
Covid may be far more widespread than we thought - jrfinkel
https://www.economist.com/graphic-detail/2020/04/11/why-a-study-showing-that-covid-19-is-everywhere-is-good-news
======
logjammin
This is a problem of insufficient data. We don't have a denominator, so
there's no way to tell if it's more widespread than we thought. In fact
there's no good way to tell how widespread it is at all. We have numerators:
number of people sick enough to show to up to an ER, or number dead, or
whatever, take your pick. But in every fraction we might want, we lack a
denominator: total number of people infected.

There's a stuningly simple way to get one: sample randomly from a population
of interest in large enough numbers (say e.g. Cook County, home of Chicago, or
hell, the entire US) and test everyone for the virus. Voila! You have a
representative chunk of your population, an estimate of virus prevalence, and
a quantifiable degree of precision about that estimate (SE's for a confidence
interval, say). With enough people in your sample, you can have extremely
accurate estimates of the spread of Covid in your population of interest. You
repeat this process over and over, through time, to track the numbers.

I'm not trivializing this kind of effort: it takes rigorous sampling designs
and dozens or hundreds of field workers, among other things. It's intense but
very straightforward. Political pollsters (and thousands of researchers in
different fields) do it every day.

No one in the US has done this, and no one with any visibility from Fauci on
down has even suggested it (that I know of; please correct me). I work in
public health, and this is first year, first semester of grad school stuff.

This matters because the public health responses to coronavirus when there's
1% or 10% or 25% or 75% of a population infected all look very different. In
short, we may be over- or underreacting to the situation with the measures we
currently have in place.

I've been going half crazy wondering what's happening about this for a while
now. After the initial fuckup, we now have tests. We have money. We can do
this. Why don't we?

(Iceland has done this!)

~~~
oldgradstudent
> I'm not trivializing this kind of effort: it takes rigorous sampling designs
> and dozens or hundreds of field workers, among other things. It's intense
> but very straightforward. Political pollsters (and thousands of researchers
> in different fields) do it every day.

I am trivializing it, when compared to the cost of stopping down there economy
as we've done.

If there a chance the results can restart the economy a bit earlier, it almost
doesn't matter how much it will cost.

------
amscanne
% of visits to primary care provider is a _terrible_ metric. People have been
actively advised to stay away from the Doctor’s office and hospitals for
routine reasons (and reschedule for later). Obviously the % visiting because
they think they have Covid is going up, even if they don’t have it!

~~~
jrfinkel
One of the study authors addressed this on Twitter. It’s certainly not hard
proof, but 8 million extra cases would be a whole lot of hypochondriacs.
Thread is short and worth a read.
[https://mobile.twitter.com/inschool4life/status/124762000834...](https://mobile.twitter.com/inschool4life/status/1247620008349519878)

------
jrfinkel
Here’s a preprint of the actual paper:
[https://www.medrxiv.org/content/10.1101/2020.04.01.20050542v...](https://www.medrxiv.org/content/10.1101/2020.04.01.20050542v1)

------
foton1981
I dont understand how would such highly contagious virus suppress and contain
itself if it started in CA months ago. As if Californians have no outbound
travel. Impossible scenario.

~~~
jrfinkel
I don’t think anyone is claiming that it suppressed and contained itself.
They’re claiming it’s more widespread and more mild. There’s a good graphic in
the economist article showing two different peaks that look the same early on.

------
vondur
I was pretty sick in late February, and ended up in the urgent care at my
local Kaiser. It was packed at the time too. Seemed like everyone was sick
with the flu.

~~~
vanniv
I was terribly sick in early February, in CA. I went to my urgent care
multiple times as I got worse.

The doctor tested me for influenza, but told me that he was seeing hundreds of
patients, all day every day, with "an unusual flu" where they were mildly sick
for a few days, recover, and then suddenly got much worse with high fevers and
chest infections -- and most of those patients were turning up with negative
influenza tests. But influenza tests have a high false negative rate, so just
because I was negative on the test didn't mean anything. The doc said that
this year, the influenza test only seemed to show positive for folks that had
a high fever the first day of their illness (which, between you and me, is
very common with influenza and very uncommon for COVID)

I was out of work for over a week, and only got out of bed when I had no
choice the entire time.

None of my doctors asked me about travel or contact with recent travelers, and
nobody ever even suggested getting a coronavirus test.

When I got back to work a week later, I learned that nearly 10% of my office
had gotten sick either the same day as me or while I was out.

Did we all have COVID-19?

maybe. Maybe not.

None of us were tested. None of us will turn up in the COVID statistics.

But in early/mid February, there definitely was some coronavirus here -- we
had a few known travel cases, and we had tons of travelers between all regions
of China and all parts of CA. It is entirely possible for folks to have
unknowingly brought the virus here in moderate numbers.

~~~
vondur
I've also read that one of the reasons that California has relatively low
infection numbers given it's circumstances, may be do to the fact that
Covid-19 had been spreading earlier in the year. Many people may have been
unknowingly infected, and either have recovered and have immunity, or
unfortunately may have died from it.

~~~
vanniv
It may be so.

Although, it seems apparent that there were not millions of cases before we
started looking, given that hospitals here were not overrun like they were in
New York.

About a month ago, I did some poking around with the CDC FluView statistics
(in-season estimates of influenza and all-cause-pneumonia deaths)

The conclusion that I came to was an upper bound on undetected COVID cases
before 3/1 of 300k.

More than that, and the hospitalization and death rates could not have hidden
in the flu and pneumonia data.

300k extra recovered cases, even if they were all in CA, would not be material
in terms of new immunity.

 _Unless_ the Asia-origin strain we had was much less dangerous than the
European-origin strain in NY (in which case more cases might hide in the data)
-- but that is a pretty tall set of assumptions.

~~~
Gibbon1
My take the rate of serious illness and death due to COVID19 is a bounded
parameter with a linear range. The infection rate is currently unbounded and
logarithmic.

Ain't got much wiggle room to work with there. You have to pretend the
morbidity rate is 20 to 50 times lower than the known lower bound (3-5%). So
doesn't square.

------
alephnan
Was this data not publicly available ? Were there not army of analysts? I
thought with Machine Learning being all the rage and hype, we’d have more
people and machine keeping tabs on all kinds of trends, this included. Good
that we have these retroactive inspections, but the whole appeal of ML is its
predictive power is it not? Or did the hedge funds just keep this knowledge to
themselves?

~~~
mr_gibbins
Could it be because AI is an overhyped rehash of the AI craze that swept
academia and industry in the 1980s, only to collapse in the 'AI winter' as
everyone realised the truth? We use AI/ML for trivial purposes right now.
Multivariate statistical analysis beats AI in many domains. Covid is a real-
world, grown-up problem. It isn't identifying pictures of cats, or creating
obscene chatbots (remember Tay?). So AI has been shown up to be a duff non-
solution.

------
DevKoala
> "I think the 3.4 percent is really a false number — and this is just my
> hunch — but based on a lot of conversations with a lot of people that do
> this, because a lot of people will have this and it's very mild, they'll get
> better very rapidly. They don't even see a doctor. They don't even call a
> doctor. You never hear about those people,..."

At the time, the person who said that was called an idiot.

~~~
Jordrok
He's still an idiot. He chose to believe that not because of research or
statistics or the advice of people with expertise, but because it was
convenient. This was at the beginning of March when there had only been 11
deaths. He was making the argument that this is no worse than the normal
seasonal flu, because he was loathe to take any drastic preventative action
that might disrupt his precious stock market.

Well, here we are now, thousands have died, with thousands more on the way,
and the economic damage has already been done. That's what happens when you
let an idiot run the country.

~~~
etrabroline
I'm loathe to defend the current US president, but almost no Western country
took this seriously until the last possible minute. There is clearly a deeper
ideological issue infecting the entire West.

~~~
darkteflon
Australia and New Zealand have done a superlative job:
[https://www.theguardian.com/world/2020/apr/09/have-
australia...](https://www.theguardian.com/world/2020/apr/09/have-australia-
new-zealand-stopped-covid-19-in-its-tracks-coronavirus).

