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One question that's been on my mind: The number of Coronavirus cases is likely far more than what's being reported. Apparently there are those who get coronavir

by brink 7y ago

One question that's been on my mind: The number of Coronavirus cases is likely far more than what's being reported. Apparently there are those who get coronavirus and are unaware that they have it before they heal. However everyone that dies of coronavirus is reported as a coronavirus case. Does this mean that there's a good chance the death rate is lower than the current calculated 3% with so many recoveries going unreported?

marshallant 7y ago
And I would like to know how many people have died not due to coronavirus but it was labeled so because they just happened to have it when they passed away.
Mountain_Skies 7y ago
Isn't also true for influenza? I had flu symptoms back in January but other than telling my manager that I was going to be out of the office due to illness, never reported my flu to anyone. Doubt I'm the only one who did this.
- learc83 7y ago
  Yes this happens, but for the flu we have done large scale antibody studies, so we have an idea that for every x number of people who get treated, y number are actually infected. The problem is we don't have the same data for this virus yet.
- zaroth 7y ago
  CDC estimates the total number of flu infections at about 10-20% of the population, depending on the year. The total number of hospital cases is usually ~1-2% of the number of infections. The, e.g. “32 million cases of flu” reported by the CDC is not based on 32 million positive test results. It’s extrapolated based on a factor of how many cases require hospitalization, and how many people seek medical care, which itself is based on antibody and behavioral surveys. > The numbers of influenza illnesses were estimated from hospitalizations based on how many illnesses there are for every hospitalization, which was measured previously (5). > Some people with influenza will seek medical care, while others will not. CDC estimates the number of people who sought medical care for influenza using data from the 2010 Behavioral Risk Factor Surveillance Survey, which asked people whether they did or did not seek medical care for an influenza-like illness in the prior influenza season (6). After reading more about it [1] you almost wonder how much better than a WAG (“Wild Ass Guess”) it really is. Frankly I am finding this whole area of medical science entirely underwhelming relative to the potential impact to lives and economies of the world. https://www.cdc.gov/flu/about/burden/how-cdc-estimates.htm https://www.cdc.gov/flu/about/burden/how-cdc-estimates.htm
deleted 7y ago
[deleted]
owenmarshall 7y ago
> However everyone that dies of coronavirus is reported as a coronavirus case. That seems unlikely. Testing capacity in lots of the world is extremely limited. The US is reserving test kits for the most sick/at risk; people at a low risk are unlikely to be tested. It seems to me that the focus would be on testing alive people, and that we are subsequently undercounting deaths - at least, in these relatively early stages.
- hef19898 7y ago
  My impression was, that everybody with syptoms who ot hospitalized also got tested. So the number of undiagnosed death should be very low. And by an order of magnitude lower than the number of untested, but infected, cases out in the wild. But as everybody points out, the correct number can only be claculated after the fact. and even the it might be of.
  - owenmarshall 7y ago
    I would definitely suspect you are right, though: many of the reports we’ve seen so far indicates community spread was occurring before the first case was detected - consider the Ohio estimate yesterday that ~1% of their population is infected. So long term a lower CFR seems to make sense.
    - hef19898 7y ago
      Sounds logical to me as well. That's also how I understood virologists and the like.
empath75 7y ago
I would say the odds that the hospitalization rate or death rate are significantly overestimated is pretty small given what it has done to the hospitals systems in places where it has spread even a little bit.
- hef19898 7y ago
  The absolute number of severe cases to be hospitalized overwhelmed hospitals. The relative number of severe cases, and fatalities, depends on the denominator. In our case, positive test results. So both things are true.
- robert2020 7y ago
  One would have to assume it’s overestimated. Authorities are going to be careful not to underestimate.
cstejerean 7y ago
So early on I was suspicious of the numbers from China, but since they have managed to control the spread (and it would be obvious if they didn’t and other cities started to look like Wuhan), that means they have done a good job of catching almost all of the cases, not just the symptomatic ones. Otherwise the ones they miss would continue to spread. Therefore it feels like at this point their data would be pretty representative of what percentage of the cases are severe vs critical and what the death rate is (accounting for both the overwhelmed medical case in Wuhan and for the under control case in rest of China). South Korea is also doing a pretty good job with testing to control the outbreak although they haven’t yet gotten it as under control as China does. So their numbers would be a good data point to cross-validate the China numbers. In countries like Italy (or Wuhan early on) the number of confirmed cases wasn’t equal to total cases as evidenced by continued growth of the epidemic. So it’s reasonable in those cases to assume that more severe cases are being found and less severe ones are being missed.
- hef19898 7y ago
  Also, Wuhan and Italy's north had their hospitals put under severe stress early on. That could have driven fatalities up as well.
- meowface 7y ago
  I'm no epidemiologist, but I think we might have to wait another month or two to see if there are any resurgences in China before we can be certain the containment really worked, no? Infectious disease expert Michael Osterholm recently said on a podcast that he and his colleagues expect there to be another outbreak in China within the next few months, once people start fully co-mingling again.
  - maxerickson 7y ago
    They've done more than lock down in China: https://twitter.com/MikeIsaac/status/1238604080571772928 https://twitter.com/MikeIsaac/status/1238604080571772928 I don't see why they would back off of the monitoring and fever clinics without some better measure in place (a vaccine or effective treatment or whatever). It's of course very likely there will be new cases. The likelihood of unchecked spreading seems much lower.
holri 7y ago
This is the reason for the estimates (also in the article mentioned) of 1% instead of the calculated 3%. 1% is still 10x more than the flu.
thawaway1837 7y ago
A lot of dying people are not being diagnosed as because of CoronaVirus. The people who are dying are usually older, or have preexisting conditions and their deaths can easily be chalked to their age/condition.
djaychela 7y ago
Yeah, I think that's referred to as "the denominator problem". Have a listen to Sam Harris' podcast on it this week - the expert on there sees 0.6% as an upper bound for mortality for coronavirus as that's the figure from South Korea, where the testing has been most intensive, and even that doesn't cover everyone.
- greedo 7y ago
  Do you mean a lower bound? If SK, which seems to be doing a relatively good job is experiencing a CFR of .6%, then countries performing worse should experience a higher CFT.
  - bonzini 7y ago
    That's the upper bound on the fatality rate if it infected the whole population. In actuality not even Hubei had 0.1% of the population infected, so the numbers will be higher if it mostly infects older people (Italy), and lower if it mostly infects younger people (South Korea).
  - tunesmith 7y ago
    0.6% is way out of date, as it was measured when many of the active cases were very early. At that time, I think I saw that deaths/cases was 0.6% and deaths/(deaths+recoveries) was 28.5%. As of today, deaths/cases is 0.9% and deaths/(deaths+recoveries) is about 9% . (Going by the numbers at worldometers.info)
- JamesBarney 7y ago
  But that's with the assumption the health system doesn't get overwhelmed. Once we run out of available oxygen, ventilators and ecmos that number starts to shoot up.
- tunesmith 7y ago
  As of yesterday, South Korea was up to 0.9% .
ianstormtaylor 7y ago
Not exactly. I'm not sure where you're getting the 3% number from. If you read the New York Times maps page data[1] and just divide the total deaths by total cases you get 3.7%, but that isn't the death rate because it doesn't take in to account a lot of factors. Instead, there's a good article[2] about how bad the virus will get, that says estimates put it in the range of 0.1% to 3%. (With the seasonal flu being somewhere around 0.1%, but the Spanish Flu of 1918 being somewhere around 3%.) That said, the general intuition that less reporting of cases means that some part of the death rate is over-inflated makes sense. But also consider that there are factors that go in the other direction. Anyone who currently has the virus but has not recovered or died can be under-inflating that rate. And there are likely lots of other factors, which is why articles often mention that the "true" death rate cannot yet be calculated. (Also the death rate varies a lot with age, and isn't the only factor in determining the "badness" of a virus. Which that second article goes into more depth on—things like how contagious it is, and how early a vaccine can be developed. So the average rate being half of the current numbers doesn't necessarily mean the concern is over-inflated as well.) [1]: https://www.nytimes.com/interactive/2020/world/coronavirus-maps.html https://www.nytimes.com/interactive/2020/world/coronavirus-m... [2]: https://www.nytimes.com/interactive/2020/world/asia/china-coronavirus-contain.html https://www.nytimes.com/interactive/2020/world/asia/china-co...
ChuckMcM 7y ago
> Does this mean that there's a good chance the death rate is lower than the current calculated 3% with so many recoveries going unreported? Yes and no. I'm not a doctor so an actual MD will step in here and correct me I'm sure. My understanding from reading both the CDC literature and the WHO literature is that there are two things, the SAR_nCOV2 virus which is out there spreading from host to host, and the COVID19 disease which is one manifestation of the virus in people. If my understanding is correct, the answer is that not everyone who gets infected by the virus will develop the disease. That can happen for a number of reasons apparently including but not limited to, a small enough sample got your immune system going fast enough that you didn't develop the disease, or you have previously been exposed to something similar enough that your immune system got ahead of the virus, or during the course of the infection your lungs didn't get involved before the immune system had begun producing anti-bodies. To explain the numbers, the fatality rate is a function of only those people who develop the disease. Your chance of developing the disease is a function of how strong your immune system is and so it develops more commonly in people with weak or otherwise compromised immune systems. But take this as just one opinion based on reading the literature. It sounds to me as if it is similar to the difference between HIV and AIDS, where you can become infected with the HIV virus but not develop AIDS if that virus is kept minimized with anti-virals.
- maxerickson 7y ago
  Can you please post a source for asymptomatic infection with SARS-CoV-2 not being considered a COVID-19 infection? Your opinion isn't good enough. Here's the WHO drawing a pretty limited distinction, with one name being used for science and one for public communication: https://www.who.int/emergencies/diseases/novel-coronavirus-2019/technical-guidance/naming-the-coronavirus-disease-(covid-2019)-and-the-virus-that-causes-it https://www.who.int/emergencies/diseases/novel-coronavirus-2...
  - Fjolsvith 7y ago
    John Hopkins states: "COVID-19 is the disease, SARS-2-CoV is the virus." [1] 1. https://www.hopkinsguides.com/hopkins/view/Johns_Hopkins_ABX_Guide/540747/all/Coronavirus_COVID_19__SARS_CoV_2_ https://www.hopkinsguides.com/hopkins/view/Johns_Hopkins_ABX...
b0rsuk 7y ago
https://read.cash/@Jiang_Zhuoer_BTC.TOP_CEO/serious-advice-from-china-on-covic-19-prevention-a3fb8fea https://read.cash/@Jiang_Zhuoer_BTC.TOP_CEO/serious-advice-f... "Is the death rate 0.5% or 5%？It depends on whether the hospital is overloaded. Let's take a look at the data."
cameldrv 7y ago
I don't think so. There was a surveillance study in I believe Guangdong province where they tested tons of random people, and compared the positive rate with cases/population, and found that they had detected most all of them. Don't have the link at hand, sorry. There was also a statistical analysis of the Diamond Princess cases. That produced an estimate that about 17% of infections were asymptomatic. [1] It's possible that there are less asymptomatic cases among the older population, but between the Guangdong and the Diamond Princess data, I doubt it. The 3.4% CFR that everyone is looking at is also dependent on some reasonably adequate level of medical care. If this thing blows up, most people are going to be on their own, and in the absence of a miracle drug that is widely available (maybe Chloroquine?), the fatality rate with home care I would expect to be something like 10-15%. [1] https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2020.25.10.2000180 https://www.eurosurveillance.org/content/10.2807/1560-7917.E...

by brink 7y ago

marshallant 7y ago

And I would like to know how many people have died not due to coronavirus but it was labeled so because they just happened to have it when they passed away.

Mountain_Skies 7y ago

Isn't also true for influenza? I had flu symptoms back in January but other than telling my manager that I was going to be out of the office due to illness, never reported my flu to anyone. Doubt I'm the only one who did this.

learc83 7y ago
Yes this happens, but for the flu we have done large scale antibody studies, so we have an idea that for every x number of people who get treated, y number are actually infected. The problem is we don't have the same data for this virus yet.
zaroth 7y ago
CDC estimates the total number of flu infections at about 10-20% of the population, depending on the year. The total number of hospital cases is usually ~1-2% of the number of infections. The, e.g. “32 million cases of flu” reported by the CDC is not based on 32 million positive test results. It’s extrapolated based on a factor of how many cases require hospitalization, and how many people seek medical care, which itself is based on antibody and behavioral surveys. > The numbers of influenza illnesses were estimated from hospitalizations based on how many illnesses there are for every hospitalization, which was measured previously (5). > Some people with influenza will seek medical care, while others will not. CDC estimates the number of people who sought medical care for influenza using data from the 2010 Behavioral Risk Factor Surveillance Survey, which asked people whether they did or did not seek medical care for an influenza-like illness in the prior influenza season (6). After reading more about it [1] you almost wonder how much better than a WAG (“Wild Ass Guess”) it really is. Frankly I am finding this whole area of medical science entirely underwhelming relative to the potential impact to lives and economies of the world. https://www.cdc.gov/flu/about/burden/how-cdc-estimates.htm https://www.cdc.gov/flu/about/burden/how-cdc-estimates.htm

deleted 7y ago

[deleted]

owenmarshall 7y ago

> However everyone that dies of coronavirus is reported as a coronavirus case. That seems unlikely. Testing capacity in lots of the world is extremely limited. The US is reserving test kits for the most sick/at risk; people at a low risk are unlikely to be tested. It seems to me that the focus would be on testing alive people, and that we are subsequently undercounting deaths - at least, in these relatively early stages.

hef19898 7y ago
My impression was, that everybody with syptoms who ot hospitalized also got tested. So the number of undiagnosed death should be very low. And by an order of magnitude lower than the number of untested, but infected, cases out in the wild. But as everybody points out, the correct number can only be claculated after the fact. and even the it might be of.
- owenmarshall 7y ago
  I would definitely suspect you are right, though: many of the reports we’ve seen so far indicates community spread was occurring before the first case was detected - consider the Ohio estimate yesterday that ~1% of their population is infected. So long term a lower CFR seems to make sense.
  - hef19898 7y ago
    Sounds logical to me as well. That's also how I understood virologists and the like.

empath75 7y ago

I would say the odds that the hospitalization rate or death rate are significantly overestimated is pretty small given what it has done to the hospitals systems in places where it has spread even a little bit.

hef19898 7y ago
The absolute number of severe cases to be hospitalized overwhelmed hospitals. The relative number of severe cases, and fatalities, depends on the denominator. In our case, positive test results. So both things are true.
robert2020 7y ago
One would have to assume it’s overestimated. Authorities are going to be careful not to underestimate.

cstejerean 7y ago

So early on I was suspicious of the numbers from China, but since they have managed to control the spread (and it would be obvious if they didn’t and other cities started to look like Wuhan), that means they have done a good job of catching almost all of the cases, not just the symptomatic ones. Otherwise the ones they miss would continue to spread. Therefore it feels like at this point their data would be pretty representative of what percentage of the cases are severe vs critical and what the death rate is (accounting for both the overwhelmed medical case in Wuhan and for the under control case in rest of China). South Korea is also doing a pretty good job with testing to control the outbreak although they haven’t yet gotten it as under control as China does. So their numbers would be a good data point to cross-validate the China numbers. In countries like Italy (or Wuhan early on) the number of confirmed cases wasn’t equal to total cases as evidenced by continued growth of the epidemic. So it’s reasonable in those cases to assume that more severe cases are being found and less severe ones are being missed.

hef19898 7y ago
Also, Wuhan and Italy's north had their hospitals put under severe stress early on. That could have driven fatalities up as well.
meowface 7y ago
I'm no epidemiologist, but I think we might have to wait another month or two to see if there are any resurgences in China before we can be certain the containment really worked, no? Infectious disease expert Michael Osterholm recently said on a podcast that he and his colleagues expect there to be another outbreak in China within the next few months, once people start fully co-mingling again.
- maxerickson 7y ago
  They've done more than lock down in China: https://twitter.com/MikeIsaac/status/1238604080571772928 https://twitter.com/MikeIsaac/status/1238604080571772928 I don't see why they would back off of the monitoring and fever clinics without some better measure in place (a vaccine or effective treatment or whatever). It's of course very likely there will be new cases. The likelihood of unchecked spreading seems much lower.

holri 7y ago

This is the reason for the estimates (also in the article mentioned) of 1% instead of the calculated 3%. 1% is still 10x more than the flu.

thawaway1837 7y ago

A lot of dying people are not being diagnosed as because of CoronaVirus. The people who are dying are usually older, or have preexisting conditions and their deaths can easily be chalked to their age/condition.

djaychela 7y ago

Yeah, I think that's referred to as "the denominator problem". Have a listen to Sam Harris' podcast on it this week - the expert on there sees 0.6% as an upper bound for mortality for coronavirus as that's the figure from South Korea, where the testing has been most intensive, and even that doesn't cover everyone.

greedo 7y ago
Do you mean a lower bound? If SK, which seems to be doing a relatively good job is experiencing a CFR of .6%, then countries performing worse should experience a higher CFT.
- bonzini 7y ago
  That's the upper bound on the fatality rate if it infected the whole population. In actuality not even Hubei had 0.1% of the population infected, so the numbers will be higher if it mostly infects older people (Italy), and lower if it mostly infects younger people (South Korea).
- tunesmith 7y ago
  0.6% is way out of date, as it was measured when many of the active cases were very early. At that time, I think I saw that deaths/cases was 0.6% and deaths/(deaths+recoveries) was 28.5%. As of today, deaths/cases is 0.9% and deaths/(deaths+recoveries) is about 9% . (Going by the numbers at worldometers.info)
JamesBarney 7y ago
But that's with the assumption the health system doesn't get overwhelmed. Once we run out of available oxygen, ventilators and ecmos that number starts to shoot up.
tunesmith 7y ago
As of yesterday, South Korea was up to 0.9% .

ianstormtaylor 7y ago

Not exactly. I'm not sure where you're getting the 3% number from. If you read the New York Times maps page data[1] and just divide the total deaths by total cases you get 3.7%, but that isn't the death rate because it doesn't take in to account a lot of factors. Instead, there's a good article[2] about how bad the virus will get, that says estimates put it in the range of 0.1% to 3%. (With the seasonal flu being somewhere around 0.1%, but the Spanish Flu of 1918 being somewhere around 3%.) That said, the general intuition that less reporting of cases means that some part of the death rate is over-inflated makes sense. But also consider that there are factors that go in the other direction. Anyone who currently has the virus but has not recovered or died can be under-inflating that rate. And there are likely lots of other factors, which is why articles often mention that the "true" death rate cannot yet be calculated. (Also the death rate varies a lot with age, and isn't the only factor in determining the "badness" of a virus. Which that second article goes into more depth on—things like how contagious it is, and how early a vaccine can be developed. So the average rate being half of the current numbers doesn't necessarily mean the concern is over-inflated as well.) [1]: https://www.nytimes.com/interactive/2020/world/coronavirus-maps.html https://www.nytimes.com/interactive/2020/world/coronavirus-m... [2]: https://www.nytimes.com/interactive/2020/world/asia/china-coronavirus-contain.html https://www.nytimes.com/interactive/2020/world/asia/china-co...

ChuckMcM 7y ago

> Does this mean that there's a good chance the death rate is lower than the current calculated 3% with so many recoveries going unreported? Yes and no. I'm not a doctor so an actual MD will step in here and correct me I'm sure. My understanding from reading both the CDC literature and the WHO literature is that there are two things, the SAR_nCOV2 virus which is out there spreading from host to host, and the COVID19 disease which is one manifestation of the virus in people. If my understanding is correct, the answer is that not everyone who gets infected by the virus will develop the disease. That can happen for a number of reasons apparently including but not limited to, a small enough sample got your immune system going fast enough that you didn't develop the disease, or you have previously been exposed to something similar enough that your immune system got ahead of the virus, or during the course of the infection your lungs didn't get involved before the immune system had begun producing anti-bodies. To explain the numbers, the fatality rate is a function of only those people who develop the disease. Your chance of developing the disease is a function of how strong your immune system is and so it develops more commonly in people with weak or otherwise compromised immune systems. But take this as just one opinion based on reading the literature. It sounds to me as if it is similar to the difference between HIV and AIDS, where you can become infected with the HIV virus but not develop AIDS if that virus is kept minimized with anti-virals.

maxerickson 7y ago
Can you please post a source for asymptomatic infection with SARS-CoV-2 not being considered a COVID-19 infection? Your opinion isn't good enough. Here's the WHO drawing a pretty limited distinction, with one name being used for science and one for public communication: https://www.who.int/emergencies/diseases/novel-coronavirus-2019/technical-guidance/naming-the-coronavirus-disease-(covid-2019)-and-the-virus-that-causes-it https://www.who.int/emergencies/diseases/novel-coronavirus-2...
- Fjolsvith 7y ago
  John Hopkins states: "COVID-19 is the disease, SARS-2-CoV is the virus." [1] 1. https://www.hopkinsguides.com/hopkins/view/Johns_Hopkins_ABX_Guide/540747/all/Coronavirus_COVID_19__SARS_CoV_2_ https://www.hopkinsguides.com/hopkins/view/Johns_Hopkins_ABX...

b0rsuk 7y ago

https://read.cash/@Jiang_Zhuoer_BTC.TOP_CEO/serious-advice-from-china-on-covic-19-prevention-a3fb8fea https://read.cash/@Jiang_Zhuoer_BTC.TOP_CEO/serious-advice-f... "Is the death rate 0.5% or 5%？It depends on whether the hospital is overloaded. Let's take a look at the data."

cameldrv 7y ago

I don't think so. There was a surveillance study in I believe Guangdong province where they tested tons of random people, and compared the positive rate with cases/population, and found that they had detected most all of them. Don't have the link at hand, sorry. There was also a statistical analysis of the Diamond Princess cases. That produced an estimate that about 17% of infections were asymptomatic. [1] It's possible that there are less asymptomatic cases among the older population, but between the Guangdong and the Diamond Princess data, I doubt it. The 3.4% CFR that everyone is looking at is also dependent on some reasonably adequate level of medical care. If this thing blows up, most people are going to be on their own, and in the absence of a miracle drug that is widely available (maybe Chloroquine?), the fatality rate with home care I would expect to be something like 10-15%. [1] https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2020.25.10.2000180 https://www.eurosurveillance.org/content/10.2807/1560-7917.E...