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Antibody tests show what parts of NYC were hit hardest

nytimes.com

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Re: Antibody tests show what parts of NYC were hit hardest

#51

Post by raducu »

DuskStar wrote: post #50
raducu wrote: post #38

27% of people have antibodies, thus 2.4 million were infected. 23k deaths, thus a 1% mortality rate. I guess this the final nail in the "this is just a flu" .

If 27% of the NYC population have antibodies, and half of people infected don't test positive for antibodies (too long after infection, mild infection that was defeated without antibodies, etc), then NYC is at or near herd immunity already. There's a lot of studies saying that antibodies go below detectable levels within 2-3 months, even though that doesn't seem to mean that these people are no longer immune.

Yes, but it would be pretty pointless to get yourself tested 3 months after you suspected you had the virus.

Re: Antibody tests show what parts of NYC were hit hardest

#52

Post by StanislavPetrov »

raducu wrote: post #49
StanislavPetrov wrote: post #42

Earlier quoted context omitted.

Agree completely that this is far more dangerous and deadly than the flu (especially as a New Yorker who knows multiple people who have died from this disease). That being said, there is some selection bias in these results as those who were tested were much more likely to have been infected. These tests were not done in randomly selected people. Most who get tested have reason to believe they were infected (or were…

You are right, I missed that the number of tests was ~1 million, no way that was randon testing. So, probably the mortality rate is higher. I wonder if there is any bayesian tricks to estimate the infection range given 1/8 people got tested, regardless of selection bias. edit: actually the overall deatheate could be lower, because we know the number of deaths, but not the exact number of infected -- if overall the in…

Nobody is suggesting the testing was random. The overall death rate and infection right could be either higher or lower, my only point is that you can't draw conclusions about the total population on a testing sample that wasn't random (and didn't try to be).

Re: Antibody tests show what parts of NYC were hit hardest

#53

Post by taeric »

raducu wrote: post #51
DuskStar wrote: post #50

Earlier quoted context omitted.

If 27% of the NYC population have antibodies, and half of people infected don't test positive for antibodies (too long after infection, mild infection that was defeated without antibodies, etc), then NYC is at or near herd immunity already. There's a lot of studies saying that antibodies go below detectable levels within 2-3 months, even though that doesn't seem to mean that these people are no longer immune.

Yes, but it would be pretty pointless to get yourself tested 3 months after you suspected you had the virus.

Is what I did. Had all symptoms right before shutdowns in Seattle, but they wouldn't test if you didn't transfer from China. Or make a stink. Months later, I was able to get a test. Came back negative. Now I have to wonder if I just waited too long. :(

Re: Antibody tests show what parts of NYC were hit hardest

#54

Post by DuskStar »

raducu wrote: post #51
DuskStar wrote: post #50

Earlier quoted context omitted.

If 27% of the NYC population have antibodies, and half of people infected don't test positive for antibodies (too long after infection, mild infection that was defeated without antibodies, etc), then NYC is at or near herd immunity already. There's a lot of studies saying that antibodies go below detectable levels within 2-3 months, even though that doesn't seem to mean that these people are no longer immune.

Yes, but it would be pretty pointless to get yourself tested 3 months after you suspected you had the virus.

It would also be pretty pointless to rely on people actively seeking out testing for a seroprevalence study. Not exactly a random subset of the population...

Re: Antibody tests show what parts of NYC were hit hardest

#55

Post by DuskStar »

tootie wrote: post #48
Auracle wrote: post #47

Earlier quoted context omitted.

For a good percentage of the population it is about as deadly as the flu though, perhaps even less. For a smaller percentage of people it’s far more deadly than the flu. I still think we could have gotten through this quicker if we didn’t lock down the young and healthy, while taking extra care to keep at risk populations safe.

Mortality rates for flu are correlated with very similar risk factors as COVID-19 and COVID is more deadly by an order of magnitude overall. Also, it is now becoming clearer that children are just as susceptible to adults and can harbor substantial infections and be highly contagious even without symptoms. https://www.washingtonpost.com/health/2020/08/20/children-co...

IIRC the CDC said that COVID-19 was actually less dangerous for people under 30 than the flu is. Of course, the CDC has not exactly covered itself in glory this year, so who knows.

Re: Antibody tests show what parts of NYC were hit hardest

#56

Post by oh_sigh »

raducu wrote: post #38

27% of people have antibodies, thus 2.4 million were infected. 23k deaths, thus a 1% mortality rate. I guess this the final nail in the "this is just a flu" .

No, 27% of people tested had antibodies. This is directly stated in the article.

Re: Antibody tests show what parts of NYC were hit hardest

#57

Post by nradov »

raducu wrote: post #38

27% of people have antibodies, thus 2.4 million were infected. 23k deaths, thus a 1% mortality rate. I guess this the final nail in the "this is just a flu" .

27% is just a lower bound on infections. Many patients, especially those with less severe symptoms, fail to produce detectible levels of antibodies.

Re: Antibody tests show what parts of NYC were hit hardest

#58

Post by dredmorbius »

My biggest concern with this study is sampling.

My read is that test subjects were entirely self-selected, which mean strong bias to those who suspected (or feared) exposure, had access to testing, and (where and when necessary) could pay for same (I don't know whether or when NYC instituted universal free test access).

That's in addition to any issues with test accuracy, procedures, or reporting itself.

The information tells a story. It's not immediately evident just how accurate that story is, an uncertainty which may further muddy conversations and decisionmaking regarding the outbreak.

As any statistician worth their salt will tell you, sample size is vastly less relevant than sample method, and a rigorous, though small (a few hundred, perhaps 1,000 or so randomly selected casess) would be highly valuable. The alternative (at far greater cost) is near-total testing. Itally have conducted comprehensive testing within specific small towns. Some smaller countries and territories (Andorra, Faroe Islands, Monaco, Luxembourg) have attained 100% test coverage. These still suggest 1-6.% CFR.

New York City's test coverage, whilst large, could still remain quite biased.

Re: Antibody tests show what parts of NYC were hit hardest

#59

Post by rumanator »

raducu wrote: post #49
StanislavPetrov wrote: post #42

Earlier quoted context omitted.

Agree completely that this is far more dangerous and deadly than the flu (especially as a New Yorker who knows multiple people who have died from this disease). That being said, there is some selection bias in these results as those who were tested were much more likely to have been infected. These tests were not done in randomly selected people. Most who get tested have reason to believe they were infected (or were…

You are right, I missed that the number of tests was ~1 million, no way that was randon testing. So, probably the mortality rate is higher. I wonder if there is any bayesian tricks to estimate the infection range given 1/8 people got tested, regardless of selection bias. edit: actually the overall deatheate could be lower, because we know the number of deaths, but not the exact number of infected -- if overall the in…

> because we know the number of deaths

We only know estimates of the number of deaths. The correct number lies somewhere between the official number of covid19 fatalities and the total number of deaths during the same period, because one hand you have excessive mortality and on the other hand you have changes to the baseline due to changes in behavioral patterns. Excessive mortality are higher than officially recognized covid19 deaths and serve as a more accurate proxy for real covid19 deaths, but at the same time the baseline mortality might vary as well.

Re: Antibody tests show what parts of NYC were hit hardest

#60

Post by nimbius »

Disclosure: I suffered through two weeks of covid

The test for me was $165, and my insurance would not cover it.

My recovery was punctuated with almost daily calls from the local hospital i tested at asking me to come back for a follow-up antibody screen for research purposes.

This was $400. It was not covered by insurance so I skipped.

I was then contacted by my insurance company asking if I had completed the antibody test and told it was covered, so I passed the antibody test and went back to work. Three weeks later I wound up fighting $600 from a hospital collections agency for covid ab lab work.

My disease advice is this: If possible, avoid being a working class American.

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