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

reuters.com

511–520 of 544 posts

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

#511
post #429

Earlier quoted context omitted.

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 u…

  Old people, those in the middle of a chemotherapy and many other people at risk aren't going to work and hence won't die in front of their coworkers.

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

#512
post #193

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…

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?

Looks like it was just published today! https://medrxiv.org/cgi/content/short/2020.04.14.20062463v1

Here’s the HN submission for discussion: https://news.ycombinator.com/item?id=22900730

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

#513

Earlier quoted context omitted.

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".

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

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

#514

Earlier quoted context omitted.

Well it’s fair to say that neither has the government, if anyone dies in possession of COVID they’re automatically a COVID death, pretty much even if they get hit by a truck. That’s not true of the flu is it?

From what I've read the CDC has told med facilities to code any death that is even suspected to be C19 as C19. No test? Doesn't matter. Patient had other serious conditions? Doesn't matter. With broader testing limited and deaths from being inflated the IFR should be suspect.

What is it about HN and simple math? And The Truth? Down voting with no explanation is soooo lazy. Yawn

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

#515
post #467

Earlier quoted context omitted.

Regardless of calculus, it becomes constant at one point. Latest when everyone is infected.

Yes, the logistic curves are lazy S curves and approach a limit asymptotically from below. Here's the calculus: At FedEx, the BoD wanted some revenue projections. We knew (1) the current revenue and (2) the revenue for serving all the target customers. So, for time t in days, let y(t) be the revenue per day at time t, t = 0 corresponds to the present, y(0) is the current revenue. Let b be the revenue when serving all…

You can't have half person infected. At some point, everyone is infected and no new person will be infected.

At that point, it is constant. You are modeling it wrong, because you ignore real world parameters.

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

#516
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…

In addition, this virus tends to prey on the weak. You don't want to have a pre-existing condition around Covid-19. If you look at the top causes of deaths in the USA in recent years then match well with C19's "favorite" targets. This instance, high blood pressure, diabetes, lung disease (e.g., COPD aka smoking), etc. The last stat I heard was 40% of USA adults have a pre-existing condition. That's a significant amou…

A study of patients in New York showed that obesity was the top chronic pre-existing condition risk factor.

https://www.medrxiv.org/content/10.1101/2020.04.08.20057794v...

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

#517
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…

From what I read the mortality rate of patients on ventilators is near 80% in NY. Are they really beneficial?

But what does that 80% mean?

We know that New York's hospitals are overrun. We also know that in countries where the hospitals aren't at capacity the mortality rate is much lower. Look at Wuhan vs the rest of China. Or Singapore/HK/Taiwan/South Korea vs Italy, Paris, New York.

So if ventilator access is low and doctors are triaging ventilators to go to the most urgent cases, is the data skewed towards severe cases and late access to ventilation support?

This anecdotal account[1] seems to suggest ventilate as early as possible to maximise the chances of saving a patient. So again, a global stat could be masking a time element and context to the data

https://www.bloomberg.com/news/articles/2020-03-24/covid-19-...

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

#518
post #49

Earlier quoted context omitted.

Herd immunity varies by disease. A lot. For each disease we estimate a number called R0, which is how many people the average person will transmit it to if no precautions are taken. Herd immunity sets in when only 1/R0 people have not managed to get it. With the flu, R0 is about 1.3. Meaning that herd immunity to a particular strain starts slowing the spread after about 1/4 of us are immune. (It can continue spreadin…

Herd immunity is derived from R0 and "susceptibility" percentage. The value for the latter also varies with disease and strain. If you look at the Italian data, their % positive level never crossed ~30%, and overall averaged https://en.wikipedia.org/wiki/2020_coronavirus_pandemic_in_I...

If you look at the Italian data, their % positive level never crossed ~30%, and overall averaged

The more likely explanation is that social distancing was implemented early enough, and tests were given to people who might or might not have had it.

There is no reason to believe that we burned through most of the vulnerable people in the population.

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

#519

Earlier quoted context omitted.

Vacous, but elegantly stated. In a small population like an aircraft carrier, the virus stops spreading exponentially very quickly.

At roughly 10% infected the epidemic curve is in the steeply exponential portion of the curve, not the flattened end. And, as a request, perhaps you could glance at the 'principle of charity' and choose some other term than 'vacuous' to describe an argument that your response clearly did not give sufficient thought to.

> And, as a request, perhaps you could glance at the 'principle of charity' and choose some other term than 'vacuous' to describe an argument that your response clearly did not give sufficient thought to.

Vacous is also a technical term[1]. The proposition

    If A then B
is said to be vacously true if A does not hold.

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

#520

Earlier quoted context omitted.

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?

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.

> current best guesses for IFR

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

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