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

reuters.com

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

#101

Post by ImaCake »

Lewton wrote: post #89
btilly wrote: post #27

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... 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…

bingo It seems like most everyone keep glossing over the fact that if you have a disease that doubles its infection count every x days, and it takes around x days to show symptoms you would always expect about 50% of infected to be asymptomatic at the time of testing

I feel that the asymptomatic thing is more wishful thinking in places where infection control has failed. Other countries have shown that you can contain the spread of Covid19, even if there are asymptomatic (or more realistic, low symptom severity) cases.

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

#102

Post by ashtonkem »

usaar333 wrote: post #100
ashtonkem wrote: post #97

Earlier quoted context omitted.

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.

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.

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.

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

#103

Post by 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.

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

#104

Post by bhouston »

ImaCake wrote: post #101
Lewton wrote: post #89

Earlier quoted context omitted.

bingo It seems like most everyone keep glossing over the fact that if you have a disease that doubles its infection count every x days, and it takes around x days to show symptoms you would always expect about 50% of infected to be asymptomatic at the time of testing

I feel that the asymptomatic thing is more wishful thinking in places where infection control has failed. Other countries have shown that you can contain the spread of Covid19, even if there are asymptomatic (or more realistic, low symptom severity) cases.

We need widespread antigen testing in a place like Italy or NYC or Sweden. Would be so informative.

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

#105

Post by ImaCake »

andrewla wrote: post #13

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.

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.

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

#106

Post by gopalv »

btilly wrote: post #27

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... 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…

> 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.

There's also a wide range of symptoms from 102F fever all the way to sp02 dropping below 80, with varying impacts on the health-care infrastructure.

At this point, conserving health infrastructure for normal incidence is as much of a problem (i.e even in the best case outcomes, there will be some cases of "stay at home, never catch the disease, but die from delayed response to a stroke").

If the asymptomatic people get immune, then this might drop the other multiplier of the R0.

Oof, optimism is hard to come by in these times.

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

#107

Post by gnopgnip »

scarface74 wrote: post #11
eximius wrote: post #10

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 ra…

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

There are a lot of people who have pre existing conditions and have no idea, even in the military. There was a marine recruit who died during basic training because of a heart defect, it wasn't an issue his whole life and it didn't come up as a problem during the in depth physical you get before hand.

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

#108

Post by gpm »

ashtonkem wrote: post #102
usaar333 wrote: post #100

Earlier quoted context omitted.

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.

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.

It's more likely that cases/infections is skewed by age, because we test severe cases more than mild cases, than infections as a whole is skewed by age. Assuming infections are uniformly distributed, or rather have a similar distribution to the flu, seems entirely reasonable until we have good data suggesting otherwise.

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

#109

Post by azinman2 »

bhouston wrote: post #104
ImaCake wrote: post #101

Earlier quoted context omitted.

I feel that the asymptomatic thing is more wishful thinking in places where infection control has failed. Other countries have shown that you can contain the spread of Covid19, even if there are asymptomatic (or more realistic, low symptom severity) cases.

We need widespread antigen testing in a place like Italy or NYC or Sweden. Would be so informative.

Some percent of confirmed recovered cases never develop antibodies it seems.

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

#110

Post by Mikeb85 »

wbronitsky wrote: post #84
Mikeb85 wrote: post #62

Earlier quoted context omitted.

Short to medium term immunity is conferred to survivors of other coronaviruses. No reason to expect it won't be the same with this one.

This reasoning seems like it needs data. Do we have any proof that Coronavirus immunity is similar across different viruses? Why should we expect that things that have the same name have the same immune response? This is a pretty cavalier take when lives are at stake.

Literally every health authority including the WHO is assuming immunity will be a thing...
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