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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

#71

Post by mathgeek »

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).

Re: Rapid Covid tests miss 90% of asymptomatic cases

#72

Post by harha »

BoxFour wrote: post #16
Symmetry wrote: post #8

Duh, they only detect levels of viral load sufficient to make a person infectious, around 1e6 RNA copies per cc of fluid. And viral load tends to peak somewhere in the 1e10 to 1e14 range, people at 1e6 really have to work at coughing directly on to growth plates to create a sample. Back in the early days of Covid-19 people didn't typically begin displaying symptoms visible without an x-ray until they'd nearly reach t…

Indeed, it appears that this is somewhat redundant. A majority, if not all, of the rapid tests I have used explicitly caution against taking one in the absence of symptoms, as it is expected to yield negligible results.

And yet they made it in policies all around the world with lots of people involved poking around in the other peoples noses and throats.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#73

Post by gjulianm »

hospitalJail wrote: post #68
b0dhimind wrote: post #56

We are all "asymptomatic" with something. Asymptomatic people don't spread as easily anyways. Typical fearmongering tyranny propaganda to inculcate fear into society, simultaneously scaring unhealthy people and leading to policies to inhibit healthy people.

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…

> 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.

I'm sorry, but what the hell are you talking about? In my city there were so many dead people they had to transform a skating rink into a morgue. ER rooms were completely overcrowded, COVID took so much effort to fight in hospitals that other diseases got later diagnoses and treatments, which resulted in even more dead people. Lots of elder people died in care homes because there wasn't any help available for them. There were no ambulances available at all. My mother had to go the hospital due to her infection worsening and she had to stay in the hospital gymnasium in couches, because there weren't enough beds nor space for them. They had to make an improvised hospital in a conference center to hold all the hospitalized people, thousands of them. We had a complete lockdown and it still took several weeks for cases to start decreasing.

We panicked so hard because it was fucking scary. 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, but I don't think it's ok to be so cavalier about it when so many people had such a hard time.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#74

Post by greazy »

pama wrote: post #70

If anyone cares to increase the resolution of a rapid test, I recommend using Fiji and treating the image of the test strip like an antibody blot image and run the quantitative gel analysis (easy to find info on the web). The software integrates the signal along the direction of the strip, correcting for lighting conditions, and the resulting single curve can clarify a little bump well before (or after) the viral loa…

> run the quantitative gel analysis (easy to find info on the web)

You lost me at this bit. Use Fiji to run the gel analysis or is this via ImageJ or something else?

Re: Rapid Covid tests miss 90% of asymptomatic cases

#75

Post by someperson »

pama wrote: post #70

If anyone cares to increase the resolution of a rapid test, I recommend using Fiji and treating the image of the test strip like an antibody blot image and run the quantitative gel analysis (easy to find info on the web). The software integrates the signal along the direction of the strip, correcting for lighting conditions, and the resulting single curve can clarify a little bump well before (or after) the viral loa…

Interesting. That processing pipeline should be implemented into a phone app

Re: Rapid Covid tests miss 90% of asymptomatic cases

#77

Post by basisword »

harha wrote: post #72
BoxFour wrote: post #16

Earlier quoted context omitted.

Indeed, it appears that this is somewhat redundant. A majority, if not all, of the rapid tests I have used explicitly caution against taking one in the absence of symptoms, as it is expected to yield negligible results.

And yet they made it in policies all around the world with lots of people involved poking around in the other peoples noses and throats.

I’ve never seen a rapid test done by anyone other than the person taking the test. And most now only require a small nose swab rather than nose and throat. In fact any PCR tests I did were also self-administered (with guidance) so that the patient didn’t accidentally cough/sneeze on the nurse.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#78

Post by gjulianm »

harha wrote: post #72
BoxFour wrote: post #16

Earlier quoted context omitted.

Indeed, it appears that this is somewhat redundant. A majority, if not all, of the rapid tests I have used explicitly caution against taking one in the absence of symptoms, as it is expected to yield negligible results.

And yet they made it in policies all around the world with lots of people involved poking around in the other peoples noses and throats.

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.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#79

Post by NotYourLawyer »

usednet wrote: post #63
blagie wrote: post #34

Earlier quoted context omitted.

.... maybe .... It depends on the purpose of the test. For example, a trillion dollar question is still long covid. Very significant numbers of people are on disability right now. About 10% of Americans have some form of long covid, and >1% are unable to work due to long covid (or >2% of the workforce). Long covid comes up even with mild and asymptomatic cases, and seems to have a strong autoimmune component. If you'…

I think its highly likely long COVID simply does not exist, at least in the way we currently imagine it. The body of evidence that long COVID has a biological/chemical/physical basis is very unconvincing. The demographics of the people who get long COVID is the most telling evidence that its more of a syndrome than an actual disease. Over 20% (!) of bisexual people have/had long COVID. Long COVID sufferers are more l…

> Over 20% (!) of bisexual people have/had long COVID.

That’s bizarre. I’m not sure what would cause those numbers regardless of whether long covid is real.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#80

Post by SketchySeaBeast »

hospitalJail wrote: post #68
b0dhimind wrote: post #56

We are all "asymptomatic" with something. Asymptomatic people don't spread as easily anyways. Typical fearmongering tyranny propaganda to inculcate fear into society, simultaneously scaring unhealthy people and leading to policies to inhibit healthy people.

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…

> 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 people are infected and there are ~450,000 deaths[1]. That's a 0.045% death rates, and that's one of our winter biggest killers.

To bring it to America, the CDC has death rates at ~0.1-0.2% [2]

[1] https://ipac-canada.org/influenza-resources [2] https://www.cdc.gov/flu/about/burden/index.html

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