Coronavirus Math

irvinehomeowner

Well-known member
These posts keep getting lost in the coronavirus thread so let's use this one to discuss just numbers and math for Covid-19.

I think there are some flaws in the numbers being thrown out there which is fine because I know it's more to stress the importance of social distancing and the need for medical supplies but some things to consider:

Death Rate %:

While this number varies from area to area, this will always be higher than the actual death rate because there is a large number of corona positive people we don't know about... maybe factors of 10+. So if a death rate is say 3% but the actual number of people who have corona are 10x more than those who have taken the test and are positive, the actual death rate is .3%.

Infection %:

Most calculations I see are a worst case scenario but this is also dependent on number tested and time span. While this may reflect a percentage over several months, this is a rolling number as not everyone is infected at the same exact time.

So using numbers from these two sites:
https://www.worldometers.info/coronavirus/#countrieshttps://ourworldindata.org/coronavirus-testing-source-data

Let's take South Korea for an example, since they have tested the most people (caveat... these numbers are pulled from the Internet so not sure how accurate):

Coronavirus Cases:
9,137
Deaths:
126
Recovered:
3,730

The death rate based on the above numbers is 1.4% of those *known to be infected*.

But let's extrapolate that out.

According to this site:https://ourworldindata.org/coronavirus-testing-source-data

316,664 have been tested. Total population of Korea is about 51.5m... so using the tested data percentage of infection (like I said, a dependent number):

9137/316664 = 2.9% infection rate

Using that number and the current death rate, we are looking at 2.9% x 51.5m x 1.4% = 20,909 deaths.

That number while compared to the population seems low, looks like a huge number in isolation. Do we really think South Korea will have about 20k dead with their stringent controls in place?

Let's say South Korea was late and is like Italy with close to a 36% infection rate and death rate of 10%:

10% of 18.54m = 1,854,0000 deaths?

Does that look right? Almost 2m South Koreans would have died? And let's using Italy's numbers on Italy itself, 2,178,000 will die?

I'm asking because this is the same kind of extrapolation people are making for the US and I don't think it's accurate.

And don't get me wrong, this is not to say this is not serious and the stress on available medical staff/devices will be more, but on the other side, it may be exaggerated when you actually look at the numbers.

I guess I'm trying to get at here is what is the actual infection rate? And of those infected, what is the actual death rate?

My math above is probably wrong, but at the same time, it's hard for me to understand the numbers being thrown about based on actual data that we can see.

TLDR: Are the numbers being forecast for the US realistic, under or over?
 
I guess math is not a popular subject. Let's talk more numbers.

The Imperial College report is one of the reasons why the Fed, Cali and NY to call for a lockdown. I think that's where Gov. Newsom got his 55% infection rate number.

Earlier this week, Oxford University called into question the accuracy of that report:
https://theweek.com/speedreads/9045...e-may-have-already-built-coronavirus-immunity

A model predicting the progression of the novel coronavirus pandemic produced by researchers at Imperial College London set off alarms across the world and was a major factor in several governments' decisions to lock things down. But a new model from Oxford University is challenging its accuracy, the Financial Times reports.

The Oxford research suggests the pandemic is in a later stage than previously thought and estimates the virus has already infected at least millions of people worldwide. In the United Kingdom, which the study focuses on, half the population would have already been infected. If accurate, that would mean transmission began around mid-January and the vast majority of cases presented mild or no symptoms.

The head of the study, professor Sunetra Gupta, an Oxford theoretical epidemiologist, said she still supports the U.K.'s decision to shut down the country to suppress the virus even if her research winds up being proven correct. But she also doesn't appear to be a big fan of the work done by the Imperial College team. "I am surprised that there has been such unqualified acceptance of the Imperial model," she said.

And today, Neil Ferguson, the man behind the Imperial College report that predicted as much as 2.2m deaths in the US and 500,000 deaths in Britain, is now scaling back his predictions.
https://thefederalist.com/2020/03/2...just-walked-back-the-apocalyptic-predictions/

But after tens of thousands of restaurants, bars, and businesses closed, Ferguson is now retracting his modeling, saying he feels ?reasonably confident? our health care system can cope when the predicted peak of the epidemic arrives in a few weeks. Testifying before the U.K.?s parliamentary select committee on science and technology on Wednesday, Ferguson said he now predicts U.K. deaths from the disease will not exceed 20,000, and could be much lower.

I still feel the lockdown was a necessary precaution but this is what I mean by flawed math and we need to be careful with the numbers being thrown.

Another popular "math" video going around on Facebook is from Dr. Emily Porter out of Texas who uses CDC's 40-70% infection rate prediction to come out with a somber conclusion that 49 out of 50 people who need ventilators won't get them:
https://www.ibtimes.sg/scary-covid-...-1-50-will-get-ventilator-support-video-41542

Porter then goes on to explain the crisis situation with a lot of numbers and calculations to make things clear for people.

"In America, we have 331 million people. The CDC (Centers for Disease Control and Prevention) is estimating that about 40 to 70 percent of them will get infected. So to make the numbers easy, I am gonna say that its 150 million people, that's about 45%. So if 150 million people get infected, 80% of them are gonna be just fine. So 20% of people will need hospitalisation,"

After mentioning about the crisis situation Italy is facing with shortage of beds in hospitals due to the Coronavirus outbreak, she added: "5-10% of the 150 million that get infected are going to need a ventilator life support. It helps their lungs rest, it helps their hearts rest, it gives their body time to heal because we don't have a cure for this virus. Let's say 5% of the people need ventilators, 5% of 150 million people is 7.5 million vents needed in America."

As per her calculation, in Texas alone, there would be about 4,000 ventilators and nationwide, it is estimated to be almost 720,00 to 120,000. She says that even if the country has a total of 150,000 ventilators, only 0.02% of people could get it, which means, one in fifty people can only get the vent support, clearly indicating the death of 49 people.

"That's scary. That should scare you. That scares me. That should scare everybody who should understand basic math, including my second grader," she added.

However, that "basic math" means 98% of the 7.5m who will need ventilators and can't get them could die... which is 7.35m... that's over 3x higher than the Imperial College report.

Her scenario also does not take into account that 7.5m people will not need ventilators at the same time.

But people I talk to say she's a doctor so her numbers have to be accurate. I'm not questioning her medical degree... just her method of math.

Again, I still agree with all the measures we are taking, but I would just like more realistic numbers.
 
This is projections run by epidemiologists and data scientists.

If anyone is truly interested in the coronavirus infection rates and hospital capacities in different states based on different courses of action, this site is the best I've seen.
https://covidactnow.org/
 
Maserson said:
Another model from UW, includes state by state breakdown with projected timelines:https://covid19.healthdata.org/projections

Sample items:
1. California will hit 6k deaths around June 1.
2. NY (state) will hit 10k deaths around May 1.

This is an awesome site. If one were to believe in these projections, Colorado and Alaska seem good places to be. Should pack my bags and work from AK or CO for a month, just in case. :)
 
The actual death rate doesn't really matter right now.  It will be figured out in time after the pandemic has run it's course.  In future years, herd immunity should start to build up, lowering the death rate from where it started in 2020.

What matters right now is managing the hospital case load so that we don't spike the number of deaths occurring for COVID, as well as other non-COVID ailments.

I agree that I'm curious about the death rate and infection rate just like you, but there is just no accurate way of calculating it right now.  The models are all based on the incomplete data available to them at the time of model creation.  As more data comes in from countries other than China, S. Korea, and Italy, the models will be adjusted up or down accordingly.
 
Liar Loan said:
The actual death rate doesn't really matter right now.  It will be figured out in time after the pandemic has run it's course.  In future years, herd immunity should start to build up, lowering the death rate from where it started in 2020.

What matters right now is managing the hospital case load so that we don't spike the number of deaths occurring for COVID, as well as other non-COVID ailments.

I agree that I'm curious about the death rate and infection rate just like you, but there is just no accurate way of calculating it right now.  The models are all based on the incomplete data available to them at the time of model creation.  As more data comes in from countries other than China, S. Korea, and Italy, the models will be adjusted up or down accordingly.

I think death rate is more related to hospital case load as we can assume that deaths are from serious cases which require hospitalization.

And if we are sheltering, how does herd immunity work?
 
irvinehomeowner said:
Liar Loan said:
The actual death rate doesn't really matter right now.  It will be figured out in time after the pandemic has run it's course.  In future years, herd immunity should start to build up, lowering the death rate from where it started in 2020.

What matters right now is managing the hospital case load so that we don't spike the number of deaths occurring for COVID, as well as other non-COVID ailments.

I agree that I'm curious about the death rate and infection rate just like you, but there is just no accurate way of calculating it right now.  The models are all based on the incomplete data available to them at the time of model creation.  As more data comes in from countries other than China, S. Korea, and Italy, the models will be adjusted up or down accordingly.

I think death rate is more related to hospital case load as we can assume that deaths are from serious cases which require hospitalization.

And if we are sheltering, how does herd immunity work?

It doesn't work, but we won't be sheltering forever.  Eventually a vaccine will be developed to help speed that up as well.
 
At a rate of increase of 20% per day (as for the last week), the US cases of COVID-19 will be over 50 million by the end of April. Even with a mortality rate of 1% only that will imply 500,000 dead people by that time. This will the Easter gift of Trump to America
 
Another way numbers get twisted...both ways. Depending on how you look at infection and death rates as a raw number and on a per capita basis. Broken down on per capita...we look pretty good.

What the Media Isn't Telling You About the United States' Coronavirus Case Numbers


When President Trump said this week that the United States had done more testing than South Korea, USA Today was quick to fact-check his claim by pointing out, "The United States population is more than six times the size of South Korea?s. On a per-capita basis, South Korea is testing far more of its citizens than the U.S." In this case, the media attempted to use a per capita comparison against Trump. CNN and MSNBC each made similar fact-checks.

On Thursday, the New York Times made a big fuss over the fact that more than 81,321 Americans have been infected with the coronavirus, which is "more cases than China, Italy or any other country has seen."

According to their report, the United States, following "a series of missteps," is now "the epicenter of the pandemic."

But, is it really?

China's confirmed cases topped out at around 80,000, but, as PJM's Victoria Taft noted, China reportedly stopped conducting tests in order to show the world they've contained the spread of the virus. So, comparing any country to China at this point is useless.
Now, here are the top six countries by confirmed cases per million people (based on population numbers from the CIA World Fact Book) in descending order:

Italy (1386.13)
Spain (1280.78)
Germany (615.57)
France (436.17)
Iran (380.72)
USA (283.30)
, let's look at confirmed deaths per million people in descending order, to see how that changes things:

Italy (146.37)
Spain (98.65)
Iran (28.00)
France (25.03)
USA (4.32)
Germany (3.79)
[url]https://pjmedia.com/trending/what-the-media-isnt-telling-you-about-the-united-states-coronavirus-case-numbers/[/url]
 
Compressed-Village said:
At a rate of increase of 20% per day (as for the last week), the US cases of COVID-19 will be over 50 million by the end of April. Even with a mortality rate of 1% only that will imply 500,000 dead people by that time. This will the Easter gift of Trump to America

There are 600,000 cases worldwide. Gavin Newsom said 56% of Californians (25 million by his count) in 8 weeks (from March 19th) for Cali alone by mid May. Since we have a population of 40 million, he must be counting those who aren't actually legal cuz 56% is "only" 22.5 million.

Does this even make sense? Yes it's a bad contagious virus. Yes we should take it seriously but numbers like this must take into account some kind of worse case scenario.
 
Ready2Downsize said:
Compressed-Village said:
At a rate of increase of 20% per day (as for the last week), the US cases of COVID-19 will be over 50 million by the end of April. Even with a mortality rate of 1% only that will imply 500,000 dead people by that time. This will the Easter gift of Trump to America

There are 600,000 cases worldwide. Gavin Newsom said 56% of Californians (25 million by his count) in 8 weeks (from March 19th) for Cali alone by mid May. Since we have a population of 40 million, he must be counting those who aren't actually legal cuz 56% is "only" 22.5 million.

Does this even make sense? Yes it's a bad contagious virus. Yes we should take it seriously but numbers like this must take into account some kind of worse case scenario.

That moron based his number on one of the cruise ships ( closed loop) then just applied it?s numbers to the state (open population) and extrapolated it up so he could put a scary number in his funds request letter. Basically, pulled it out of thin air. His office would not back up the number.
 
Liar Loan said:
irvinehomeowner said:
Liar Loan said:
The actual death rate doesn't really matter right now.  It will be figured out in time after the pandemic has run it's course.  In future years, herd immunity should start to build up, lowering the death rate from where it started in 2020.

What matters right now is managing the hospital case load so that we don't spike the number of deaths occurring for COVID, as well as other non-COVID ailments.

I agree that I'm curious about the death rate and infection rate just like you, but there is just no accurate way of calculating it right now.  The models are all based on the incomplete data available to them at the time of model creation.  As more data comes in from countries other than China, S. Korea, and Italy, the models will be adjusted up or down accordingly.

I think death rate is more related to hospital case load as we can assume that deaths are from serious cases which require hospitalization.

And if we are sheltering, how does herd immunity work?

It doesn't work, but we won't be sheltering forever.  Eventually a vaccine will be developed to help speed that up as well.
I'm somewhat optimistic we will see some treatments before the vaccine (mainly because Vaccine is just going to take more time than we think given clinical trials around LT safety vs. a vaccine from existing medication). The one Trump keeps hyping seems like vapor ware, however, I have read in some medical journals there are some emerging treatments that potentially look promising (cutting down severity and cutting down symptomatic window by as much as 50%.  All these "shelter in place" orders are really just buying time.  During this time, you get more manageable outbreaks (than if everyone was just out in the open and getting wildly infected) and thus hospitals can buy more time before hitting capacity, we also get out of the peak flu season windows (again, creating a bit of capacity) and potentially get to warmer weather where the virus is less contagious (virus won't die, but potentially 50% less contagious/harder to get...which is huge).  It isn't going to go away though, which means you probably see manageable containment over summer months (with people getting sick but hospitals able to manage it better) leading back to winter when things are going to hit another crunch point (if a treatment/vaccine aren't ready by that point).  My gut is we'll have 20-25% of the population having already been infected (maybe more once they figure out better viral indicators of those who potentially already have immunity or were asymptomatic). 
 
So I know TI has Chinese readership... or people who know people in China.

Can we get the real story from someone brave enough to post it here?

Are the numbers accurate?

Is it true that some metro areas have had no outbreaks?

This article from someone who lives in Beijing basically said everyone was on strict lockdown, is that what is needed to flatten our curve?
https://www.forbes.com/sites/simina...iving-in-the-locked-down-city-for-two-months/

This one says they are trying to get back to normal:
https://www.sciencemag.org/news/2020/03/can-china-return-normalcy-while-keeping-coronavirus-check

But this one says, there could be a second wave of re-infection:
https://www.npr.org/sections/goatsa...onavirus-patients-test-negative-then-positive

What to believe? That's why I like looking at the math... as long as the reported numbers are truly indicative of reality.
 
This is from a month ago when the videos of forced lockdown, doors weld shut, dorms purged etc. videos were coming out of China and the horror show was full on.. I was getting worried and reached out to my coworker in Shanghai and he was much calmer than I had expected.

Basically, the demeanor was...yeah, we are in lockdown, we are working from home, but it's ok....we will be fine in few days etc...basically optimism.

I guses more or less the same thing is happening everywhere, where people have their worldview and belief system based on what lens they are looking through. I was clearly looking from panic-struck social media and leaked videos of China and clearly my colleague had a different lens.
 
Has anybody picked up any official estimates of the infected multiplier?  By that I mean, if we are reporting 500 positive tests in OC, what is the multiplier for likely cases walking around asymptomatic or not sick enough to march off to the hospital?  I.e. are there really 1000, 2000, 5000, 10000, 15000, 20000 or more?

Any guesstimates from people.  I heard N.J. is only testing most symptomatic.  I think NYC is only testing those at the hospital.  Not sure what CA is doing.

 
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