
How Bad Is the Coronavirus? Let’s Run the Numbers - kqr2
https://www.bloombergquint.com/opinion/how-bad-is-the-coronavirus-let-s-compare-with-sars-ebola-flu
======
brink
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?

~~~
cstejerean
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.

~~~
meowface
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
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.

~~~
meowface
I know nothing about all of this, but I guess the idea is there are too many
closely concentrated people and too many variables to control for, so if there
are new cases, they could potentially turn into new outbreaks if they aren't
detected and handled in time. And it's likely just a matter of probability
whether or not they all get detected. Even the most advanced and restrictive
surveillance state in the world can't possibly catch everything with 100%
probability.

I think there's a decent chance the outcome won't be nearly as bad as the
worst case scenario, but the worst case scenario is pretty scary. There is a
non-zero probability that this wave is only beginning, that there are going to
be future outbreaks and pandemic waves this year, and that by year's end
there'll be millions of deaths globally.

~~~
maxerickson
In the video he talks about taking temperatures every time someone enters a
building.

Anyone with a fever is screened for the infection using a portable CT scanner
(they don't do a full image, they take a couple slices).

People with suspect CT results are tested and held in quarantine until the
test result comes in.

The virus simply _will not_ spread as fast in those conditions as it did when
local officials were covering up, and people can start moving around more
without backing off those conditions.

------
pmoriarty
From a Penn State epidemiologist (note that the quote below speaks of the
"infection fatality rate", which is different from the "case fatality rate",
the difference is explained in the article)[1]:

 _" Scientists working at the London School of Hygiene and Tropical Medicine,
Imperial College London and the Institute for Disease Modeling have used these
approaches to estimate the infection fatality rate. Currently, these estimates
range from 0.5% to 0.94% indicating that COVID-19 is about 10 to 20 times as
deadly as seasonal influenza. Evidence coming in from genomics and large-scale
testing of fevers is consistent with these conclusions. The only potentially
good news is that the epidemic in Korea may ultimately show a lower CFR than
the epidemic in China._

...

 _" On balance, it is reasonable to guess that COVID-19 will infect as many
Americans over the next year as influenza does in a typical winter --
somewhere between 25 million and 115 million. Maybe a bit more if the virus
turns out to be more contagious than we thought. Maybe a bit less if we put
restrictions in place that minimize our travel and our social and professional
contacts._

 _" The bad news is, of course, that these infection numbers translate to
350,000 to 660,000 people dying in the U.S., with an uncertainty range that
goes from 50,000 deaths to 5 million deaths. The good news is that this is not
a weather forecast. The size of the epidemic, i.e., the total number of
infections, is something we can reduce if we decrease our contact patterns and
improve our hygiene. If the total number of infections decreases, the total
number of deaths will also decrease."_

[1] - [https://www.marketwatch.com/story/why-this-epidemiologist-
is...](https://www.marketwatch.com/story/why-this-epidemiologist-is-more-
worried-about-coronavirus-than-he-was-a-month-ago-2020-03-09)

------
travisporter
This guy did some back of the envelope calcs I found interesting/scary

[https://medium.com/@tomaspueyo/coronavirus-act-today-or-
peop...](https://medium.com/@tomaspueyo/coronavirus-act-today-or-people-will-
die-f4d3d9cd99ca)

~~~
williamstein
Thanks for posting this. It's exactly the sort of analysis I would want to do
if I had way more time, and he explains his reasoning completely in a way that
a non expert can understand (and provides his models), perhaps because he is
not a professional epidemiologist.

~~~
jorisw
Meaning the calculations are worthless.

------
throwaway_pdp09
A general question to all. Disclaimer, I'm no epidemiologist and not even a
statistician. I may totally misunderstand something here. That said, I copied
the data from the US, UK and Italy on cases (go to
[https://en.wikipedia.org/wiki/2019%E2%80%9320_outbreak_of_no...](https://en.wikipedia.org/wiki/2019%E2%80%9320_outbreak_of_novel_coronavirus_%282019-nCoV%29)
and click on the relevant flag in the table, copy the data off the graph,
scrub with regexes).

I dumped this into Tableau, graphed it and put an exponential trend line over
the top. The UK and US data dropped almost perfectly onto an exponential
(R-squared > 0.99 for both, P value better than 0.0001 for both, whatever
those mean). The visual fit was remarkably good.

The italian data very obviously did not fit so well. It clearly was flatter
than the best fit exponential (strange, given that covid is totally ablaze
there) and it had an R-squared of 0.946, though it's P value was still less
than 0.0001.

Can anyone comment? The raw data for italy is below.

    
    
      date,cases
      2020-02-21,20
      2020-02-22,79
      2020-02-23,150
      2020-02-24,227
      2020-02-25,320
      2020-02-26,445
      2020-02-27,650
      2020-02-28,888
      2020-02-29,1128
      2020-03-01,1694
      2020-03-02,2036
      2020-03-03,2502
      2020-03-04,3089
      2020-03-05,3858
      2020-03-06,4636
      2020-03-07,5883
      2020-03-08,7375
      2020-03-09,9172
      2020-03-10,10149
      2020-03-11,12462
      2020-03-12,15113
      2020-03-13,17660
      2020-03-14,21157
    

Edit: for comparison, US data is below.

    
    
      date,cases
      2020-02-26,15
      2020-02-27,15
      2020-02-28,19
      2020-02-29,24
      2020-03-01,42
      2020-03-02,57
      2020-03-03,85
      2020-03-04,111
      2020-03-05,175
      2020-03-06,252
      2020-03-07,352
      2020-03-08,495
      2020-03-09,643
      2020-03-10,911
      2020-03-11,1182
      2020-03-12,1577
      2020-03-13,2184
      2020-03-14,2628

~~~
maxerickson
A possible explanation is that their testing can't keep up with the spread.
~13,000 test per day for the last several days, with more positive results
yesterday for the same number of tests.

~~~
throwaway_pdp09
If true that would apply much more to the US data, where I understand the
amount of testing has been extremely low.

In any case the data is surely of confirmed cases, so these have got past the
testing, no? And I'm not sure if that would produce a flatter-than-exponential
curve, which seems to be what it is.

~~~
maxerickson
It depends on how many tests are needed. If they are running 13,000 and need
50,000, the growth will look flat.

And then for the US, if most places are doing a high percentage of the needed
tests, then the test results should reflect the real growth. Given the
limitations on testing, we likely won't have a good understanding of this for
weeks to come (people on the internet saying they should have been tested is
only worth so much).

------
casefields
Mirror: [http://archive.md/fyPMl](http://archive.md/fyPMl)

------
jorisw
Justin Fox is a Bloomberg Opinion columnist covering business.

A total layman on the subject matter. Stop writing about corona if you’re not
an expert. Stop reading and sharing non-expert opinions.

------
lucas_membrane
tldr:

This article leaves off about where a similar report on epidemiological models
did a couple of weeks ago: Covid-19 will be very very hard to control if
persons showing no symptoms spread the disease too often, but we do not know
whether or not they do.

~~~
avocado4
This article does explicitly discuss pre-symptomatic transmission,
specifically it being worse than SARS but better than flu in that regard.

------
zaroth
This article does a better job than most, but I think still only half-asses
the thought process necessary to logically reason about COVID.

The naive or “known” CFR is the fatality rate to-date divided by the number of
positive tests to date.

For example, China at one point decided to consider a large number of people
as positive cases based on purely clinical symptoms because they didn’t have
the test capacity or specificity to definitively diagnose them. Which is why
their case count gapped up one day.

The CFR after all cases have concluded is an upper bound on the IFR. There
seems to be no true consensus on the percentage of asymptomatic or very mild
cases which would not seek treatment or even testing. This number (which is
basically unknowable during an outbreak) is a multiplier on the case count,
and acts to reduce the true IFR.

Lastly, as we’ve seen quite clearly... How bad it is depends almost entirely
upon the person, or at a higher level, the demographics of the people who are
infected.

Italy as of March 11;

> _Of the patients who died, 42·2% were aged 80–89 years, 32·4% were aged
> 70–79 years, 8·4% were aged 60–69 years, and 2·8% were aged 50–59 years
> (those aged >90 years made up 14·1%). The male to female ratio is 80% to 20%
> with an older median age for women (83·4 years for women vs 79·9 years for
> men)._

Likewise, the outbreak in a WA nursing home was devastating to an elderly
population where they would see 5-10 patients die in an _average_ month.

IMO the path forward is either successful containment—which seems extremely
unlikely given the transmission characteristics, but apparently China was able
to do it? But where you constantly have to be watching for pockets of
reemergence and clamp them down.

Or, if we can keep the virus away from high-risk populations while it spreads
“like a flu” through the majority of the population, then you will see herd
immunity kick in which ultimately works like a vaccinated population to
prevent further outbreak and protect the at-risk population from ever becoming
infected.

[1] -
[https://www.thelancet.com/journals/lancet/article/PIIS0140-6...](https://www.thelancet.com/journals/lancet/article/PIIS0140-6736\(20\)30627-9/fulltext)

~~~
empath75
China’s method of containment was to scan pretty much the entire population
for fever and quarantine everyone who might have been infected immediately and
involuntarily, including taking children from parents. Needless to say, that
will never happen in the us or Europe.

~~~
alfiedotwtf
> taking children from parents. Needless to say, that will never happen in the
> US

They separated Native American and immigrant families in the recent past, why
stop now

------
booleandilemma
At this point I’m more worried about food, water, and toilet paper shortages
due to people hoarding 20 times more than what they need. The virus itself
doesn’t sound too bad if you’re under 70.

~~~
empath75
Even for people under 40, it’s 20 times deadlier than the flu is.

~~~
mitchdoogle
People don't need numbers any more. It's only going to matter to some people
if someone they view as a 'healthy, normal' person tests positive. Even more
of a freak-out if someone like that dies. If a famous celebrity or athlete
gets were to die from this, it would set off a lot more worrying

~~~
wincy
Imagine how tortured you’d be as the doctor that let Tom Hanks die. If he dies
people will freak out.

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cmdshiftf4
Why does a blog post require 14 sources of javascript?

Will await a mirror.

