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Rapid Covid tests miss 90% of asymptomatic cases

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Re: Rapid Covid tests miss 90% of asymptomatic cases

#181

Earlier quoted context omitted.

> My city had none of those problems I think you missed the part where I said "Maybe the reason it wasn't for you is that you lived in a place where the government took precautions before it got too big". > COVID standard of care w.r.t. intubation was uniquely terrible. That's what happens when you're dealing with a disease that's literally three months old and that's saturating the entire health system. We also gave…

So many of these comments -- they have no point. Just vendettas / resent. Anybody who was paying attention saw the crisis in the healthcare system, and its fall-out. But there's a strong ideological bias among many now to look back in the rear view mirror and pretend nothing was there. But in a way it's not surprising as concern for the vulnerable is clearly not a widely accepted cultural value in many of our societi…

Sooooo many people want to pretend that A MILLION extra deaths are all just "old people being old" or "but but but death WITH covid vs death BY covid".

They have to do this because their ideology is that everything about covid was wrong, the vaccine didn't work, it's all the democrats fault and they invented the problem, so any acknowledgement that it actually killed at least a million americans must be avoided, otherwise they have to admit to themselves that not only are they wrong and the people they listen to lied to them, but they were selfish assholes about it.

It really sucks. We could have had a great unifying cause to rally against. We could have genuinely improved health outcomes in the US. Fuck, even Donald Trump himself eventually realized this was a bad thing and helped get the vaccine going. But half of the republican platform right now is covid denial. They have to invent a magic reality where their ignorance doesn't kill people, and people who have studied stuff for decades don't know anything.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#182

Earlier quoted context omitted.

Not to mention, I think people are going to look back at something with a 1% death rate and wonder why we panicked so hard. Various winter viruses kill on the same order of magnitude, and they kill the same old, obese, sick population. I'm a bit worried we will have something awful, killing healthy people or large swaths 5-20% of the population, and we will be too desensitized to care. It def seems like it was a poli…

IFR was actually between 0.1% and 0.3% depending on what source you use. 1% was an early assumption back when there were only dozens of cases, but of course, back then only the most severe cases were being identified.

Without a source your assertion is valueless. Every covid denier claims it "only" killed a flu comparable number of people with zero evidence.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#184

Earlier quoted context omitted.

> Quarantining you at home, for example, makes sense when you're dealing with a deadly disease Intuitively yes, in reality no. It was known by March 2020 that quarantines had no effect because of the outcome of trying it on the Diamond Princess, a sealed environment where quarantine could be perfectly enforced. That didn't stop SARS-CoV-2 spreading between cabins and causing COVID apparently at random, i.e. it'd prop…

Again, there are people who get paid to spend all their time determining whether, for example, overestimation is worse or underestimation is. It is an absolute certainty that the response to covid was suboptimal. Apart from how complex the situation and the response was, just given that responses varied widely from region to region guarantees that most were not perfect. But while it's certainly possible to nitpick so…

You make the same argument in another post, will reply once.

Your examples of experts you trust are all engineers, not public health scientists. Air disasters, power outages and rocket explosions are immediate, visible and concrete failures. You can't consensus your way out of a plane crash. If a plane goes down ordinary people demand serious answers and because plane travel is run by the private sector the operators are all very incentivized to cooperate with a real investigation, in order to reassure the public it won't happen again. The investigations into these failures are very deep, very real, root cause what went wrong and generate concrete changes.

Scientists aren't operating in the same environment. Many people use as a test of scientific competence "do you agree with other scientists" and nothing else, which is circular reasoning. When scientists fail there's a tendency for them to argue that oh well the situation was complex, lots of unknowns, did the best we could, consensus of experts etc. People are trained to never argue with scientists so they can do this.

Engineers don't get the same privilege. Saying "the experts decided it" is worth nothing to governments, the media or the public if your oil drilling ship just sank.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#185

Earlier quoted context omitted.

These are exceedingly rare, like almost never happen.

That's unfortunately not the case. PCR false positives are a massive problem. Scientists liked to claim during COVID that PCR tests don't have false positive because they use an obscure definition that doesn't match how people normally use the term. I wrote about this problem back in 2020 when it started becoming apparent that the public health establishment wasn't attempting to stop or even measure COVID PCR test fa…

The subtitle of your Jul 2020 essay criticizing PCR tests is "Why COVID-19 is guaranteed to never end". But in fact, judging by confirmed (by PCR, or by other tests grounded in PCR as you say) COVID-19 deaths, the pandemic has ended--the daily count has decreased by a factor of ~50 from the peak.

Does that not suggest to you that maybe you were wrong? It's not just the decrease in testing, since test positivity has decreased from the peaks even as total test count plummeted.

There is no evidence that PCR tests greatly overcounted SARS-CoV-2 infections:

1/2. The specificity of commonly-used PCR tests for SARS-CoV-2 is clearly very high, >99.9%, since there have been regions (e.g. Australia) where total positivity was Sloppy lab work could result in false positives by cross-contamination, but contamination has to come from a true positive sample; so this is a problem only when the true positivity is high. Sloppy clerical work could result in any possible incorrect result, but you've presented no evidence that this is a significant problem in aggregate.

Lots of papers studied the relationship between PCR positivity and culturable virus, for example

https://academic.oup.com/cid/article/72/11/e921/5912603?logi...

It's true that at high Ct, the cultures are often negative; but (a) the relationship between Ct and culturable virus may vary dramatically with small changes in PCR protocol, (b) a patient early in their infection may have high Ct now but lower Ct later, and (c) it's not clear whether all naturally infectious patients would be positive by artificial culture anyways. Based on these factors, most public health authorities chose not to use an artificially lower Ct. So a positive PCR test doesn't necessarily mean that a patient is infectious now, but it does mean that they are or were recently (weeks to months) infected.

For emphasis, it is absolutely expected that some samples will be positive by PCR but negative by cell culture--the PCR is testing for any RNA matching the primers, but the culture is testing for replication-competent whole virus. Presence of the latter implies the former, but the converse isn't true. The public messaging on that wasn't very good, and perhaps they initially misinformed you; but no one with any background in molecular biology was confused here.

3. Your idea that the PCR test is simply assumed to be accurate is completely false. The point of papers like the one I linked above is to compare two test methods, find the places where they disagree, and try to judge--from the experimental results and from our understanding of the biochemistry of the test methods--the reasons for those disagreements. They're not assuming either method to be perfect. Based on many such comparisons--against cell culture, against electron microscopy, against antibody tests, against excess mortality once that got big enough to distinguish statistically (which it mostly wasn't by Jul 2020), etc.--public health authorities judged PCR to be the best available gold standard, and good enough for many statistical purposes.

The public messaging was again pretty bad there, and if you looked only to that then I understand why you'd feel misled. The actual scientific literature is there for anyone who wishes to read it, though.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#186
post #55

Earlier quoted context omitted.

Regrettably, there are individuals who exhibit evident symptoms yet would gladly travel and deceive on a simple questionnaire. That might explain why governments adopt a blanket rapid test approach irrespective of the potential for false positives (even given the potential, as the article alludes to, for false negatives).

This fact is evidence for my hypothesis that humans are engineered by viruses as a means of transportation.

In the same manner that humans have been domesticated by wheat, with all the best land, food, water, and cushiest existence on the planet. (I believe that this was a comment by Niven or Heinlein.)

Re: Rapid Covid tests miss 90% of asymptomatic cases

#187
post #168

Earlier quoted context omitted.

Yeah, I read that part and was like... but I remember reading & hearing pretty damn early in the pandemic that a fairly high percentage of infections are asymptomatic, and continuing to see that stated periodically and never (that I read or heard) contradicted for the whole rest of the pandemic. And sure enough, most households I know that had Covid roll through (which is, at this point, practically every household o…

Yes that's how it went. That experience was very common. It was unexpected. The models deployed to justify lockdown assumed 100% susceptibility to COVID-the-disease on the grounds that the virus was "novel". Although they had some crude notion of chance involved in transmission, they didn't have any notion that you could be heavily and repeatedly exposed to the virus and just never catch it at all. When did governmen…

Ah, OK, I see the distinction you intended now. Thanks.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#188

Earlier quoted context omitted.

So many of these comments -- they have no point. Just vendettas / resent. Anybody who was paying attention saw the crisis in the healthcare system, and its fall-out. But there's a strong ideological bias among many now to look back in the rear view mirror and pretend nothing was there. But in a way it's not surprising as concern for the vulnerable is clearly not a widely accepted cultural value in many of our societi…

Sooooo many people want to pretend that A MILLION extra deaths are all just "old people being old" or "but but but death WITH covid vs death BY covid". They have to do this because their ideology is that everything about covid was wrong, the vaccine didn't work, it's all the democrats fault and they invented the problem, so any acknowledgement that it actually killed at least a million americans must be avoided, othe…

I think it's deeper than just they need to believe the "democrats" or whatever invented it, or so on. There are people intensely invested in an ideological model of the world where solidarity and any kind of collective action are inherently immoral and also that their own self-interest is paramount. They've been taught it since they were kids, regardless of party. Being a selfish asshole is a virtue to them.

It's an ideological-ethical system based on might-makes-right and "I'll take whatever I want try to stop me" and at the time the pandemic hit, its chief exponent ("grab em by the pussy") was the president of the United States.

Around here in Canada half the people who were going on about "F*ck Trudeau" and anti-mask this and anti-vax that were also taking CERB ("Canada Emergency Response Benefit") payments from the government and bilking the taxpayer for money at the same time. My nextdoor neighbours for example.

Savage capitalism as an ideology, who the fuck cares about my neighbour, and screw the old people, all this shit is inconvenient, they gonna die anyways

All that said, western governments seemed to come up with marvelous ways of making the whole lockdown & etc suck for the working classes the most. Easy for folks like me who got to work from home but pretty damn vile if you were an hourly wage worker. So I get where a lot of the anger comes from.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#189
post #168

Earlier quoted context omitted.

Yeah, I read that part and was like... but I remember reading & hearing pretty damn early in the pandemic that a fairly high percentage of infections are asymptomatic, and continuing to see that stated periodically and never (that I read or heard) contradicted for the whole rest of the pandemic. And sure enough, most households I know that had Covid roll through (which is, at this point, practically every household o…

Yes that's how it went. That experience was very common. It was unexpected. The models deployed to justify lockdown assumed 100% susceptibility to COVID-the-disease on the grounds that the virus was "novel". Although they had some crude notion of chance involved in transmission, they didn't have any notion that you could be heavily and repeatedly exposed to the virus and just never catch it at all. When did governmen…

> But if neither you nor anyone else ever notice you got sick, then you didn't get sick using any conventional definition of sickness because disease is defined as a collection of symptoms.

So was Typhoid Mary sick? Is an asymptomatic patient with a positive HIV test? Kary Mullis--the inventor of PCR!--says no:

> A man with gray hair and a goatee raises his hand. He says he's been HIV-positive since 1984, that he took the anti-AIDS drug AZT for a couple years but stopped. Now, he says, his T-cell count -- the number of a kind of white blood cell that is killed by HIV -- has gone way down.

> Mullis interrupts him: "Change doctors!"

> The man continues. His T-cell count is down to 150, which is usually thought of as dangerously low. He asks Mullis for advice.

> "I would say there is no evidence that I can find in the scientific literature that you should worry about HIV or your T-cell count," Mullis tells him. "If you'd stop worrying, maybe you'll be all right. You look pretty healthy to me."

https://www.washingtonpost.com/archive/lifestyle/1998/11/03/...

Do you think he gave that patient good advice?

Re: Rapid Covid tests miss 90% of asymptomatic cases

#190
post #85

Earlier quoted context omitted.

I can figure out for myself if I have symptoms or not

How? I wouldn't know the difference between a seasonal cold (or flu) or COVID, mostly because I've never had COVID.

You likely have had COVID-19 at some point without knowing it. In most patients it presents with minimal symptoms and is clinically similar to the common cold. Other coronaviruses that we classify as "common cold" viruses such as HCoV-OC43 are genetically very similar to SARS-CoV-2.
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