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Rapid Covid tests miss 90% of asymptomatic cases

nature.com

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Re: Rapid Covid tests miss 90% of asymptomatic cases

#101

Post by cmrdporcupine »

gjulianm wrote: post #89
peyton wrote: post #83

Earlier quoted context omitted.

My city had none of those problems. COVID standard of care w.r.t. intubation was uniquely terrible. Disrupting the daily routines of elders in nursing homes is well-known to drive mortality.

> 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 societies.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#102

Post by SketchySeaBeast »

peyton wrote: post #88
SketchySeaBeast wrote: post #80

Earlier quoted context omitted.

> I think people are going to look back at something with a 1% death rate and wonder why we panicked so hard. What has a comparable death rate that nearly the entire population has been exposed to? > Various winter viruses kill on the same order of magnitude, and they kill the same old, obese, sick population. Name this virus please. If you're thinking the flu, it's estimated that each year worldwide about a billion…

Age-adjusted death rate in the US was about 4x worse than influenza and pneumonia. There’s a real argument the COVID response was disproportionate.

I cited sources to make my arguments in good faith, I'd thank you to do the same.

Regardless, that's moved the discussion a bit, but it's myopic to look at just death rates. What about the rate of hospitalization? ICU use? Death is just one facet of care, and it's assuming a medical system that could absorb the excess load across all areas. If it couldn't that would have lead to markedly increased death rates as those who required more mild care found themselves without that required assistance.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#103

Post by rlpb »

mathgeek wrote: post #71
rlpb wrote: post #42

What I think really matters for most people is not to find out whether they have covid or not, but whether they are infectious or not. I'd really like to see research (any at all!) into how effective different test methods are at predicting infectiousness and am disappointed that this never seems to get addressed. Because who cares if you're asymptomatic but your viral load is low and you're unlikely to infect others…

> What I think really matters for most people is not to find out whether they have covid or not, but whether they are infectious or not. While some folks are certainly still worried about spreading the virus, for most folks it's always been about whether a positive test requires them to restrict their movement or activities (e.g. whether or not one could fly on a plane in 2020-2022).

> for most folks it's always been about whether a positive test requires them to restrict their movement or activities

Sure but that problem is once removed from the real problem. The underlying reason for restrictions is infectiousness. If tests measured infectiousness accurately, rules on restrictions would follow and use those tests instead.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#104

Post by gjulianm »

2-718-281-828 wrote: post #91

this means that level of endemic infection was reached much sooner than claimed by pretty much all western governments AND it means that case fatality or even just case i'm-not-feeling-well rate is so low that this so called pandemic probably never really was a problem either to begin with or at least since omicron.

> this means that level of endemic infection was reached much sooner than claimed by pretty much all western governments

No, it doesn't mean that. An easy reason is that most western governments used PCRs for case confirmations. Another easy reason is that "90% miss on asymptomatic cases" does not mean "90% of all cases are asymptomatic", in fact, quite a lot of "asymptomatic cases" evolve later to "symptomatic cases".

> pandemic probably never really was a problem either to begin with

I already said this in another comment, but it was a huge problem, and a lot of us lived through it and it was scary. You might not have seen it thanks precisely to those precautions you now criticize, but a lot of cities had a very significant collapse of the healthcare system and a massive amount of deaths. Ignoring this reality is incredibly damaging and I don't understand why so many people like you are so cavalier about this.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#105

Post by mike_hearn »

rlpb wrote: post #42

What I think really matters for most people is not to find out whether they have covid or not, but whether they are infectious or not. I'd really like to see research (any at all!) into how effective different test methods are at predicting infectiousness and am disappointed that this never seems to get addressed. Because who cares if you're asymptomatic but your viral load is low and you're unlikely to infect others…

It was researched and the results were beyond poor, which is why you never heard about them.

IIRC ~75% of PCR positive samples couldn't have any virus cultured from them at all. Viral culturing isn't easy, but PCR tests can trigger on destroyed virus, so it's not a surprise that you can't get replicating virus out of many such samples especially at CT>40.

But even if you can grow virus, that doesn't mean someone is infectious. To determine that the ground truth is contact tracing and followup. But this showed that many people who were clearly sick with COVID never infected people they were in close contact with. Even within the home, most cases did not transmit, I think. I got direct experience of this when my wife got COVID and was sick for a couple of weeks, I was then quarantined by the government at home but never got sick. How this could happen was never officially explained.

This reveals one of the core scientific problems with the epidemiological simulations that were driving policy: they assumed infection is a one-way event i.e. 100% pre-existing susceptibility. I infect you, because I'm sick, you never were when we get close together we roll a dice and if it comes up 3-6 then you get infected too. This isn't how it works in reality. People's immune systems differ significantly and some are just stronger than others. To be infected I have to be infected but you have to be susceptible. The COVID models basically ignored this and assumed a homogenous population. When adjusted to reflect a more realistic heterogeneous population herd immunity thresholds went down a lot:

https://www.medrxiv.org/content/10.1101/2020.04.27.20081893v...

This research wasn't merely unnoticed, it was actively suppressed. Journals refused to publish it because, "Given the implications for public health, it is appropriate to hold claims around the herd immunity threshold to a very high evidence bar, as these would be interpreted to justify relaxation of interventions, potentially placing people at risk."

https://twitter.com/mgmgomes1/status/1291162358962937857

Re: Rapid Covid tests miss 90% of asymptomatic cases

#106

Post by Broken_Hippo »

elzbardico wrote: post #32

Asymptomatic people have small viral loads. It is reasonable to suppose that a rapid test won't be sensible enough for those cases. And besides that, it makes really very little sense testing asymptomatic people.

* And besides that, it makes really very little sense testing asymptomatic people.*

It only makes little sense if you don't really care about others. You can infect others with covid 48 hours before you have symptoms. If you know you've been exposed, why wouldn't you check? Plus, you can have symptoms without being infectious.

Similar things with other viruses, too.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#107

Post by Sparkle-san »

VancouverMan wrote: post #96
Sparkle-san wrote: post #82

Earlier quoted context omitted.

COVID was the 3rd leading cause of death in 2020 and 2021 in the US and kills an order of magnitude more than the flu typically does.

We have to be extremely cautious when considering any death statistics from that era. For example, even as early as June of 2020, the public health authority in Canada's most-populous city (with the fourth highest population in North America) revealed that the counting of deaths was being done using a methodology that sounds quite dubious: "Individuals who have died with COVID-19, but not as a result of COVID-19 are…

You can also look at the sudden spike in deaths and easily tell something was happening. In the US there was an increase in mortality of 19% between 2019 and 2020 which is 535k deaths. The typical increase between 2010 and 2019 per year is 1.63%

Re: Rapid Covid tests miss 90% of asymptomatic cases

#108

Post by maxbond »

harha wrote: post #85
gjulianm wrote: post #78

Earlier quoted context omitted.

Precisely the point of most of those policies was to use rapid tests to ensure you weren't being infections at that moment or close to it. I honestly don't know what's so controversial about them.

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

Sometimes in society, we adopt laws that are about keeping other people safe more than they are about keeping yourself comfortable.

You might feel inconvenienced. Ultimately, you're the beneficiary of this too. Your life is going to be a lot longer, because the people around you are occasionally inconvenienced for your benefit.

If this isn't acceptable to you, I'm sorry about that, that's tough.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#109

Post by gjulianm »

cmrdporcupine wrote: post #81

Even symptomatic they've been pretty useless for our family. My daughter was sick with 'rona twice last year (the rest of us seem to have never gotten it) and in both cases it barely registered visually just once on the tests after doing many many tests that showed negative. So I wonder how many times they've shown us false negatives. My wife has suddenly just now become ill with something fever/fluish and it's testi…

> My daughter was sick with 'rona twice last year (the rest of us seem to have never gotten it) and in both cases it barely registered visually just once on the tests after doing many many tests that showed negative.

Well, if anything your experience seems to confirm how these rapid tests work. At least my perception has always been that these were advertised to check not whether you had COVID or not (PCR is the gold standard) but whether you can infect others or not. Your daughter barely testing positive on one out of many tests and the rest of the family not getting the disease are coherent in that sense, as your daughter didn't seem to be specially infectious.

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