majority. Those detected would be able to seek medical treatment as needed. Those with high risk would still need to be shielded.
This type of test would effectively and drastically cut down the infectious contact spreading due to long incubation period and large number of asymptomatic spreaders. These are issues the typical flu does not present.
Death6
>“Men, it has been well said, think in herds; it will be seen that they go mad in herds, while they only recover their senses slowly, and one by one.” Charles Mackay may have written those words in 1841 in his social science classic, Extraordinary Popular Delusions and the Madness of Crowds, but what he has to say about mass manias and the behavior of crowds remains absolutely relevant today<
Reasonable questions about DIY testing. But isn’t this an empirical question? At least one company is developing such tests. Maybe they will produce something that can be tried with a few hundred or thousand people and the results evaluated. Maybe it will be too expensive, too inaccurate, won’t scale, who knows. Maybe it will be helpful.
Death,
Even if I thought it was the best idea ever, it’s not happening on any relevant time scale for practical reasons.
Jonathan,
Scale is the only relevant question. Without scale, why bother. Testing for symptomatic individuals only makes sense if it will allow the majority that are just having a cold to get on with their lives. Random testing of asymptomatic individuals only makes sense if you are establishing prevalence. We already know this is here. The justification for this only works if you can test nearly everyone and the test is sensitive enough to pick up infections before they become contagious. The former is impossible and the latter is very questionable.
And then there is the question of compliance. Here’s what’s happening in supposedly well ordered and regimented Israel:
https://news.trust.org/item/20200823164934-pzroc
Long story short, it didn’t take long for them to figure out how to evade the government contact tracing. Not that it should surprise anyone with even the slightest knowledge of Israel.
I read a completely unsurprising story about how contact tracers here are hitting a brick wall as far as cooperation is concerned.
There was a moment, maybe as long as a year ago when some sort of test might have allowed this to have been contained and snuffed out. Now it’s just going to run its course, we may have flattened the curve but we won’t be able to suppress it permanently short of a vaccine or achieving wide spread immunity naturally.
MCS: Based on your most recent comment you don’t appear to have read the article. The concept is not to be as sensitive as other tests because there’s no need to be able to detect people who might be infected but have low enough viral loads that they can’t spread it.
For many reasons including those you listed our current system is hopeless. This seems like a potentially viable alternate approach.
The Israeli system tells people who are calculated to have been exposed to covid to self-isolate. It has a high error rate. Of course most people won’t comply, given the certain high personal cost and uncertain public benefit of doing so. I think it’s more likely that the system proposed in the Harvard article, which leaves it up to individuals to decide what to do if they score positive on a self-test, is more likely to be effective. As I said, an empirical question.
Brian,
I did read the article and my point was exactly that. However, every time I hear something about how infectious different stages might be, they are immediately contradicted somewhere else. leading me to the conclusion that nobody really knows. A low sensitivity test is synonymous with false negatives for low virus titers.
In any event, aseptic packaging capacity is finite and not quickly expandable. Most of it is already in use for drugs and materials that are in critical demand. If a vaccine becomes available, I expect that it will be stretched to provide the equivalent of a day or two worth of these tests over weeks in the form of vaccine vials.
The really important question is what about next time? How much capacity are we willing to support on contingency? What capacities does it make sense to have when we don’t know exactly what the need will be? I’m not talking about piles of masks and gloves, though we need those as well. Do we need factories manned and ready with the personnel going through the motions of drills and simulations like the SAC missile crews? Certainly the ability to field a test quickly in enough quantity to actually contain an outbreak might be a good idea. Much easier said than done when you won’t even know what sort of organism it will be. A virus is a good bet but not guaranteed, and which type? Would it be prudent to retrofit ventilation systems to contain airborne pathogens like we do for seismic hazards?
There are so many things to be wary of in so many places, many not readily accessible. Here we had a country with a well developed health system that choose to delay notice deliberately. Even if China had been 100% straight, there’s evidence that we wouldn’t have known in time to do anything useful. What if the next challenge comes from deep in Africa or the Amazon?
MCS: ok, I understand your concern about the logistics, but not your attack of the concept, since it seems reasonable to me, given the alternative, or lack thereof.
” A low sensitivity test is synonymous with false negatives for low virus titers.”
Right, because the idea is those levels don’t matter, and it’s better to detect higher loads faster, than lower loads slower.
If those levels don’t matter then those people that don’t know they’re sick aren’t spreaders. Why incur the huge costs to stop something that isn’t happening? Just another solution in need of a problem. We already have more of them than we need, what we need is something that will actually make a difference in the real world.
I’m sure there are plenty of people that would love for everyone else to get in the habit of checking in with the government for permission to leave their house every day. Remember that the last time we heard from Harvard Magazine it was about the coming educational apocalypse caused by people actually educating their children without proper deference to the “official” sources.
“If those levels don’t matter then those people that don’t know they’re sick aren’t spreaders.”
Yes, exactly. That’s the point of a higher sensitivity, that you don’t need to detect those people.
“Why incur the huge costs to stop something that isn’t happening?”
Because the whole concept is you have to find the infectious people fast. So you have to test everyone, and get a response immediately.
And the cost for this idea isn’t huge, it’s utterly trivial to the massive damage we’re still doing to the economy.
Everything about our response right now is completely insane, but that’s the world we’re in. Given our current situation and constraints, I think this seems like a plausible way out, assuming the production problem can be overcome. I honestly don’t see another option, except letting the Dems win the election so that they and the media can say it’s all fine and we can go back to “normal”, but the costs for that are pretty catastrophic as well…
Brian: “Everything about our response right now is completely insane, but that’s the world we’re in.”
Amen, brother! So let’s not make things worse.
We now know from masses of data that Covid-19 poses only a trivial risk to children and working age people. Most people are apparently already resistant to the infection. For the most part, the minority who do catch the infection don’t even know it — it present no health risk to most “cases”. The people at risk are a small subset of the general population — those who are quite old (70+) and/or have pre-existing conditions.
Covid-19 is not Ebola! Given the nature of this generally mild infection, the sane approach would be to focus resources on helping that small at-risk group. Testing everyone every day would be destroying the village in order to save it. Especially when large numbers of people have more urgent daily concerns — think about the mother in Democrat Chicago, trying to keep her child safe from the much more serious risk of daily random shootings.
Daily testing for the few million people who have daily contact with the at-risk group would be sane, and would be two orders of magnitude more feasible than testing everyone.
And in this world we live in, we always have to be careful about misuse. If the white teenage Far Left rioters in Democrat cities are able to test for the infection, they may well deliberately infect each other and spread out to cause more problems to a society they detest.
What Brian said. If we are going to throw money at something, I’d rather it be cheap, self-administered testing than the USPS. We could serge this effort in a couple of months with funding rather than await many months for a vaccine that doesn’t even exist yet, that many will refuse to take and whose effectiveness is likely about 50%.
This test is ready to be scaled and is not difficult to produce (unlike a vaccine or ventilators). It has been tied up in a food fight between the CDC testing requirements and the FDA being unable to comprehend the difference between health care measures and clinical diagnosis.
It’s not all about the election, we are past the point where this daily testing option would have likely made an impact, medically and economically. Hopefully the natural course of such an infection will continue to yield a downward trend.
This means is needed as quickly as possible to save as much of our economy as possible from further and long term damage. Not instead of other means, but as an addition.
Death6
“Or we could simply look at the current morbidity statistics and decide that Covid-19 has now become Much Ado About Not Much.”
Here ya go: https://www.worldometers.info/coronavirus/ The US is at the top, winning as always. ;) I hope that daily is right, as it will be down a lot from last week.
Here ya go: https://www.worldometers.info/coronavirus/ The US is at the top, winning as always. ;)
Adjust the results for population size and get back to us. Then further adjust the results for international differences in how disease and death data are collected and reported, allowing for outright lying by the Chinese and probably other non-US govts, and get back to us again.
Does this make you happier :https://www.worldometers.info/coronavirus/country/us/
I did not mean that you should compare yourselves to anyone, that’s you. ;) Just looking at your own numbers is just fine for my purpose, in answering Gavin.
You can sort the columns, and a couple of them are per capita, so that info is there.
Deaths per capita lists the US 10th, better than countries like Sweden, UK, Spain, Italy, etc.
And “we” have done not great, but our situation is probably uniquely difficult for being able to contain a disease like this.
China of course should be excluded, since their numbers are and always have been complete lies.
I’m not seeing any comments about testing pooled samples at choke points. Suppose all the sewage at an office building was tested at close of business. (one expensive test, but done only once per day, so relatively cheap). Suppose all the passengers about to board an aircraft donate a specimen before boarding, and pooled sample tested. Suppose the basketball team’s pooled sample gets tested. (Coming back from road games — away from wives — test the pool for STDs, while you’re at it.)
We talk about “herd” immunity but we have thousands of herds. No need to test every beast in the pasture.
Pengun: “Just looking at your own numbers is just fine for my purpose”
Purpose being — to obfuscate?
The worldmeters info to which you linked (assuming it is correct) listed 430 Covid-19 related deaths in the US “yesterday”. As we all know, most of those deaths were people dying WITH Covid, not necessarily FROM Covid. To put that in plain English, many of yesterday’s 430 people would have died anyway of something more serious. Sad, but that is reality.
Now put those 430 deaths in context. On an average day, about 7,800 people die in the US. So about 5% of people who died “yesterday” in the US had been exposed to the Covid virus; the percent who died specifically from Covid is much smaller. Based on NCHS data, about 1,800 of the people who died “yesterday” died from heart disease; about 1,640 died from cancer; about 460 died from accidents; another 460 died from (non-Covid) lung diseases.
There are limited resources in this world, even in Canada. If a country chooses to focus those resources on the small number of people truly dying from Covid-19, it would not be able to help the much larger number of people dying from other causes. That presumably is why US hospitals have so many patients from Canada.
@ Gavin – ” As we all know, most of those deaths were people dying WITH Covid, not necessarily FROM Covid. To put that in plain English, many of yesterday’s 430 people would have died anyway of something more serious.”
That is simply untrue, no matter how many times you keep saying it. Those are not” with” versus “from” numbers. I don’t know where you got the idea, but those are Cause of Death numbers. If you think they are wrong, show some evidence other than “Oh one guy from a motorcycle accident was called C19, so everything else is suspect.”
“And the cost for this idea isn’t huge” Where I come from $350,000,000 a day is a respectable piece of money, especially if the prospect is month after month with no end in sight. The dollar a test is just a number he picked out of the air as far as I can see. Aseptic packaging alone probably costs that much or more. The cost doesn’t matter if it doesn’t exist. If we had started to build the machinery to go into the production plants a year or two ago, we might be getting close to production now. You don’t build a 128 billion dollar industry with the snap of your fingers.
Using it on a more targeted basis might make sense but then the cost of false negatives goes up a lot if you’re using it to protect vulnerable people and we already have tests as good or better.
The false positive rate has to be a small fraction of the infection rate. A false positive fate of 10% doesn’t usually turn into 1% if you do it twice, there’s a very good chance that whatever caused the first one will do it again. while the false negative rate only affects the small proportion of infected individuals, false positives affect everyone that takes the test. A 10% false negative rate still gets you 9 infected individuals. Using the latest numbers I could find, the rate of positives is about 6% of 600,000 symptomatic individuals. That puts a lower limit of one positive per 1,000 with universal testing. At that rate, almost any false positive rate would swamp the true positive rate. A 1% false positive rate, and that would be a phenomenally low rate, would produce 10 false positives for every true one. It turns out that when they said you had to be careful about testing asymptomatic people they knew what they were talking about.
The only redeeming feature of the whole idea is that it is so completely impractical that we’ve probably wasted more time hashing it over here than anyone in the government.
MCS: You claim to have read the article but basically everything you say is countered in it. For instance, you’re hung up on a false negative problem when not detecting low loads is the explicit strategy. Similarly you seem to think that when it says its less sensitive it means really high false positive rate when that’s not at all what it means, it’s referring again to that sensitivity choice.
What are the rates of false positive and false negative? So far, all I see is a lot of hot air and hand waving. Show me the numbers.
Here’s some numbers:
https://www.boston.com/sports/nfl/2020/08/23/nfl-has-77-apparently-false-positive-covid-19-tests-from-lab
AVI: “Those are not” with” versus “from” numbers. I don’t know where you got the idea, but those are Cause of Death numbers.”
Come on, AVI. You are better than this. You work in the real world. You know all the problems that occur in the real world with reporting data. If you are asserting that because some website labels a number “Cause of Death”, that is the unequivocal fact — then your analysis is likely to be flawed.
Take a look at English hospital deaths where Covid is listed as a cause. For 2020 through July 31, the official National Health Service data list 29,378 deaths. Of those 27,990 also listed the presence of a pre-existing condition. That is 95% of Covid-19 related deaths.
Now, if you want to convince yourself that all of those 27,990 English patients would still be alive if not for Covid-19 as the “Cause of Death”, feel free. But perhaps you might understand why other people might not be convinced.
There is some interesting analysis of English data at Hector Drummond’s site.
https://hectordrummond.com/2020/08/14/week-31-graphs-from-christopher-bowyer/
@ Gavin – try taking that to a court of law or other place with strict rules about what is factual and what isn’t: “C’mom, Yer Honor, we smart people know that there are flaws in all numbers and (wink, wink) people is jes’ human, so we can disregard everything we don’t like, right?” Because that is all you are saying with your “let’s just be cynical here” argument.”
Yes, England reworked some of its numbers, because upon review, like decent honest people, they felt it was more accurate to apply a slightly different standard. To expand that into “See, we don’t trust any of it” is just doubling down on your first impression withour regard to new information. The famous quote (attributed to many) “When the facts change I change my mind. What do you do?” applies here. You are nearly out of credibility with me. I already have half a dozen people here I simply skip over and you are about to become one of them. Provide evidence that you can reconsider your original positions.
AVI — I will be honored if you add me to your skip list.
You seem to be approaching the question of morbidity from Covid-19 with a firm conclusion already set in your mind. Covid-19 is certainly a disease which has helped to usher some older, sicker people into the next world a little earlier than would otherwise have been the case — but there is no serious basis for the whole “Project Fear” thing for the general population.
If you cannot even acknowledge that there is a difference between “dying with” and “dying from”, then you are not likely to add anything useful to the discussion. The English data clearly shows that only a small percentage of people who are knocked out by Covid-19 were affected solely by the Covid virus and nothing else. But if you want to ignore data which does not fit your preconceptions and sign up for Project Fear, that is your choice.
In the meantime, focusing only on the virus is a huge distraction from the evolving economic disaster triggered by the generally inappropriate Lock Downs imposed as a result of Project Fear. That is where it would be useful for you to focus your attention.
Now I just got/have one person who’s posts I’ll be skipping.
It’s really very simple. We are closing in on 200,000 Americans dead but for wuflu. The are undoubtedly a few that have been miscategorized. There are undoubtedly others that were missed. Where the balance is can not be more than a small proportion of total number. It is certainly far too slender a thread on which to hang any substantive argument.
Under normal circumstances,the causes of at least a third of deaths are attributed wrongly. No one is willing to pay for the increased number of autopsies to close the gap between the judgement/guess of attending physicians and reality outside of suspected foul play. All of the statistics about mortality are based on this same pile of loose sand.
In a better world, we would have samples available from a year or more ago to confirm or deny some of suspicions that this may have been circulating for far longer than the official time line. Since it now appears that antibodies are short lived, that evidence may either not exist at all or only be available from samples preserved in particular ways.
The question everyone wants answered is whether the pain and dislocation we are only beginning to experience actually saved any lives. Outside of those few that could be isolated until the epidemic ended one way or another, there was never any prospect that anyone would avoid exposure sooner or later. The margin of victory will have to be measured in terms of improved treatment and avoidance of acute shortages of facilities. There were a very few moments when this truth was current, the narrative seems to have moved to unconditional victory with nothing but the vanity of politicians and “hope” for justification.
It’s important to remember that the early decisions were made on the basis of little or no actual knowledge and only the most tenuous information. Some are more defensible than others. The Northeastern nursing home massacre is an example of politicians acting on bad advice and unwilling to back down. I don’t know how the lock downs should be considered. It’s not going to be easy to prove that there is anyone alive because of them although there are certainly some. The really hard question will be whether the other costs and deaths they caused are worth it.
We don’t seem to be living in a time when reasoned political arguments get much traction. This is just one of the areas where we will see who the winner is in November. Not that I expect the losers to withdraw for quiet contemplation.
@ Gavin – I never said there was no distinction between dying with and dying from, and I think my posts over the last 7 months are considerable evidence that I have not had a preconceived idea of what the truth should be. So you don’t read very carefully, but expect to be taken seriously.
AVI — I don’t understand why you have decided to go “Ad Hominem” instead of knocking my erroneous views out of the park with superior logic and astute observations based on better data. Perhaps I am not the only one who does not read very carefully?
Assuming that what we have here is a failure to communicate properly, let me be plain about how I assess the information of which I am aware. Of course, if additional data becomes available, I am willing to admit my errors and update my assessment. I hope you can say the same, AVI.
From the available data — if we did not have a specific test for Covid-19 and if China’s rulers had not started the ball rolling by showing photos of bodies lying in the street (something which was never observed anywhere else), there would by now have been an article on page 48 of the New York Times noting that 2020 has been a bad flu season (although not the worst) and that — unusually — the deaths peaked in spring rather than winter. And the world would have moved on without paying much more attention to this than to any other flu season.
The observed facts on mortality do not support the Lock Downs, the unemployment, the bankruptcies, the unrepayable increase in debt, the human distress. I find the English data to be interesting because it is uniform collection over a large (~55 Million) population and is probably a little less tainted by politics than US data. It shows that people who died while testing positive for Covid-19 were overwhelmingly old and sick. Only 1 person in 20 who died in a hospital setting with a positive test for Covid-19 did not already have a significant pre-existing condition. Bottom line — for healthy school age and working age people, Covid-19 is nothing to get excited about; those people will probably catch it (population immunity, etc), but probably won’t notice and if they do notice, it will likely seem no worse than a bout of the common cold. We should be focusing our always-limited resources on protecting the identified At Risk population of the old and the sick.
If that is a serious misreading of the observed facts, I am all ears, ready to listen.