The article mentioned using bar-coding to run pooled tests - that sounds really interesting. Anyone know if there's a link to a paper on that? The article doesn't link to anything on that unfortunately but that sounds really interesting. I'm trying to visualize how that works with qpcr, where the barcode is attached and where the primers bind (and presuambly after amplification you sanger them to read the barcode?).
Awesome! Thanks for finding that. So they do give up the extra specificity from the reverse primer by having it be a constant region in the barcode, I guess having a sanger step makes up for that a bit though since you can read what it ligated to past the barcode and see if it's a SARS-COV-2 fragment, but that does slow down getting the results. Like a truck of hard drives barreling down a street versus sending data over fiber. Get a lot of reads in giant batches or get less reads but with less latency.
The only data that is somewhat reliable in this pandemic is COVID deaths. Testing the population that is very sick / dying is crucial to understanding the baseline for the worst part of the problem.
Once you have that under control, and we are not nearly there yet, you have to get every first responder tested regularly so you can prevent them from spreading the disease and give them some assurance that coming to work isn’t a death sentence.
Next we have to focus on getting a baseline of the population regularly tested to estimate the spread of the disease. This should be randomized and geographically distributed so we can start to obtain reliable data about the spread of the disease and deploy resources proactively.
I would say the number of hospitalizations is reliable as well. Those are the only two numbers I've really been paying attention to, because the number of total cases is really just a factor of testing, and doesn't yet give us an accurate picture of the situation.
I disagree. In order for a hospitalization to count, they have to have a positive test. First, we have to factor in test inaccuracy and then the fact that doctors are still triaging tests even if a patient has symptoms. These numbers can't be considered accurate until we have enough tests to test everyone in the waiting room indiscriminately.
We have enough tests to cover people who are candidates for ventilators or have similarly severe symptoms. That’s still a lagging indicator, but not nearly as delayed as deaths.
> The only data that is somewhat reliable in this pandemic is COVID deaths.
I agree,, especially as you included the word “somewhat”. We have pretty good numbers on people who died in hospitals, but people who died at home appear to be seriously under counted.
Additionally, consequential deaths are currently invisible. These are people who died, say, ecause the coronavirus crowded out their access to hospitals. There’s been a drop in ER visits for things like heart conditions. Some of those people would have recovered fine anyway but some may have arterial blockage that will kill them. You don’t Want these numbers in the primary statistics (as they say nothing about control of the pandemic) but you do want these very hard to track numbers to understating future capacity planning, ethical procedures, and long term economic consequences.
You can get part of that with excess death rates. From the weeks overall deaths subtract the average death rate for this week in past years. That should give both people who died at home and consequential deaths.
I'd reckon it's "doable" but not "easy", putting it in the realm of professional epidemiology. People are also dying less in car crashes, pollution-induced asthma, etc. There's quite a bit that may need to be accounted for. I suspect analyses will have decent error bars a year or so from now, but it's unlikely we'll get precise realtime estimates from this methodology. Would love to be proved wrong.
There are a lot of people not going to hospitals either because elective procedures were canceled or they fear getting corona virus. These will contribute to excess deaths but not be caused by coronavirus.
France started testing systematically in EHPAD (nursing home for retired fully dependent elders). That's why they have the most dramatic fatality rate out of every country now.
Not sure it was a good idea to test and attribute all the deaths to COVID.
The number of deaths may be off but that is likely to be dwarfed by the much higher number of total cases that haven't been confirmed. Between this study, the LA study, and the Santa Clara study there could be 10-80x as many cases. That is more significant that the death count being off by a couple percent when it comes to determining the fatality rate.
Deaths is a lagging indicator though, so even if it's reliable it comes in a bit late to make any policy changes off of it, and nobody likes waiting for 3 weeks to a month after each little change to see how it's reflected in death rates. Maybe it's reliable in the statistical sense, but not reliable in the sense that a layperson or a politician would be able to rely on it to guide decision making.
>> Maybe it's reliable in the statistical sense, but not reliable in the sense that a layperson or a politician would be able to rely on it to guide decision making.
This seems to be what we're relying on in the UK. Hospital admissions for Covid show a good/relatively quick estimate of how measures are working and then a few weeks later a reflection of that trend in deaths confirms it.
The countries that have fought it most effectively do so by contact tracing: whenever someone is found to have it, test everyone they've come into contact with recently.
This works best with really intrusive surveillance of mobile phone locations :(
I disagree that only deaths are reliable, fully tested patient ICU load is both easily measurable, fairly well controlled, and lower latency (roughly 2-4 weeks shorter!). I do agree that testing the dying is useful although it presents its own statistical challenges (dying with after a car accident with COVID).
Deaths can lie too. What does it take for a death to be labelled as covid-19 death? That the person who died was merely tested positive, or do they do autopsies for all those who tested positive? How about covid-19 deaths that aren't counted as covid-19 deaths, for a reason or another? How about people dying less of regular influenza this year because of covid-19 and lockdowns?
Even looking back at monthly 2020 deaths in comparison to earlier years might not truly reveal the final impact of covid-19.
In the US, if the person tested positive, it is classified as covid19 death.
Also it seems that 98% of covid19 deaths have at least one comorbidity, 75% at least two. So I would expect that in many cases the virus may have just accelerated something that would have happened within a few months anyway. So you kind of need to look at how the full year death rate evolved to have an idea of the net impact of the virus.
That's a misunderstanding of how death works. Everything is a comorbidity on some level.
> just accelerated something that would have happened within a few months anyway
That's absolutely not what this means. Asthma is a comorbidity. Are asthmatics just a few months from death? I have hypertension, am I about to kick the bucket? Sixty percent of the US population (no doubt including many of the posters on this very thread) are overweight, yet somehow we keep coming back.
Almost nothing kills "by itself". Everything adds up, and eventually the body stops working. Other diseases work this way too, yet you don't complain that yearly influenza deaths are inflated. Would you have argued that AIDS deaths were "really" due to the final infection and not HIV?
The study I got these numbers from doesn't seem to classify asthma or obesity as a comorbidity. The largest ones are hypertension, diabetes, ischemic heart disease, atrial fibrilation, active cancer in past 5y, heart failure, COPD, dementia, stroke and chronic liver disease. Not familiar with all items in this list but some seem pretty serious.
So you think that stroke victims and retirees with dementia are just months from the grave? FWIW: I've personally been living with diagnosed atrial fibrilation for almost three decades. Diabetes is, literally, a lifelong illness for its sufferers.
In fact, please cite me any of those factors which will reasonable by expected to kill you in months. Even heart failure and cancer patients tend to live years to decades with treatment.
Of the people who died of this virus, yes, it is likely that a not insignificant percentage were in pretty bad shape. We are not talking about the whole population who have these comorbidities in the country.
Many coroners in my state have been quoted as saying they are unable to test the dead, as tests are prioritized for the living. Our state health department says that they do not report suspected COVID-19 deaths to the CDC if the person did not test positive.
I believe, at least in New York, people are being counted as covid-19 deaths if they were in contact with someone who was diagnosed. They can count as a covid-19 death without ever being tested for it.
This is tricky to understand, but "all cause excess mortality" is pretty well understood by statisticians. They use it all the time for flu.
Here's one document from the UK that mentions the kind of testing they do to arrive at "deaths to flu" figures. They have international programmes to see what respiratory diseases are circulating, they test people who arrive in hospital for those, they know roughly how many people in the population they expect to die (because RTAs, cancer, heart disease, etc all stay sort of stable from one year to the next). They also do survey work to see if people have flu symptoms but haven't seen a doctor, and they can see how many people attend various healthcare settings for flu.
It's all a lot more complicated than "did someone write flu on a death certificate".
This seems to ignore the importance of testing symptomatic people to rule out COVID (the most common outcome) so care givers can stop wasting PPE (which is is short supply).
> Non-covid diseases still require the use of PPE.
The PPE required for some COVID-19 symptoms in the absence of clear indication of a droplet/airborne transmissible condition are different than for COVID-19. You don't usually use droplet, much less airborne, protections for every patient presenting with a fever, or GI symptoms, or several of the other ways COVID-19 can present, but you must with the prevalence of COVID-19 until you can rule it out.
And it's even more critical to identify COVID-19 or it's absence in sick patients when part of your containment strategy involves segregating ftreatment facilities (part of the capacity surge has been in establishing either new COVID-19 specific facilities or new facilities to handle non-COVID-19 cases while existing capacity is dedicated to COVID-19.)
That works up to a point, but test accuracy makes it risky to be too definitive in interpreting the results. For example the Abbott test appears to have a 15% false negative rate[1]. That's potentially a lot of infectious people who would incorrectly be ruled out.
> During a pandemic, it's more likely than not that any negative test on a symptomatic person is false.
I don't think we've reached the point where COVID-19 is the leading cause of fever, much less GI symptoms, so unless you define “symptomatic” extremely narrowly (like, “in need of a ventilator”) that's probably not true in this pandemic at this time in the US.
"This type of voluntary contact tracing is labor-intensive and requires some training, but it does not require highly specialized skills. Technology can speed it up without risking a permanent erosion of privacy or the further intrusion of for-profit firms into our personal lives."
This requires a huge leap of faith, which frankly, under surveillance capitalism you would be a fool to accept at face value.
Austria developed such an app, but only 3% of people could be convinced to install it which makes it completely useless even if it would have worked (which I believe it would not for technical reasons).
Since many states cannot deficit spend, the strategy of 'leaving it to the states' is a deliberate strategy of abdicating responsibility at the federal executive level.
With a federal unitary executive disinterested in expanding testing, and no other backstop, we are left without a country-wide strategy.
I'm thinking that we won't get out from under this shroud until we get a new president.
The only thing stopping states from deficit spending (selling bonds to pay for general obligations) are the states’ own rules. As we have seen, constitutional requirements are not an impediment in a pandemic.
> As we have seen, constitutional requirements are not an impediment in a pandemic
Agreed. It’ll be interesting to see the 1A cases that come out of this though. There is only so much tolerance to freedom of religion, right to peaceful assembly, and right to petition the government that people will accept. Of course, if there was even a single issue with freedom of press there would be nonstop coverage from the very same.
I’m pro-self-quarantine but I can recognize the issue with ticketing people who went to a drive in church service, or walking alone, or playing outside with their kids. I haven’t see “THE” case that could go to Supreme Court, but I wonder if it’s out there.
i'm both impressed and worried over the level of compliance from the American people. It's good that everyone is working together to "flatten the curve" however it's also worrisome how willing citizens are to do throw their rights out the window. I'm sure many politicians are rubbing their chins right now wondering if the rights of the people even matter anymore.
You are projecting that citizens are willing to throw their rights out the window. A more neutral perspective would be that people are willing to make sacrifices when they feel it's worth it. Also, people aren't "throwing their rights out the window" -- it's more like people are chilling them in the fridge for a small window of time. To prevent their friends, families, and countrymen from death.
(Also, it's not clear that America is all that compliant.)
It’s good idea to accept that the risk analysis of someone making 6 figures here is absolutely different than that of someone who is living paycheck to paycheck. This is why it’s been so frustrating to see “YOU’RE TRYING TO MURDER PEOPLE” from one side and “muh freedom” from the other. There is nuance of course.
I think it’s super interesting how differently this all looks to different people.
But I can’t think even during Spanish Flu that First Amendment rights were so heavily infringed - good reasons or not. Best I could find on the topic was the heavy fines for spitting in public in 1918.
The 1918 flu pandemic is not a good baseline, except for identifying where we fell short in science, public policy, and action. Remember, 50M+ people died (>500K Americans) at a time when there were maybe 1.5B people around.
People weren't quarantined. The death toll was much higher. Not saying those two are directly correlated -- many other factors -- but there's not a good comparison on the "rights" front because of that death toll.
Which constitutional requirements do you think are being violated? And if you're going to say first amendment, be sure to explain precisely why they wouldn't survive strict scrutiny. (And if you're not aware of the legal meaning of "strict scrutiny," then you are probably ignorant of what the Constitution has actually been held to mean by the authority that has the power to interpret it.)
Controlling a pandemic is certainly a compelling interest, but as far as I know no government has attempted to show that a general closure of businesses and churches is the least restrictive means that will achieve it. Many acknowledge that there are less restrictive means, and have a medium-term plan to move to those lesser restrictions, but say we shouldn't explore them right now because it's too dangerous.
The authority of the state to impose broad quarantines has a history in our jurisprudence going all the way back to John Marshall. See, for instance, Gibbons v Ogden.
"Quarantine" historically refers to segregation of people or populations who've been exposed to a disease from the general public. The idea of a general quarantine, where everyone is segregated from everyone else, was as far as I can tell invented out of whole cloth a few months ago.
Since there are literally laws on the books in many states that explicitly delegate this power, for this precise purpose, "invented out of whole cloth a few months ago" seems an extraordinary claim. Find a credible source?
When you do so, remember that the "lockdown" we're experiencing falls far short of a "general quarantine". You can in fact leave your house, and travel between states, free from pretty much any tracking or extra surveillance. Most of the police power being exercised falls under business regulation; where you're feeling the lockdown the most is likely in the fact that you have so few places to go right now.
Because it's easy to find sources discussing the legal controversy of general quarantines. But you'll notice they're mostly talking about the due process concerns of doing the equivalent of imprisoning people without trials, not closing the bars.
It is if you assume your Constitutional rights are that that any citizen intuits from a casual reading of the Bill of Rights. It suffices in this context to point out that, if you're an American, you don't live in a country that operates on that principle; we've had centuries of jurisprudence that put the Bill of Rights into actual practice, and many of the principles routinely assumed to be violating the plain meaning of the amendments were established by the framers of those amendments.
(Courts, for what it's worth, continue to function).
What was perhaps acceptable as a temporary emergency measure is not acceptable as the new normal. The current measures are overly restrictive and cannot continue for two years.
And while I don't care about religion myself, I understand that religious people feel the same way about closing all churches for years. We'll also have to find less restrictive ways to control the virus while allowing the churches to reopen.
I'm not sure why you'd expect me to respond to (let alone defend) an argument that nobody is making. Clearly things will not continue exactly as they have been for two years. If the same protective needs exist 2 years from now, the courts will have adapted. The churches, for whatever it's worth to you, already have.
Regarding the courts: Ken White is a good source for what's actually happening.
My point is coronavirus will still be here in six months or two years.
So if we agree that less restrictive measures will be in place in the future, I would ask why such measures aren't also sufficient today?
I would argue that, given that this lockdown must end before we eliminate the virus, we should begin adapting and testing less restrictive measures as quickly as possible.
Your argument is specious. I said that the measures in place 2 years from now won't be the same as the ones we have now, not that things will simply be "less restrictive". Maybe they will be, maybe they won't. The reason they aren't different now is that it takes time to adapt. The reason we don't simply reduce restrictions right now is that doing so will kill people.
Not relaxing restrictions will also kill people from increased domestic violence, from depression and suicide due to business failure, unemployment, homelessness, etc, and from poor health due to inactivity.
It's always a tradeoff. And now we're seeing data showing that the virus is more widespread and less dangerous than previously believed, so it's time to reevaluate that trade.
Decisions are being made in light of the data. We'll know more in May than we did in March. As they say: in the best case, if we execute perfectly, it'll look like we never should have done anything. Your lips to God's ears! Meanwhile, the discussion here is about the Constitutionality of lockdown orders. From what I can tell, there's no serious argument about the lawfulness of orders that have actually occurred; the "debate", such as it is, is about hypothetical future orders that don't appear to be on the table anywhere.
> if we execute perfectly, it'll look like we never should have done anything
And ironically, if it turns out the virus is less dangerous than previously believed, and we actually overreacted, it will also look like we overreacted.
But I agree; I don't dispute the Constitutionality of the orders given in March, when nothing was known and it was wise to be prudent. Now, more is known and orders can be much more carefully tailored and less restrictive, as required by strict scrutiny.
The subtext of your comment, that "strict scrutiny" requires fine-grained analysis of every application of state police power, doesn't match up with my understanding of how any of this works. The reality is that almost any reasonable thing that governments do to combat C19, perhaps excepting things that are demonstrably and deliberately not viewpoint neutral, are going to be allowed.
> strict scrutiny requires fine-grained analysis of every application of state police power
That's what strict scrutiny means, but it's a very high standard that certainly doesn't apply to every case. As I understand it, it's more likely to be applied when fundamental rights are infringed, but I would never try to predict how the Court might rule on any particular case.
I agree with you, but you said this and I thought people may be interested in experiences from England about online court appearances.
> (Courts, for what it's worth, continue to function).
In England we split courts up, so we have a variety of criminal courts, courts of protection, family courts, etc.
Before Covid-19 they were all trying to "go digital", and were having mixed results. Now, because of Covid-19, they've just had to make it work somehow.
Sarah's father had a stroke. He was taken to hospital. He started to refuse to eat or drink. The doctors decided he did not have mental capacity to make that choice, and so they fitted a nasogastric tube. He told his daughter that this was wrong, and he pulled out (!!!) his tube several times. They gave him a PEG tube, and he was eventually discharged to a nursing home. He wants the medical treatment (feeding) to stop; she wants what he wants; so now they go to the court to get an order. They lost the case.
This is, of course, a very distressing case for all involved. But this woman says that the informal nature of a skype case, with people's pets wandering in and out and people talking in a casual way to each other made it worse.
There's some sense that because Sarah wasn't in the same room as the judge and the lawyers that they didn't recognise her distress.
So, court cases are going ahead, but there's some considerable adjustment needed.
Also, they're not always going ahead. Here's a case about a form of child abuse (fabricated or induced illness). It's a really serious case, and the mother risks being separated from her child (or the child risks remaining with an abusive mother). The judge decided that this isn't a case that can be heard remotely. http://www.transparencyproject.org.uk/p-a-child-remote-heari...
Controlling a pandemic is a compelling state interest, but it would be hard to argue that current lockdown restrictions are narrowly tailored and use the least restrictive means possible, when other states and other nations have controlled the outbreak without lockdowns.
And even in states that can deficit spend, it seems like their efforts are stymied by the lack of the federal executive being unwilling/unable to manage supply lines. Congress handing money to university research hospitals is a necessary component to the TTSI strategy, but it will result in very little unless the executive branch steps in to coordinate access to the raw materials for these tests.
But the tests aren't perfect, so how to get actionable data from them isn't clear. We saw this with the flawed west coast studies. If a test has false positive or false negative rates even as high as 1%, and we run hundreds of thousands to millions of tests per day...that's thousands or tens of thousands wrongly quarantined for 14 days, and the same number who are contagious but told it's okay to go out.
We are currently quarantining about 300 million here in the US, so tens of thousands would be a massive improvement.
The way to think about this is: who do we need to test so we can start un-quarantining people.
The goal is not to find out who has it because right now, we are essentially behaving as if the entire US population is infected. The goal is to efficiently determine who is very unlikely to have it so that those people can start incrementally returning to normal life.
It's not worth testing symptomatic people: they've already "failed" one test in that we at least know they have symptoms. Simply continue to treat them as infected.
It's all about putting people into risk categories. Then each group's members can act in the optimal way for their group. Then retest/rebalance periodically.
I'm pretty sure GP means actual quarantine. We are not quarantining hundreds of millions. We are advising hundreds of millions to practice social distancing.
Depends on the circumstances. I live alone and work from home, so there's very little difference for me between the current situation and an indefinite quarantine.
On a continuum from my usual daily activities (gym for lifting, climbing, ultimate, soccer) and my current activities (bodyweight exercises in my home and runs around my neighbourhood), I’m much closer to indefinite quarantine than I am to a normal state of affairs.
These are good points (though broad strokes). Mostly I'm just pointing out subtleties or challenges with this approach.
One difference is if a business re-opens and expects people to come in to work, the US probably needs legal protections so quarantined workers don't get fired or forced to come in illegally.
I've been saying this since the beginning of this whole thing.
I don't understand why we haven't focused all of our testing on people that aren't sick so we can catch the asymptomatic cases that are out in the world spreading it to everyone.
Because we don't have enough tests. We could reopen the country if we could test enough people, but we're stuck. Even in New York and New Jersey, tests are still limited to symptomatic people because there isn't enough testing capacity.
It's a problem of limited resource allocation. The _point_ is that we have limited tests, so given limited supply why are we wasting the tests on those we think are sick. The limited supply could still be directed towards asymptomatic carriers. Wouldn't be testing everyone we want, but it's still more valuable than the allocation of tests right now.
It's far too widespread right now to successfully control via contact tracing and isolation, even if we had infinite testing capacity. The optimal use of testing right now is whatever produces the largest number of positive results, so that large case counts stay in the headlines, helping to ensure political support for stay at home orders. And that's more or less how the tests are being allocated.
The point is to catch as many infected people as possible with limited available resources. When someone is found to have the virus, then contact tracing is used to identify even more infected people and to shut down local outbreaks asap. Only a minority of people with mild symptoms actually have the virus.
Keep in mind, we've learned so much. At the beginning there were some authorities (China, WHO) claiming there was no human-to-human transmission. It's too bad they would have ever made that statement, because I think people latched onto that and didn't let go of the idea.
> At the beginning there were some authorities (China, WHO) claiming there was no human-to-human transmission.
I don't understand how this misconception persists. That is not what the WHO statement said.
The statement was that the outbreak was not being sustained by community transmission, and that they believed (this was very early on) that the cases from the Wuhan market were all due to exposure to a single case or pathogen.
This was, obviously, wrong. But at the time it wasn't unreasonable to believe. That's the way most outbreaks work when you catch them early.
At no point did anyone say that a respiratory coronavirus was not contagious, which is how people insist on treating that statement. Of course these things are contagious, that's how they spread.
Is that supposed to be disputing what the parent said?
> Preliminary investigations conducted by the Chinese authorities have found no clear evidence of human-to-human transmission of the novel #coronavirus (2019-nCoV) identified in #Wuhan, #China🇨🇳.
I've been wondering why there hasn't been more programs to test representative samples of individuals, just like a political poll.
If I was in a Governor's or Mayor's shoes right now and I know there aren't enough resources to test everyone, I'd want some data like that to work with to make policy decisions.
While you are in the process of opening things back up, you keep a close eye on your daily/weekly representative sample numbers to see if anything needs to be dialed back. It gives you much closer to immediate feedback.
I suppose the immediate problem is getting a hold of a representative sample of people willing to be tested, but that feels solvable. I'm sure I'm not the first one to think of it, just curious why it isn't being done, as it feels immensely useful (maybe this is just the 538 political nerd in me wanting virus polls?).
The confidence intervals are wide enough it wouldn't be very useful. If you sample 1000 people and get 0 positives, the 95% confidence interval is 0% - 0.36%. If you're the governor of Illinois, with a population of 12.67 million people, that upper bound equates to 45,612 people: far, far too many to handle with contact tracing and isolation. So you need to look to other metrics to make the decision about whether to issue or revoke a stay at home order.
So what are they looking at? Basically, if they have any evidence of community transmission, they need to issue the order or keep it in place. That means that if there are too many symptomatic people to even attempt contact tracing, you're not even close. Once you're low enough you can do contact tracing, you wait until you have a handful at most of symptomatic people you can't trace back to a known case. Until then, all you can do is keep the stay at home order in place, buy/beg/borrow/steal ventilators and PPE, and build testing and contact tracing capacity.
> Another promising pathway is to pool many tests and run them together. If a pooled sample tests negative, everyone in the pool is negative. If it is positive, the members of the pool can be tested individually.
Well, it took a global pandemic, but we finally found a use for bloom filters!
This idea is called group testing [0] and has been used by the army for quite a while. It is also a well-studied problem in information theory as a (useful) basic model and we know optimal solutions to it.
What is surprising is that group testing tells us that we can actually do better: the specific construction you pinpoint the people who come up positive, without needing to have a test for each person [1] and this result is optimal in the expected number of tests. I'm surprised that most labs haven't already been doing this (but I would suspect some have).
Wootters has wonderful notes on the mathematical background for this—I really recommend them. [2]
This is exciting. I've been following the idea for a month or so. Did you know that a group in Israel has tested the idea and found that it worked with the swab tests?
I have a link on my notes below. I'll add your site to the reference list at the top tonight.
Hi,
Yes we are aware and have reached out to them. There are a few more studies out there. One from Stanford and one from Germany too. We're currently working to refine the software and also improve the presentation (there are some mistakes) and write a paper.
sampling bias debate reminds me of this stats legend from ww2:
the USAF wanted to armor planes where the bullet holes were. statistician abe wald recommended armoring where the bullet holes weren't on the theory that those were the non-survivable hits
can't interpret a statistic until you think about what's excluded from the sample
We don't really know that 'the USAF' wanted anything; that bit has the 'citation needed' flag set in wikipedia. The paper itself makes no comment on the presumed answer to the question, focusing mostly on mathematical models.
there's an american math society article about this -- it evaluates the fun version of the story in the context of wald's actual paper and a journal entry by another scientist named wallis
>sampling bias debate reminds me of this stats legend from ww2:
the USAF wanted to armor planes where the bullet holes were. statistician abe wald recommended armoring where the bullet holes weren't on the theory that those were the non-survivable hits
It wasn't quite that simple, but the story has a gem of truth. As this article quotes Stephen Stigler (son of George Stigler who worked with Abraham Wald):
>..."The military was inclined to provide protection for those parts that on returning planes showed the most hits. Wald assumed, on good evidence, that hits in combat were uniformly distributed over the planes. It follows that hits on the more vulnerable parts were less likely to be found on returning planes than hits on the less vulnerable parts, since planes receiving hits on the more vulnerable parts were less likely to return to provide data. From these premises, he devised methods for estimating vulnerability of various parts."
This was covered about a month ago in episode 595 of This Week in Virology[1], in answer to a listener question:
Rich Condit: Garrett writes: The CDC guidelines are to test hospitalized patients and symptomatic health care workers first, and the symptomatic general public last. This seems backwards to me.
Alan Dove: Yeah. I just had this conversation with my wife after she had some, I mentioned this before, she had some coughing and shortness of breath, got immediately sent to the ER in the hospital where she works, and they did a chest x-ray, it was clear, and they said, "Ok, you don't meet criteria for testing. Go back to work." And she's been fine since then, and she, we were talking about it and she said, "Well, isn't that exactly who they should test, because then I could go and infect patients?" and I said, "Well, if they had enough tests, yes. But if you expand the testing to the people who are less sick, you don't have enough tests. Whereas if you restrict the testing to the people who are sickest, you do have enough tests." So it's a.. it's not the right way to do it, but it's the way that you actually can do it.
Vincent Racaniello: Yeah, we're in this position because we don't have enough tests. We didn't ramp up...
Dove: Because we don't have enough tests. We didn't prepare fast enough.
Racaniello: If we had, we could test a lot of people and get an idea of how many actual infections there were, which would be very useful. But... we can't. So we're stuck with this current policy.
We will never have enough testing capacity if this is not the policy objective. Right now no government leadership is working towards a goal of millions of tests per day. That is what this article is trying to change.
People with bad symptoms aren't the one's going out into the world spreading the virus and the difference in treatment between a Covid and non-Covid patient (from what I've heard) is minimal.
A) You'll know which communities have infections. Many places are saying: "it's not bad here, why should we isolate?"
B) If you know that someone with bad symptoms has the virus, then you can go test everyone they contacted. You'll find more people who currently have mild or no symptoms.
Maybe someone here can explain to me how this is supposed to work. Let's assume we have enough tests in the US to test every single person in the country every 3 days, and are contact tracing everyone with a smartphone, and providing smartphones to everyone without.
Now, with all this in place, isn't the best we can do to alert people after they have already been exposed to the virus?
It feels a bit like the safe sex crusaders switching to say everybody can have unprotected sex now, we'll let you know if you catch something, hopefully before you infect your next partner. Which I suppose is more reasonable for the group, but ... as the individual who is expected to actually go out in the world to consume or whatever, this doesn't feel like a viable solution.
What am I missing?
> Now, with all this in place, isn't the best we can do to alert people after they have already been exposed to the virus?
No, the best we can do in that case is treat COVID-19 like a dangerous communicable disease that isn't too widespread for surveillance and do specific quarantines of the infected and exposed, which then vastly limits the possibility that anyone else gets exposed, while not requiring shelter-in-place restrictions for those not already infected/exposed.
That's the whole point of disease surveillance with widespread testing and extensive contact tracing, and why it is key for a general reopening of the economy in the absence of an effective cure/vaccine.
The target is to ensure that each case infects no more than one additional person (‘R<1’).
Each infected person will come into contact with some other people. Testing allows three things—
- first, we can tell this person to stay at home and so stop them from infecting more people;
- second, we can tell the people they have seen to stay at home with good contact-tracing, so that even if they get it they don’t spread it further; and
- third, with enough tests and contact tracing, those who were exposed but not infected don’t have to stay at home.
We are winning so long as R<1, even if there is some chance the infection spreads; we do not need R=0.
The other way of reducing R requiring much less testing and contact tracing is a lockdown. This has obvious downsides. The point of a programme of testing and conyact tracing is that we can turn the cost of avoiding disaster from a lockdown to sticking some things up people’s noses.
So I guess I'm still not seeing this. Can you give me a concrete idea of what this looks like? Let's assume that it is the middle of August and the food situation is still somehow stable, I install my contact tracing app, I get a clean test. Then what?
If we miss one person, that one person can still infect an entire office building by coughing in an elevator. Because of the two week incubation period, those people will not know they're infected until at least a couple of days in, even assuming testing daily. We don't yet know how long a person can infect before testing positive, but this amount of time is most likely not 0. If this amount of time is less than 24 hours the person can still make it anywhere in the US by air. If any longer they can make it anywhere in the world. How do we not have constant low-level infection everywhere?
Since this is infectious before symptoms show up, it's basically impossible to eliminate it entirely.
But suppose A starts showing symptoms, tests positive. We can immediately notify B1, B2 and B3 that they need to quarantine, immediately. Before they start showing symptoms. And therefore we're cutting down on the time that they were infectious and spreading. Therefore generation C is only a couple of people instead of dozens. We can notify C generation as well, immediately if we wish. This causes a large quarantine - there are a lot of false positives who are quarantining without being infected - but it would massively reduce the spread. If you can immediately test all of generation B and C, you can perhaps avoid some of the quarantining (assuming a negative is reliable).
Maybe contact tracing misses some, maybe some new infected come from other countries, maybe some people don't quarantine when told. All these things keep the infection going. But it can be held down to a manageable level.
Why would it be? China, South Korea, Hong Kong have all pretty much managed to lower their amounts of new cases down to basically zero, and their society is open for business albeit with social distancing and mandatory mask usage.
The trick is to NOT stop testing once your case count starts going down, instead give the test to everybody that wants one.
A few million spent on 99.9% negative tests daily > a few billion spent on the economy being shut off daily
So I think the word manageable is doing a lot of work here.
Specifically, manageable to the hospitals, which is what I believe most people mean when they say this, does not do anything to manage consumer confidence. Which my entire question is about. How do I, as an individual consumer, feel confident enough in the systems set up to go back to some semblance of normal?
Learning that my chance of getting infected from going to the grocery store has dropped from 20%? to... 5%? 1%? Whatever the risk is, it needs to be multiplied by the average number of places a normal consumer went to over a week before this outbreak. Which means that I'm still gonna get it eventually, just I might not block somebody else from getting a hospital bed. Which is obviously better than nothing! But I really think people are missing the human aspect of precisely what this entails.
Consider user stories. As a single mother do you still feel confident going out to get groceries knowing there's an n% chance of getting it and bringing it home to your kids? If you die there's no one else to look after them.
The objective isn't to eradicate the virus at this point - that ship has sailed. The goal is to catch enough cases early enough that we can direct just the exposed people to isolate so that we can keep the total patient load at a manageable level without needing to keep the economy on pause forever.
> Now, with all this in place, isn't the best we can do to alert people after they have already been exposed to the virus?
The goal isn't to "alert" infectious cases, it's to quarantine them so they don't create new infections. Even baring a legal order, someone who knows they are covid-positive is much more likely to stay home and away from others. That reduces the rate of spread, which is ultimate goal.
> but ... as the individual
It's not an individual level solution. There are no individual level solutions (except complete and total isolation I guess). Outbreaks are community events.
No, we need to test everybody, so we can't be testing the wrong people (the reason we need to test sick people is different than the reasons we need to test other people, but they all need tested.)
But we don't have nearly enough testing capacity (either tests or the organized infrastructure to administer them, though both problems are being worked on) to meaningfully test the general population, whether or not we focussed our entire effort on the most important subset for reopening, so it would be extraordinarily stupidly premature to shift our current testing priority in that direction. This also means that general reopening is, a fortiori, extraordinarily stupidly premature.
The article explained its reasoning. Maybe you could explain yours. Specifically what is the value of testing very sick people when it cannot affect the treatment plan ?
I appreciate the HN title ("We're Testing the Wrong People") in contrast to the article title ("Without More Tests, America Can't Reopen"), even though it's usually against policy to have them be different.
But the HN title is actionable: if we can change our testing policy and deploy our tests more usefully, that's great to know and eminently achievable.
But "not testing enough" isn't really actionable. There's a shortage of tests because there's a shortage of the raw materials that goes into making the tests. The U.S. already has tested far and away more people than anyone else, and is second only behind Italy in tests per capita, and has a "positive test to test" rate roughly in line with (as low of a rate as) any other country's rate. See [0] and related charts.
"Just test more" isn't really useful at this point.
That requires that you compare the US to Iceland, Faeroe Islands, Falkland Islands, UAE, Malta, Gibraltar, Luxembourg, Bahrain, Estonia, San Marino, Cyprus, Isle of Man, Lithuania, Brunei, Qatar, Liechtenstein, Ireland, Latvia, Andorra, Channel Islands, Bermuda, Aruba.
Nice try.
Back on planet earth, here's the list of actual sane comparables that are in front of the US, in order:
Italy, Germany, Spain, Australia, Russia, Canada
And Russia is fake. They haven't tested much at all.
The US has tested at a higher rate than South Korea (which is behind all of those tiny nations also).
The US testing rate is just behind Belgium, a nation 1/29th the size of the US. And it's not very far behind Singapore at this point, either.
Many of the countries testing "more per capita" have a lower population than cities that many here on hacker news wouldn't even consider "real cities". Scaling testing in the Isle of Man above the US only takes a total of 1100 tests. Of course they are testing more per-capita than we are.
It's like saying that Saint Lucia has over 10 Nobel Prize laureates per million population but then finding out that the country has a population of 180,000 and that works out to 2 laureates in the country.
Sometimes, I feel like concepts such as these need to be translated into terms the average hackernews reader will understand.
Let's say your key metric you're trying to maintain or improve is P50 request latency. Its relatively easy to exhibit an acceptable P50 to 10 users, from 1 VM. Its actually harder to deliver the same P50 to 100 users, from 10 VMs. Even harder for 1000 users and 100 VMs, snd so on. You run into previously fine bottlenecks you didn't know existed. Issues which were invisible at ten users become cascading failures at thousands.
It just keeps getting harder the more users you add, even though you're adding proportionally more underlying VMs. There is no end to how difficult it gets, until eventually, it becomes impossible.
Testing is a problem with difficulty that scales with population size. Of the top ten countries by population size, there are only two countries that have higher testing per capita than the US: Russia and China. Those three countries are pretty close; no one else, anywhere in the top ten, is remotely close to the US, Russia, and China.
(Kind of funny how the top two testers in the top 10 countries by population are dictatorships, who have every reason to maintain a strong, powerful image. Funny how it works out like that, isn't it? Do you believe their numbers?)
I run the fastest website on the planet. No one but my mom visits it, but its still the fastest. Lithuania (the world's top daily tester per capita yesterday) is that website. The US is, uh, lets say Google. Should you bemoan Google for taking longer to load?
> The U.S. [...] is second only behind Italy in tests per capita
Where are you getting those numbers? I don't think that's correct. The Worldometer data may not be the best, but they have the US well down in the middle of the pack at ~13k tests/Mpop.
Lots of large developed nations have the US beat by quite a bit, in fact. And Iceland is literally a full order of magnitude higher!
In fact US testing policy has been largely a disaster. It's not the only disaster, but this is an area (large scale PCR laboratory work) where the US is supposed to be good at stuff. And yet there's been almost no attention paid to the problem at the highest levels of government.
Oh, wow, that was my mistake. Thanks. I was getting the data from here [0], which for me had a lot of countries selected but not all of them. I didn't realize that it did not include by default a number of countries. When I include them all I see that the U.S. is in the middle of the pack.
That's the title of the page. My guess is that HN's parser gives precedence to the title versus meta tags, so I didn't bother changing it after I submitted the story.
I think this article is getting things out of order. The question right now shouldn't be who to test, but rather how do we increase the volume of testing. The article states that we should be running 500k tests a day, as if we're not simply because we choose not too. Right now we don't have the capacity and so we can't scale up at all.
Why don't we have the capacity? Well the complete lack of coordination and leadership at the federal level means that each individual entity, whether it be state level government or a private entity, is having to do everything from scratch. That means developing SOPs, procuring supplies, and validating both the processes and reagents. This is being done on emergency orders as well, so some of the standards are relaxed to quickly get things up and running.
There's also a shortage of reagents and kits because we didn't have or need this testing just a few months ago. There's also international competition for these resources, and because the US has decided it doesn't want to actually work with or coordinate with other countries, it's a free for all.
Because everyone's frantically working on the same thing, but looking out for themselves it also means that true high throughput solutions are slow to develop as well.
I could go on and on, but it's a clusterfuck and no one at the federal level either A) seems to care or B) thinks that it's their responsibility.
Source: wife is currently in charge of starting up Covid testing
The Danish Serum Institute published an alternative workflow for testing without using the scarce reagent. Instead, they use an old method of heating the samples like boiling an egg.
See Fomsgaard and Rosenstierne’s preprint on medrxiv here:
There's, frankly, probably not enough reagents and consumables on the planet for the US to achieve 500k tests a day. As far as I know no country anywhere has managed this level of testing. Germany - who've been doing the best at testing lately - have been stuck at about 50,000 tests a day for a few weeks now, maybe even decreasing slightly. If you take into account the difference in population, that's only the equivalent of the US doing 200,000 tests a day - and of course scaling up to a larger population is harder. That doesn't stop the American press making it sound like not achieving those 500,000 tests a day is the result of some uniquely American political failing though.
There are even plans to increase testing to 4,5 million(!) tests per week in Germany, or ~650k per day. Currently there is unused testing capacity, so it looks like the old restrictive conditions for testing (basically: symptoms and (contact to infected person or stay in high risk area)) are still in place and should be updated ASAP.
100% there is a shortage of reagents and kits. There are certain countries that are not letting reagents and kits ship out, and we are in no position to call them out on that.
>That doesn't stop the American press making it sound like not achieving those 500,000 tests a day is the result of some uniquely American political failing though.
I don't think we're unique in where we are in comparison with other countries as far as testing, but we are in a unique position in regards to being able to put some strong leverage on getting other countries to work together to respond to this pandemic. We're not doing that and as a result, other countries are having to "roll their own" response to this pandemic just like we are. The lack of coordination within our country is putting us at a unique disadvantage, even if we had better coordination world wide.
This pandemic is a exceptional global crisis in a way we've never seen before, and thus should've led to a addressing it at a global scale in a way we had never seen before. Instead the global response has been crippled in numerous ways at various different points in time.
The American political failing is in not being the true world leaders, and the world is, IMHO, worse off for it.
I completely agree that increasing test capacity is the thing that blocks everything else, and we need to solve that first.
But in order to try to generate the political will and get the backing to make this happen, it helps to get the word out about the big picture of exactly why having so many tests is important.
New legislation is coming that provides some funding for testing, but out of $484 billion that it authorizes, only $25 billion in it for testing[0]. Meanwhile, a report from Harvard estimates that $50 to $300 billion will be needed[1]. So the amount of money made available so far is 1/2 to 1/12 of what one source has estimated that we need.
The political will should be fewer American lives lost. Politicians are framing this about the economy and states rights and other BS as a way to distract the public from the fact that people have died because we didn't act soon enough and decisively enough.
I also don't think we need to get the word out about how testing is important. People are cooped up in their homes precisely because we don't know who has it and who doesn't. Testing could resolve that.
I have little faith in the legislation from Washington for many reasons. The primary one being that before the crisis, during it, and at this very moment there is a lack of acknowledgment of the actual scale of this pandemic. Even worse a large part of the legislature fails to take this seriously, thus making the scale of the issue a secondary problem. What's been passed so far has already missed the mark as far as funding testing and properly ensuring that those who need the money get it. Instead, big business gets "relief" with little oversight, which given the past actions of this administration clearly isn't just by accident.
The reality is that testing is still significantly behind and efforts to increase testing won't make the news cycles. I strongly doubt that we'd be able to scale up quickly enough to make a meaningful dent in this anymore than strictly following stay at home orders. Unfortunately even that is too much to ask us to do as a society it seems.
accurate? Because according to that, adding up the number of tests done by Italy, Spain, France, the UK, and Germany (a combined population roughly the same as the US), they've done about 5.6 million tests vs the USA's 4.4 million tests.
And we've done more tests per capita than South Korea.
Which really doesn't sound like we're doing that badly.
Everyone has an opinion. The only opinions I am taking seriously right now are from professional epidemiologists - not doctors, nurses, oncologists, bioethicists, or economists. This article is just noise to me.
If the goal is to stop deaths and prevent economic damage, then what is the alternative to testing (both for antibodies and for active presence of the virus), assuming that testing everyone in the US multiple times in the near term is not possible? Without testing a lot of people will not willingly return to work, which is already hurting the economy. Without testing we don't know the new places where the virus is spreading until a week or two later, so reactionary measures like contact tracing don't work as well. Total lockdown reduces deaths, but destroys the economy and reduces the scope of life.
Maybe we need to use the tools we already have, such as flu surveillance and data from hospitals, to detect excess non-flu infections. We seem to be able to do flu tests, are they more scalable so that at least flu can be ruled out in many cases?
If widespread testing can not happen because we can't build factories to make reagents/swabs/tubes/PCR array machines/etc. fast enough, we need to start thinking of alternatives. We don't actually seem to understand yet how the virus spreads, too many clinicians trained in handling infectious disease are getting sick despite PPE. If the new small antibody test results are right, then the virus is spreading much faster than can be accounted for via droplet spread as the main mechanism; we may have to consider birds, mosquitoes, surfaces, skin touching, and other methods as possible common spreading mechanisms. If we understood transmission better then it might be possible to tell people how to truly protect themselves, and then they could go back to work. So understanding transmission better is something that could be used in addition to whatever testing is available in order to prevent deaths and economic damage. But people may not follow the new rules based on that understanding, so get the social scientists involved to get the message across. Get OSHA involved to set best practices for workplaces. It seems like there is probably a lot that can be done, even without testing, and at present we may have to assume testing will not be sufficient in the near term (3-6 months).
But someone has to start thinking about these things and doing them, and I'm not seeing any evidence of this in the news. Given that contact tracing is not already ramping up (I've seen only Massachusetts as having a plan to scale it up but I tend to only see East Coast news) I have to wonder if anyone is even thinking about alternatives to testing if testing at scale is not possible.
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[ 30.6 ms ] story [ 1114 ms ] thread("A Massively Parallel COVID-19 Diagnostic Assay for Simultaneous Testing of 19200 Patient Samples")
I think Figure 1b is the diagram you want.
Once you have that under control, and we are not nearly there yet, you have to get every first responder tested regularly so you can prevent them from spreading the disease and give them some assurance that coming to work isn’t a death sentence.
Next we have to focus on getting a baseline of the population regularly tested to estimate the spread of the disease. This should be randomized and geographically distributed so we can start to obtain reliable data about the spread of the disease and deploy resources proactively.
I agree,, especially as you included the word “somewhat”. We have pretty good numbers on people who died in hospitals, but people who died at home appear to be seriously under counted.
Additionally, consequential deaths are currently invisible. These are people who died, say, ecause the coronavirus crowded out their access to hospitals. There’s been a drop in ER visits for things like heart conditions. Some of those people would have recovered fine anyway but some may have arterial blockage that will kill them. You don’t Want these numbers in the primary statistics (as they say nothing about control of the pandemic) but you do want these very hard to track numbers to understating future capacity planning, ethical procedures, and long term economic consequences.
https://www.nytimes.com/interactive/2020/04/21/world/coronav...
Not sure it was a good idea to test and attribute all the deaths to COVID.
This seems to be what we're relying on in the UK. Hospital admissions for Covid show a good/relatively quick estimate of how measures are working and then a few weeks later a reflection of that trend in deaths confirms it.
This works best with really intrusive surveillance of mobile phone locations :(
Even looking back at monthly 2020 deaths in comparison to earlier years might not truly reveal the final impact of covid-19.
Also it seems that 98% of covid19 deaths have at least one comorbidity, 75% at least two. So I would expect that in many cases the virus may have just accelerated something that would have happened within a few months anyway. So you kind of need to look at how the full year death rate evolved to have an idea of the net impact of the virus.
> just accelerated something that would have happened within a few months anyway
That's absolutely not what this means. Asthma is a comorbidity. Are asthmatics just a few months from death? I have hypertension, am I about to kick the bucket? Sixty percent of the US population (no doubt including many of the posters on this very thread) are overweight, yet somehow we keep coming back.
Almost nothing kills "by itself". Everything adds up, and eventually the body stops working. Other diseases work this way too, yet you don't complain that yearly influenza deaths are inflated. Would you have argued that AIDS deaths were "really" due to the final infection and not HIV?
In fact, please cite me any of those factors which will reasonable by expected to kill you in months. Even heart failure and cancer patients tend to live years to decades with treatment.
A lot of people fall into those categories.
Here's one document from the UK that mentions the kind of testing they do to arrive at "deaths to flu" figures. They have international programmes to see what respiratory diseases are circulating, they test people who arrive in hospital for those, they know roughly how many people in the population they expect to die (because RTAs, cancer, heart disease, etc all stay sort of stable from one year to the next). They also do survey work to see if people have flu symptoms but haven't seen a doctor, and they can see how many people attend various healthcare settings for flu.
It's all a lot more complicated than "did someone write flu on a death certificate".
https://assets.publishing.service.gov.uk/government/uploads/...
The PPE required for some COVID-19 symptoms in the absence of clear indication of a droplet/airborne transmissible condition are different than for COVID-19. You don't usually use droplet, much less airborne, protections for every patient presenting with a fever, or GI symptoms, or several of the other ways COVID-19 can present, but you must with the prevalence of COVID-19 until you can rule it out.
And it's even more critical to identify COVID-19 or it's absence in sick patients when part of your containment strategy involves segregating ftreatment facilities (part of the capacity surge has been in establishing either new COVID-19 specific facilities or new facilities to handle non-COVID-19 cases while existing capacity is dedicated to COVID-19.)
[1] https://www.npr.org/sections/health-shots/2020/04/21/8387942...
It's also quite likely that a positive test on an asymptomatic person is also false -- depending on how prevalent it is in the general population.
I don't think we've reached the point where COVID-19 is the leading cause of fever, much less GI symptoms, so unless you define “symptomatic” extremely narrowly (like, “in need of a ventilator”) that's probably not true in this pandemic at this time in the US.
There are places with single-digit positive test rates, that would require a 90%+ false negative rate, which, as far as we know, is not the case.
This requires a huge leap of faith, which frankly, under surveillance capitalism you would be a fool to accept at face value.
Austria developed such an app, but only 3% of people could be convinced to install it which makes it completely useless even if it would have worked (which I believe it would not for technical reasons).
With a federal unitary executive disinterested in expanding testing, and no other backstop, we are left without a country-wide strategy.
I'm thinking that we won't get out from under this shroud until we get a new president.
Agreed. It’ll be interesting to see the 1A cases that come out of this though. There is only so much tolerance to freedom of religion, right to peaceful assembly, and right to petition the government that people will accept. Of course, if there was even a single issue with freedom of press there would be nonstop coverage from the very same.
I’m pro-self-quarantine but I can recognize the issue with ticketing people who went to a drive in church service, or walking alone, or playing outside with their kids. I haven’t see “THE” case that could go to Supreme Court, but I wonder if it’s out there.
(Also, it's not clear that America is all that compliant.)
I think it’s super interesting how differently this all looks to different people.
But I can’t think even during Spanish Flu that First Amendment rights were so heavily infringed - good reasons or not. Best I could find on the topic was the heavy fines for spitting in public in 1918.
People weren't quarantined. The death toll was much higher. Not saying those two are directly correlated -- many other factors -- but there's not a good comparison on the "rights" front because of that death toll.
When you do so, remember that the "lockdown" we're experiencing falls far short of a "general quarantine". You can in fact leave your house, and travel between states, free from pretty much any tracking or extra surveillance. Most of the police power being exercised falls under business regulation; where you're feeling the lockdown the most is likely in the fact that you have so few places to go right now.
Because it's easy to find sources discussing the legal controversy of general quarantines. But you'll notice they're mostly talking about the due process concerns of doing the equivalent of imprisoning people without trials, not closing the bars.
This lockdown is infringing on pretty much all our Constitutional rights, across the board.
(Courts, for what it's worth, continue to function).
And we can't go 2 years without jury trials while waiting for a vaccine. We'll have to find less restrictive ways to coexist with this virus.
Churches are an especially unpersuasive example of overreach, since several churches have been implicated in super-spreader events.
https://www.ktvu.com/news/justice-delayed-california-courts-...
What was perhaps acceptable as a temporary emergency measure is not acceptable as the new normal. The current measures are overly restrictive and cannot continue for two years.
And while I don't care about religion myself, I understand that religious people feel the same way about closing all churches for years. We'll also have to find less restrictive ways to control the virus while allowing the churches to reopen.
Regarding the courts: Ken White is a good source for what's actually happening.
So if we agree that less restrictive measures will be in place in the future, I would ask why such measures aren't also sufficient today?
I would argue that, given that this lockdown must end before we eliminate the virus, we should begin adapting and testing less restrictive measures as quickly as possible.
It's always a tradeoff. And now we're seeing data showing that the virus is more widespread and less dangerous than previously believed, so it's time to reevaluate that trade.
And ironically, if it turns out the virus is less dangerous than previously believed, and we actually overreacted, it will also look like we overreacted.
But I agree; I don't dispute the Constitutionality of the orders given in March, when nothing was known and it was wise to be prudent. Now, more is known and orders can be much more carefully tailored and less restrictive, as required by strict scrutiny.
That's what strict scrutiny means, but it's a very high standard that certainly doesn't apply to every case. As I understand it, it's more likely to be applied when fundamental rights are infringed, but I would never try to predict how the Court might rule on any particular case.
> (Courts, for what it's worth, continue to function).
In England we split courts up, so we have a variety of criminal courts, courts of protection, family courts, etc.
Before Covid-19 they were all trying to "go digital", and were having mixed results. Now, because of Covid-19, they've just had to make it work somehow.
Here's some discussion from (the excellent) Transparency Project: http://www.transparencyproject.org.uk/remote-hearings-a-gulf...
They link to quite a few different blogs and comments, but I really want to highlight this one. It's from the courts of protection. http://www.transparencyproject.org.uk/remote-justice-a-famil...
Sarah's father had a stroke. He was taken to hospital. He started to refuse to eat or drink. The doctors decided he did not have mental capacity to make that choice, and so they fitted a nasogastric tube. He told his daughter that this was wrong, and he pulled out (!!!) his tube several times. They gave him a PEG tube, and he was eventually discharged to a nursing home. He wants the medical treatment (feeding) to stop; she wants what he wants; so now they go to the court to get an order. They lost the case.
This is, of course, a very distressing case for all involved. But this woman says that the informal nature of a skype case, with people's pets wandering in and out and people talking in a casual way to each other made it worse.
There's some sense that because Sarah wasn't in the same room as the judge and the lawyers that they didn't recognise her distress.
So, court cases are going ahead, but there's some considerable adjustment needed.
Also, they're not always going ahead. Here's a case about a form of child abuse (fabricated or induced illness). It's a really serious case, and the mother risks being separated from her child (or the child risks remaining with an abusive mother). The judge decided that this isn't a case that can be heard remotely. http://www.transparencyproject.org.uk/p-a-child-remote-heari...
The way to think about this is: who do we need to test so we can start un-quarantining people.
The goal is not to find out who has it because right now, we are essentially behaving as if the entire US population is infected. The goal is to efficiently determine who is very unlikely to have it so that those people can start incrementally returning to normal life.
It's not worth testing symptomatic people: they've already "failed" one test in that we at least know they have symptoms. Simply continue to treat them as infected.
One difference is if a business re-opens and expects people to come in to work, the US probably needs legal protections so quarantined workers don't get fired or forced to come in illegally.
I don't understand why we haven't focused all of our testing on people that aren't sick so we can catch the asymptomatic cases that are out in the world spreading it to everyone.
We don't treat Covid patients any differently than any other patients that develop pneumonia
I don't understand how this misconception persists. That is not what the WHO statement said.
The statement was that the outbreak was not being sustained by community transmission, and that they believed (this was very early on) that the cases from the Wuhan market were all due to exposure to a single case or pathogen.
This was, obviously, wrong. But at the time it wasn't unreasonable to believe. That's the way most outbreaks work when you catch them early.
At no point did anyone say that a respiratory coronavirus was not contagious, which is how people insist on treating that statement. Of course these things are contagious, that's how they spread.
> Preliminary investigations conducted by the Chinese authorities have found no clear evidence of human-to-human transmission of the novel #coronavirus (2019-nCoV) identified in #Wuhan, #China🇨🇳.
Edit: by default we should ASSUME community transmission
If I was in a Governor's or Mayor's shoes right now and I know there aren't enough resources to test everyone, I'd want some data like that to work with to make policy decisions.
While you are in the process of opening things back up, you keep a close eye on your daily/weekly representative sample numbers to see if anything needs to be dialed back. It gives you much closer to immediate feedback.
I suppose the immediate problem is getting a hold of a representative sample of people willing to be tested, but that feels solvable. I'm sure I'm not the first one to think of it, just curious why it isn't being done, as it feels immensely useful (maybe this is just the 538 political nerd in me wanting virus polls?).
https://scanpublichealth.org
So what are they looking at? Basically, if they have any evidence of community transmission, they need to issue the order or keep it in place. That means that if there are too many symptomatic people to even attempt contact tracing, you're not even close. Once you're low enough you can do contact tracing, you wait until you have a handful at most of symptomatic people you can't trace back to a known case. Until then, all you can do is keep the stay at home order in place, buy/beg/borrow/steal ventilators and PPE, and build testing and contact tracing capacity.
Well, it took a global pandemic, but we finally found a use for bloom filters!
What is surprising is that group testing tells us that we can actually do better: the specific construction you pinpoint the people who come up positive, without needing to have a test for each person [1] and this result is optimal in the expected number of tests. I'm surprised that most labs haven't already been doing this (but I would suspect some have).
Wootters has wonderful notes on the mathematical background for this—I really recommend them. [2]
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[0] https://en.wikipedia.org/wiki/Group_testing
[1] Of course, we require an upper bound on the total prevalence, but even a weak upper bound yields fairly good savings in testing.
[2] Page 3 on of http://web.stanford.edu/~marykw/classes/CS250_W18/lectureNot...
> the specific construction lets you pinpoint the people who come up positive
A bottle neck seems to be that it's not really possible to pool more than at most 32 patients at a time.
It's an early work in progress but have a look: https://www.pcr-pooling.com
I have a link on my notes below. I'll add your site to the reference list at the top tonight.
https://github.com/EFavDB/pooling
the USAF wanted to armor planes where the bullet holes were. statistician abe wald recommended armoring where the bullet holes weren't on the theory that those were the non-survivable hits
can't interpret a statistic until you think about what's excluded from the sample
It certainly makes for a good drama though.
there's an american math society article about this -- it evaluates the fun version of the story in the context of wald's actual paper and a journal entry by another scientist named wallis
It wasn't quite that simple, but the story has a gem of truth. As this article quotes Stephen Stigler (son of George Stigler who worked with Abraham Wald):
>..."The military was inclined to provide protection for those parts that on returning planes showed the most hits. Wald assumed, on good evidence, that hits in combat were uniformly distributed over the planes. It follows that hits on the more vulnerable parts were less likely to be found on returning planes than hits on the less vulnerable parts, since planes receiving hits on the more vulnerable parts were less likely to return to provide data. From these premises, he devised methods for estimating vulnerability of various parts."
http://www.ams.org/publicoutreach/feature-column/fc-2016-06
This paper goes into detail for those interested in statistics:
https://people.ucsc.edu/~msmangel/Wald.pdf
Rich Condit: Garrett writes: The CDC guidelines are to test hospitalized patients and symptomatic health care workers first, and the symptomatic general public last. This seems backwards to me.
Alan Dove: Yeah. I just had this conversation with my wife after she had some, I mentioned this before, she had some coughing and shortness of breath, got immediately sent to the ER in the hospital where she works, and they did a chest x-ray, it was clear, and they said, "Ok, you don't meet criteria for testing. Go back to work." And she's been fine since then, and she, we were talking about it and she said, "Well, isn't that exactly who they should test, because then I could go and infect patients?" and I said, "Well, if they had enough tests, yes. But if you expand the testing to the people who are less sick, you don't have enough tests. Whereas if you restrict the testing to the people who are sickest, you do have enough tests." So it's a.. it's not the right way to do it, but it's the way that you actually can do it.
Vincent Racaniello: Yeah, we're in this position because we don't have enough tests. We didn't ramp up...
Dove: Because we don't have enough tests. We didn't prepare fast enough.
Racaniello: If we had, we could test a lot of people and get an idea of how many actual infections there were, which would be very useful. But... we can't. So we're stuck with this current policy.
[1]- http://www.microbe.tv/twiv/twiv-595/ about 1 hour and 19 minutes in to the program
People with bad symptoms aren't the one's going out into the world spreading the virus and the difference in treatment between a Covid and non-Covid patient (from what I've heard) is minimal.
B) If you know that someone with bad symptoms has the virus, then you can go test everyone they contacted. You'll find more people who currently have mild or no symptoms.
Now, with all this in place, isn't the best we can do to alert people after they have already been exposed to the virus?
It feels a bit like the safe sex crusaders switching to say everybody can have unprotected sex now, we'll let you know if you catch something, hopefully before you infect your next partner. Which I suppose is more reasonable for the group, but ... as the individual who is expected to actually go out in the world to consume or whatever, this doesn't feel like a viable solution. What am I missing?
No, the best we can do in that case is treat COVID-19 like a dangerous communicable disease that isn't too widespread for surveillance and do specific quarantines of the infected and exposed, which then vastly limits the possibility that anyone else gets exposed, while not requiring shelter-in-place restrictions for those not already infected/exposed.
That's the whole point of disease surveillance with widespread testing and extensive contact tracing, and why it is key for a general reopening of the economy in the absence of an effective cure/vaccine.
Each infected person will come into contact with some other people. Testing allows three things—
- first, we can tell this person to stay at home and so stop them from infecting more people;
- second, we can tell the people they have seen to stay at home with good contact-tracing, so that even if they get it they don’t spread it further; and
- third, with enough tests and contact tracing, those who were exposed but not infected don’t have to stay at home.
We are winning so long as R<1, even if there is some chance the infection spreads; we do not need R=0.
The other way of reducing R requiring much less testing and contact tracing is a lockdown. This has obvious downsides. The point of a programme of testing and conyact tracing is that we can turn the cost of avoiding disaster from a lockdown to sticking some things up people’s noses.
edit: typo in first para
But suppose A starts showing symptoms, tests positive. We can immediately notify B1, B2 and B3 that they need to quarantine, immediately. Before they start showing symptoms. And therefore we're cutting down on the time that they were infectious and spreading. Therefore generation C is only a couple of people instead of dozens. We can notify C generation as well, immediately if we wish. This causes a large quarantine - there are a lot of false positives who are quarantining without being infected - but it would massively reduce the spread. If you can immediately test all of generation B and C, you can perhaps avoid some of the quarantining (assuming a negative is reliable).
Maybe contact tracing misses some, maybe some new infected come from other countries, maybe some people don't quarantine when told. All these things keep the infection going. But it can be held down to a manageable level.
The trick is to NOT stop testing once your case count starts going down, instead give the test to everybody that wants one.
A few million spent on 99.9% negative tests daily > a few billion spent on the economy being shut off daily
So I think the word manageable is doing a lot of work here. Specifically, manageable to the hospitals, which is what I believe most people mean when they say this, does not do anything to manage consumer confidence. Which my entire question is about. How do I, as an individual consumer, feel confident enough in the systems set up to go back to some semblance of normal? Learning that my chance of getting infected from going to the grocery store has dropped from 20%? to... 5%? 1%? Whatever the risk is, it needs to be multiplied by the average number of places a normal consumer went to over a week before this outbreak. Which means that I'm still gonna get it eventually, just I might not block somebody else from getting a hospital bed. Which is obviously better than nothing! But I really think people are missing the human aspect of precisely what this entails.
Consider user stories. As a single mother do you still feel confident going out to get groceries knowing there's an n% chance of getting it and bringing it home to your kids? If you die there's no one else to look after them.
The goal isn't to "alert" infectious cases, it's to quarantine them so they don't create new infections. Even baring a legal order, someone who knows they are covid-positive is much more likely to stay home and away from others. That reduces the rate of spread, which is ultimate goal.
> but ... as the individual
It's not an individual level solution. There are no individual level solutions (except complete and total isolation I guess). Outbreaks are community events.
But we don't have nearly enough testing capacity (either tests or the organized infrastructure to administer them, though both problems are being worked on) to meaningfully test the general population, whether or not we focussed our entire effort on the most important subset for reopening, so it would be extraordinarily stupidly premature to shift our current testing priority in that direction. This also means that general reopening is, a fortiori, extraordinarily stupidly premature.
But the HN title is actionable: if we can change our testing policy and deploy our tests more usefully, that's great to know and eminently achievable.
But "not testing enough" isn't really actionable. There's a shortage of tests because there's a shortage of the raw materials that goes into making the tests. The U.S. already has tested far and away more people than anyone else, and is second only behind Italy in tests per capita, and has a "positive test to test" rate roughly in line with (as low of a rate as) any other country's rate. See [0] and related charts.
"Just test more" isn't really useful at this point.
[0] https://ourworldindata.org/grapher/full-list-total-tests-for...
That requires that you compare the US to Iceland, Faeroe Islands, Falkland Islands, UAE, Malta, Gibraltar, Luxembourg, Bahrain, Estonia, San Marino, Cyprus, Isle of Man, Lithuania, Brunei, Qatar, Liechtenstein, Ireland, Latvia, Andorra, Channel Islands, Bermuda, Aruba.
Nice try.
Back on planet earth, here's the list of actual sane comparables that are in front of the US, in order:
Italy, Germany, Spain, Australia, Russia, Canada
And Russia is fake. They haven't tested much at all.
The US has tested at a higher rate than South Korea (which is behind all of those tiny nations also).
The US testing rate is just behind Belgium, a nation 1/29th the size of the US. And it's not very far behind Singapore at this point, either.
Many of the countries testing "more per capita" have a lower population than cities that many here on hacker news wouldn't even consider "real cities". Scaling testing in the Isle of Man above the US only takes a total of 1100 tests. Of course they are testing more per-capita than we are.
Let's say your key metric you're trying to maintain or improve is P50 request latency. Its relatively easy to exhibit an acceptable P50 to 10 users, from 1 VM. Its actually harder to deliver the same P50 to 100 users, from 10 VMs. Even harder for 1000 users and 100 VMs, snd so on. You run into previously fine bottlenecks you didn't know existed. Issues which were invisible at ten users become cascading failures at thousands.
It just keeps getting harder the more users you add, even though you're adding proportionally more underlying VMs. There is no end to how difficult it gets, until eventually, it becomes impossible.
Testing is a problem with difficulty that scales with population size. Of the top ten countries by population size, there are only two countries that have higher testing per capita than the US: Russia and China. Those three countries are pretty close; no one else, anywhere in the top ten, is remotely close to the US, Russia, and China.
(Kind of funny how the top two testers in the top 10 countries by population are dictatorships, who have every reason to maintain a strong, powerful image. Funny how it works out like that, isn't it? Do you believe their numbers?)
I run the fastest website on the planet. No one but my mom visits it, but its still the fastest. Lithuania (the world's top daily tester per capita yesterday) is that website. The US is, uh, lets say Google. Should you bemoan Google for taking longer to load?
> P50 request latency
I for one don't even know what P50 means.
Where are you getting those numbers? I don't think that's correct. The Worldometer data may not be the best, but they have the US well down in the middle of the pack at ~13k tests/Mpop.
Lots of large developed nations have the US beat by quite a bit, in fact. And Iceland is literally a full order of magnitude higher!
In fact US testing policy has been largely a disaster. It's not the only disaster, but this is an area (large scale PCR laboratory work) where the US is supposed to be good at stuff. And yet there's been almost no attention paid to the problem at the highest levels of government.
[0] https://ourworldindata.org/grapher/full-list-cumulative-tota...
Why don't we have the capacity? Well the complete lack of coordination and leadership at the federal level means that each individual entity, whether it be state level government or a private entity, is having to do everything from scratch. That means developing SOPs, procuring supplies, and validating both the processes and reagents. This is being done on emergency orders as well, so some of the standards are relaxed to quickly get things up and running.
There's also a shortage of reagents and kits because we didn't have or need this testing just a few months ago. There's also international competition for these resources, and because the US has decided it doesn't want to actually work with or coordinate with other countries, it's a free for all.
Because everyone's frantically working on the same thing, but looking out for themselves it also means that true high throughput solutions are slow to develop as well.
I could go on and on, but it's a clusterfuck and no one at the federal level either A) seems to care or B) thinks that it's their responsibility.
Source: wife is currently in charge of starting up Covid testing
See Fomsgaard and Rosenstierne’s preprint on medrxiv here:
https://www.medrxiv.org/content/10.1101/2020.03.27.20044495v...
>That doesn't stop the American press making it sound like not achieving those 500,000 tests a day is the result of some uniquely American political failing though.
I don't think we're unique in where we are in comparison with other countries as far as testing, but we are in a unique position in regards to being able to put some strong leverage on getting other countries to work together to respond to this pandemic. We're not doing that and as a result, other countries are having to "roll their own" response to this pandemic just like we are. The lack of coordination within our country is putting us at a unique disadvantage, even if we had better coordination world wide.
This pandemic is a exceptional global crisis in a way we've never seen before, and thus should've led to a addressing it at a global scale in a way we had never seen before. Instead the global response has been crippled in numerous ways at various different points in time.
The American political failing is in not being the true world leaders, and the world is, IMHO, worse off for it.
But in order to try to generate the political will and get the backing to make this happen, it helps to get the word out about the big picture of exactly why having so many tests is important.
New legislation is coming that provides some funding for testing, but out of $484 billion that it authorizes, only $25 billion in it for testing[0]. Meanwhile, a report from Harvard estimates that $50 to $300 billion will be needed[1]. So the amount of money made available so far is 1/2 to 1/12 of what one source has estimated that we need.
---
[0] https://www.cnbc.com/2020/04/21/coronavirus-senate-passes-48...
[1] See Appendix B starting on p. 42 of this PDF: https://ethics.harvard.edu/files/center-for-ethics/files/roa...
I also don't think we need to get the word out about how testing is important. People are cooped up in their homes precisely because we don't know who has it and who doesn't. Testing could resolve that.
I have little faith in the legislation from Washington for many reasons. The primary one being that before the crisis, during it, and at this very moment there is a lack of acknowledgment of the actual scale of this pandemic. Even worse a large part of the legislature fails to take this seriously, thus making the scale of the issue a secondary problem. What's been passed so far has already missed the mark as far as funding testing and properly ensuring that those who need the money get it. Instead, big business gets "relief" with little oversight, which given the past actions of this administration clearly isn't just by accident.
The reality is that testing is still significantly behind and efforts to increase testing won't make the news cycles. I strongly doubt that we'd be able to scale up quickly enough to make a meaningful dent in this anymore than strictly following stay at home orders. Unfortunately even that is too much to ask us to do as a society it seems.
https://www.realclearpolitics.com/coronavirus/
accurate? Because according to that, adding up the number of tests done by Italy, Spain, France, the UK, and Germany (a combined population roughly the same as the US), they've done about 5.6 million tests vs the USA's 4.4 million tests.
And we've done more tests per capita than South Korea.
Which really doesn't sound like we're doing that badly.
Maybe we need to use the tools we already have, such as flu surveillance and data from hospitals, to detect excess non-flu infections. We seem to be able to do flu tests, are they more scalable so that at least flu can be ruled out in many cases?
If widespread testing can not happen because we can't build factories to make reagents/swabs/tubes/PCR array machines/etc. fast enough, we need to start thinking of alternatives. We don't actually seem to understand yet how the virus spreads, too many clinicians trained in handling infectious disease are getting sick despite PPE. If the new small antibody test results are right, then the virus is spreading much faster than can be accounted for via droplet spread as the main mechanism; we may have to consider birds, mosquitoes, surfaces, skin touching, and other methods as possible common spreading mechanisms. If we understood transmission better then it might be possible to tell people how to truly protect themselves, and then they could go back to work. So understanding transmission better is something that could be used in addition to whatever testing is available in order to prevent deaths and economic damage. But people may not follow the new rules based on that understanding, so get the social scientists involved to get the message across. Get OSHA involved to set best practices for workplaces. It seems like there is probably a lot that can be done, even without testing, and at present we may have to assume testing will not be sufficient in the near term (3-6 months).
But someone has to start thinking about these things and doing them, and I'm not seeing any evidence of this in the news. Given that contact tracing is not already ramping up (I've seen only Massachusetts as having a plan to scale it up but I tend to only see East Coast news) I have to wonder if anyone is even thinking about alternatives to testing if testing at scale is not possible.