9 ms·

Saliva based Covid test: results in 45 minutes

218 points by goldenshale 6y ago

the-dude 6y ago
n=60, deactivated virus, no humans.
- xipho 6y ago
  University of Illinois CU is running this [right now](https://illinoisnewsroom.org/university-of-illinois-creates-saliva-covid-19-test-with-a-plan-to-use-it-on-thousands-of-students-this-fall/ https://illinoisnewsroom.org/university-of-illinois-creates-...). They are returning results in hours.
- starpilot 6y ago
  less space than a nomad
  - yjftsjthsd-h 6y ago
    Yes, and we'll have fusion reactors, HIV vaccines, and a cure to cancer any year now. Science is less subjective than consumer electronics.
faitswulff 6y ago
The study "Saliva is more sensitive for SARS-CoV-2 detection in COVID-19 patients than nasopharyngeal swabs" [0] was published in April, so I'm glad some additional steps have been taken to test it. [0]: https://www.medrxiv.org/content/10.1101/2020.04.16.20067835v1 https://www.medrxiv.org/content/10.1101/2020.04.16.20067835v...
war1025 6y ago
Off topic, but related enough that I feel its relevant to mention: I learned this week that many blood donation and plasma centers [1][2] are doing Coronavirus antibody tests for anyone* that donates right now. I've heard a lot of people in my social / online circles comment how they wish they knew whether or not they had antibodies. Seems like a great way to find out. [1] https://www.redcrossblood.org/donate-blood/dlp/covid-19-antibody-testing.html https://www.redcrossblood.org/donate-blood/dlp/covid-19-anti... [2] https://www.lifeservebloodcenter.org/donate/recovered-covid-19-patient-plasma-donation/ https://www.lifeservebloodcenter.org/donate/recovered-covid-... * Probably not literally anyone, but it sounds like they are giving them out pretty freely.
- isthisreality 6y ago
  I recommend reading this blog post [1] about the unknowns of immunity. Antibodies are only part of the immunity picture, as this tweetstorm [2] concisely explains. [1] https://blogs.sciencemag.org/pipeline/archives/2020/07/07/more-on-t-cells-antibody-levels-and-our-ignorance https://blogs.sciencemag.org/pipeline/archives/2020/07/07/mo... [2] https://twitter.com/EricTopol/status/1278400526716211200?s=19 https://twitter.com/EricTopol/status/1278400526716211200?s=1...
- rbritton 6y ago
  Can confirm it’s not anyone but probably anyone eligible to donate. My sister could not due to visiting Guatemala in the last year.
  - Bombthecat 6y ago
    What's the reason here? Do they expect an infection after a year?
    - untog 6y ago
      There are a lot of not-altogether-scientific reasons. Gay people can’t give blood. If I recall correctly British people can’t either because of Foot and Mouth disease, something that happened in the 90s.
      - vinay427 6y ago
        They are based on reasons that are statistically founded in some way because not everyone's blood can be tested as extensively as anyone would like, so reducing risk factors helps. I can't speak for every country but this is at least the case for the ones I've lived in and donated in. Also, it's no longer true in many (most?) places that "gay people" can't give blood, as the distinguishing factor nowadays is usually recent sexual activity.
        cyphar 6y ago
chris_va 6y ago
Technically, you are really just waiting for the thermal inertia of the testing device. The reaction kinetics are really quite fast. During the last SARS outbreak, this sort of thing was proposed: https://pubs.rsc.org/en/Content/ArticleLanding/2011/AN/c1an15365j#!divAbstract https://pubs.rsc.org/en/Content/ArticleLanding/2011/AN/c1an1... ... to do 3 minute tests. I assume grant funding dried up, since who could guess that after 2 outbreaks that we'd have a 3rd?
- drewwwwww 6y ago
  the method described in the article uses a constant temperature of reaction. edited to add: https://en.wikipedia.org/wiki/Reverse_Transcription_Loop-mediated_Isothermal_Amplification https://en.wikipedia.org/wiki/Reverse_Transcription_Loop-med...
- redis_mlc 6y ago
  > I assume grant funding dried up, since who could guess that after 2 outbreaks that we'd have a 3rd? Yes, that's what I've read. Any US research scientists still working on SARS-1 after 2003 were told "you're on your own." Kudos to Canada for being as diligent as Taiwan in attacking COVID-19 - they remember it wiping out Toronto hospital staff in 2003. Check out the Youtube CBC channel for their impressive nation-wide mobilization. Makes you wonder wtf Chinese virology labs were doing for 20 years with coronavirus if they weren't working on a cure, doesn't it? (There's 40 labs total across China.)
  - ethbro 6y ago
    > Makes you wonder wtf Chinese virology labs were doing for 20 years with coronavirus if they weren't working on a cure, doesn't it? (There's 40 labs total across China.) Like most things in a command economy, they worked on whatever was a political priority. I'd hazard to guess it wasn't a priority in the intervening years for the same reason there was little free market incentive to address it: yes, it's bad when it happens, but it doesn't happen that often. Ergo, they were probably just as starved of resources. The preexisting US effort was mostly funded through DARPA for the same reasons. https://www.darpa.mil/our-research https://www.darpa.mil/our-research (e.g. ADEPT, P3, Prometheus, PREPARE)
Symmetry 6y ago
This seems like a really good idea but I worry about regulatory approval. Tests like these will tend to catch any Covid-19 cases in the window where you have a real chance of infecting someone from maybe 2 days pre-symptom onset to a few days post onset. And that's really all you need from an epidemiological standpoint. But from a medical standpoint if someone comes into your ER a week post symptom onset you want to know if they've got Covid-19 whether or not they're still infected, from a medical standpoint. And in that use case this is less likely to produce the correct answer than the already existing PCR test and the time lag probably isn't that important. It would be reasonable to allow it anyways but the FDA's rules are set up for the benefit of medical uses rather than epidemiological uses and I wouldn't be optimistic about it getting allowed baring pressure from above. Also >One researcher spiked 30 out of 60 saliva samples with inactivated SARS-CoV-2 in the lab. Then they shuffled the samples and gave them to another scientist to test with the RT-LAMP technology. I wonder if that required a BSL-3 facility or not. Generally you can do medical work on this virus with any sort of facility or laboratory you have on hand but you're only allowed to do science involving the virus if you have a special laboratory with negative pressure and special failsafes and so on.
- averros 6y ago
  Given widespread SARS2 infection in the general population, requiring to work on this virus in BSL-certified lab is rather... silly.
- icegreentea2 6y ago
  Spiking inactivated virus does not require BSL-3. You only need BSL-3 for isolating and growing live virus. So the vendors that create inactivated virus are doing so in BSL-3 facilities, but once it's inactivated you can work with it at much lower stringency. Seems like BSL-2 is standard.
rusbus 6y ago
This test relies on RT-LAMP to generate copies of the RNA instead of PCR which the "regular" tests use. It's pretty sensitive, but not as sensitive as state of the art PCR[1]. It's also way faster. No magic, just a slightly different technique with different trade offs. [1] https://www.frontiersin.org/articles/10.3389/fmicb.2018.02089/full https://www.frontiersin.org/articles/10.3389/fmicb.2018.0208...
x87678r 6y ago
Emirates had something about 10 minute test back in April before boarding. I never figured out how they did that. https://www.emirates.com/media-centre/emirates-becomes-first-airline-to-conduct-on-site-rapid-covid-19-tests-for-passengers/ https://www.emirates.com/media-centre/emirates-becomes-first...
- henryl 6y ago
  OK. I need to know how.
- ianwalter 6y ago
  Not sure how they can do that but my company's device can do it in 20: https://www.forbes.com/sites/johncumbers/2020/07/01/a-new-20-minute-covid-19-test-will-use-crispr-gene-editing-technology-to-deliver-results-at-the-doctors-office-supermarket-or-workplace/ https://www.forbes.com/sites/johncumbers/2020/07/01/a-new-20...
- markus92 6y ago
  They’re antibody tests, those are extremely quick.
- nYanzFa 6y ago
  Interesting, I'd never consent to such a test. Where are the results stored and why would I give DNA to a Dubai Health Authority?
ilyagr 6y ago
This reminds me of an excellent video on use of cheap and less sensitive tests on "This Week in Virology". https://youtu.be/kDj4Zyq3yOA https://youtu.be/kDj4Zyq3yOA (Feel free to skip to around 6:35). Preprint: https://www.medrxiv.org/content/10.1101/2020.06.22.20136309v2 https://www.medrxiv.org/content/10.1101/2020.06.22.20136309v... Update: the colorado.edu article also links to this preprint when it discusses the "separate computer modelling study".
- headmelted 6y ago
  Upvoting for TWIV, which is my daily exercise podcast of choice until this thing is over (and probably afterwards too).
- acqq 6y ago
  The visual explanation of the ideas and concepts presented there, also mentioned in the later podcast: Medcram: “Coronavirus Pandemic Update 98: At Home COVID-19 Testing - A Possible Breakthrough” https://www.youtube.com/watch?v=h7Sv_pS8MgQ https://www.youtube.com/watch?v=h7Sv_pS8MgQ Also, regarding the Ct value, from: “Interpreting the COVID-19 Test Results: a Guide for Physiatrists” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7268832/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7268832/ In PCR tests “the diagnosis is made based on the threshold cycle (Ct) value. Ct is defined as the cycle number when the sample fluorescence exceeds a chosen threshold above the calculated background fluorescence.5 In other words, the lower the Ct value of a specific gene, the more the gene exists in the sample. However, the problem with a Ct-based diagnosis is that there is no absolute or constant Ct cut-off value, and Ct cut-off values are different for each diagnostic reagent even for the same gene.”
- aquadrop 6y ago
  Yep, this was an eye opening video, showing how current mindset for virus test accuracy is wrong. If early on we channeled even small portion of all the trillions used to help with covid negative effects, world would be much better off now.
latchkey 6y ago
Israel is 30 seconds. https://hamodia.com/2020/06/30/israeli-company-introduces-coronavirus-test-results-30-seconds/ https://hamodia.com/2020/06/30/israeli-company-introduces-co...
- ergwwrt 6y ago
  How to learn more about this sensor?
averros 6y ago
With isothermal amplification it's hard to control the amplification factor (with conventional thermocycling PCR each cycle (if reagents aren't exhausted) is close to doubling of sensitivity. This makes LAMP technique purely qualitative... and medical diagnosis of active infection requires detection of specific viral load above some threshold indicative of actual infection (rather than exposure or sample contamination).
Markoff 6y ago
sound promising for air travel with 59/60 accuracy and last positive sample inconclusive
iandanforth 6y ago
A virologist is quoted comparing the search for a corona virus vaccine to the search for an HIV vaccine? Have I misread all the science over the last six months? That seems like an absurd comparison.
- bosswipe 6y ago
  Mind explaining why it's absurd?
  - iandanforth 6y ago
    They are very different and HIV is very nasty. As a retrovirus that targets the immune systems (T-Cells, macrophages etc) with an unusually high genetic variability it is really hard to reliably invoke the kind of immune response that normal vaccines rely on for their efficacy. Corona virus on the other hand is an RNA virus that mainly attacks the respiratory system and invokes a strong (often too strong) immune response. They just arn't very similar beasts, if you had to draw an analogy about the difficulty of the problem it would be that we don't yet have a cure for the common cold (which is a corona virus.)
    - josephcsible 6y ago
      > the common cold (which is a corona virus.) A minority of them are. Most instances of the common cold are caused by rhinoviruses.
    - acqq 6y ago
      > They just aren't very similar beasts It took a lot of HIV vaccine research to figure that out. Before that research, nobody knew. Of course now it is knows, when the people started, it wasn't clear what the problems will be. Likewise, a lot of research is needed this time too. And the logistic needed to have the results usable is simply huge and everything needs time even if some steps are overlapped. On that level, of still being far from having a ready solution, one can compare, on the level of the sameness of the virus it is of course now known that the viruses behave differently.
gboss 6y ago
I really do not understand what the hold up is. In California I know over ten people whose results have taken more than seven or eight days to come back. This is in the past two weeks. I am still waiting for my results from Sunday six days ago. It really is inexcusable how mismanaged this epidemic is in the United States.
- TaylorAlexander 6y ago
  Agreed. Our president and many others focused on a vaccine while ignoring the need for PPE, tests, and contact tracing. Tens of thousands of Americans have died needlessly because we have failed to control the outbreak.
- qserasera 6y ago
  perhaps you should question what they're doing with your sample
- matt_kantor 6y ago
  I was tested nine days ago in the bay area. Still waiting for my results.
- MertsA 6y ago
  I live in Florida and was exposed to some respiratory illness with symptoms consistent with Covid-19. As soon as I had symptoms I immediately did what I could to get tested and specifically went for the fastest PCR test I could find (I'm in between primary care providers, couldn't find a way to even try to get a rapid test in my area). My insurance provider lists the only testing location covered as an undisclosed drive through site located somewhere in a city a good hour and a half drive away from me, with the second closest location being a 2 hour drive. The county had a free testing event scheduled for 2 days later but only had 400 tests, was first come first serve, and explicitly stated that you couldn't line up before they started testing as they literally weren't opening the gate to let traffic off of the street before then. The county also listed a 10 day wait before test results would even be available which is just flat out useless. Luckily the day before the county testing event my wife managed to find free testing offered by Quest in a somewhat nearby city that advertised that results would be available in 3-5 days instead of the 10 that the county claimed. I went there, got the nasal swab done, filled out a bunch of forms with clipboards and pens that were being reused with no sanitization between people, and signed up for Quest's online accounts to get the results. Today is literally the first day that I'm free from quarantine. Not because I got my test results back, but because the latency in testing has gotten so drawn out that even if that test eventually comes back positive, I already meet the CDC guidelines for ending quarantine. That test was completely useless for me and only serves to add some data to the statistics around the pandemic. Right now, if you want to get tested and you're not a high priority case (i.e. hospitalized), at least in my area, you can't even do that for all practical purposes. It would be arguably better if they just randomly tested only 50% and had a more reasonable backlog than testing 100% with a backlog so long that all but the high priority tests are useless by the time the results are available. We've had literally months of time to ramp up testing nationwide. This pandemic is far from over and it's already killed 145,000 Americans. This is inexcusable incompetence by the legislative and executive branch.
postingawayonhn 6y ago
They've been using a saliva test here in Australia for several weeks for children and others who struggle with the nasal swab. Accuracy is apparently only 87% though. https://www.news.com.au/national/saliva-test-with-87-per-cent-success-rate-to-bolster-victorian-war-on-covid19/video/03cb674d50ace2fc30ef1a2a4a4a14fb https://www.news.com.au/national/saliva-test-with-87-per-cen...
- coatmatter 6y ago
  87% sounds pretty good to me if it encourages a lot more people to get tested. I do wonder how many are avoiding a test because the know from others' reports that it's most uncomfortable. Think about the number of people who are afraid of simple medical procedures such as injections and apply that number to those who don't wish to get "brain scraped". It's a problem.
nxpnsv 6y ago
Antibody tests give similar results in 10min with a drop of blood.
- amiga_500 6y ago
  But you have to wait longer for the antibodies to appear in the human.
  - nxpnsv 6y ago
    True, usecase perhaps is more to confirm that what you had was covid, kind of complementary to this.
femto113 6y ago
"Because no swabs are required, and no fancy equipment is needed, the tests are less vulnerable to backlogs" That, sadly, is nonsense unless you have thousands of technicians available to process the tests. What we have here is a classic latency vs throughput problem. 45 minutes to an answer is a lot better than 24-48 hours which is about the best achievable with the PCR tests. But even if only a third of the 45 minutes is a tech messing with "pipettes, a heating source and an enzyme mixture" and the rest is waiting for reactions at best one tech could do perhaps 30 a day. On the other hand the "fancy equipment" in PCR labs can do thousands of such tests in one go (UW Virology here in Seattle is doing over 5000/day[1]). [1] http://depts.washington.edu/labmed/covid19/ http://depts.washington.edu/labmed/covid19/
- markus92 6y ago
  PCR test can be done in a few hours at most. It’s mostly the whole logistical problem that takes time.
  - femto113 6y ago
    Yes, the time's not the test, it's getting the sample from where its collected to the lab (e.g. a doctors office that may only get collected from once a day), assembling a batch, running it, collating the results and sending them back out. Any batch-oriented, industrial-scale testing operation will suffer the same delays regardless of the actual process.
blargmaster33 6y ago
Will say that you have Covid 100% of the time since that is in the interest of the global elite.
ergwwrt 6y ago
This is still not a home test. Keep working..
- uptown 6y ago
  This company claims to have a home testing kit: https://nanologix.com/ https://nanologix.com/ https://youtu.be/HVcSchmwXgc https://youtu.be/HVcSchmwXgc
Jaxkr 6y ago
I competed against this team in this year’s CU New Venture Challenge. They got first, we (https://docforge.dev https://docforge.dev) got second. They are doing some amazing work with this and SickStick.

218 points by goldenshale 6y ago

the-dude 6y ago

n=60, deactivated virus, no humans.

xipho 6y ago
University of Illinois CU is running this [right now](https://illinoisnewsroom.org/university-of-illinois-creates-saliva-covid-19-test-with-a-plan-to-use-it-on-thousands-of-students-this-fall/ https://illinoisnewsroom.org/university-of-illinois-creates-...). They are returning results in hours.
starpilot 6y ago
less space than a nomad
- yjftsjthsd-h 6y ago
  Yes, and we'll have fusion reactors, HIV vaccines, and a cure to cancer any year now. Science is less subjective than consumer electronics.

faitswulff 6y ago

The study "Saliva is more sensitive for SARS-CoV-2 detection in COVID-19 patients than nasopharyngeal swabs" [0] was published in April, so I'm glad some additional steps have been taken to test it. [0]: https://www.medrxiv.org/content/10.1101/2020.04.16.20067835v1 https://www.medrxiv.org/content/10.1101/2020.04.16.20067835v...

war1025 6y ago

Off topic, but related enough that I feel its relevant to mention: I learned this week that many blood donation and plasma centers [1][2] are doing Coronavirus antibody tests for anyone* that donates right now. I've heard a lot of people in my social / online circles comment how they wish they knew whether or not they had antibodies. Seems like a great way to find out. [1] https://www.redcrossblood.org/donate-blood/dlp/covid-19-antibody-testing.html https://www.redcrossblood.org/donate-blood/dlp/covid-19-anti... [2] https://www.lifeservebloodcenter.org/donate/recovered-covid-19-patient-plasma-donation/ https://www.lifeservebloodcenter.org/donate/recovered-covid-... * Probably not literally anyone, but it sounds like they are giving them out pretty freely.

isthisreality 6y ago
I recommend reading this blog post [1] about the unknowns of immunity. Antibodies are only part of the immunity picture, as this tweetstorm [2] concisely explains. [1] https://blogs.sciencemag.org/pipeline/archives/2020/07/07/more-on-t-cells-antibody-levels-and-our-ignorance https://blogs.sciencemag.org/pipeline/archives/2020/07/07/mo... [2] https://twitter.com/EricTopol/status/1278400526716211200?s=19 https://twitter.com/EricTopol/status/1278400526716211200?s=1...
rbritton 6y ago
Can confirm it’s not anyone but probably anyone eligible to donate. My sister could not due to visiting Guatemala in the last year.
- Bombthecat 6y ago
  What's the reason here? Do they expect an infection after a year?
  - untog 6y ago
    There are a lot of not-altogether-scientific reasons. Gay people can’t give blood. If I recall correctly British people can’t either because of Foot and Mouth disease, something that happened in the 90s.
    - vinay427 6y ago
      They are based on reasons that are statistically founded in some way because not everyone's blood can be tested as extensively as anyone would like, so reducing risk factors helps. I can't speak for every country but this is at least the case for the ones I've lived in and donated in. Also, it's no longer true in many (most?) places that "gay people" can't give blood, as the distinguishing factor nowadays is usually recent sexual activity.
      - cyphar 6y ago

chris_va 6y ago

Technically, you are really just waiting for the thermal inertia of the testing device. The reaction kinetics are really quite fast. During the last SARS outbreak, this sort of thing was proposed: https://pubs.rsc.org/en/Content/ArticleLanding/2011/AN/c1an15365j#!divAbstract https://pubs.rsc.org/en/Content/ArticleLanding/2011/AN/c1an1... ... to do 3 minute tests. I assume grant funding dried up, since who could guess that after 2 outbreaks that we'd have a 3rd?

drewwwwww 6y ago
the method described in the article uses a constant temperature of reaction. edited to add: https://en.wikipedia.org/wiki/Reverse_Transcription_Loop-mediated_Isothermal_Amplification https://en.wikipedia.org/wiki/Reverse_Transcription_Loop-med...
redis_mlc 6y ago
> I assume grant funding dried up, since who could guess that after 2 outbreaks that we'd have a 3rd? Yes, that's what I've read. Any US research scientists still working on SARS-1 after 2003 were told "you're on your own." Kudos to Canada for being as diligent as Taiwan in attacking COVID-19 - they remember it wiping out Toronto hospital staff in 2003. Check out the Youtube CBC channel for their impressive nation-wide mobilization. Makes you wonder wtf Chinese virology labs were doing for 20 years with coronavirus if they weren't working on a cure, doesn't it? (There's 40 labs total across China.)
- ethbro 6y ago
  > Makes you wonder wtf Chinese virology labs were doing for 20 years with coronavirus if they weren't working on a cure, doesn't it? (There's 40 labs total across China.) Like most things in a command economy, they worked on whatever was a political priority. I'd hazard to guess it wasn't a priority in the intervening years for the same reason there was little free market incentive to address it: yes, it's bad when it happens, but it doesn't happen that often. Ergo, they were probably just as starved of resources. The preexisting US effort was mostly funded through DARPA for the same reasons. https://www.darpa.mil/our-research https://www.darpa.mil/our-research (e.g. ADEPT, P3, Prometheus, PREPARE)

Symmetry 6y ago

This seems like a really good idea but I worry about regulatory approval. Tests like these will tend to catch any Covid-19 cases in the window where you have a real chance of infecting someone from maybe 2 days pre-symptom onset to a few days post onset. And that's really all you need from an epidemiological standpoint. But from a medical standpoint if someone comes into your ER a week post symptom onset you want to know if they've got Covid-19 whether or not they're still infected, from a medical standpoint. And in that use case this is less likely to produce the correct answer than the already existing PCR test and the time lag probably isn't that important. It would be reasonable to allow it anyways but the FDA's rules are set up for the benefit of medical uses rather than epidemiological uses and I wouldn't be optimistic about it getting allowed baring pressure from above. Also >One researcher spiked 30 out of 60 saliva samples with inactivated SARS-CoV-2 in the lab. Then they shuffled the samples and gave them to another scientist to test with the RT-LAMP technology. I wonder if that required a BSL-3 facility or not. Generally you can do medical work on this virus with any sort of facility or laboratory you have on hand but you're only allowed to do science involving the virus if you have a special laboratory with negative pressure and special failsafes and so on.

averros 6y ago
Given widespread SARS2 infection in the general population, requiring to work on this virus in BSL-certified lab is rather... silly.
icegreentea2 6y ago
Spiking inactivated virus does not require BSL-3. You only need BSL-3 for isolating and growing live virus. So the vendors that create inactivated virus are doing so in BSL-3 facilities, but once it's inactivated you can work with it at much lower stringency. Seems like BSL-2 is standard.

rusbus 6y ago

This test relies on RT-LAMP to generate copies of the RNA instead of PCR which the "regular" tests use. It's pretty sensitive, but not as sensitive as state of the art PCR[1]. It's also way faster. No magic, just a slightly different technique with different trade offs. [1] https://www.frontiersin.org/articles/10.3389/fmicb.2018.02089/full https://www.frontiersin.org/articles/10.3389/fmicb.2018.0208...

x87678r 6y ago

Emirates had something about 10 minute test back in April before boarding. I never figured out how they did that. https://www.emirates.com/media-centre/emirates-becomes-first-airline-to-conduct-on-site-rapid-covid-19-tests-for-passengers/ https://www.emirates.com/media-centre/emirates-becomes-first...

henryl 6y ago
OK. I need to know how.
ianwalter 6y ago
Not sure how they can do that but my company's device can do it in 20: https://www.forbes.com/sites/johncumbers/2020/07/01/a-new-20-minute-covid-19-test-will-use-crispr-gene-editing-technology-to-deliver-results-at-the-doctors-office-supermarket-or-workplace/ https://www.forbes.com/sites/johncumbers/2020/07/01/a-new-20...
markus92 6y ago
They’re antibody tests, those are extremely quick.
nYanzFa 6y ago
Interesting, I'd never consent to such a test. Where are the results stored and why would I give DNA to a Dubai Health Authority?

ilyagr 6y ago

This reminds me of an excellent video on use of cheap and less sensitive tests on "This Week in Virology". https://youtu.be/kDj4Zyq3yOA https://youtu.be/kDj4Zyq3yOA (Feel free to skip to around 6:35). Preprint: https://www.medrxiv.org/content/10.1101/2020.06.22.20136309v2 https://www.medrxiv.org/content/10.1101/2020.06.22.20136309v... Update: the colorado.edu article also links to this preprint when it discusses the "separate computer modelling study".

headmelted 6y ago
Upvoting for TWIV, which is my daily exercise podcast of choice until this thing is over (and probably afterwards too).
acqq 6y ago
The visual explanation of the ideas and concepts presented there, also mentioned in the later podcast: Medcram: “Coronavirus Pandemic Update 98: At Home COVID-19 Testing - A Possible Breakthrough” https://www.youtube.com/watch?v=h7Sv_pS8MgQ https://www.youtube.com/watch?v=h7Sv_pS8MgQ Also, regarding the Ct value, from: “Interpreting the COVID-19 Test Results: a Guide for Physiatrists” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7268832/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7268832/ In PCR tests “the diagnosis is made based on the threshold cycle (Ct) value. Ct is defined as the cycle number when the sample fluorescence exceeds a chosen threshold above the calculated background fluorescence.5 In other words, the lower the Ct value of a specific gene, the more the gene exists in the sample. However, the problem with a Ct-based diagnosis is that there is no absolute or constant Ct cut-off value, and Ct cut-off values are different for each diagnostic reagent even for the same gene.”
aquadrop 6y ago
Yep, this was an eye opening video, showing how current mindset for virus test accuracy is wrong. If early on we channeled even small portion of all the trillions used to help with covid negative effects, world would be much better off now.

latchkey 6y ago

Israel is 30 seconds. https://hamodia.com/2020/06/30/israeli-company-introduces-coronavirus-test-results-30-seconds/ https://hamodia.com/2020/06/30/israeli-company-introduces-co...

ergwwrt 6y ago
How to learn more about this sensor?

averros 6y ago

With isothermal amplification it's hard to control the amplification factor (with conventional thermocycling PCR each cycle (if reagents aren't exhausted) is close to doubling of sensitivity. This makes LAMP technique purely qualitative... and medical diagnosis of active infection requires detection of specific viral load above some threshold indicative of actual infection (rather than exposure or sample contamination).

Markoff 6y ago

sound promising for air travel with 59/60 accuracy and last positive sample inconclusive

iandanforth 6y ago

A virologist is quoted comparing the search for a corona virus vaccine to the search for an HIV vaccine? Have I misread all the science over the last six months? That seems like an absurd comparison.

bosswipe 6y ago
Mind explaining why it's absurd?
- iandanforth 6y ago
  They are very different and HIV is very nasty. As a retrovirus that targets the immune systems (T-Cells, macrophages etc) with an unusually high genetic variability it is really hard to reliably invoke the kind of immune response that normal vaccines rely on for their efficacy. Corona virus on the other hand is an RNA virus that mainly attacks the respiratory system and invokes a strong (often too strong) immune response. They just arn't very similar beasts, if you had to draw an analogy about the difficulty of the problem it would be that we don't yet have a cure for the common cold (which is a corona virus.)
  - josephcsible 6y ago
    > the common cold (which is a corona virus.) A minority of them are. Most instances of the common cold are caused by rhinoviruses.
  - acqq 6y ago
    > They just aren't very similar beasts It took a lot of HIV vaccine research to figure that out. Before that research, nobody knew. Of course now it is knows, when the people started, it wasn't clear what the problems will be. Likewise, a lot of research is needed this time too. And the logistic needed to have the results usable is simply huge and everything needs time even if some steps are overlapped. On that level, of still being far from having a ready solution, one can compare, on the level of the sameness of the virus it is of course now known that the viruses behave differently.

gboss 6y ago

I really do not understand what the hold up is. In California I know over ten people whose results have taken more than seven or eight days to come back. This is in the past two weeks. I am still waiting for my results from Sunday six days ago. It really is inexcusable how mismanaged this epidemic is in the United States.

TaylorAlexander 6y ago
Agreed. Our president and many others focused on a vaccine while ignoring the need for PPE, tests, and contact tracing. Tens of thousands of Americans have died needlessly because we have failed to control the outbreak.
qserasera 6y ago
perhaps you should question what they're doing with your sample
matt_kantor 6y ago
I was tested nine days ago in the bay area. Still waiting for my results.
MertsA 6y ago
I live in Florida and was exposed to some respiratory illness with symptoms consistent with Covid-19. As soon as I had symptoms I immediately did what I could to get tested and specifically went for the fastest PCR test I could find (I'm in between primary care providers, couldn't find a way to even try to get a rapid test in my area). My insurance provider lists the only testing location covered as an undisclosed drive through site located somewhere in a city a good hour and a half drive away from me, with the second closest location being a 2 hour drive. The county had a free testing event scheduled for 2 days later but only had 400 tests, was first come first serve, and explicitly stated that you couldn't line up before they started testing as they literally weren't opening the gate to let traffic off of the street before then. The county also listed a 10 day wait before test results would even be available which is just flat out useless. Luckily the day before the county testing event my wife managed to find free testing offered by Quest in a somewhat nearby city that advertised that results would be available in 3-5 days instead of the 10 that the county claimed. I went there, got the nasal swab done, filled out a bunch of forms with clipboards and pens that were being reused with no sanitization between people, and signed up for Quest's online accounts to get the results. Today is literally the first day that I'm free from quarantine. Not because I got my test results back, but because the latency in testing has gotten so drawn out that even if that test eventually comes back positive, I already meet the CDC guidelines for ending quarantine. That test was completely useless for me and only serves to add some data to the statistics around the pandemic. Right now, if you want to get tested and you're not a high priority case (i.e. hospitalized), at least in my area, you can't even do that for all practical purposes. It would be arguably better if they just randomly tested only 50% and had a more reasonable backlog than testing 100% with a backlog so long that all but the high priority tests are useless by the time the results are available. We've had literally months of time to ramp up testing nationwide. This pandemic is far from over and it's already killed 145,000 Americans. This is inexcusable incompetence by the legislative and executive branch.

postingawayonhn 6y ago

They've been using a saliva test here in Australia for several weeks for children and others who struggle with the nasal swab. Accuracy is apparently only 87% though. https://www.news.com.au/national/saliva-test-with-87-per-cent-success-rate-to-bolster-victorian-war-on-covid19/video/03cb674d50ace2fc30ef1a2a4a4a14fb https://www.news.com.au/national/saliva-test-with-87-per-cen...

coatmatter 6y ago
87% sounds pretty good to me if it encourages a lot more people to get tested. I do wonder how many are avoiding a test because the know from others' reports that it's most uncomfortable. Think about the number of people who are afraid of simple medical procedures such as injections and apply that number to those who don't wish to get "brain scraped". It's a problem.

nxpnsv 6y ago

Antibody tests give similar results in 10min with a drop of blood.

amiga_500 6y ago
But you have to wait longer for the antibodies to appear in the human.
- nxpnsv 6y ago
  True, usecase perhaps is more to confirm that what you had was covid, kind of complementary to this.

femto113 6y ago

"Because no swabs are required, and no fancy equipment is needed, the tests are less vulnerable to backlogs" That, sadly, is nonsense unless you have thousands of technicians available to process the tests. What we have here is a classic latency vs throughput problem. 45 minutes to an answer is a lot better than 24-48 hours which is about the best achievable with the PCR tests. But even if only a third of the 45 minutes is a tech messing with "pipettes, a heating source and an enzyme mixture" and the rest is waiting for reactions at best one tech could do perhaps 30 a day. On the other hand the "fancy equipment" in PCR labs can do thousands of such tests in one go (UW Virology here in Seattle is doing over 5000/day[1]). [1] http://depts.washington.edu/labmed/covid19/ http://depts.washington.edu/labmed/covid19/

markus92 6y ago
PCR test can be done in a few hours at most. It’s mostly the whole logistical problem that takes time.
- femto113 6y ago
  Yes, the time's not the test, it's getting the sample from where its collected to the lab (e.g. a doctors office that may only get collected from once a day), assembling a batch, running it, collating the results and sending them back out. Any batch-oriented, industrial-scale testing operation will suffer the same delays regardless of the actual process.

blargmaster33 6y ago

Will say that you have Covid 100% of the time since that is in the interest of the global elite.

ergwwrt 6y ago

This is still not a home test. Keep working..

uptown 6y ago
This company claims to have a home testing kit: https://nanologix.com/ https://nanologix.com/ https://youtu.be/HVcSchmwXgc https://youtu.be/HVcSchmwXgc

Jaxkr 6y ago

I competed against this team in this year’s CU New Venture Challenge. They got first, we (https://docforge.dev https://docforge.dev) got second. They are doing some amazing work with this and SickStick.