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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

#131

Post by lamontcg »

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…

> but whether they are infectious or not.

We don't have a labor and cost effective test for this, and we require the test to be done in a BSL-3 facility.

So what remains is that we need to solve public health problems with tests that produce only correlates of infectiousness. Those correlates will be necessarily imperfect, but they're all that we have to craft policy around.

The perfect home test which only detects infectious virus doesn't exist.

And I'd just like to see more published studies which actually cultured virus rather than using PCR as a proxy for infectious virus, but even that is hard to get. So many lazy scientific studies out there conflating PCR positive with virus, but there's a lot more researchers who can do PCR than researchers than have access+funding to a BSL-3 lab.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#132

Post by zanfr »

whywhywhywhy wrote: post #12
henry-j wrote: post #5

Referenced paper: https://doi.org/10.7326/M23-0385 Not much behind the paywall of the article OP linked: “Rapid antigen tests are much more reliable at detecting COVID-19 in people with symptoms than in those without, finds the largest study to compare home rapid tests with gold-standard PCR tests1. Apurv Soni at the UMass Chan Medical School in Worcester, Massachusetts, and his colleagues, followed 5,353 initially u…

>The authors say that an informational campaign about the proper way to take rapid tests might help to preserve public confidence in the tests’ utility.” Why do we have to spend tax payer money for a campaign to try and force people to care about the utility of a product that can't accurately detect a symptomless virus. Honestly starting to forget it was ever even a thing.

because HIV is usually symptomless until it isnt?

Re: Rapid Covid tests miss 90% of asymptomatic cases

#133

Post by mullingitover »

BoxFour wrote: post #55
tinco wrote: post #27

Earlier quoted context omitted.

I got stuck in the United States, was not allowed to fly back home until I got a negative result on a rapid test. It still took a week to test negative after I'd been symptom free.

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.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#134

Post by usednet »

zanfr wrote: post #126
NotYourLawyer wrote: post #79

Earlier quoted context omitted.

> 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.

whats causing it the poster's own biases

Take a look at the CDC's offical long COVID data and do your own calculations.

https://www.cdc.gov/nchs/covid19/pulse/long-covid.htm

Re: Rapid Covid tests miss 90% of asymptomatic cases

#135

Post by zanfr »

thenerdhead wrote: post #53

The only time I tested positive was being asymptomatic when my kids showed symptoms. When I actually got it with symptoms, I never tested positive. I’d do a antibody test shortly after showing I did though. I am not surprised by this finding. I would also think the opposite(symptomatic) has a significant figure too. Sadly I can’t find an archive of the entire article to read more.

I regularly do S and N antibody tests

S to monitor my vaccination status (surprise surprise you may not need to be revaxed constantly, but too many people dont botehr checking their antibodies)

N to check if I ever had it (signs point to now, and I'd be surprised if I did since I wear elastomerics and PAPRs)

Re: Rapid Covid tests miss 90% of asymptomatic cases

#136

Post by jrmg »

BoxFour wrote: post #55
tinco wrote: post #27

Earlier quoted context omitted.

I got stuck in the United States, was not allowed to fly back home until I got a negative result on a rapid test. It still took a week to test negative after I'd been symptom free.

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).

You’re now expected just to mask up and travel. Recently just had this experience with a family member.

Airline would not do anything at all. Travel agent (website) would only book a new flight, but not refund the old one - they said (probably truthfully) that the airline ties their hands. Travel insurance would only pay out if the trip was _cut short_ because of a COVID diagnosis (how does that even work?), or if they were placed under mandatory quarantine by a government authority.

Seems unethical to me on all fronts but that’s how things are.

I suppose it’s not much different to how people are now, in most countries, just expected to go to work unless they’re heavily symptomatic (and even the “unless they’re heavily symptomatic” seems like lip-service that is not universally observed).

Re: Rapid Covid tests miss 90% of asymptomatic cases

#137

Post by [deleted] »

hospitalJail wrote: post #65
yabones wrote: post #7

In my anecdotal experience, rapid tests are only really good for telling you if what you're sick with is covid or not, and barely even that. They will not give you a predictive result, and will not identify an early stage illness, only when you're at or near the peak of symptoms.

Conspiracy: The false negatives are designed to let people live their life. Nah, they are just ineffective for all the reasons people already mentioned ITT. False positives would have made this a no-go, even if they were safer. With Covid being endemic, its time to move on. If you must care, there are n95 masks.

[deleted]

Re: Rapid Covid tests miss 90% of asymptomatic cases

#138

Post by zanfr »

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…

if I may interject for a second, have you looked at 2022 ? it is a massacre. also need I remind you what they consider to be death from covid is a 20 days window... and some people drop dead a month after they "recover" ?

Re: Rapid Covid tests miss 90% of asymptomatic cases

#139

Post by mike_hearn »

freshpots wrote: post #121
mike_hearn wrote: post #93

Earlier quoted context omitted.

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…

But aren't we talking about rapid tests? There is a big difference between false positives when it comes to PCR vs rapid tests. False positives with rapid tests are known to be far less prevalent.

Other types of test are calibrated against PCR tests. That's why the article says:

"[...] finds the largest study to compare home rapid tests with gold-standard PCR tests"

PCR is assumed to be the truth to which rapid tests should aspire.

> False positives with rapid tests are known to be far less prevalent.

That's probably true if you use a normal definition of false positive, but under the intellectual framework public health uses you can't say this because you can't have less prevalent than zero.

Re: Rapid Covid tests miss 90% of asymptomatic cases

#140

Post by zanfr »

usednet wrote: post #134
zanfr wrote: post #126

Earlier quoted context omitted.

whats causing it the poster's own biases

Take a look at the CDC's offical long COVID data and do your own calculations. https://www.cdc.gov/nchs/covid19/pulse/long-covid.htm

because we all know the CDC has been a reliable source of information with them constantly changing to stats to whatever they liked to see... suuure
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