
Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free - mancerayder
https://www.reuters.com/article/us-health-coronavirus-usa-military-sympt/coronavirus-clue-most-cases-aboard-u-s-aircraft-carrier-are-symptom-free-idUSKCN21Y2GB
======
vrtx0
IMHO, this article is intentionally misleading. The incubation period is
currently estimated to be 2-14 days (mean is 5.6 days per CDC, similar per
WHO). The article doesn’t mention any dates or time frames, but does mention:

”Roughly 60 percent of the over 600 sailors who tested positive so far have
not shown symptoms of COVID-19” — note how “so far” is ambiguous in that
sentence. It also states, “The Navy’s testing of the entire 4,800-member crew
of the aircraft carrier - which is about 94% complete...”, which seems to
indicate nowhere near enough time has elapsed to draw any sort of conclusion.

This paper [1] found that testing of all pregnancy patients in a hospital
yielded 34% asymptomatic cases. That number drops to 8% “shortly after
discharge”, and could be lower than 8% (Again, no timeframe is stated).

[1]
[https://www.sciencedirect.com/science/article/pii/S258993332...](https://www.sciencedirect.com/science/article/pii/S2589933320300483)

~~~
nostromo
Just as one data point, the captain of the ship raised alarms about the virus
spreading late last month. So it’s not exactly a recent outbreak.

Of course, without testing from that period it’s impossible to know.

~~~
xorfish
If the virus spreads exponentially, you would expect most cases to be
presymptomatic at any given time.

~~~
watwut
Not when the amount of people is limited. Exponential spread in isolated group
of 3000 people necessary becomes non exponential at some point.

~~~
saalweachter
Eh, so far only 600 of the 4800 member crew has tested positive. That should
still be comfortably in the "mostly exponential" territory.

~~~
gojomo
The article isn't clear what kind of tests these were.

If, as is most likely, they're PCR tests for viral RNA, then they'll only
detect active (or recently-active) infections. So anyone who's gotten-over an
infection, symptomatic or not, will test negative. The number of infections
reported here is a floor on the actual number who have been infected – which
could be 2x, 4x, or more.

If instead these are antibody tests, then they're only indicating 600 _total_
infections. But that kind of test is less likely here: such tests are not very
useful for diagnosis of active infections, as they only turn positive late in
a case. They could be useful for tallying past infected status – but there's a
lot of rumbling that early antibody tests haven't been as reliable as hoped.

~~~
saalweachter
That's actually in the range of possibilities, I guess.

The best current data on the IFR for 20-40 year olds is low enough that you
might not get any deaths out of a ship-wide infection[0], so you don't have
the same "Where were all the dead bodies if this ran through the population
earlier?" question you do for cities and countries.

The current estimate of the recovery time is around 25 days, and the date of
exposure is believed to be March 5th. Assuming we're looking at an exact
snapshot of infections today, that gives you March 23rd as the day everyone
recovered on the ship was infected by, about 18 days after the first exposure.
Assuming some small number (~10) were initially infected, that would only
require a doubling period of ~2 days, which is shorter than seen elsewhere,
but you're also in an ideal environment (close quarters, communal living) for
spread.

I don't know if I believe that to be what happened here, but we should
hopefully be able to determine it from the data after the fact with further
monitoring and testing.

[0] There's been one, and you could have up to around 6 or 10 while being
consistent with the current data; more than a couple dozen would raise a lot
of questions.

------
gdubs
Stanford’s study should give us more info soon. They recently screened a
decent sized group in Santa Clara County to get a sense of how widespread it
is, using their newly developed finger-prick test which looks for both
antigens and antibodies (whether you have it / had it and recovered).
Currently the test is being prioritized for frontline healthcare workers while
they work on scaling up:

[https://www.stanforddaily.com/2020/04/04/stanford-
researcher...](https://www.stanforddaily.com/2020/04/04/stanford-researchers-
test-3200-people-for-covid-19-antibodies/)

~~~
zephyrnh
It's been 12 days since they tested everyone. My understanding is that the
results for serological tests are available right away, so I was expecting
them to publish results within a few days. Any idea why they haven't yet?

~~~
usaar333
Perhaps they can't get statistical significance. You'd ballpark a 0.5%
infection rate in the Bay Area going by deaths and current best guesses for
IFR. Your false positive rate might exceed that.

These tests are better done in highly infected areas like NYC.

~~~
oldgradstudent
> current best guesses for IFR

The entire point of the study is that we don't have good estimates of the IFR.

~~~
usaar333
We have randomized PCR studies and ships where everyone got tested. Yes, there
is error there (false negatives), but there's an upper bound to how much there
can be.

------
manfredo
Random testing in Germany has also revealed higher than expected rates of
people with antibodies. Their IFR (infected fatality rate) was 2% overall
based on non-random testing. Random testing has yielded an IFR or 0.37%.

This does not increase the risk. These tests only test people who _had_
coronavirus. The larger this portion, the more herd immunity there is in the
population. It implies that there _were_ a larger than expected number of
people who had the virus, at some point in time. But that's a lagging
indicator.

~~~
system2
If 0.37% is true, why are the hospitals in this shape?

~~~
yomly
Imagine all 65M people in the UK caught the virus then a 10,000 case fatality
number would give a rate of 0.015%.

The rate itself has no time element so it tells you nothing about the number
of people in hospital right now and hence isn't very illustrative of how
hospitals can be swamped by this disease.

More interestingly (for me at least) is that the mortality rate is dependent
on a patient's access to a ventilator. This means if you caught the virus
early in the spread of the pandemic your odds of surviving are substantially
higher than if you caught it right at the peak of infection.

This is impossible to reflect in a simple global mortality rate and so really
paints a different picture of the virus - the death rate in South Korea vs
other places really highlights this.

I guess to your point, hospitals are more in this way because the virus is so
infectious, rather than it being a universally dangerous disease as may be
seen from a higher mortality rate. Remember, a high number of people
experience little to no symptoms from catching this.

This variability in symptoms doesn't seem to be as true for other lethal
diseases like say malaria or dengue fever

~~~
cm2187
Though my understanding is that the survival rate of a covid19 patient once he
requires a ventilator is around 50%. If that's true, at worst, if we ran out
of ventilators, the death rate would double. That's bad and we should avoid it
but the doubling of a tiny number will still be a small number.

Which is why I am still confused by the ratio of 1:10 that the White House has
shown between the death toll under lockdown vs no lockdown.

For the reason above, I would only expect the death rate to double. No
lockdown means a lot more people get infected faster. But lockdown still
requires to build herd immunity, we are only slowing it down. So the same
number of people will get infected ultimately. So either they implied that the
lockdown would be permanent until we get a vaccine (at best 2021 Q1), or it
completely disregarded what happened after the initial few weeks of lockdown
and then the numbers were at best grossly misleading.

~~~
chiefalchemist
We've been on lockdown because approx 1% of the US population has tested
positive. That means 99% are not. How can we come out of lockdown when we are
effectively still where we started. We're not even close to herd immunity.

~~~
jimbokun
The actual CDC plan is here:

[https://fm.cnbc.com/applications/cnbc.com/resources/editoria...](https://fm.cnbc.com/applications/cnbc.com/resources/editorialfiles/2020/04/16/WHReopeningDoc.pdf)

It's not just "full lockdown vs no lockdown".

~~~
chiefalchemist
Right. So why were we in full lockdown then? I can't imagine 1% is that
significant.

------
scythe
Do we know if these cases are truly _asymptomatic_ or just _presymptomatic_ as
was observed on the Diamond Princess?

48% asymptomatic initially:
[https://www.niid.go.jp/niid/en/2019-ncov-e/9407-covid-dp-
fe-...](https://www.niid.go.jp/niid/en/2019-ncov-e/9407-covid-dp-fe-01.html)

18% asymptomatic retrospectively:
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7078829/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7078829/)

Also, 58% of asymptomatic COVID-19 infections still show damage to the lungs
on CT: [https://appliedradiology.com/articles/study-investigates-
dia...](https://appliedradiology.com/articles/study-investigates-diamond-
princess-cruise-ship-covid-19-findings)

~~~
danieltillett
Do you know any studies of the outcome of the 32 Diamond Princess patients
that were the ICU at the time the boat was emptied? I have been looking and I
can’t find any data on what was the final clinical outcome of all patients on
the Diamond Princess?

~~~
iso947
Wiki said there have been 14 deaths so far, most recently just 3 days ago.

~~~
danieltillett
It seems they are only tracking the Japanese deaths. It doesn’t seem like
anyone is tracking the seriously ill who were transported home, or those that
became ill once they got home. Even on these incomplete number the true death
rate is 2%.

------
ivoras
Adding to that, Netherlands' study of antibodies in blood donors' samples
shows about 10x difference between the number of reported / tested cases and
actual cases in the general population (i.e. a lot more people got it and were
not sick):

[https://www.nytimes.com/reuters/2020/04/16/world/europe/16re...](https://www.nytimes.com/reuters/2020/04/16/world/europe/16reuters-
health-coronavirus-netherlands-study.html)?

~~~
feral
The Netherlands has 3.3k deaths vs 29k confirmed cases, which would give a CFR
of ~10%

I.e. the Netherlands aren't testing much.

A 10x reduction there brings it back to the CFR range we see in countries with
bigger testing programs.

I'm not a specialist but have been following this for a while, and have yet to
see evidence the IFR for this isnt around 0.5-1% (assuming decent healthcare).

That's what we saw in the Diamond Princess data, and a bunch of other places.

~~~
Gibbon1
My current bet is younger healthy people are more likely to be asymptomatic.
And older people much less so. Theodore Roosevelt with likely a young
population, most are asymptomatic. Diamond Princess much older population most
are symptomatic.

~~~
alexbanks
This is a thing I've been thinking about a lot. We're quick to say "We're not
testing enough", but also quick to throw statistics around "disproving" the
amount of asymptomatic cases. I am on the side of "It's probably orders of
magnitude widespread than most countries think", and the number of totally
asymptomatic cases is actually far far higher. You can't test only the old and
the already sick and then accurately assess likelihood to develop symptoms.
Your sample is totally wrong.

~~~
feral
Humanity's understanding of this disease is much more sophisticated than the
two comments above this would imply.

Researchers are not stupidly looking at Diamond Princess and getting confused
because the population is old.

Rather it's a powerful dataset because it enables us to quantify the
asymptomatic people of all ages, because people were tested fairly
exhaustively before being allowed leave, regardless of symptoms, and because
we've had enough time for many of the cases to play out.

The diamond princess data revealed a large number of asymptomatic cases in
China, the absence of which were skewing the detected cases in China much
older.

Anyway, you don't need to think anything complicated about correcting for
ages, etc

You can just look at the data from the Netherlands where they conclude they
have 3% population infection, by looking at the random serological testing,
and then look at the number of confirmed deaths they have, and do the very
simple math.

It's very hard to do that and then say we're missing say 10x higher numbers of
asymptomatic cases all over the place.

This blog post I wrote a while back is Ireland specific but has figures on CFR
and IFR I think are still valid, and references to the academic articles I got
them from: [https://medium.com/@fergal.reid/predicting-the-impact-of-
cor...](https://medium.com/@fergal.reid/predicting-the-impact-of-coronovirus-
on-ireland-bff1b6d00d6a)

~~~
roel_v
"Humanity's understanding of this disease is much more sophisticated than the
two comments above this would imply."

I think we can generalize this to pretty much every comment made in this
thread, and others like it, regardless of how certain some of them sound.

~~~
noizejoy
And quite a few other threads, too :-(

------
GANG718
This is because they're testing the entire population as opposed to simply
those who end up hospitalized and those around them.

We need population testing to get an actual idea of how many people in an area
have it. There's likely way more cases nationwide than being reported. In NYC,
most asymptomatic/low symptom cases of coronavirus aren't going to be tested
until antibody testing later on.

~~~
JoeAltmaier
Yes. Many institutions test only if preparing to admit. Anybody else is told
to go home and recover in isolation.

~~~
glofish
if the US has 33K deaths and the death rate is 0.6% then the US must have at
least 5 million cases. If the death rate is lower (most likely around 0.3%)
then it means 10 million infections.

Also a good news actually.

~~~
pesfandiar
Those death rates in US are optimistic in my opinion. What if the actual rate
is higher because of worse health in impoverished demographics, or the simple
fact people might avoid healthcare because of its prohibitive costs?

~~~
three_seagrass
Lots of people in NYC are getting dragged out of their homes in body bags that
will never get tested.

[https://www.yahoo.com/news/teams-retrieving-280-bodies-
day-1...](https://www.yahoo.com/news/teams-retrieving-280-bodies-
day-170100636.html)

~~~
radioactivist
They are now including many of the suspected (but untested) cases in their
reported numbers now. It increased the total from New York by a significant
amount, see [1].

The increase is roughly in line with similar estimates from excess mortality
[2], so I would guess they are catching most of the deaths with the new
reporting scheme.

[1]
[https://www1.nyc.gov/assets/doh/downloads/pdf/imm/covid-19-d...](https://www1.nyc.gov/assets/doh/downloads/pdf/imm/covid-19-deaths-
confirmed-probable-daily-04142020.pdf)

[2]
[https://www.nytimes.com/interactive/2020/04/10/upshot/corona...](https://www.nytimes.com/interactive/2020/04/10/upshot/coronavirus-
deaths-new-york-city.html)

------
btilly
This figure does not surprise me. It is in line with Iceland finding that 50%
of people they tested were asymptomatic.

However as [https://www.propublica.org/article/what-we-need-to-
understan...](https://www.propublica.org/article/what-we-need-to-understand-
about-asymptomatic-carriers-if-were-going-to-beat-coronavirus) notes, in other
samples about 75% of people who were asymptomatic at the time of the test went
on to develop symptoms. So the fact that these sailors are currently
asymptomatic does not mean that they will remain so.

See [https://www.cebm.net/covid-19/covid-19-what-proportion-
are-a...](https://www.cebm.net/covid-19/covid-19-what-proportion-are-
asymptomatic/) for more on how different data points are all over the place.

~~~
sharemywin
Not to mention. There's a giant filter called basic training which going to
skew the numbers. you have a bunch of kids running around in the best shape of
there lives and hey what do you know they handle the virus better than
average.

~~~
capkutay
What about pregnant women? They're known to be more vulnerable to certain
types of illnesses (especially viral infections), yet 29 out of 33 pregnant
women who tested positive of COVID-19 in NY were still asymptomatic:

[https://www.medpagetoday.com/infectiousdisease/covid19/85965](https://www.medpagetoday.com/infectiousdisease/covid19/85965)

~~~
Scipio_Afri
Women are less effected overall. It is thought it is due to ACE2 receptor
distribution in the body being different than men, but they don't know.
However there is statistically significant worse outcomes/disease severity for
men.

Pregnant women basically puts the cap of the upper age at around 40. This
disease the virus causes in the body is very much worse for those that are
older.

The study tested pregnant women admitted to the hospital to give birth. There
are a lot of doctor appointments and lab work to check things in their last
trimester. So they could've contracted it through those high risk places or
routine contact with health care workers who I would say are also high risk.

Still, the study showed _on admission_ that they were positive so they
probably didn't get it from the hospital, unless on admission actually means
some time after. That assumes it might be able to be detected so soon into the
infect as well. It is a bit strange in that regard that it is such a high
number.

------
andrewla
There's always the chance that the test itself is not particularly good and
just has a high false positive rate. Although it is difficult for a PCR test
to produce a match if there is no genetic material present, it may amplify
trace signals, depending on the cutoffs chosen.

~~~
ImaCake
I looked into this a few weeks ago. The PCR test has an incredibly low false
positive rate, below 1%. It is low enough that it is feasible to test a
100,000 people and expect basically zero false positives. The false negative
rate is somewhere around 30%. So the real danger with PCR is that you will
miss cases.

The opposite is true for the antibody tests. The false negative rate is around
10% and the false positive rate is also around 10%. So in 100,000 tests, you
would expect to miss about 1,000 true positives. But, and this is critical,
you would also mistakenly get 1,000 false positives - even if only 1/100,000
people are actually infected!

Next time you see someone claiming 50% asymptomatics. First thing to ask is
whether they used PCR. Or if they used an assay with a terrible false positive
rate.

~~~
danieltillett
If not done well PCR has an incredibly high false positive rate. If you
contaminate your set up area (or equipment) with past PCR amplification
material you will get a very high rate of PCR positivity.

Of course if you do things correctly this shouldn’t happen, but if the average
pathology lab technician is as skilled as my ex-students and colleagues (and
myself) then I would be not be so keen to rule out false positives.

Yes there is a major issue with false negatives, especially when the swab was
not performed or stored correctly. RNA is not very stable and it is very easy
to destroy all the viral RNA if you are not careful.

~~~
ImaCake
I am familiar with these drawbacks, having worked as a research assistant
doing RT-PCR and qPCR. My understanding from a brief stint in industry is that
there is a lot more quality control to be found in industrial and diagnostic
labs than is typically found in a research lab. So I imagine there is still an
appreciable amount of false positives even in a diagnostic lab, but they do
have a lot more quality control in place to reduce it.

~~~
danieltillett
Yes normally this is the case, but when they are under immense pressure to
pump through the samples we should expect the normal high standards drop.

------
manifestsilence
So people who are fit enough to pass active duty basic training tend not to
have symptoms. Solution: put everyone through basic training?

~~~
Loughla
Solution: put everyone through basic training. Corequisite Solution: make
everyone be 18-34 years old.

~~~
youareostriches
Carrousel! [https://scifi.stackexchange.com/questions/22080/what-did-
the...](https://scifi.stackexchange.com/questions/22080/what-did-the-crowd-
think-it-took-to-win-renewal-in-carrousel)

------
Leary
Sailors are very young. You can't assume that the proportion of people who are
asymptomatic to be the same for every age group.

The 60% asymptomatic percentage is also a lot lower than some of the
assumptions flowing around the internet (~90%).

~~~
elihu
Yep. From the article:

> Still, the case of the Theodore Roosevelt offers a case study for
> researchers about how the virus spreads asymptomatically in a confined
> environment among mostly younger adults.

...but they don't mention what the average age is. Presumably someone has the
data to produce an interesting scatterplot of age versus symptom severity.

~~~
jki275
Average age is probably early 20s. Huge number of first term Sailors between
18 and 22.

------
nednar
It's the first time I see news about the aircraft carrier. Could someone
summarize why the captain got fired for testing his whole crew in an
environment where a lot of people have to live very closely together? My first
assumption is that it was a really good decision.

~~~
WrtCdEvrydy
He sent an email to his commander and his commander's commander about how the
situation was deteriorating... which were then leaked to the press and was
promptly relieved of command by Acting Navy Secretary Thomas Modly who later
on resigned.

Most people think it was a good call but it also may have compromised the
safety of the carrier because now it's known they may be operating under less
than perfect condition.

~~~
khuey
The Washington Post managed to get the original letter:
[https://twitter.com/DanLamothe/status/1250840016806445056](https://twitter.com/DanLamothe/status/1250840016806445056)

It's pretty clear he was canned by a political appointee for political
reasons.

~~~
philwelch
Yes and no. He was relieved because he went around the chain of command, which
is a universal career-ending move in the military even if you do it for all
the right reasons—which he did.

Also, although he was relieved of command, he wasn’t “fired” or “canned” or
discharged from the Navy. He will undoubtedly go into an early retirement with
a full pension at his current rank of Captain. That doesn’t change the
fundamental unfairness of how he’s been treated, but he’s going to be fine.
And I think he knew and accepted the consequences of his actions.

~~~
michaelt
Do you mean e-mailing your commander's commander is a universal career-ending
move in the navy?

Or was he discharged on evidence or assumption he leaked to the press himself?

~~~
joncrane
Emailing your commander's commander with a groundbreaking complaint is
extremely dangerous to your career, yes.

(And not just in the Navy)

------
eximius
This is mixed news. While this indicates the death rate may be lower and the
infection rate higher among the general population, the demographic of
individuals in the US military are going to be of significantly higher health
than the general population.

So, it doesn't necessarily ease the risk for demographics already identified
as 'at-risk'. If anything, their risk might be understated given the higher
infection rate.

~~~
scarface74
Especially once you consider all of the pre-existing conditions that make you
ineligible to be in the military.

~~~
cryoshon
this is a really good point. AFAIK, 100% of the canonical pre-existing
conditions which are highly dangerous with COVID are disqualifiers for joining
the military.

this cohort will give us a much better picture of how the virus impacts a
totally healthy and young population. as with countless other pieces of
evidence, it should also help to put the "it's just a flu bro" falsehood to
bed.

~~~
jjtheblunt
Does the mortality rate across entire population (not particular
subpopulations) exceed that of the flu?

~~~
ashtonkem
Yes. Current understanding of the mortality rate is that it’s roughly 10x more
lethal than the flu across all age demographics. This means you might only
have a 0.2% of dying as a 20 year old, but you only had a 0.02% chance of
dying of the flu.

The caveat is that mortality rate is intimately tied with the availability of
certain types of care; if you need a vent and the hospital is full, you die
even if otherwise you would’ve lived. Thus case mortality rate will change
dramatically once the hospitals fill up.

~~~
usaar333
I don't think that's true. covid has stronger age dependence. Just look at the
ratio of covid vs. influenza deaths on the CDC's website
([https://www.cdc.gov/nchs/nvss/vsrr/COVID19/index.htm](https://www.cdc.gov/nchs/nvss/vsrr/COVID19/index.htm)).
3:1 covid:flu for over 85, but 1:1 for 25-35 and 1:10 for children. (relative
ratios as we don't know total covid infections).

This is especially striking with children: if the US had the same number of
covid infections as seasonal flu, you'd probably have lower pediatric deaths
from covid than flu.

~~~
ashtonkem
These statistics don’t support that conclusion, because these statistics are
for _total_ deaths. You can’t meaningfully compare the total deaths from a
disease that’s done for the season (Flu) with one that’s still on going
(COVID-19).

What you should be comparing is case fatality rates.

~~~
usaar333
But can you not compare the ratios between age groups? That's all I'm doing
here - showing deaths have a higher age correlation with covid than flu. - not
making any statement about absolute CFR/IFR.

~~~
ashtonkem
No, because you don’t know what the infection rate is by each demographic.

You have to compare just the case fatality rate. Comparing fatality ratios
alone is too likely to measure unrelated factors.

~~~
usaar333
Fair enough, but would there be a reason it would be different? And even if it
were, is that actually relevant?

Anyway, here's some IFR estimations for covid by Imperial college:
[https://www.thelancet.com/journals/laninf/article/PIIS1473-3...](https://www.thelancet.com/journals/laninf/article/PIIS1473-3099\(20\)30243-7/fulltext)

You see significantly higher multipliers by age group than for flu. As one
example, they are guessing teenagers have 1/17th the mortality rate of say a
40 year old. For flu (going by deaths), it's about 1/5th.

~~~
ashtonkem
There is absolutely plenty of reason for the infection rate to be different by
demographic: _we closed schools down_. We don’t do that for the flu.

~~~
usaar333
We also don't Shelter in place for flu. Bay Area school closure date is 1 day
before SIP.

Sweden and Iceland never closed schools for young kids. Data doesn't look any
different.

~~~
kaitai
Sweden has a substantially higher case fatality rate for COVID-19 compared to
other industrialized nations, so it's an interesting case.

------
twomoretime
Now hopefully we can get a better estimate of the range of the latent period.
That these cases are asymptomatic does not mean they won't show symptoms at
some later date. It also does not mean they are invulnerable to reinfection,
and if this virus indeed has Antibody Dependent Enhancement like SARS, this
could create an extremely dangerous setup for a second wave with a
significantly higher, order of magnitude, death rate.

All of the bits and pieces are floating around in papers, hopefully they won't
be confirmed like everything else that started as errant literature.

------
dboreham
People reading here may be interested in recent UK statistical office data,
analyzed here: [https://youtu.be/F39kVKSCP40](https://youtu.be/F39kVKSCP40)

This is data that examines among other things the overall death rate
irrespective of reported cause.

------
syntaxing
Is it possible that more people are asymptomatic because the sample population
is more athletic? I would imagine there's a certain physique that's maintained
and required for the military.

------
alkonaut
Were they testing for the virus or for antibodies? If it was testing for the
virus tests only show positive for a few days then testing everyone on board
will miss those who already had it, correct?

~~~
greedo
According to the Captain's email, sailors were tested, and results known the
next day. I don't know what equipment they had onboard the Roosevelt, but the
quick turnaround might indicate the type of test. These tests were also
performed around Mar29.

~~~
alkonaut
Sounds like RT-PCR tests. Serological tests probably aren’t available in that
scale yet (unsure).

Regardless, it’s going to be extremely interesting now that countries start
doing random serological tests.

I read today about a group of Swedish athletes who visited a competition in
Wuhan in October and some developed severe respiratory issues afterwards that
couldn’t be diagnosed.

Edit: 5 were tested and 1 was positive which was interpreted as being a later
infection. So no October infection.

------
surge
This was what was coming out when it was blowing through China, this was what
the big concern back February. This isn't news. A good deal of people will
never notice they have it which is why the spread of this thing is so
difficult to contain.

I guess maybe people doubted it really was that hard to stop or were not
paying attention before, but its why its is absolutely critical everyone
isolate even without symptoms.

------
icedchai
Nothing new here. People were talking about asymptomatic spread by younger
people for _months_. Why is Esper surprised?

------
aazaa
Nowhere does the article mention which kind of test was run. Was it qPCR or
serological?

The latter tests whether you have had an infection. The former tests whether
you currently have one.

The distinction between _presymptomatic_ and _asymptomatic_ is tricky as well,
but is less of an issue with a serological test than a qPCR.

------
mrfusion
Could past infections from other corona viruses be Protecting people? I’d like
to see research on that.

~~~
vardump
Like
[https://en.wikipedia.org/wiki/Human_coronavirus_NL63](https://en.wikipedia.org/wiki/Human_coronavirus_NL63).

"Human coronavirus NL63 (HCoV-NL63) is a species of coronavirus that was
identified in late 2004 in a seven-month-old child with bronchiolitis in the
Netherlands.[1] The virus is an enveloped, positive-sense, single-stranded RNA
virus which enters its host cell by the _ACE2_ receptor."

To add, I also wonder whether those with contacts to disease super spreaders
(aka toddlers in kindergarten) have better immunity against covid-19, just by
being previously infected by other coronaviruses. Possibly some currently
unknown ones as well.

------
thesz
Let me cite full abstract of the research on CT scans of symptom-free COVID-19
patients [1]

Purpose

To evaluate the chest CT findings in an environmentally homogeneous cohort
from the cruise ship “Diamond Princess” with Coronavirus Disease 2019
(COVID-19).

Materials and Methods

This retrospective study comprised 104 cases (mean age, 62 years ± 16, range
25-93) with COVID-19 confirmed with RT-PCR. CT images were reviewed and the CT
severity score was calculated for each lobes and the entire lung. CT findings
were compared between asymptomatic and symptomatic cases. Results

Of 104 cases, 76 (73%) were asymptomatic, 41 (54%) of which had lung opacities
on CT. Other 28 (27%) cases were symptomatic, 22 (79%) of which had abnormal
CT findings. Symptomatic cases showed lung opacities and airway abnormalities
on CT more frequently than asymptomatic cases [lung opacity; 22 (79%) vs 41
(54%), airway abnormalities; 14 (50%) vs 15 (20%)]. Asymptomatic cases showed
more GGO over consolidation (83%), while symptomatic cases more frequently
showed consolidation over GGO (41%). The CT severity score was higher in
symptomatic cases than asymptomatic cases, particularly in the lower lobes
[symptomatic vs asymptomatic cases; right lower lobe: 2 ± 1 (0-4) vs 1 ± 1
(0-4); left lower lobe: 2 ± 1 (0-4) vs 1 ± 1 (0-3); total score: 7 ± 5 (1-17)
vs 4 ± 2 (1-11)].

Conclusion

This study documented a high incidence of subclinical CT changes in cases with
COVID-19. Compared to symptomatic cases, asymptomatic cases showed more GGO
over consolidation and milder extension of disease on CT.

[1]
[https://pubs.rsna.org/doi/full/10.1148/ryct.2020200110?fbcli...](https://pubs.rsna.org/doi/full/10.1148/ryct.2020200110?fbclid=IwAR10SZ4I0ORtt5eu9wz55JaMJLfeRhg-
mgfNsABwnbksoSClINKVXvHA7OU&)

One with asymptomatic illness very probably (3/4) will get lungs damage.

~~~
kavalg
When you say damage, do you mean permanent damage? Or maybe it is still not
clear?

~~~
officialjunk
permanent [https://www.nationalgeographic.com/science/2020/02/here-
is-w...](https://www.nationalgeographic.com/science/2020/02/here-is-what-
coronavirus-does-to-the-body/)

~~~
kavalg
Thanks for the link! My question was more into the direction whether permanent
damage can occur in mild/asymptomatic cases and it looks like it is not the
case. Anyways, if I am wrong and anyone has better information on this, please
share it.

------
dcaisen
Is there any info on the sensitivity/specificity of this test and/or on how
they confirm that positive results aren't false positives?

------
Mikeb85
All the data points to the fact that coronavirus is more widespread and less
deadly than most outlets are reporting (after all, increase the denominator,
the % goes down).

The countries with the lowest death rates are also the countries that did the
most comprehensive testing. Ditto for this aircraft carrier.

Of course governments and outlets are fearmongering lest they be accused of
not doing enough, but this thing is way overblown and I fear we'll be living
with the consequences for an entire generation.

~~~
coherentpony
Are you of the opinion that this is simply just a slightly worse flu?

> All the data points to the fact that coronavirus is more widespread and less
> deadly than most outlets are reporting

You couldn't be more wrong. There are nurses and doctors working on the front
lines dealing with patients, and they're completely and utterly overloaded.
Lack of resources. Lack of help from local and federal governments. They're
the ones telling us this is way more deadly than it seems.

~~~
Mikeb85
> Are you of the opinion that this is simply just a slightly worse flu?

I mean I'm about 95% sure I already had it. Had literally every single symptom
but the local health authority (Alberta, Canada) wouldn't test me. My SO had
it worse but again, they wouldn't test her.

Felt like a worse flu + more coughing and shortness of breath. Worse fever. My
symptoms were bad for about 3 days, then felt like a cold for about a week,
then a cough stuck around another week or two after. My SO had bad symptoms
for about a week, was moderately sick for another week and a bit, but her
symptoms disappeared pretty quickly afterwards. In either case, because we
didn't require hospitalisation, AHS wouldn't test us.

Anyhow, there's a massive body of evidence that there's many times more people
infected than confirmed cases. Are you disputing that? Do you actually think
there is no one infected other than confirmed cases?

Our health authority, until a few days ago, wouldn't test anyone that wasn't a
severe case or an at-risk group... You could literally have every single
symptom and they'd simply tell you to stay home. Now they've only expanded
testing because there's way less hospitalisations than their models
predicted...

Edit

> There are nurses and doctors working on the front lines dealing with
> patients, and they're completely and utterly overloaded. Lack of resources.
> Lack of help from local and federal governments.

Maybe that's a failing of your health care system? In Canada hospitalisation
rates are way less than predicted. Our province also gave away a bunch of PPE
because it doesn't appear as though they'll get used.

Edit 2 - described more symptoms

~~~
wbronitsky
This is the terrible take that will be everywhere in the next few weeks; “I
think I had it, therefore I am an expert on the spread of this disease”. There
is no data or coherent argumentation here. I’m sorry you were sick, but this
isn’t an argument based on facts, it’s an anecdote based off of little that
might put people in danger.

We need to inoculate ourselves from this argument because we are about to see
it everywhere. Confirmation bias par excellence

~~~
Theodores
I too am a 'pretty sure I had it already' person. I have also spoken to others
that, like me, think they might have had it already.

In the weeks before the story went crazy I bought a dehumidifier in the belief
that this might help me eradicate a dry cough that would not go away. Not for
one moment did I think I had coronavirus at the time, however, as time went
on, I began to wonder. Placebo or not, the dehumidifier was an extraordinary
measure and my symptoms had been remarkably similar to those of the dreaded
disease.

Because none of us were tested and because we didn't go to hospital we can be
readily dismissed by those that only believe the TV news.

The founding myth is also a bit odd. We have a flying mammal - a bat - passing
the disease on to an ant-eating mammal nobody ever sees in zoos - the Malayan
pangolin - for this creature to be smuggled into China to then make it to a
seafood market to then infect Wuhan. The sources for this are lacking and it
is lazy reporting dressed up as science. I am surprised Father Christmas isn't
in there somewhere.

The Spanish Flu of a century ago was only called that because neutral Spain
wanted to know what was going on with the flu whereas the warmongering nations
were blind to the epidemic that was wiping out their troops. There is a theory
that the Chinese folk brought in to dig the trenches of WW1 were the source of
the so-called Spanish Flu.

I am open to the idea that the Chinese happened to do the research and pick up
on covid-19 first, hence the idea that it came from Wuhan. But did it really?
There are 7 billion or so humans with many billions of intensively farmed
animals yet it was some endangered species that doomed us all? I am
increasingly believing the anecdata is stronger than this 'pangolin story'. I
am definitely open to the idea this virus was doing the rounds outside China
although there is no proof. However, I see this as like the Spanish Flu, now
believed to have not started in Spain.

There is a Chinese saying about people too afraid to eat food in case they
choke on it. Right now we are on track for everyone to stay indoors for
eternity lest a Baby Boomer get it.

~~~
asdf21
Same, I had it starting January 4th in the SF (North) Bay Area, I'm about 90%
sure.

I was probably basically a super spreader too, tbh. I went to work every day,
'cause I tend to power through whatever is thrown at me. At least I avoided
shaking hands.

People were even talking about it back then... they didn't know it was Corona,
but friends I know who are nurses were saying there is a "weird, bad
respiratory infection" going around, and a lot of "atypical pneumonia" and a
"really bad flu season but it's a weird flu".

We already had it weeks and weeks before the shelter-in-place in the Bay Area,
I'm very sure.

~~~
roca
There is strong evidence COVID-19 was not circulating in the Bay Area in
January. Samples collected by the Seattle Flu Study in Jan/Feb 2020 have been
retested and COVID-19 was not found before Feb 21. As Trevor Bedford says, had
COVID-19 been circulating in CA it almost certainly would have showed up
quickly in WA. There is other evidence based on the genetics of sequenced
viruses. Details:
[https://twitter.com/trvrb/status/1249414291297464321](https://twitter.com/trvrb/status/1249414291297464321)

~~~
asdf21
Thoughts?

[https://www.straitstimes.com/world/united-
states/coronavirus...](https://www.straitstimes.com/world/united-
states/coronavirus-bug-circulated-in-us-weeks-earlier-than-thought-mistaken-
for-flu)

------
Bombthecat
Super healthy trained people can fight the virus easier? Who would have
thought...

------
LatteLazy
While this is interesting...

* Sailors are not in any way representative of the general population.

* Sailors in the US Navy are notoriously overworked and there is a strong culture of working when sick. So we're they actually asymptomatic or did they report for work shivering and sweating and semi delerious?

------
glofish
I find this to be good even excellent news.

It is quite possible the virus is not nearly as dangerous and lethal as people
fear. If the young have nothing to worry about the prospects are pretty good.

The best way to reach herd immunity is to have lots of immune people around
you.

~~~
jbotz
Since about a week ago data has been coming in from antibody testing in
Europe... and the results are that IFR (infection fatality rate) is clearly
less than 0.5% (0.37% in one city in germany[1]) and the number of actually
infected people at least 15 times to 30 times higher than the confirmed number
of cases.

[1] [https://www.n-tv.de/wissen/Heinsberg-Studie-entraetselt-
Coro...](https://www.n-tv.de/wissen/Heinsberg-Studie-entraetselt-Coronavirus-
article21704605.html)

~~~
joshuahedlund
I'm not so sure that's clear yet. Just going on blunt metrics, the virus has
already killed 0.1% of NYC's entire population, probably on pace to hit 0.2%
if the down-curve even only roughly matches the up-curve. So it would have had
to have spread to 50% of the population for the fatality rate there to be only
0.4%, which seems unlikely (there's only a smattering of antibody data around
the world so far but nothing has found spread even close to 50%, especially at
the level of a metropolis)

~~~
claytongulick
When you include 3,700 non-positive deaths in your total death count, yeah -
the numbers look scary.

The reporting we're seeing is CFR, __not __mortality rate. They are very
different things.

Mortality rate is the number of deaths caused by a disease.

CFR (Case Fatality Rate) is the total number of deaths by those diagnosed with
a disease.

They are very different numbers, and have very different meaning for different
analysis and methodologies.

Saying that that virus has killed .1% of NYC's population is inaccurate.

~~~
joshuahedlund
Even w/o those non-positives, the death count for NYC is in the neighborhood
of 8,000[0] (and still rising at a decent clip) for a population of 8 million.
That's 0.1%.

You can also look at individual counties[1] and you get some variation but the
same picture. Ex. 2.7k deaths in Queens for a population of 2.3mil, 0.4k
deaths in Richmond for a population of 0.4mil

(That's 0.1% for the entire population and not even nearing the maximum yet,
so obviously the IFR's and CFR's will be even higher.)

[0][https://www1.nyc.gov/assets/doh/downloads/pdf/imm/covid-19-d...](https://www1.nyc.gov/assets/doh/downloads/pdf/imm/covid-19-deaths-
confirmed-probable-daily-04152020.pdf)
[1][https://covid19tracker.health.ny.gov/views/NYS-
COVID19-Track...](https://covid19tracker.health.ny.gov/views/NYS-
COVID19-Tracker/NYSDOHCOVID-19Tracker-
Fatalities?%3Aembed=yes&%3Atoolbar=no&%3Atabs=n)

~~~
glofish
also while this may sound insensitive 0.1% of the population is not the same
as X percent of old and sick people

it is not like the virus takes down everyone equally. The overwhelming
majority of those affected are both old and fairly sick already.

Again I am not implying anything other than there is clear skew and the
measures should target those that are at risk. It makes no sense to create
generic, unworkable rules where we lock up all 20 year olds that have no risk
whatsoever. It is not realistic.

~~~
macintux
There’s also the problem that healthy young adults are generally very stupid
when it comes to assessing risk. Sure, they’re probably only at mild risk of
days of debilitating hospitalization, but they’re also going to be fairly
careless about people at greater risk around them.

Locking everyone up gives us a chance to gather data, prepare treatments, and
find a way to protect those at risk. Letting spreaders run around carelessly
will not make anything but the economy better.

------
jyounker
We can't tell anything from the article. * We don't know how many people were
tested. * We don't know how many people tested positive. * We don't know the
false positive rate for the test.

~~~
badfrog
> We don't know how many people were tested.

> We don't know how many people tested positive.

Both of those are in the article.

------
JPKab
Might also be important to note that sailors on an aircraft carrier are
primarily college-aged.

~~~
tropo
Also 0% with asthma, obesity, diabetes, etc.

~~~
rootusrootus
Not true. For various reasons, the military grants medical waivers and allows
some people with asthma and other afflictions to remain enlisted.

~~~
jki275
Asthma, no. Diabetes, no. There is not a single person on that ship with
either, they’re both disqualifying from shipboard service.

There are probably some people who are overweight to a varying degree, but
again people who get overweight and don’t get back within standards get
removed from the Navy.

------
ngcc_hk
Is this related to the three strain theory?

------
buboard
There's another air craft carrier in france where 1/3 of soldiers got it.

That said, soldiers everywhere are young and healthy , and usually vaccinated
extra

------
rezeroed
Clue to what? Are we still pretending this isn't an old people, unhealthy
people sickness?

------
blakesterz
>> The majority of the positive cases so far are among sailors who are
asymptomatic, officials say.

I don't know much about this kind of thing, but isn't the most important word
in that sentence "sailors"? I would think people living on an aircraft carrier
are, on average, way different in many major ways than the average American.
So it seems like making any kinds of assumptions based on this wouldn't be
super reliable.

~~~
londons_explore
I'd take issue at the use of the word 'sailor', when it's been an awfully long
time since the navy used sails to get into battle...

~~~
elSidCampeador
A sailor in the Navy is anyone that's not an officer

~~~
jki275
A Sailor in the Navy is anyone in the Navy, period.

And it’s capitalized.

------
m0zg
Young people in the best shapes of their lives tolerate C19 well. I thought it
was common knowledge.

------
paypalcust83
There are multiple, dynamic risk-factors being discovered, treatment options,
and different genomes of this species of virus circulating.

1) Being overweight is a major risk-factor for requiring critical care, and
most US military folks aren't weight-enabled.

2) Being older is another risk factor. Also, most US military folks aren't
well-aged either, typically in their 20's-30's.

3) Having type A blood group is a _potential_ risk factor. Type O blood group
is a _potential_ protection factor.

4) Being male was a risk-factor for the L-strain. It's possible the military
folks caught an S-strain that has less gender specificity, but it also may
have nothing to do with it.

5) SARS-CoV-2 as a species maybe drifting genetically towards more
communicability but less virulence. H1N1, HIV and others have also shown this
pattern.

6) COVID-19 may not be best helped with non/invasive high-pressure ventilation
that causes extreme barotrauma. In fact, it may not even be the same as
previous instances of ARDS.

7) It's possible they were exposed to a variant of one of the newer genomes of
S-strain that goes up to 78% "asymptomatic" community spread.

8) "Asymptomatic" means subclinical in terms of manifested, obvious symptoms.
There is still the real possibility of internal organ damage regardless. Only
a vaccine will be able to end this threat.

~~~
empath75
> 5) SARS-CoV-2 as a species maybe drifting genetically towards more
> communicability but less virulence. H1N1, HIV and others have also shown
> this pattern.

This is not true for either of those diseases.

------
asdf21
I'm calling it now, I bet many people (>20%) have had it, whether they realize
it or not.

To be honest, I think it was all over the Bay Area in late December, Early
January (when I'm pretty sure I had it) and Feb.

~~~
chasebank
I thought the same thing until this afternoon.

In January I fell extremely ill, covid symptoms, including lower right lung
pneumonia.

Today I tested negative for covid and antibodies. It seems to have been just a
coincidence with a bad viral season.

~~~
misun78
Where were you able to test for antibodies and how accurate is this test?
Asking since AFAIK, now widespread testing exists right now.

------
misja111
This is not news. The same was already reported one month ago in the Italian
village of Vo, where the entire population was tested for Corona. Summary is
here:
[https://www.bmj.com/content/368/bmj.m1165](https://www.bmj.com/content/368/bmj.m1165)

"In an open letter to the authorities in the Tuscany region,1 Romagnani wrote
that the great majority of people infected with covid-19—50-75%—were
asymptomatic, but represented “a formidable source” of contagion."

In the same report was another interesting paragraph as well:

He noted that Romagnani’s findings appeared to contradict a WHO report based
on covid-19 in China.2 This suggested that “the proportion of truly
asymptomatic infections is unclear but appears to be relatively rare and does
not appear to be a major driver of transmission.”

edit: really, downvoted? Because of the mentioning of China?

