Mostly dodgy: SARS-Cov-2 rapid tests - Page 1
Forum section: electronics / general

author: Haenk
author_rank: Super Contributor
timestamp: January 13, 2022, 02:50:15 pm
content: https://www.pei.de/SharedDocs/Downloads/DE/newsroom/dossiers/evaluierung-sensitivitaet-sars-cov-2-antigentests.pdf?__blob=publicationFile&v=71German Paul Ehrlich Institut (document german / english)You better crosscheck your rapid tests, a lot of them are utter rubbish, with a detection rate close to "useless".I will have to dump a bunch of my tests (pointless to use non-working tests), but already ordered much better ones.

author: jonovid
author_rank: Super Contributor
timestamp: January 13, 2022, 03:11:49 pm
content: Quote from: Haenk on January 13, 2022, 02:50:15 pmI would add to that rubbish , odd statistics & most news media

author: SiliconWizard
author_rank: Super Contributor
timestamp: January 13, 2022, 05:53:42 pm
content: Your link gives me this: "Bad Request The server detected a syntax error in your request."Have they maybe made it unaccessible since you posted it?

author: nali
author_rank: Frequent Contributor
timestamp: January 13, 2022, 06:13:04 pm
content: Quote from: SiliconWizard on January 13, 2022, 05:53:42 pmDid the same for me an hour earlier but seems to be OK now. Maybe they've just been flooded with requests.

author: thm_w
author_rank: Super Contributor
timestamp: January 13, 2022, 10:51:19 pm
content: QuoteIf you look at the results for Cq <25, almost all of the rapid tests are very good (>90%).But Cq25-30 performance degrades.So the question is, is <25 Cq still reasonable threshold to use?As far as I can tell the author disagrees with the conclusion that you have made:QuoteI also don't see a mention of false positives, although that would be less of an issue.

author: newbrain
author_rank: Super Contributor
timestamp: January 15, 2022, 07:09:46 am
content: Quote from: thm_w on January 13, 2022, 10:51:19 pmYou just quoted their statement about false positives, that's the specificity.

author: SiliconWizard
author_rank: Super Contributor
timestamp: January 15, 2022, 06:44:22 pm
content: If we cannot conclude about specificity of the tests, what can we really conclude?

author: WatchfulEye
author_rank: Regular Contributor
timestamp: January 20, 2022, 11:25:06 am
content: Quote from: SiliconWizard on January 15, 2022, 06:44:22 pmTherr has never been much doubt that the specificity of rapid SARS-CoV-2 tests is mostly adequate. For example, initial acceptance testing by UK gov suggested the first round of tests had specificity of around 99.7 — 99.93% depending on conditions (trained/untrained persons performing and reading the test). More recent reanalysis suggests that the tests in widespread UK use are getting at least 99.9% specificity (and up to 99.97%) in real world conditions.Whether this specificity is adequate in practice depends on prevalence as well as social/economic cost of false positives. UK policy until recently was to require a PCR test to confirm a positive rapid test, as the number of false positives expected leading to mandated isolation was considered unacceptable. This balance can change over time - higher prevalence and lower cost of false positive (shorter isolation period, fewer vulnerable people, etc.) means that a lower specificity may be acceptable.The concern with rapid tests has always been sensitivity which proved a major problem in deploying the tests in the first place in the UK, as the government struggled to find any which could pass their acceptance testing. That this study has found several brands with inadequate sensitivity is no surprise at all.

author: Haenk
author_rank: Super Contributor
timestamp: January 20, 2022, 12:01:53 pm
content: Quote from: WatchfulEye on January 20, 2022, 11:25:06 amHence my warning. My daughters school supplied a couple of packages of "Roche" tests for home testing, which are on the really expensive side. However these tests are far away from being the best available, not even "good".Our local discounters (including Aldi and Lidl) also only offer brands with very limited testing reliability. As most people are already vaccinated a 3rd time, infected people will likely show only very low numbers of virii, and a lot of tests will simply not detect these levels. So these folks unknowingly spread the virus - and with a more reliable test they might have avoided this.

author: PartialDischarge
author_rank: Super Contributor
timestamp: January 20, 2022, 12:34:29 pm
content: Quote from: Haenk on January 13, 2022, 02:50:15 pmIs that news? This is like masks, useless, but for the psychologically afraid they have something to believe in so they can feel safe, while the smart ones are making money over this nonsenseYou can order "better" test, they will all be rubbish

author: Zero999
author_rank: Super Contributor
timestamp: January 20, 2022, 12:55:05 pm
content: Quote from: Haenk on January 20, 2022, 12:01:53 pmIf someone tests negative, their viral load is normally low enough to mean it's unlikely they'll transmit the virus to all, but really close contacts, i.e. their family.It's getting silly now. The virus is endemic, like the other respiratory viruses we have. In the UK, the all cause mortality rate is below the 5 year average and patients in intensive care, with COVID-19, are still falling. The only purpose of testing should be to diagnose sick people, to determine the course of treatment. There is no point in continuing mass testing and isolating mild cases. It's a massive waste of money.Vaccines have helped a lot, but there's no point in immunizing healthy children and boosters for healthy adults under 60. The risk vs benefit ratio doesn't justify it, especially against Omicron, which is milder than Delta. There's data to suggest, that in males under 40, the risks of myocarditis due to some vaccines, exceeds that of SARS-Cov-2. What's worse is the number of infections is under-reported, yet the number of vaccinations is known, making the ratio of excess myocarditis due to vaccination higher. Vaccinating young men made sense when Delta was prevalent, as there are other complications of infection, such as pneumonia, but it makes less sense for Omicron and boosters probably do more harm than good.https://www.medrxiv.org/content/10.1101/2021.12.23.21268276v1.full.pdfEDIT:For those who don't have time to read the study. Here's a graph showing the excess myocarditis events, per million, in men under 40, for different doses of the vaccines used in the UK and SARS-Cov-2 infection. I've added the manufacturers of the vaccines, for those unfamiliar with them.It's obvious that:For the second dose of all vaccines used, excess events of myocarditis exceed those following infection.The risk of myocarditis, following the third dose of Pfizer also exceeds SARS-Cov-2.The third dose of the AstraZeneca and Moderna, have a lower risk of myocarditis, compared to SARS-Cov-2.Notes:AstraZeneca isn't widely used for the third dose and I believe it's no longer used in under 40s, unless the person can't have any of the other vaccines, which might explain why the excess myocarditis events don't show up on the third dose.A half dose of the Moderna is used for the third dose in the UK, which could explain why there are no excess myocarditis events, following it.Moderna is no longer routinely used for the first and second doses, in under 40s in the UK, due to the unacceptably high risk of myocarditis.Conclusion:Why the heck are they still giving booster doses of Pfizer to men <40?They should look into using AstraZeneca for the first dose, in men <40 (blood clots were almost exclusively reported in women) and a half dose of Moderna for the second and third/booster doses.

author: AVGresponding
author_rank: Super Contributor
timestamp: January 20, 2022, 02:25:24 pm
content: Quote from: MasterTech on January 20, 2022, 12:34:29 pmIf masks are useless, why do surgical staff wear them in the operating theatre?

author: Zero999
author_rank: Super Contributor
timestamp: January 20, 2022, 02:42:31 pm
content: Quote from: AVGresponding on January 20, 2022, 02:25:24 pmSurgeons use medical grade surgical masks. The cloth masks worn by most people are completely useless.At the start of the pandemic, I supported wearing masks and thought it was silly that the world health organisation recommended otherwise. There wasn't solid proof, only some computer models, but it made sense on the precautionary principle, that the harm was minimal vs the possible benefit of reducing the spread. Now it seems more likely that ordinary cloth masks are useless. If we're serious about minimising the spread of SARS-Cov-2 we aught to be wearing surgical masks.https://www.nature.com/articles/d41586-021-02457-yNow at this stage in the UK, it's pretty pointless trying to limit the spread of the virus, because its impact is fading fast. As I mentioned above, deaths are below the 5 year average and numbers in intensive care are falling. Hospital admissions are also starting to fall, but this figure is exaggerated, as many people in hospital, with COVID-19, are there for other reasons.It would have been nice to have known this at the start of the pandemic, but I suppose we didn't have enough surgical masks for everyone and what we did have, should have been reserved for clinicians.

author: AVGresponding
author_rank: Super Contributor
timestamp: January 20, 2022, 06:48:26 pm
content: Quote from: Zero999 on January 20, 2022, 02:42:31 pmThat's not an argument against masks; it's an argument against ineffective masks.

author: Zero999
author_rank: Super Contributor
timestamp: January 20, 2022, 09:02:05 pm
content: Quote from: AVGresponding on January 20, 2022, 06:48:26 pmGood, then we agree. The type of mask that most people use, which is recommended by the government and has even been mandated at various points in the pandemic, is completely useless at preventing the spread of SARS-Cov-2. It should have been dropped, as soon as this data came to light. The harms: litter, communication difficulties, especially in the deaf and risk of other infections, due to people wearing dirty masks, outweigh the benefits: none.

author: PlainName
author_rank: Super Contributor
timestamp: January 20, 2022, 10:24:03 pm
content: QuoteIs that 'completely useless' as in 'has zero detectable effect' or as in 'isn't 100% effective'?

author: PlainName
author_rank: Super Contributor
timestamp: January 20, 2022, 10:28:23 pm
content: QuoteIs that deaths or merely 'events' that required intervention?How does that compare to the equivalent unvaccinated Covid stats (deaths or interventions, as the case may be)?

author: AVGresponding
author_rank: Super Contributor
timestamp: January 20, 2022, 10:29:45 pm
content: Quote from: dunkemhigh on January 20, 2022, 10:24:03 pmA brief look at the numbers in the link provided show it's not very effective, though still better than nothing, as the reduction in spread isn't down in the noise, so it's a real effect.As Zero999 points out, the risk/benefit equation is complex, I think it remains to be seen which side of the scale weighs most.

author: thm_w
author_rank: Super Contributor
timestamp: January 20, 2022, 10:40:12 pm
content: Quote from: Haenk on January 20, 2022, 12:01:53 pmDid you read my post, or read the summary of your link?"SD Biosensor, Inc. (Roche Diagnostics GmbH Cq <25 88,9%""The current state of the art was defined as corresponding to a minimal sensitivity of 75% for the pools with Cq ≤25."Where exactly did they say that 89% was "not good". Sure they are probably not the best available.

author: PlainName
author_rank: Super Contributor
timestamp: January 20, 2022, 10:42:05 pm
content: QuoteWhat is the risk aspect in wearing masks?

author: mazurov
author_rank: Frequent Contributor
timestamp: January 20, 2022, 11:00:20 pm
content: Quote from: dunkemhigh on January 20, 2022, 10:42:05 pmIn the states you can be  attacked by a redneck or someone else who is too eager to force their opinion on you. Risk-averse people may get uncomfortable.Personally, I like wearing a mask. Makes ignoring other people easier.

author: Zero999
author_rank: Super Contributor
timestamp: January 20, 2022, 11:14:32 pm
content: Quote from: AVGresponding on January 20, 2022, 10:29:45 pmIt's not statistically significant. Cloth masks might have a small effect, but they appear not to be worth it.Quote from: dunkemhigh on January 20, 2022, 10:42:05 pmReread thepost.I'm not anti-mask, just anti-ineffective-mask.I admit, I do wear a mask, but only because it makes others around me, who are ignorant of its ineffectiveness feel better.Quote from: dunkemhigh on January 20, 2022, 10:28:23 pmEvents that required intervention. Please read the study. It's very well written, in plain English.QuoteI would like to see data on the number of COVID-19 deaths in different age groups, separated by sex and co-morbidities, vs vaccination, but haven't been able to find it. Note that the study was performed when the more virulent variants: Delta and Alpha were in wide circulation. Even if the data exists, now the milder Omicron has replaced Delta, it shifts the risk vs benefit analysis somewhat.Figures can be manipulated. The number of COVID-19 deaths, in previously healthy people, with no co-morbidities, from March 2020, to September 2021 is 17,371, concentrated in the older population. They were 3774 COVID-19 deaths in the under 65s. I'd like to see the number for the under 18s. Now I'm fully aware that there are many people with long term health problems, who would have lived for many years, had it not been for COVID, so it's not a simple calculation.https://www.ons.gov.uk/aboutus/transparencyandgovernance/freedomofinformationfoi/deathsfromcovid19withnootherunderlyingcauses?s=09I'm not anti-vax. I'm just anti-unnecessary-vaccination. I rushed out to get vaccinated, when it was first offered to me. It made sense to vaccinate all healthy adults, including men under 40, especially when Delta was the most prevalent, but I'm sceptical of boosters in healthy adults, especially now we have milder Omicron.

author: PlainName
author_rank: Super Contributor
timestamp: January 21, 2022, 12:06:28 am
content: QuoteWorth what?I am sceptical of claims that cloth masks are useless. I know they are not perfect but studies I've seen have suggested they do have an effect for the wearer, just not particularly high. However, the primary benefit is for other people and I've not yet seen an actual study on that aspect. Nevertherless, a simple experiment shows they have significant effect on expelled material.So far as I'm aware, most of the 'they are useless' justifications are based on the size of Covid molecules vs size of hole in the cloth, which is not an appropriate metric.QuoteWell that's what I figured, but I wanted to check that I hadn't missed something.QuoteWell, the chart shows that if one is going to have a booster, mRNA isn't the best choice. The others seem fine. But, again, this is just unrelated numbers and you might as well quote road deaths (since you will likely be traveling to get a jab). For it to mean anything they numbers need to be compared against non-vaccinations (no Covid, no jabs, nothing, as the control, and no-jabbed Covids as the alternative).As it happens, I appear to be prone to blood clots and have to take medication for the rest of my life to protect against them. If SAGE or equivalent say I should have a booster I will have one (I already get the flu jab every year and the after-effects of the Covid jabs reminded me exactly why I don't even think about not having one). OTOH, if Johnson says I should have one I'd probably be scouring the net looking for what his kickback is

author: Simon
author_rank: Unknown
timestamp: January 21, 2022, 09:14:36 am
content: sorry but this will just go into a political mess soon like ass covid threads do - thread locked. We do not do covid here, this is an electronics forum.