4 ms·

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 ca

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.

exhilaration 7y ago
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.
- blueplanet200 7y ago
  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.
  - scott00 7y ago
    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.
- RandallBrown 7y ago
  But what's the point of testing people that are already sick? We don't treat Covid patients any differently than any other patients that develop pneumonia
  - uxp100 7y ago
    We often put covid and suspected covid in separate areas of the hospital from others, with a different staff.
    - uxp100 7y ago
      kjust to be clear, this is just what friends have told me, this is the communal we, I do not work in a hospital.
  - corny 7y ago
    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.
beamatronic 7y ago
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.
- ajross 7y ago
  > 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.
  - throwaway2048 7y ago
    There is currently a big push to scapegoat the WHO as the cause of the pandemic.
    - nv-vn 7y ago
      There is also a big push by the WHO to censor anything critical of China
      - throwaway2048 7y ago
        what power does the WHO have to "censor anything critical of China"
  - eschutte2 7y ago
    https://twitter.com/who/status/1217043229427761152?lang=en https://twitter.com/who/status/1217043229427761152?lang=en
godtoldmetodoit 7y ago
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?).
- RandallBrown 7y ago
  Seattle has been running a test like this. I believe they're allocating 300 tests per day. https://scanpublichealth.org https://scanpublichealth.org
- scott00 7y ago
  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.

exhilaration 7y ago

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.

blueplanet200 7y ago
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.
- scott00 7y ago
  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.
RandallBrown 7y ago
But what's the point of testing people that are already sick? We don't treat Covid patients any differently than any other patients that develop pneumonia
- uxp100 7y ago
  We often put covid and suspected covid in separate areas of the hospital from others, with a different staff.
  - uxp100 7y ago
    kjust to be clear, this is just what friends have told me, this is the communal we, I do not work in a hospital.
- corny 7y ago
  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.

beamatronic 7y ago

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.

ajross 7y ago
> 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.
- throwaway2048 7y ago
  There is currently a big push to scapegoat the WHO as the cause of the pandemic.
  - nv-vn 7y ago
    There is also a big push by the WHO to censor anything critical of China
    - throwaway2048 7y ago
      what power does the WHO have to "censor anything critical of China"
- eschutte2 7y ago
  https://twitter.com/who/status/1217043229427761152?lang=en https://twitter.com/who/status/1217043229427761152?lang=en

godtoldmetodoit 7y ago

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?).

RandallBrown 7y ago
Seattle has been running a test like this. I believe they're allocating 300 tests per day. https://scanpublichealth.org https://scanpublichealth.org
scott00 7y ago
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.