[BostonCard]

R0 is an estimate and based on both the behavior of the virus and its hosts.  Think of a virus that might be intrinsically not very infectious, like HIV, which requires intimate contact to spread (offset by the long time period that someone can be infectious but asymptomatic).  In a population that has very few sexual partners, the R0 will not be very high; in a population where individuals have a lot of sexual partners, the virus will spread quickly.

Likewise with the coronavirus, which will depend on how much contact and how close the contact is while individuals are able to transmit it.

BC

[BostonCard]

R0 is an estimate and based on both the behavior of the virus and its hosts.  Think of a virus that might be intrinsically not very infectious, like HIV, which requires intimate contact to spread (offset by the long time period that someone can be infectious but asymptomatic).  In a population that has very few sexual partners, the R0 will not be very high; in a population where individuals have a lot of sexual partners, the virus will spread quickly.

Likewise with the coronavirus, which will depend on how much contact and how close the contact is while individuals are able to transmit it.

BC

[burger]

I live 2 miles from the hospital where the first case of unknown origin in the US is being treated.  My Nextdoor feed is now half hysteria, half misinformation, and half "this is nothing" (thankfully I'm not on Facebook--I'm sure it's worse).  It is actually soothing to come here and see people discussing this rationally.

Fun article today: my local case of "unknown origin" may have an origin.  https://www.nytimes.com/2020/02/27/us/po...lower.html

[burger]

I live 2 miles from the hospital where the first case of unknown origin in the US is being treated.  My Nextdoor feed is now half hysteria, half misinformation, and half "this is nothing" (thankfully I'm not on Facebook--I'm sure it's worse).  It is actually soothing to come here and see people discussing this rationally.

Fun article today: my local case of "unknown origin" may have an origin.  https://www.nytimes.com/2020/02/27/us/po...lower.html

[OutsiderFan]

Ro study at Los Alamos National Lab link to PDF: https://arxiv.org/abs/2002.03268

[OutsiderFan]

Ro study at Los Alamos National Lab link to PDF: https://arxiv.org/abs/2002.03268

[French Rage]

My Nextdoor feed is now half hysteria, half misinformation, and half "this is nothing" (thankfully I'm not on Facebook--I'm sure it's worse).

This is true for anywhere at anytime, though.  :P

[French Rage]

My Nextdoor feed is now half hysteria, half misinformation, and half "this is nothing" (thankfully I'm not on Facebook--I'm sure it's worse).

This is true for anywhere at anytime, though.  :P

[BostonCard]

Ro study at Los Alamos National Lab link to PDF: https://arxiv.org/abs/2002.03268

Thanks for the link.  One big question on all these estimates is the number of asymptomatic or lightly symptomatic (patients who feel like they have a run of the mill URI) who are contagious but not getting tested, and thus not included in the stats.  My guess is that estimates of R0 are probably low because of it (on the flip side, estimates of mortality are probably on the high side for the same reason; there are a lot fewer deaths who didn’t get tested than lightly symptomatic patients), as you can see in the disparity of the death rate in China versus countries that have done meticulous contact tracing).

BC

[BostonCard]

Ro study at Los Alamos National Lab link to PDF: https://arxiv.org/abs/2002.03268

Thanks for the link.  One big question on all these estimates is the number of asymptomatic or lightly symptomatic (patients who feel like they have a run of the mill URI) who are contagious but not getting tested, and thus not included in the stats.  My guess is that estimates of R0 are probably low because of it (on the flip side, estimates of mortality are probably on the high side for the same reason; there are a lot fewer deaths who didn’t get tested than lightly symptomatic patients), as you can see in the disparity of the death rate in China versus countries that have done meticulous contact tracing).

BC

[M T]

The reported mortality rates mean that you as an individual probably have a decent chance of survival, but applied to entire populations, the implications are not good.

I have removed a calculation that I did here (available upon request) because it could be misunderstood and is alarming if misunderstood.  The final conclusion, based on the Chinese CDC numbers and the population distribution of the US, was that the death rate (across the total population) for those confirmed with Covid-19 will be 3 times than if they don't get the disease.

While some don't believe the denominator of the number of cases in China, I've yet to see any demonstration that they are wrong.  On a newscast, I saw a woman from WHO that was investigating that.  My understanding is that she said they haven't found that the numbers are wrong.  I've not been able to find that newscast.  I did find a WHO-China joint mission which seemed to accept the denominator, as reported 24-Feb

Earlier today the WHO-China joint mission concluded its visit and delivered its report.
As you know, the team has traveled to several different provinces, including Wuhan.
The team has made a range of findings about the transmissibility of the virus, the severity of disease and the impact of the measures taken.
They found that the fatality rate is between 2% and 4% in Wuhan, and 0.7% outside Wuhan.
They found that for people with mild disease, recovery time is about two weeks, while people with severe or critical disease recover within three to six weeks.

(emphasis added)

HOWEVER, note that the fatality rate (0.7%) outside Wuhan was 1/3 to 1/6  of the rate in Wuhan.  This suggests to me that the fatality rate was much lower when the health care system wasn't overloaded.   I hope that to be the case in the rest of the world IF steps are taken to limit transmission, thus avoiding overwhelming the health care system.

[M T]

The reported mortality rates mean that you as an individual probably have a decent chance of survival, but applied to entire populations, the implications are not good.

I have removed a calculation that I did here (available upon request) because it could be misunderstood and is alarming if misunderstood.  The final conclusion, based on the Chinese CDC numbers and the population distribution of the US, was that the death rate (across the total population) for those confirmed with Covid-19 will be 3 times than if they don't get the disease.

While some don't believe the denominator of the number of cases in China, I've yet to see any demonstration that they are wrong.  On a newscast, I saw a woman from WHO that was investigating that.  My understanding is that she said they haven't found that the numbers are wrong.  I've not been able to find that newscast.  I did find a WHO-China joint mission which seemed to accept the denominator, as reported 24-Feb

Earlier today the WHO-China joint mission concluded its visit and delivered its report.
As you know, the team has traveled to several different provinces, including Wuhan.
The team has made a range of findings about the transmissibility of the virus, the severity of disease and the impact of the measures taken.
They found that the fatality rate is between 2% and 4% in Wuhan, and 0.7% outside Wuhan.
They found that for people with mild disease, recovery time is about two weeks, while people with severe or critical disease recover within three to six weeks.

(emphasis added)

HOWEVER, note that the fatality rate (0.7%) outside Wuhan was 1/3 to 1/6  of the rate in Wuhan.  This suggests to me that the fatality rate was much lower when the health care system wasn't overloaded.   I hope that to be the case in the rest of the world IF steps are taken to limit transmission, thus avoiding overwhelming the health care system.

[OutsiderFan]

HOWEVER, note that the fatality rate (0.7%) outside Wuhan was 1/3 to 1/6  of the rate in Wuhan.  This suggests to me that the fatality rate was much lower when the health care system wasn't overloaded.   I hope that to be the case in the rest of the world IF steps are taken to limit transmission, thus avoiding overwhelming the health care system.

This is the reason we can’t F around with this virus. Look at Iran to see what happens when healthcare system can’t handle to burden of needing to get so many people on oxygen or ventilators. We simply must prevent geometric and exponential spread or we won’t be able to handle the load.

My other concern is people not going to hospital for care and refusing tests because they can’t afford paying medical bills. And then there is the potential of wearing down health care workers if they are overloaded. Some reports from China have shown psychological damage to healthcare workers from stress and being so overworked, akin to PTSD.

[OutsiderFan]

HOWEVER, note that the fatality rate (0.7%) outside Wuhan was 1/3 to 1/6  of the rate in Wuhan.  This suggests to me that the fatality rate was much lower when the health care system wasn't overloaded.   I hope that to be the case in the rest of the world IF steps are taken to limit transmission, thus avoiding overwhelming the health care system.

This is the reason we can’t F around with this virus. Look at Iran to see what happens when healthcare system can’t handle to burden of needing to get so many people on oxygen or ventilators. We simply must prevent geometric and exponential spread or we won’t be able to handle the load.

My other concern is people not going to hospital for care and refusing tests because they can’t afford paying medical bills. And then there is the potential of wearing down health care workers if they are overloaded. Some reports from China have shown psychological damage to healthcare workers from stress and being so overworked, akin to PTSD.

[BostonCard]

MT, the fatality rate is for diagnosed cases. There’s good reason to believe not all cases of mild disease are diagnosed or confirmed.

BC

[BostonCard]

MT, the fatality rate is for diagnosed cases. There’s good reason to believe not all cases of mild disease are diagnosed or confirmed.

BC

[Snorlax94]

HOWEVER, note that the fatality rate (0.7%) outside Wuhan was 1/3 to 1/6  of the rate in Wuhan.  This suggests to me that the fatality rate was much lower when the health care system wasn't overloaded.   I hope that to be the case in the rest of the world IF steps are taken to limit transmission, thus avoiding overwhelming the health care system.

This is the reason we can’t F around with this virus. Look at Iran to see what happens when healthcare system can’t handle to burden of needing to get so many people on oxygen or ventilators. We simply must prevent geometric and exponential spread or we won’t be able to handle the load.

My other concern is people not going to hospital for care and refusing tests because they can’t afford paying medical bills. And then there is the potential of wearing down health care workers if they are overloaded. Some reports from China have shown psychological damage to healthcare workers from stress and being so overworked, akin to PTSD.

This runs the risk of being considered a “political comment” but it stuns me and concerns me that the federal government doesn’t appear to be taking covid 19 seriously. Some in government and in the media keep insisting “it’s just a cold.” 

It boggles my mind that money wasn’t allocated a month ago for communities to stock up on more masks, gloves, barriers, ventilators and possible treatments (i know there is already an existing stockpile, but in a bad scenario, it won’t be enough). It boggles my mind that the federal government hasn’t urged for ramped up production of possibly needed supplies. 

I am also a bit mystified that the US seems like the only developed country without a fast, accurate, functioning test. Recently, it seems like an ill patient went many days undiagnosed (though thankfully suspected) because the CDC dragged its feet to run tests, then took a long time to get results.

I was just in Hawaii and I can’t imagine the current government would ever do anything to risk those international tourist dollars, whatever the risk. (I could see one more travel restriction on s korea and don’t think they’d do anything more except in a doomsday scenario).

I am also cynical that further restrictions aren’t being taken because the government wants to protect the profits of the travel and hospitality industries. I know people who have already purchased tickets to travel abroad and feel pressured to go because they don’t want to lose the money. I think it’d be worth it to pass a law making non-refundable international travel refundable. I could see that being a great protective measure, but am very cynical. I do worry that covid 19 could spread more widely due to prioritizing $$ > lives.

Too political?

[Snorlax94]

HOWEVER, note that the fatality rate (0.7%) outside Wuhan was 1/3 to 1/6  of the rate in Wuhan.  This suggests to me that the fatality rate was much lower when the health care system wasn't overloaded.   I hope that to be the case in the rest of the world IF steps are taken to limit transmission, thus avoiding overwhelming the health care system.

This is the reason we can’t F around with this virus. Look at Iran to see what happens when healthcare system can’t handle to burden of needing to get so many people on oxygen or ventilators. We simply must prevent geometric and exponential spread or we won’t be able to handle the load.

My other concern is people not going to hospital for care and refusing tests because they can’t afford paying medical bills. And then there is the potential of wearing down health care workers if they are overloaded. Some reports from China have shown psychological damage to healthcare workers from stress and being so overworked, akin to PTSD.

This runs the risk of being considered a “political comment” but it stuns me and concerns me that the federal government doesn’t appear to be taking covid 19 seriously. Some in government and in the media keep insisting “it’s just a cold.” 

It boggles my mind that money wasn’t allocated a month ago for communities to stock up on more masks, gloves, barriers, ventilators and possible treatments (i know there is already an existing stockpile, but in a bad scenario, it won’t be enough). It boggles my mind that the federal government hasn’t urged for ramped up production of possibly needed supplies. 

I am also a bit mystified that the US seems like the only developed country without a fast, accurate, functioning test. Recently, it seems like an ill patient went many days undiagnosed (though thankfully suspected) because the CDC dragged its feet to run tests, then took a long time to get results.

I was just in Hawaii and I can’t imagine the current government would ever do anything to risk those international tourist dollars, whatever the risk. (I could see one more travel restriction on s korea and don’t think they’d do anything more except in a doomsday scenario).

I am also cynical that further restrictions aren’t being taken because the government wants to protect the profits of the travel and hospitality industries. I know people who have already purchased tickets to travel abroad and feel pressured to go because they don’t want to lose the money. I think it’d be worth it to pass a law making non-refundable international travel refundable. I could see that being a great protective measure, but am very cynical. I do worry that covid 19 could spread more widely due to prioritizing $$ > lives.

Too political?

[oldalum]

 the fatality rate is for diagnosed cases. There’s good reason to believe not all cases of mild disease are diagnosed or confirmed.

Yes! And we don't know if there are significant numbers of asymptomatic cases, because only symptomatic people are being tested! But viral infections in general do produce asymptomatic cases, no reason to think this virus will be any different. The denominator is unknown and unknowable at this point. The publicized fatality rates are estimates, not reliable facts, and are likely too high.

[oldalum]

 the fatality rate is for diagnosed cases. There’s good reason to believe not all cases of mild disease are diagnosed or confirmed.

Yes! And we don't know if there are significant numbers of asymptomatic cases, because only symptomatic people are being tested! But viral infections in general do produce asymptomatic cases, no reason to think this virus will be any different. The denominator is unknown and unknowable at this point. The publicized fatality rates are estimates, not reliable facts, and are likely too high.

[OutsiderFan]

I just saw a BBC report that the UK has already tested 7,000+ people and is planning many drive up testing services. They showed the operation. It’s apparently really simple. To me, this is something that should be part and parcel of a coordinated government response. Don’t make anyone pay for it - brand it as a CDC program - and put the testing drive ups in mall parking lots.

But do we even have a way to coordinate from CDC to state health officials to local? 

OMG, I just went to CDC website to see their updated requirements for testing in wake of UC Davis case. Though they no longer require someone to have had or been close to someone who recently travelled to China specifically, they still are requiring fever as prerequisite for testing EVEN THOUGH IT HAS ASYMPTOMATIC TRANSMISSION! This is just irresponsible. Think the UK and South Korea are requiring fever for drive up tests?

Perhaps this is why the State of New York is developing its own test, maybe planning to flaunt the CDC guidelines for who to test as well. https://www.buzzfeednews.com/article/dan...w-york-cdc

Of course, this doesn’t address the who pays for the tests question. 

On that same BBC report, a UK health official questioned the merits of quarantines and shutdowns because they don’t seem to be working that well other than the way the Chineses shut things down that could never be pulled off in western countries, people can’t stop doing dumb things like hoarding food all at once and because seizing up the economy will  not be worth the cost. In a world economy propped up by debt, with paycheck to paycheck economies and JIT delivery, he may be right.

It’s a balancing act I have little confidence humans can successfully make. IOW, no matter how a government decides to handle, there is going to be major pain felt. Protect population health and economy tanks. Encourage business as usual and overrun the medical system.

[OutsiderFan]

I just saw a BBC report that the UK has already tested 7,000+ people and is planning many drive up testing services. They showed the operation. It’s apparently really simple. To me, this is something that should be part and parcel of a coordinated government response. Don’t make anyone pay for it - brand it as a CDC program - and put the testing drive ups in mall parking lots.

But do we even have a way to coordinate from CDC to state health officials to local? 

OMG, I just went to CDC website to see their updated requirements for testing in wake of UC Davis case. Though they no longer require someone to have had or been close to someone who recently travelled to China specifically, they still are requiring fever as prerequisite for testing EVEN THOUGH IT HAS ASYMPTOMATIC TRANSMISSION! This is just irresponsible. Think the UK and South Korea are requiring fever for drive up tests?

Perhaps this is why the State of New York is developing its own test, maybe planning to flaunt the CDC guidelines for who to test as well. https://www.buzzfeednews.com/article/dan...w-york-cdc

Of course, this doesn’t address the who pays for the tests question. 

On that same BBC report, a UK health official questioned the merits of quarantines and shutdowns because they don’t seem to be working that well other than the way the Chineses shut things down that could never be pulled off in western countries, people can’t stop doing dumb things like hoarding food all at once and because seizing up the economy will  not be worth the cost. In a world economy propped up by debt, with paycheck to paycheck economies and JIT delivery, he may be right.

It’s a balancing act I have little confidence humans can successfully make. IOW, no matter how a government decides to handle, there is going to be major pain felt. Protect population health and economy tanks. Encourage business as usual and overrun the medical system.

[M T]

 the fatality rate is for diagnosed cases. There’s good reason to believe not all cases of mild disease are diagnosed or confirmed.

Yes! And we don't know if there are significant numbers of asymptomatic cases, because only symptomatic people are being tested! But viral infections in general do produce asymptomatic cases, no reason to think this virus will be any different. The denominator is unknown and unknowable at this point. The publicized fatality rates are estimates, not reliable facts, and are likely too high.

WHO's sitrep 30 (19 Feb) states

The confirmed case fatality ratio, or CFR,is the total number of deaths divided by the total number of confirmed cases at one point in time. Within China, the confirmed CFR, as reported by the Chinese Center for Disease Control and Prevention,9is 2.3%. This is based on 1023 deaths amongst 44 415 laboratory-confirmed cases as of 11 February. This CFR does not include the number of more mild infections that may be missed from current surveillance,which has largely focused on patients with pneumonia requiring hospitalization; nor does it account for the fact that recently confirmed cases may yet develop severe disease, and some may die. As the outbrak continues, the confirmed CFR may change

WHO's sitrep 38 (27 Feb) gives numbers that indicate current values of 4.0% CFR for Hubei and 3.5% CFR for China.
Hubei province: 2641 deaths in 65596 confirmed cases
China (total): 2747 deaths in 78630 confirmed cases.

The larger CFR now compared to 8 days earlier could be due just the maturity of the disease in the area.  Hubei has had more sick people longer, and more have eventually died. Other areas have not had many people sick for as long, potentially meaning that in a few weeks their CFR numbers will look similar. 

If, for whatever purpose, you want to make some other estimate different than CFR, you're free to do so.  But, the 4.0%, 3.5%, and 2.3% are measures, not estimates.

WHO-China Joint Mission Press Conference and article

A big question that still remains unanswered is how many mild cases go undetected, a metric that is key for getting a better handle on the disease's severity and fatality rate. Aylward said the group saw bits of information, such as testing of samples from China's flu surveillance system and testing of convenience samples, that hint the number of milder cases may not be great.

There are more interesting bits in that article.

Regarding the clinical spectrum, Aylward said about 88% of patients remember having a fever and 68% had a dry cough. Only about 12% had a runny nose, hinting that COVID-19 might not have much upper respiratory involvement. Some patients reported a prodrome that consisted of fatigue, muscle pain, and a vague feeling of being unwell.

[M T]

 the fatality rate is for diagnosed cases. There’s good reason to believe not all cases of mild disease are diagnosed or confirmed.

Yes! And we don't know if there are significant numbers of asymptomatic cases, because only symptomatic people are being tested! But viral infections in general do produce asymptomatic cases, no reason to think this virus will be any different. The denominator is unknown and unknowable at this point. The publicized fatality rates are estimates, not reliable facts, and are likely too high.

WHO's sitrep 30 (19 Feb) states

The confirmed case fatality ratio, or CFR,is the total number of deaths divided by the total number of confirmed cases at one point in time. Within China, the confirmed CFR, as reported by the Chinese Center for Disease Control and Prevention,9is 2.3%. This is based on 1023 deaths amongst 44 415 laboratory-confirmed cases as of 11 February. This CFR does not include the number of more mild infections that may be missed from current surveillance,which has largely focused on patients with pneumonia requiring hospitalization; nor does it account for the fact that recently confirmed cases may yet develop severe disease, and some may die. As the outbrak continues, the confirmed CFR may change

WHO's sitrep 38 (27 Feb) gives numbers that indicate current values of 4.0% CFR for Hubei and 3.5% CFR for China.
Hubei province: 2641 deaths in 65596 confirmed cases
China (total): 2747 deaths in 78630 confirmed cases.

The larger CFR now compared to 8 days earlier could be due just the maturity of the disease in the area.  Hubei has had more sick people longer, and more have eventually died. Other areas have not had many people sick for as long, potentially meaning that in a few weeks their CFR numbers will look similar. 

If, for whatever purpose, you want to make some other estimate different than CFR, you're free to do so.  But, the 4.0%, 3.5%, and 2.3% are measures, not estimates.

WHO-China Joint Mission Press Conference and article

A big question that still remains unanswered is how many mild cases go undetected, a metric that is key for getting a better handle on the disease's severity and fatality rate. Aylward said the group saw bits of information, such as testing of samples from China's flu surveillance system and testing of convenience samples, that hint the number of milder cases may not be great.

There are more interesting bits in that article.

Regarding the clinical spectrum, Aylward said about 88% of patients remember having a fever and 68% had a dry cough. Only about 12% had a runny nose, hinting that COVID-19 might not have much upper respiratory involvement. Some patients reported a prodrome that consisted of fatigue, muscle pain, and a vague feeling of being unwell.

[Goose]

I just saw a BBC report that the UK has already tested 7,000+ people and is planning many drive up testing services. They showed the operation. It’s apparently really simple. To me, this is something that should be part and parcel of a coordinated government response. Don’t make anyone pay for it - brand it as a CDC program - and put the testing drive ups in mall parking lots.



But do we even have a way to coordinate from CDC to state health officials to local? 



OMG, I just went to CDC website to see their updated requirements for testing in wake of UC Davis case. Though they no longer require someone to have had or been close to someone who recently travelled to China specifically, they still are requiring fever as prerequisite for testing EVEN THOUGH IT HAS ASYMPTOMATIC TRANSMISSION! This is just irresponsible. Think the UK and South Korea are requiring fever for drive up tests?

OF, before you conclude that a "drive up" testing approach is a good idea, it might be wise to consider that a limited number of testing kits are currently available. If they get consumed by people who are "just being safe" but have a low probability of being positive we will really have a problem if this outbreak becomes widespread. The capacity to manufacture these kits is also limited. We can't just order a bunch of them and have them show up in a week. The CDC is certainly being cautious about using them up, but that may be because they know we don't have "enough" and can't get "enough" soon.

[Goose]

I just saw a BBC report that the UK has already tested 7,000+ people and is planning many drive up testing services. They showed the operation. It’s apparently really simple. To me, this is something that should be part and parcel of a coordinated government response. Don’t make anyone pay for it - brand it as a CDC program - and put the testing drive ups in mall parking lots.



But do we even have a way to coordinate from CDC to state health officials to local? 



OMG, I just went to CDC website to see their updated requirements for testing in wake of UC Davis case. Though they no longer require someone to have had or been close to someone who recently travelled to China specifically, they still are requiring fever as prerequisite for testing EVEN THOUGH IT HAS ASYMPTOMATIC TRANSMISSION! This is just irresponsible. Think the UK and South Korea are requiring fever for drive up tests?

OF, before you conclude that a "drive up" testing approach is a good idea, it might be wise to consider that a limited number of testing kits are currently available. If they get consumed by people who are "just being safe" but have a low probability of being positive we will really have a problem if this outbreak becomes widespread. The capacity to manufacture these kits is also limited. We can't just order a bunch of them and have them show up in a week. The CDC is certainly being cautious about using them up, but that may be because they know we don't have "enough" and can't get "enough" soon.

[burger]

WHO's sitrep 30 (19 Feb) states

The confirmed case fatality ratio, or CFR,is the total number of deaths divided by the total number of confirmed cases at one point in time. Within China, the confirmed CFR, as reported by the Chinese Center for Disease Control and Prevention,9is 2.3%. This is based on 1023 deaths amongst 44 415 laboratory-confirmed cases as of 11 February. This CFR does not include the number of more mild infections that may be missed from current surveillance,which has largely focused on patients with pneumonia requiring hospitalization; nor does it account for the fact that recently confirmed cases may yet develop severe disease, and some may die. As the outbrak continues, the confirmed CFR may change

WHO's sitrep 38 (27 Feb) ginumbers that indicate current values of 4.0% CFR for Hubei and 3.5% CFR for China.

Hubei province: 2641 deaths in 65596 confirmed cases
China (total): 2747 deaths in 78630 confirmed cases.

The larger CFR now compared to 8 days earlier could be due just the maturity of the disease in the area.  Hubei has had more sick people longer, and more have eventually died. Other areas have not had many people sick for as long, potentially meaning that in a few weeks their CFR numbers will look similar. 

If, for whatever purpose, you want to make some other estimate different than CFR, you're free to do so.  But, the 4.0%, 3.5%, and 2.3% are measures, not estimates.

A few things here.  First, this is not the standard (and best, I think) way to calculate the CFR.  CFR should be an estimate of how likely you are to die if you get the disease.  So, you calculate that as (#dead)/(#dead + #recovered).  When you do that, you get higher numbers than the current estimates in China, but many cases have yet to be resolved, and that measure of CFR is declining over time.

But...as above, this doesn't count the mild/asymptomatic cases that aren't showing up in hospitals or getting tested in China.  How many of those are there?  The Diamond Princess might give us an answer.  They have 4 deaths in 700 cases so far (I think 30+ still are in the hospital with uncertain outcome).  The rest of Japan has 200 cases 4 deaths.  So that implies that the testing regime in Japan at least is only getting ~40% of cases. And that means that CFR may be much lower than currently estimated.

Like I said above, there's tons of uncertainty still.

[burger]

WHO's sitrep 30 (19 Feb) states

The confirmed case fatality ratio, or CFR,is the total number of deaths divided by the total number of confirmed cases at one point in time. Within China, the confirmed CFR, as reported by the Chinese Center for Disease Control and Prevention,9is 2.3%. This is based on 1023 deaths amongst 44 415 laboratory-confirmed cases as of 11 February. This CFR does not include the number of more mild infections that may be missed from current surveillance,which has largely focused on patients with pneumonia requiring hospitalization; nor does it account for the fact that recently confirmed cases may yet develop severe disease, and some may die. As the outbrak continues, the confirmed CFR may change

WHO's sitrep 38 (27 Feb) ginumbers that indicate current values of 4.0% CFR for Hubei and 3.5% CFR for China.

Hubei province: 2641 deaths in 65596 confirmed cases
China (total): 2747 deaths in 78630 confirmed cases.

The larger CFR now compared to 8 days earlier could be due just the maturity of the disease in the area.  Hubei has had more sick people longer, and more have eventually died. Other areas have not had many people sick for as long, potentially meaning that in a few weeks their CFR numbers will look similar. 

If, for whatever purpose, you want to make some other estimate different than CFR, you're free to do so.  But, the 4.0%, 3.5%, and 2.3% are measures, not estimates.

A few things here.  First, this is not the standard (and best, I think) way to calculate the CFR.  CFR should be an estimate of how likely you are to die if you get the disease.  So, you calculate that as (#dead)/(#dead + #recovered).  When you do that, you get higher numbers than the current estimates in China, but many cases have yet to be resolved, and that measure of CFR is declining over time.

But...as above, this doesn't count the mild/asymptomatic cases that aren't showing up in hospitals or getting tested in China.  How many of those are there?  The Diamond Princess might give us an answer.  They have 4 deaths in 700 cases so far (I think 30+ still are in the hospital with uncertain outcome).  The rest of Japan has 200 cases 4 deaths.  So that implies that the testing regime in Japan at least is only getting ~40% of cases. And that means that CFR may be much lower than currently estimated.

Like I said above, there's tons of uncertainty still.

[oldalum]

If, for whatever purpose, you want to make some other estimate different than CFR, you're free to do so.  But, the 4.0%, 3.5%, and 2.3% are measures, not estimates.

To be precise, they are measures that are being used as estimates of the true CFR because they are the best information we have. In this context, the term "estimate" is a statistical term: we are using a measured value from a sample of a population to estimate an unknown population parameter. The true population parameter is the item of interest: what can we expect the case fatality rate will be if the infection spreads among the general population in specific areas/countries. The information you provided from WHO explains why the current sample is inaccurate and the (sample) CFR will change over time and become a better estimate of the true population CFR. And a population's CFR, as has been pointed out, depends on the unique age and illness distribution of that population as well as its health care system and resources.

[oldalum]

If, for whatever purpose, you want to make some other estimate different than CFR, you're free to do so.  But, the 4.0%, 3.5%, and 2.3% are measures, not estimates.

To be precise, they are measures that are being used as estimates of the true CFR because they are the best information we have. In this context, the term "estimate" is a statistical term: we are using a measured value from a sample of a population to estimate an unknown population parameter. The true population parameter is the item of interest: what can we expect the case fatality rate will be if the infection spreads among the general population in specific areas/countries. The information you provided from WHO explains why the current sample is inaccurate and the (sample) CFR will change over time and become a better estimate of the true population CFR. And a population's CFR, as has been pointed out, depends on the unique age and illness distribution of that population as well as its health care system and resources.

[TheRicker]

3M Quick Reference Guide:  Disposable Respirators.  PDF.
Scroll down to page 3, under N95 Respirator and surgical masks.

http://multimedia.3m.com/mws/media/14342...rators.pdf

Possible alternatives to N95 surgical and healthcare masks
https://multimedia.3m.com/mws/media/1798...lletin.pdf

Provided for reference only.

[TheRicker]

3M Quick Reference Guide:  Disposable Respirators.  PDF.
Scroll down to page 3, under N95 Respirator and surgical masks.

http://multimedia.3m.com/mws/media/14342...rators.pdf

Possible alternatives to N95 surgical and healthcare masks
https://multimedia.3m.com/mws/media/1798...lletin.pdf

Provided for reference only.

[burger]

OF, before you conclude that a "drive up" testing approach is a good idea, it might be wise to consider that a limited number of testing kits are currently available. If they get consumed by people who are "just being safe" but have a low probability of being positive we will really have a problem if this outbreak becomes widespread. The capacity to manufacture these kits is also limited. We can't just order a bunch of them and have them show up in a week. The CDC is certainly being cautious about using them up, but that may be because they know we don't have "enough" and can't get "enough" soon.

I agree that there's no need to just test everyone but, what's happened so far with the CDC is criminal malpractice.  Until yesterday, they were only testing people with travel history to China or an association with a known virus patient.  Also, they still have not figured out any way to do the testing outside of Atlanta--yes, all the tests have to be shipped to Georgia. 

Meanwhile, every other developed country is testing far more people than we are.  Every day I'm reading about faster and cheaper tests.  We're stuck in the dark ages, test wise.  Whoever was making these decisions at CDC (or above them) should have been fired already.  i fear this mismanagement will only get worse as the crisis deepens.

[burger]

OF, before you conclude that a "drive up" testing approach is a good idea, it might be wise to consider that a limited number of testing kits are currently available. If they get consumed by people who are "just being safe" but have a low probability of being positive we will really have a problem if this outbreak becomes widespread. The capacity to manufacture these kits is also limited. We can't just order a bunch of them and have them show up in a week. The CDC is certainly being cautious about using them up, but that may be because they know we don't have "enough" and can't get "enough" soon.

I agree that there's no need to just test everyone but, what's happened so far with the CDC is criminal malpractice.  Until yesterday, they were only testing people with travel history to China or an association with a known virus patient.  Also, they still have not figured out any way to do the testing outside of Atlanta--yes, all the tests have to be shipped to Georgia. 

Meanwhile, every other developed country is testing far more people than we are.  Every day I'm reading about faster and cheaper tests.  We're stuck in the dark ages, test wise.  Whoever was making these decisions at CDC (or above them) should have been fired already.  i fear this mismanagement will only get worse as the crisis deepens.

[OutsiderFan]

OF, before you conclude that a "drive up" testing approach is a good idea, it might be wise to consider that a limited number of testing kits are currently available. If they get consumed by people who are "just being safe" but have a low probability of being positive we will really have a problem if this outbreak becomes widespread. The capacity to manufacture these kits is also limited. We can't just order a bunch of them and have them show up in a week. The CDC is certainly being cautious about using them up, but that may be because they know we don't have "enough" and can't get "enough" soon.

If it was hard to test, there is no way these other countries could be doing tests on the scale they are. I didn't say everyone should be tested. There should be some criteria. Moreover, the point of doing widespread testing is for surveillance, to get a picture for what is happening in terms of community spread. It is not to identify every virus carrier per se, but to understand what is happening for planning purposes. Without widespread testing we are blind.

[OutsiderFan]

OF, before you conclude that a "drive up" testing approach is a good idea, it might be wise to consider that a limited number of testing kits are currently available. If they get consumed by people who are "just being safe" but have a low probability of being positive we will really have a problem if this outbreak becomes widespread. The capacity to manufacture these kits is also limited. We can't just order a bunch of them and have them show up in a week. The CDC is certainly being cautious about using them up, but that may be because they know we don't have "enough" and can't get "enough" soon.

If it was hard to test, there is no way these other countries could be doing tests on the scale they are. I didn't say everyone should be tested. There should be some criteria. Moreover, the point of doing widespread testing is for surveillance, to get a picture for what is happening in terms of community spread. It is not to identify every virus carrier per se, but to understand what is happening for planning purposes. Without widespread testing we are blind.

[2006alum]

 Whoever was making these decisions at CDC (or above them) should have been fired already.  i fear this mismanagement will only get worse as the crisis deepens.

Well, unfortunately they already were fired - back in 2018: https://fortune.com/2020/02/26/coronavir...-us-trump/

[2006alum]

 Whoever was making these decisions at CDC (or above them) should have been fired already.  i fear this mismanagement will only get worse as the crisis deepens.

Well, unfortunately they already were fired - back in 2018: https://fortune.com/2020/02/26/coronavir...-us-trump/

[oldalum]

the latest from the CDC and NIH on the case fatality rate, articles published today in the New England J of Medicine: free NEJM article

On the basis of a case definition requiring a diagnosis of pneumonia, the currently reported case fatality rate is approximately 2%. In another article in the Journal, Guan et al. report mortality of 1.4% among 1099 patients with laboratory-confirmed Covid-19; these patients had a wide spectrum of disease severity. If one assumes that the number of asymptomatic or minimally symptomatic cases is several times as high as the number of reported cases, the case fatality rate may be considerably less than 1%. This suggests that the overall clinical consequences of Covid-19 may ultimately be more akin to those of a severe seasonal influenza (which has a case fatality rate of approximately 0.1%) or a pandemic influenza (similar to those in 1957 and 1968) rather than a disease similar to SARS or MERS, which have had case fatality rates of 9 to 10% and 36%, respectively.

[oldalum]

the latest from the CDC and NIH on the case fatality rate, articles published today in the New England J of Medicine: free NEJM article

On the basis of a case definition requiring a diagnosis of pneumonia, the currently reported case fatality rate is approximately 2%. In another article in the Journal, Guan et al. report mortality of 1.4% among 1099 patients with laboratory-confirmed Covid-19; these patients had a wide spectrum of disease severity. If one assumes that the number of asymptomatic or minimally symptomatic cases is several times as high as the number of reported cases, the case fatality rate may be considerably less than 1%. This suggests that the overall clinical consequences of Covid-19 may ultimately be more akin to those of a severe seasonal influenza (which has a case fatality rate of approximately 0.1%) or a pandemic influenza (similar to those in 1957 and 1968) rather than a disease similar to SARS or MERS, which have had case fatality rates of 9 to 10% and 36%, respectively.