Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free • Hacker News Board

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#491

Post by gpderetta » Fri, Apr 17, 2020, 1:58 PM UTC

innomatics wrote: post #359

robocat wrote: post #316

Earlier quoted context omitted.

When looking at a single region like Bergamo, the death toll is four times higher than normal... Absolutely nothing like a normal flu season spike. See graph in http://archive.is/AaJ76 If you look at the euromomo information for a country it is averaged across all regions, that includes those regions that started lockdown before severe outbreak, so the spike averages down to be small. I.e. you can’t look at the count…

Agree with your points although the link was blocked for me. Do you think that a very mild flu season could possibly have made this outbreak worse?

> Agree with your points although the link was blocked for me.

Euromomo [1] has per country breakdown. While some countries are relatively unaffected (yet?), bringing the average down, some, like Italy, Uk, Spain are way beyond the 2017 peak.

As pointed elsethread, possibly because of lockdown, at least in Italy, the worst has been confined to the northen regions (about one fourth of the population but more than half the confirmed cases). If allowed to spread equally everywhere, the numbers would presumably be higher.

[1] https://www.euromomo.eu/outputs/zscore_country_total.html

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#492

Post by scythe » Fri, Apr 17, 2020, 2:13 PM UTC

danieltillett wrote: post #240

scythe wrote: post #20

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-... 18% asymptomatic retrospectively: 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…

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?

I know this is a rather unorthodox source, but 538 reports a death rate of 1.2%.

https://fivethirtyeight.com/features/a-comic-strip-tour-of-t...

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#493

Post by rezeroed » Fri, Apr 17, 2020, 2:16 PM UTC

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

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#494

Post by TheOtherHobbes » Fri, Apr 17, 2020, 2:16 PM UTC

bluGill wrote: post #478

yomly wrote: post #419

Earlier quoted context omitted.

Yep you're right, your odds are best towards the tail of the pandemic

In most cases, but the 1918 Spanish flu famously got more deadly after a mutation, if you got it early you were better off. I'm still hoping to get it late assuming better treatment (or better yet vaccine), but I recognize there is no way to know if this is correct in this case.

The best case with mass immunity is that R drops below 0 and the virus burns itself out.

The worst case is that immunity primes the body for a massive and lethal immune system overreaction if the virus returns and/or mutates. This seems to have happened in 1918, which is why the second wave was more deadly.

Generally viruses seem to become less lethal over time, so this is rare and unlikely - and we'd be very unlucky indeed if it happened now.

But it isn't entirely impossible. The smart thing to do would be to have some high-quality monitoring in place to catch it if it starts happening, with high quality contingency planning for an international response.

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#495

Post by riffraff » Fri, Apr 17, 2020, 2:19 PM UTC

innomatics wrote: post #303

riffraff wrote: post #294

Earlier quoted context omitted.

As someone pointed out to me, the euromomo website is useful for this, it tracks the total mortality rate across Europe and compares it with the historical data. By ignoring the hospitalized/homestuck difference one can have a clearer idea of what is happening. Sadly I don't know of a way to get the data for the whole world.

Euromomo data is really interesting to me because of these two points: 1) the spike in death rate caused by Covid-19 this year is of the same magnitude as the normal flu season spike in 2016 2) this year's flue season spike was low compared to recent years. Maybe due to a warmer summer? One interpretation could be that a large number of vulnerable people escaped death from regular ILIs this European season, only to s…

> 1) the spike in death rate caused by Covid-19 this year is of the same magnitude as the normal flu season spike in 2016

the current number depends on lockdown measures. We didn't have lockdowns in 2016, and it is likely if we didn't have them now we'd be much worse. You can look at the graph for Sweden which decided to only apply mild measures for a comparison which shows this is much worse than the 16/17 flu.

The rest of the reasoning is still correct, and I have heard it pointed out before, though I believe you meant warmer _winter_ :)

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#496

Post by TheOtherHobbes » Fri, Apr 17, 2020, 2:25 PM UTC

yomly wrote: post #429

cm2187 wrote: post #421

Earlier quoted context omitted.

The 15% looks implausible given the fatality rates mentioned here. But I would expect a lot of the medical care to be scalable so unmitigated doesn't mean no medical care. We have been building field hospitals in the UK and US (though have barely used them so far), using hotels, etc. Providing oxygen should be fairly straightforward. I understood ventilators was the part that caused a serious scalability bottleneck.

Yes - part of the strategy of flattening the curve is to buy time to scale capacity. Dedicated covid19 hospitals also have the advantage of isolating covid19 patients from high risk non-covid19 patients (e.g immunocompromised cancer patients) As the disease is so easily transmitted hospitals are partly buckling due to contamination within hospitals. A regular 50 year old probably has a good chance of surviving corona…

The "We shouldn't have killed our economy for this" online comments miss some obvious truths - which is that the economy would be crippled by a high peak regardless.

At best people wouldn't go to work, at worst they'd struggle in and pass out - or maybe die - in front of their coworkers.

So the economy would have ground to a halt anyway as people stayed at home to protect themselves. But it would have done it in an uncontrolled way that didn't inspire confidence in a return to normality.

Which is the economic reason for flattening the peak. Serious damage was always inevitable, but there's a huge difference between a barely controlled but orderly temporary shutdown with mitigation measures, and a shutdown caused by mass panic and paranoia.

In fact even laggard countries have been forced to take some measures, because when their lives are at risk people and their managers act on their own initiative no matter what the official line is.

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#497

Post by jacobush » Fri, Apr 17, 2020, 2:26 PM UTC

cm2187 wrote: post #489

bigbob2 wrote: post #483

Earlier quoted context omitted.

> If it is “only” two times more, then we need to have an adult conversation on how many lives are worth saving vs our society going through something akin to the great depression. Why is it that only two choices ever exist when this argument is presented? Choose either death by virus or death by status quo economy. It seems like a more pleasant alternative would be reshaping our economic systems to be more resilient…

The ownership and distribution models aren't the problem. The problem is that while everyone is locked up at home, no one consumes, we don't go to restaurants, to malls, we don't do tourism. And in some case we don't produce either, construction is halted, etc. There is almost no economic activity going on. No economic model works when everyone is effectively on house arrest.

That sounds like an argument based on faith.

Edit:

that we can not "be reshaping our economic systems to be more resilient against such a crisis" seems like arguing from faith. There is no natural law that dictates that everything has to go to haywire just because things are on a pause, or that the current systems, particularly in the US, constitutes the optimal way to handle this.

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#498

Post by jimbokun » Fri, Apr 17, 2020, 2:47 PM UTC

cm2187 wrote: post #408

yomly wrote: post #345

Earlier quoted context omitted.

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…

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 lockdow…

The actual CDC recommendations are here:

https://fm.cnbc.com/applications/cnbc.com/resources/editoria...

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#499

Post by jimbokun » Fri, Apr 17, 2020, 2:48 PM UTC

chiefalchemist wrote: post #447

cm2187 wrote: post #408

Earlier quoted context omitted.

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 lockdow…

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.

The actual CDC plan is here:

https://fm.cnbc.com/applications/cnbc.com/resources/editoria...

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

Re: Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free

#500

Post by saalweachter » Fri, Apr 17, 2020, 2:49 PM UTC

gojomo wrote: post #475

saalweachter wrote: post #468

Earlier quoted context omitted.

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

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 test…

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.