5 ms·

> So, I just copied the data from WHO sitreps and the total-cases diff of diffs has been increasingly negative for three of the last four days. So it's still ge

by vosper 7y ago

> So, I just copied the data from WHO sitreps and the total-cases diff of diffs has been increasingly negative for three of the last four days. So it's still getting worse, but the second derivative might be negative. Could you explain what this means in layman's terms?

adrianN 7y ago
The rate at which new people get infected is going down.
- PeterisP 7y ago
  Only if we assume that the published rates of new infection reflect reality. The statistics refer to diagnosis of 2019-nCov based on conclusive test results. They do not include diagnosis solely made on symptoms - if somebody in China had flu-like symptoms and died from pneumonia, that's not considered a diagnosis of 2019-nCov infection and thus it's not an 2019-nCov death unless proper tests were performed. Even if we assume that all the test results are reported, we know that large quantities of suspected cases in Wuhan are not tested - hospitals report there's an insufficient quantity of RNA test kits available, there are some reports that outpatients aren't tested, and bed capacity is limited, so anybody who does not have space in the hospital system is not tested. And if they die, they're excluded from statistics of 2019-nCov patients because they were not tested. So if you have a system that's capable to test X people per day, even if you report all the test results perfectly honestly, you're not going to see more than X new infections per day... no matter how many new infections you actually have. If it's nontrivial for Japan to test 3600 people quarantined on a ship, how would it be possible to test everyone who's sneezing from 11 million people quarantined in a city?
yarg 7y ago
The second derivative is the acceleration. If it's negative it can still be getting worse (positive first derivative), but it's slowing down. The second derivative is the rate at which the rate of change is changing.
- blackrock 7y ago
  Sounds about right. This will get worse before it gets better. This is an interesting chart to new map the new daily infection rate. https://twitter.com/Tom_Fowdy/status/1226659915160117248 https://twitter.com/Tom_Fowdy/status/1226659915160117248 The daily count of new cases is going down. China’s containment effort might be successful. However, this may not account for everything. * They have limited daily testing kits. Especially in the early days of this crisis. * There may be people who had died, but they didn’t get tested, so they won’t be counted in this statistic. The moral dilemma is: Do you burn a precious test kit on a dead corpse to verify that they had the virus, or do you save it for someone still living? * The city and the province’s medical system is under severe strain, and there are not enough supplies to go around. They may not even be able to account for everything or everyone, because their medical system is suffering from a massive denial of service attack right now. * They may have ramped up test kit production this weekend to 10k/day, so this may skew the numbers higher, as they are able to test more people. * There are reports that the testing is not fully accurate, if you’re in the early stage, where the virus hasn’t generated enough markers to be detected yet. So, this is a false negative, where you are actually infected, but the test says that you are not. This might be why they will only clear you, if you get two negative tests in a row.
  - ImaCake 7y ago
    Yes, but likely at a predictable and slowing rate. Some graphs I've seen look something like a bell curve.
  - DyslexicAtheist 7y ago
    if a virus would wipe out say 50% or 75% of humanity, it would be terrible for us but wouldn't be that bad for mother nature. It may provide a couple of decades (if not centuries) in which nature is able to recover from us. I think thanks to global warming, there will be many more diseases coming our way. Things that our immune system has never previously had to fight against and for which there is no cure.
    - jokowueu 7y ago

by vosper 7y ago

adrianN 7y ago

The rate at which new people get infected is going down.

PeterisP 7y ago
Only if we assume that the published rates of new infection reflect reality. The statistics refer to diagnosis of 2019-nCov based on conclusive test results. They do not include diagnosis solely made on symptoms - if somebody in China had flu-like symptoms and died from pneumonia, that's not considered a diagnosis of 2019-nCov infection and thus it's not an 2019-nCov death unless proper tests were performed. Even if we assume that all the test results are reported, we know that large quantities of suspected cases in Wuhan are not tested - hospitals report there's an insufficient quantity of RNA test kits available, there are some reports that outpatients aren't tested, and bed capacity is limited, so anybody who does not have space in the hospital system is not tested. And if they die, they're excluded from statistics of 2019-nCov patients because they were not tested. So if you have a system that's capable to test X people per day, even if you report all the test results perfectly honestly, you're not going to see more than X new infections per day... no matter how many new infections you actually have. If it's nontrivial for Japan to test 3600 people quarantined on a ship, how would it be possible to test everyone who's sneezing from 11 million people quarantined in a city?

yarg 7y ago

The second derivative is the acceleration. If it's negative it can still be getting worse (positive first derivative), but it's slowing down. The second derivative is the rate at which the rate of change is changing.

blackrock 7y ago
Sounds about right. This will get worse before it gets better. This is an interesting chart to new map the new daily infection rate. https://twitter.com/Tom_Fowdy/status/1226659915160117248 https://twitter.com/Tom_Fowdy/status/1226659915160117248 The daily count of new cases is going down. China’s containment effort might be successful. However, this may not account for everything. * They have limited daily testing kits. Especially in the early days of this crisis. * There may be people who had died, but they didn’t get tested, so they won’t be counted in this statistic. The moral dilemma is: Do you burn a precious test kit on a dead corpse to verify that they had the virus, or do you save it for someone still living? * The city and the province’s medical system is under severe strain, and there are not enough supplies to go around. They may not even be able to account for everything or everyone, because their medical system is suffering from a massive denial of service attack right now. * They may have ramped up test kit production this weekend to 10k/day, so this may skew the numbers higher, as they are able to test more people. * There are reports that the testing is not fully accurate, if you’re in the early stage, where the virus hasn’t generated enough markers to be detected yet. So, this is a false negative, where you are actually infected, but the test says that you are not. This might be why they will only clear you, if you get two negative tests in a row.
- ImaCake 7y ago
  Yes, but likely at a predictable and slowing rate. Some graphs I've seen look something like a bell curve.
- DyslexicAtheist 7y ago
  if a virus would wipe out say 50% or 75% of humanity, it would be terrible for us but wouldn't be that bad for mother nature. It may provide a couple of decades (if not centuries) in which nature is able to recover from us. I think thanks to global warming, there will be many more diseases coming our way. Things that our immune system has never previously had to fight against and for which there is no cure.
  - jokowueu 7y ago