4 ms·

#2 isn’t obvious to me. Can you explain why?

hef19898 6y ago
Bluntly put, it takes time to die from any disease.
heavyset_go 6y ago
It takes about two weeks for symptoms to arise and become severe, and then about another two weeks of severe symptoms that require ventilators before people die.
- jupp0r 6y ago
  The pre symptomatic time wouldn’t be part of this gap unless the infected person got a test before symptom onset, which I believe is rare (most people who test positive get tested after they develop symptoms)
  - SketchySeaBeast 6y ago
    No, these measures affect new cases, not the already ill - so you've got to build in those 2 weeks to display symptoms for those people who would or wouldn't now be infected.
    - jupp0r 6y ago
      It’s new cases. Those are people that have tested positive. This usually happens days after the actual time they have been infected. At the time of infection, you’d test negative because it takes time for viral replication to increase viral load to levels that are over thresholds used in the PCR testing process.
      - SketchySeaBeast 6y ago
        But we're not talking testing negative, are we? We're talking those people showing up in the system (the > 2 week lag in time it takes to change course), or did I miss a level of questioning that threw this off course?
        jupp0r 6y ago
        The original question was what the delay between “new cases” and “new deaths” charts was.
  - emn13 6y ago
    If you look at the graphs side-by side for areas with clearly defined peaks (I looked at MA, NY, Italy, Spain, UK, Netherlands) the peak fatality rate is no more than a week behind peak case numbers, and perhaps less. Testing rates in at least some of those areas were fairly constant around the peaks, so that doesn't seem a likely confounding factor. I'm not sure what to make of the meaning of such a short gap, and of course people may now be testing earlier than they did in the early hot spots, so I'm not sure if this has any predictive value.
    - heavyset_go 6y ago
      Testing in the beginning lagged significantly from the initial infection.
    - rsynnott 6y ago
      One caution about those numbers; many/most sites show cases based on the day that reporting was received and aggregated, _not_ on the day it was taken. This doesn't matter very much now, as turnaround on tests in most places is quick. But a couple of months ago delays of weeks were common.
  - rsynnott 6y ago
    People are far more likely to be tested before symptoms today than a few months ago; at least in Ireland when a case is detected everyone they've had contact with is tested, and some of those will be pre-symptomatic positives. And then anyone _they've_ had contact with will be tested and so on.
jupp0r 6y ago
It takes time to die from this disease and time for that death to show up in the official numbers.
mononcqc 6y ago
The time for symptoms to show up is of roughly 2 weeks but the median time is at about 6-8 days. After symptoms show up, it takes a while before people get hospitalized, and then mortality seem to take roughly 21-24 days after hospitalization. This means that from the time someone is infected until they die, a month and a half can have gone through. By the time you take new isolation measures, you have to wait roughly two weeks to see if daily infection rates start to vary. But the lethality at this point, assuming no change in healthcare system overload, can be more or less statically predicted for weeks after the fact. Those are called "lagging indicators"; the main thing you try to prevent are deaths, which you can lower by reducing the overload on the healthcare systems, which you can lower by controlling infection rates and keeping them low. Due to the duration of the disease's evolution, you get to see if your policies really worked more than a month and a half after enacting them, which is extremely slow for a disease that propagates at exponential rates. So people look for proxies like infection rates that are still lagging, but far less so. Do note that the one good metric you want in the end is going to be "excess deaths", which counts the impact of not just the diseases, but of all other side issues that the disease may have caused. This can usually take months up to years to properly account and analyze.
- ghiculescu 6y ago
  Yep. That was obvious. Thanks!
  - jacquesm 6y ago
    I don't understand. If it wasn't obvious before then it can't be obvious now. You've had it explained to you. If it was obvious then that would not have been necessary.
    - s1artibartfast 6y ago
      Sometimes I will look all over for my keys, only to find them in my pocket. This is the obvious place to check first, but I am not perfect, so sometimes I overlook it.
  - 6y ago

hef19898 6y ago

Bluntly put, it takes time to die from any disease.

It takes about two weeks for symptoms to arise and become severe, and then about another two weeks of severe symptoms that require ventilators before people die.

jupp0r 6y ago
The pre symptomatic time wouldn’t be part of this gap unless the infected person got a test before symptom onset, which I believe is rare (most people who test positive get tested after they develop symptoms)
- SketchySeaBeast 6y ago
  No, these measures affect new cases, not the already ill - so you've got to build in those 2 weeks to display symptoms for those people who would or wouldn't now be infected.
  - jupp0r 6y ago
    It’s new cases. Those are people that have tested positive. This usually happens days after the actual time they have been infected. At the time of infection, you’d test negative because it takes time for viral replication to increase viral load to levels that are over thresholds used in the PCR testing process.
    - SketchySeaBeast 6y ago
      But we're not talking testing negative, are we? We're talking those people showing up in the system (the > 2 week lag in time it takes to change course), or did I miss a level of questioning that threw this off course?
      - jupp0r 6y ago
        The original question was what the delay between “new cases” and “new deaths” charts was.
- emn13 6y ago
  If you look at the graphs side-by side for areas with clearly defined peaks (I looked at MA, NY, Italy, Spain, UK, Netherlands) the peak fatality rate is no more than a week behind peak case numbers, and perhaps less. Testing rates in at least some of those areas were fairly constant around the peaks, so that doesn't seem a likely confounding factor. I'm not sure what to make of the meaning of such a short gap, and of course people may now be testing earlier than they did in the early hot spots, so I'm not sure if this has any predictive value.
  - heavyset_go 6y ago
    Testing in the beginning lagged significantly from the initial infection.
  - rsynnott 6y ago
    One caution about those numbers; many/most sites show cases based on the day that reporting was received and aggregated, _not_ on the day it was taken. This doesn't matter very much now, as turnaround on tests in most places is quick. But a couple of months ago delays of weeks were common.
- rsynnott 6y ago
  People are far more likely to be tested before symptoms today than a few months ago; at least in Ireland when a case is detected everyone they've had contact with is tested, and some of those will be pre-symptomatic positives. And then anyone _they've_ had contact with will be tested and so on.

jupp0r 6y ago

It takes time to die from this disease and time for that death to show up in the official numbers.

mononcqc 6y ago

The time for symptoms to show up is of roughly 2 weeks but the median time is at about 6-8 days. After symptoms show up, it takes a while before people get hospitalized, and then mortality seem to take roughly 21-24 days after hospitalization. This means that from the time someone is infected until they die, a month and a half can have gone through. By the time you take new isolation measures, you have to wait roughly two weeks to see if daily infection rates start to vary. But the lethality at this point, assuming no change in healthcare system overload, can be more or less statically predicted for weeks after the fact. Those are called "lagging indicators"; the main thing you try to prevent are deaths, which you can lower by reducing the overload on the healthcare systems, which you can lower by controlling infection rates and keeping them low. Due to the duration of the disease's evolution, you get to see if your policies really worked more than a month and a half after enacting them, which is extremely slow for a disease that propagates at exponential rates. So people look for proxies like infection rates that are still lagging, but far less so. Do note that the one good metric you want in the end is going to be "excess deaths", which counts the impact of not just the diseases, but of all other side issues that the disease may have caused. This can usually take months up to years to properly account and analyze.

ghiculescu 6y ago
Yep. That was obvious. Thanks!
- jacquesm 6y ago
  I don't understand. If it wasn't obvious before then it can't be obvious now. You've had it explained to you. If it was obvious then that would not have been necessary.
  - s1artibartfast 6y ago
    Sometimes I will look all over for my keys, only to find them in my pocket. This is the obvious place to check first, but I am not perfect, so sometimes I overlook it.
- 6y ago