[Continuation] The One Covid-19 Science and Medicine Thread Part 2 - Page 11

GodMark2 · 14th July 2020, 11:46 AM

Originally Posted by marting

Seems to me the difference between the expected value of 1840 (by calculation assuming TFN rate=0 as it's not given) and the 2000 false negatives in Puppycow's example is quibbling. IE: 18.4% v 20%.

My use of the term "long way" was not in reference to the size of the incongruity, but the possibilities of miscommunication arising from using well-defined terms in an incorrect manner, with the user having emphatic conviction that the incorrect interpretation was correct. This often leads to further misunderstanding as neither side feels the need to specifically define the term, as both believe their definition to be obvious. This can then snowball into further distrust as each side begins to fortify their position, attacking the other side with less and less logic and more and more emotion. Eventually, both sides can end up seeing the other as completely lacking any rational basis.

Cutting off such a path by specifying the exact definitions being used can go a "long way" toward facilitating productive conversation.

Darat · 14th July 2020, 12:19 PM

Originally Posted by rjh01

That is even worse. The positive results were 3 months apart! That would mean that Covid 19 is a chronic illness. It would also mean that after Australia clears everyone from the virus it could spontaneously reappear, not from overseas but from these cases.

It would also suggest that people who. have had a case confirmed need to be isolated for quite sometime.

marting · 14th July 2020, 12:24 PM

Originally Posted by GodMark2

My use of the term "long way" was not in reference to the size of the incongruity, but the possibilities of miscommunication arising from using well-defined terms in an incorrect manner, with the user having emphatic conviction that the incorrect interpretation was correct. This often leads to further misunderstanding as neither side feels the need to specifically define the term, as both believe their definition to be obvious. This can then snowball into further distrust as each side begins to fortify their position, attacking the other side with less and less logic and more and more emotion. Eventually, both sides can end up seeing the other as completely lacking any rational basis.

Cutting off such a path by specifying the exact definitions being used can go a "long way" toward facilitating productive conversation.

I agree. But it would have been best if you had also shown the impact of using proper definitions on the numbers in Puppycow's post. Otherwise, it just leaves many scratching their heads and thinking you are objecting to the major point of Puppycow's post. For example this would be more elucidating in addition to adding the formula and link:

Originally Posted by Puppycow

I just want to add a little bit more to this for clarification after reading more.

A false positive rate of 2% does not mean that 2% of all positive results are false positives, it means that 2% of all tests conducted (both positive and negative) are false positives.

True false positive rate is the percentage of actual negatives that are detected as positives.

Quote:

What this means in practice is that, if say the true rate is 8% and the false positive rate of 2%, then 20% of all positive results are false positives.

Which is 18.4% since the false positive rate only applies to actual negatives falsely detected.

Quote:

The lower the true rate is, the greater the proportion of positive results will be false positives.

So out of say, 10,000 positive tests (out of 100,000 total tests given), 2,000 of those may be false positives.

1840, not 2000, would be the expected number of false positives in the example.

Quote:

Given that, the scenario where someone gets "reinfected" because of a false positive test seems quite likely to occur given enough tests conducted.

Right.

Delphic Oracle · 14th July 2020, 12:27 PM

Using the wrong formula and arriving at a result sorta close to the one in the correct formula is not laudable or mean that the correction is "quibbling."

No half credit for that.

"Close" is a lingerie shop without a front window.

arthwollipot · 14th July 2020, 02:33 PM

First Dog on the Moon on surviving a second lockdown

Quote:

Do remember that the lockdown isn't the problem - the virus is the problem. The lockdown is a seat belt and you are a passenger in a dreadful analogy being driven at high speed by the virus who is probably drunk.

marting · 14th July 2020, 02:33 PM

"Absence of Apparent Transmission of SARS-CoV-2 from Two Stylists After Exposure at a Hair Salon with a Universal Face Covering Policy — Springfield, Missouri, May 2020"

https://www.cdc.gov/mmwr/volumes/69/wr/mm6928e2.htm

Quote:

What is added by this report?

Among 139 clients exposed to two symptomatic hair stylists with confirmed COVID-19 while both the stylists and the clients wore face masks, no symptomatic secondary cases were reported; among 67 clients tested for SARS-CoV-2, all test results were negative. Adherence to the community’s and company’s face-covering policy likely mitigated spread of SARS-CoV-2.

While this seemed compelling back when it was reported, I though it not totally compelling because it's well known that the propensity to spread is highly heterogeneous. Since only two hairdressers had Covid-19 there was a reasonable chance that both were not good spreaders. The CDC report shows that one was. They refer to her as stylist A. All of her 4 close contacts, as well as her co-worker, tested positive for Covid-19.

Quote:

Six close contacts of stylists A and B outside of salon A were identified: four of stylist A and two of stylist B. All four of stylist A’s contacts later developed symptoms and had positive PCR test results for SARS-CoV-2. These contacts were stylist A’s cohabitating husband and her daughter, son-in-law, and their roommate, all of whom lived together in another household. None of stylist B’s contacts became symptomatic.

Highly consistent with masks working when both the infected and uninfected wear them. It provides no info. re the relative efficacy of masks for the infected v the uninfected.

Chris_Halkides · 14th July 2020, 06:50 PM

Originally Posted by GodMark2

This would go a long way toward explaining many misunderstandings earlier.

I covered these definitions in comment #2592 of the first thread. Motulsky's book is one worth having.

The Atheist · 14th July 2020, 06:53 PM

Originally Posted by marting

Highly consistent with masks working when both the infected and uninfected wear them. It provides no info. re the relative efficacy of masks for the infected v the uninfected.

Pity that horse has bolted.

When people are prepared to commit violence, and even murder, over wearing a face mask, you've already lost.

The Atheist · 14th July 2020, 07:53 PM

More good news on vaccines: https://www.nzherald.co.nz/world/new...ectid=12348208

Still needs more work, but we're making quick progress.

arthwollipot · 14th July 2020, 09:25 PM

Moving to Stage 3 this quickly is pretty impressive. It's important to remember that the first vaccines approved for general use are unlikely to be the most effective. But they'll be better than nothing.

Aridas · 14th July 2020, 09:46 PM

Originally Posted by The Atheist

Uh-oh.

That "can you catch Covid again" question may have been answered in the positive.

https://www.vox.com/platform/amp/202...-herd-immunity

tl;dr version:

Guy has mild Covid, recovers & tests negative twice.

Then gets a bad dose, requiring multiple hospital visits.

This would be unbelievably bad news for a second wave, considering the overwhelming majority of people having a very mild/asymptomatic dose in the first wave.

Those shades of 1918 just went up a notch.

He wouldn't be the first, by a long shot? There have been reports of people with repeat cases for quite a while, now, beyond just testing positive again, IIRC. Still, when it comes to concern related to reinfections during a second wave, I would think that the seemingly probable lung scarring from the first case (even in asymptomatic cases) would likely be something to focus on more as a reason for likely worse symptoms if the body's defenses don't remain strong.

Puppycow · 14th July 2020, 10:29 PM

Originally Posted by GodMark2

According to Wikipedia, you are exactly incorrect. False positive rate^WP

This would go a long way toward explaining many misunderstandings earlier.

Originally Posted by marting

Seems to me the difference between the expected value of 1840 (by calculation assuming TFN rate=0 as it's not given) and the 2000 false negatives in Puppycow's example is quibbling. IE: 18.4% v 20%.

Thank for clarifying that. My statement was incorrect. You have to subtract the true positives from the denominator. However, it still means a larger number than 2% of the positive results. As you say, in my hypothetical example, that would result in 1840, not 2000 false positives.

arthwollipot · 14th July 2020, 10:43 PM

Quote:

Police in the ACT have politely been requesting that people in Canberra stop answering the door in the nude during Covid-19 compliance requests.

In a press conference this morning detective superintendent, Jason Kennedy, said those in isolation had been offering police a “warm reception”.

But, as News.com.au reports, some of the welcomes were a little too friendly; “Some of them may need a reminder to put some clothes on before they open the door for a compliance check,” he said.

“We did get a few surprises on the weekend.

The ACT has again recorded no new cases of Covid-19 on Wednesday.

Source

Go Canberra!

The Don · 14th July 2020, 11:55 PM

Some more data about people with Covid-19 who are asymptomatic

Quote:

And the study showed 69% of those who did test positive reported no symptoms on the day of their test or the previous week, though they may have developed symptoms later.

https://www.bbc.co.uk/news/uk-53414363

rjh01 · 15th July 2020, 12:13 AM

Originally Posted by arthwollipot

Source

Go Canberra!

I wonder why the police were calling on those houses for? Had they just had a test? What made the residents answer the door in the nude? Was it a show of disrespect or something?

ohms · 15th July 2020, 03:19 AM

Originally Posted by The Atheist

More good news on vaccines: https://www.nzherald.co.nz/world/new...ectid=12348208

Still needs more work, but we're making quick progress.

And some more:

https://www.itv.com/news/2020-07-15/...-robert-peston

The vaccine is currently in Phase III trials in the UK, Brazil and S.Africa with a large trial due to start in the USA next month.

Arcade22 · 15th July 2020, 07:20 AM

Quote:

This report is a comparison between Finland and Sweden, two in many ways similar countries who applied different measures regarding schools during the covid-19 pandemic. There is no difference in the overall incidence of the laboratory confirmed covid-19 cases in the age group 1-19 years in the two countries and the number of laboratory confirmed cases does not fluctuate with school closure or change in testing policy in Finland. In Sweden, the number of laboratory confirmed cases is affected by change in testing policy. Severe covid-19 disease as measured in ICU admittance is very rare in both countries in this age group and no deaths were reported. Outbreak investigations in Finland has not shown children to be contributing much in terms of transmission and in Sweden a report comparing risk of covid-19 in different professions, showed no increased risk for teachers.

In conclusion, closure or not of schools had no measurable direct impact on the number of laboratory confirmed cases in school-aged children in Finland or Sweden. The negative effects of closing schools must be weighed against the positive indirect effects it might have on the mitigation of the covid-19 pandemic.

https://www.folkhalsomyndigheten.se/...d-children.pdf

The Atheist · 15th July 2020, 11:51 AM

Originally Posted by Aridas

He wouldn't be the first, by a long shot? There have been reports of people with repeat cases for quite a while, now, beyond just testing positive again, IIRC.

Yes, the defence that the test was faulty the first time is getting pretty hard to accept.

Originally Posted by Arcade22

https://www.folkhalsomyndigheten.se/...d-children.pdf

Not to mention, none of the studies on schools have taken into account the immense harm done by having kids not at school.

Puppycow · 15th July 2020, 04:54 PM

Originally Posted by The Atheist

Yes, the defence that the test was faulty the first time is getting pretty hard to accept.

Why?

If I'm right about this, it seems highly likely that there would be multiple examples of apparent reinfections due to false positive test results. Of course, it's just speculation on my part, but the hypothesis has to be ruled out somehow, and I don't see how it is ruled out.

Anyway, seems like something that could be studied. Can samples be retested by another lab or are they immediately destroyed after being tested?

The Atheist · 15th July 2020, 05:37 PM

Originally Posted by Puppycow

Why?

If I'm right about this, it seems highly likely that there would be multiple examples of apparent reinfections due to false positive test results. Of course, it's just speculation on my part, but the hypothesis has to be ruled out somehow, and I don't see how it is ruled out.

I'm going on the now numerous cases of claims of reinfection. People have been trying to explain them away as false positives and/or false negatives, but the more cases there are, the more likely it is actually being reinfected.

Originally Posted by Puppycow

Anyway, seems like something that could be studied. Can samples be retested by another lab or are they immediately destroyed after being tested?

They wouldn't be kept either way, mainly for logistical reasons. Whether they could be re-tested I don't know, but I'm presuming not, because the virus will break down if it gets dry, so you'd be faced with keeping millions of tests and cost would be prohibitive.

It's just something else we need to wait for more work.

arthwollipot · 15th July 2020, 05:46 PM

Originally Posted by rjh01

I wonder why the police were calling on those houses for? Had they just had a test? What made the residents answer the door in the nude? Was it a show of disrespect or something?

You know exactly as much as I do. The only time I've ever answered the door in the nude it was someone who was wondering whether I was the owner of the car that had parked him in.

GraculusTheGreenBird · 15th July 2020, 08:14 PM

Originally Posted by The Atheist

I'm going on the now numerous cases of claims of reinfection. People have been trying to explain them away as false positives and/or false negatives, but the more cases there are, the more likely it is actually being reinfected.

Why?

Why, as more cases occur, is it more likely to be actual reinfections, rather than false positives which we know for a fact happen?

pipelineaudio · 15th July 2020, 08:36 PM

Originally Posted by The Atheist

I'm going on the now numerous cases of claims of reinfection. People have been trying to explain them away as false positives and/or false negatives, but the more cases there are, the more likely it is actually being reinfected.

I doubt these are reinfections, I think they are Long Haulers

GraculusTheGreenBird · 15th July 2020, 08:39 PM

Wouldn't these claims of reinfection have to exceed the false positive rate for it to be more likely that they were real rather than false positives in the first place?

The Atheist · 15th July 2020, 10:46 PM

Originally Posted by GraculusTheGreenBird

Why?

Why, as more cases occur, is it more likely to be actual reinfections, rather than false positives which we know for a fact happen?

Simple maths. If more and more people get reinfected, and the longer period between infections, we can be more confident of what's happening.

It will be solved one way or the other in the next few months.

RoMo · 15th July 2020, 11:02 PM

Originally Posted by The Atheist

They wouldn't be kept either way, mainly for logistical reasons. Whether they could be re-tested I don't know, but I'm presuming not, because the virus will break down if it gets dry, so you'd be faced with keeping millions of tests and cost would be prohibitive.

The swabs are sent in viral transport media so they don't dry out. (We do keep ours).

pipelineaudio · 16th July 2020, 12:17 AM

Lots on Long Haulers at the beginning of this episode, including some who seemed to be PCR negative for a bit

https://www.microbe.tv/twiv/?fbclid=..._5oMB1C0P7fXxs

Giordano · 16th July 2020, 07:38 AM

A good NY Times article comparing the various COVID-19 treatments and what is known about their efficacy:
https://www.nytimes.com/interactive/...gtype=Homepage

TellyKNeasuss · 16th July 2020, 10:51 AM

Originally Posted by Giordano

A good NY Times article comparing the various COVID-19 treatments and what is known about their efficacy:
https://www.nytimes.com/interactive/...gtype=Homepage

Or a different way of looking at the data:

https://www.bio.org/policy/human-hea...peline-tracker

Neither article includes a mention of the Japanese drug nafamostat mesylate, which has performed well in lung cell culture trials but which doesn't seem to be a priority for clinical trials.

Chris_Halkides · 16th July 2020, 11:06 AM

Originally Posted by TellyKNeasuss

Neither article includes a mention of the Japanese drug nafamostat mesylate, which has performed well in lung cell culture trials but which doesn't seem to be a priority for clinical trials.

This compound is an inhibitor of serine proteases; acting as a very slow alternate substrate in a model system. The acyl enzyme is very slow to hydrolyze. The target is the serine protease TMPRSS2.

Skeptical Greg · 16th July 2020, 11:08 AM

Originally Posted by arthwollipot

You know exactly as much as I do. The only time I've ever answered the door in the nude it was someone who was wondering whether I was the owner of the car that had parked him in.

How did that turn out?

Darat · 16th July 2020, 11:13 AM

Originally Posted by Skeptical Greg

How did that turn out?

They've been married for 30 years......

The Atheist · 16th July 2020, 11:47 AM

Originally Posted by RoMo

The swabs are sent in viral transport media so they don't dry out. (We do keep ours).

Ok, thanks.

How long are they viable for?
How long are they kept?

Skeptic Ginger · 16th July 2020, 02:55 PM

Originally Posted by The Atheist

I'm going on the now numerous cases of claims of reinfection. People have been trying to explain them away as false positives and/or false negatives, but the more cases there are, the more likely it is actually being reinfected....

No it is not.

These claims don't stand up to epidemiological standards.

Who were they exposed to the second time? Is that data even being collected?

Are the people who test positive after testing negative experiencing relapse in symptoms? Is that data even being collected?

We have seen people experience weeks of symptoms without testing negative.

Skeptic Ginger · 16th July 2020, 03:01 PM

Originally Posted by The Atheist

Ok, thanks.

How long are they viable for?
How long are they kept?

Most commercial labs don't keep specimens more than a week. The storage would need to be immense. Research labs may keep specimens longer.

And AFAIK the only way to see if the virus is viable would be to infect an animal model or at least infect a cell culture where reproduction could be detected.

Not sure who would be funding that research, maybe a university?

arthwollipot · 16th July 2020, 03:04 PM

Originally Posted by Skeptical Greg

How did that turn out?

He was more embarrassed than I was. It was late at night, so had already gone to bed.

The Atheist · 16th July 2020, 03:40 PM

Originally Posted by Skeptic Ginger

No it is not.

It absolutes is; that's how maths works.

We're still well off being able to say that it is second infections, though - as you say, more research is needed.
_______________________

Meanwhile, on the subject of immune system response, here's a clear English piece that may be of value:

https://blogs.sciencemag.org/pipelin...he-coronavirus

Or, it could be dogs!

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7215164/

Whether correct or not, it does show the breadth of work being undertaken to find answers.

arthwollipot · 16th July 2020, 03:41 PM

Well this is pretty impressive:

Due to coronavirus, there have been just four confirmed cases of the flu this season in the ACT

Quote:

Canberra could skip this year's flu season entirely, with just four confirmed cases of influenza in the past three months, and zero people hospitalised.

Measures taken to prevent the spread of COVID-19, as well as improved vaccination rates, have flattened what was predicted to be another bad flu season.

The flu season normally begins in late March and peaks in August — at this time last year, there had been just over 2,000 confirmed influenza cases in Canberra.

By the end of last year's flu season there were about 4,000 confirmed cases.

So far in 2020, there have been 189 confirmed cases of flu in Canberra, but nearly all of those were recorded in the first two months of the year.

"Influenza activity in the ACT is currently at an historic low, with only four cases notified in the last 12 weeks (to 12 July)," a spokeswoman for Canberra Health Services said.

"This likely in part reflects physical distancing and good hygiene associated with the COVID-19 response, in addition to vaccination rates."

The Atheist · 16th July 2020, 05:27 PM

Originally Posted by arthwollipot

Well this is pretty impressive:

Nice work!

NZ's had so few cases I can't find a single report of influenza up to the end of May.

Ulf Nereng · 16th July 2020, 06:50 PM

Here's a research paper on T-cell immunity:

https://www.biorxiv.org/content/10.1...888v1.full.pdf

I may be wrong about this, but it looks to me like they are saying that people who have had previous exposure to older corona-viruses retain a long-lasting resistance to new infections from corona-viruses generally. This is because they can recognize features that are common to all the corona-viruses and mount a response against that. I'm not sufficiently scientific literate to tell for sure, though, so please comment if you can, folks.

This might explain why children normally get a very mild infection. They get infected with the common cold corona viruses all the time, like the litte pests they are! This is a hypothesis that has been mentioned before, but now it looks like it has a better scientific foundation, I think.

14th July 2020, 11:46 AM	#401
GodMark2 Master Poster Join Date: Oct 2005 Location: Oregon, USA Posts: 2,211	Originally Posted by marting Seems to me the difference between the expected value of 1840 (by calculation assuming TFN rate=0 as it's not given) and the 2000 false negatives in Puppycow's example is quibbling. IE: 18.4% v 20%. My use of the term "long way" was not in reference to the size of the incongruity, but the possibilities of miscommunication arising from using well-defined terms in an incorrect manner, with the user having emphatic conviction that the incorrect interpretation was correct. This often leads to further misunderstanding as neither side feels the need to specifically define the term, as both believe their definition to be obvious. This can then snowball into further distrust as each side begins to fortify their position, attacking the other side with less and less logic and more and more emotion. Eventually, both sides can end up seeing the other as completely lacking any rational basis. Cutting off such a path by specifying the exact definitions being used can go a "long way" toward facilitating productive conversation.
	__________________ Knowing that we do not know, it does not necessarily follow that we can not know.

14th July 2020, 12:19 PM	#402
Darat Lackey Administrator Join Date: Aug 2001 Location: South East, UK Posts: 97,852	Originally Posted by rjh01 That is even worse. The positive results were 3 months apart! That would mean that Covid 19 is a chronic illness. It would also mean that after Australia clears everyone from the virus it could spontaneously reappear, not from overseas but from these cases. It would also suggest that people who. have had a case confirmed need to be isolated for quite sometime.
	__________________ I wish I knew how to quit you

14th July 2020, 12:24 PM	#403
marting Master Poster Join Date: Sep 2003 Posts: 2,265	Originally Posted by GodMark2 My use of the term "long way" was not in reference to the size of the incongruity, but the possibilities of miscommunication arising from using well-defined terms in an incorrect manner, with the user having emphatic conviction that the incorrect interpretation was correct. This often leads to further misunderstanding as neither side feels the need to specifically define the term, as both believe their definition to be obvious. This can then snowball into further distrust as each side begins to fortify their position, attacking the other side with less and less logic and more and more emotion. Eventually, both sides can end up seeing the other as completely lacking any rational basis. Cutting off such a path by specifying the exact definitions being used can go a "long way" toward facilitating productive conversation. I agree. But it would have been best if you had also shown the impact of using proper definitions on the numbers in Puppycow's post. Otherwise, it just leaves many scratching their heads and thinking you are objecting to the major point of Puppycow's post. For example this would be more elucidating in addition to adding the formula and link: Originally Posted by Puppycow I just want to add a little bit more to this for clarification after reading more. A false positive rate of 2% does not mean that 2% of all positive results are false positives, it means that 2% of all tests conducted (both positive and negative) are false positives. True false positive rate is the percentage of actual negatives that are detected as positives. Quote: What this means in practice is that, if say the true rate is 8% and the false positive rate of 2%, then 20% of all positive results are false positives. Which is 18.4% since the false positive rate only applies to actual negatives falsely detected. Quote: The lower the true rate is, the greater the proportion of positive results will be false positives. So out of say, 10,000 positive tests (out of 100,000 total tests given), 2,000 of those may be false positives. 1840, not 2000, would be the expected number of false positives in the example. Quote: Given that, the scenario where someone gets "reinfected" because of a false positive test seems quite likely to occur given enough tests conducted. Right.
marting Master Poster Join Date: Sep 2003 Posts: 2,265	__________________ Flying's easy. Walking on water, now that's cool.

14th July 2020, 02:33 PM	#405
arthwollipot Observer of Phenomena Pronouns: he/him Join Date: Feb 2005 Location: Ngunnawal Country Posts: 71,117	First Dog on the Moon on surviving a second lockdown Quote: Do remember that the lockdown isn't the problem - the virus is the problem. The lockdown is a seat belt and you are a passenger in a dreadful analogy being driven at high speed by the virus who is probably drunk.
	__________________ We will meet them on the beach, we will meet them on the phone hook-ups. - Scott Morrison, probably

14th July 2020, 02:33 PM	#406
marting Master Poster Join Date: Sep 2003 Posts: 2,265	"Absence of Apparent Transmission of SARS-CoV-2 from Two Stylists After Exposure at a Hair Salon with a Universal Face Covering Policy — Springfield, Missouri, May 2020" https://www.cdc.gov/mmwr/volumes/69/wr/mm6928e2.htm Quote: What is added by this report? Among 139 clients exposed to two symptomatic hair stylists with confirmed COVID-19 while both the stylists and the clients wore face masks, no symptomatic secondary cases were reported; among 67 clients tested for SARS-CoV-2, all test results were negative. Adherence to the community’s and company’s face-covering policy likely mitigated spread of SARS-CoV-2. While this seemed compelling back when it was reported, I though it not totally compelling because it's well known that the propensity to spread is highly heterogeneous. Since only two hairdressers had Covid-19 there was a reasonable chance that both were not good spreaders. The CDC report shows that one was. They refer to her as stylist A. All of her 4 close contacts, as well as her co-worker, tested positive for Covid-19. Quote: Six close contacts of stylists A and B outside of salon A were identified: four of stylist A and two of stylist B. All four of stylist A’s contacts later developed symptoms and had positive PCR test results for SARS-CoV-2. These contacts were stylist A’s cohabitating husband and her daughter, son-in-law, and their roommate, all of whom lived together in another household. None of stylist B’s contacts became symptomatic. Highly consistent with masks working when both the infected and uninfected wear them. It provides no info. re the relative efficacy of masks for the infected v the uninfected.
marting Master Poster Join Date: Sep 2003 Posts: 2,265	__________________ Flying's easy. Walking on water, now that's cool.

14th July 2020, 12:27 PM	#404
Delphic Oracle Philosopher Join Date: Sep 2016 Posts: 5,418	Using the wrong formula and arriving at a result sorta close to the one in the correct formula is not laudable or mean that the correction is "quibbling." No half credit for that. "Close" is a lingerie shop without a front window.

14th July 2020, 06:50 PM	#407
Chris_Halkides Penultimate Amazing Join Date: Dec 2009 Posts: 10,050	Intuitive Biostatistics Originally Posted by GodMark2 This would go a long way toward explaining many misunderstandings earlier. I covered these definitions in comment #2592 of the first thread. Motulsky's book is one worth having.
	__________________ It is possible both to be right about an issue and to take oneself a little too seriously, but I would rather be reminded of that by a friend than a foe. (a tip of the hat to Foolmewunz)

14th July 2020, 06:53 PM	#408
The Atheist The Grammar Tyrant Join Date: Jul 2006 Posts: 28,610	Originally Posted by marting Highly consistent with masks working when both the infected and uninfected wear them. It provides no info. re the relative efficacy of masks for the infected v the uninfected. Pity that horse has bolted. When people are prepared to commit violence, and even murder, over wearing a face mask, you've already lost.
	__________________ The point of equilibrium has passed; satire and current events are now indistinguishable.

14th July 2020, 07:53 PM	#409
The Atheist The Grammar Tyrant Join Date: Jul 2006 Posts: 28,610	More good news on vaccines: https://www.nzherald.co.nz/world/new...ectid=12348208 Still needs more work, but we're making quick progress.
	__________________ The point of equilibrium has passed; satire and current events are now indistinguishable.

14th July 2020, 09:25 PM	#410
arthwollipot Observer of Phenomena Pronouns: he/him Join Date: Feb 2005 Location: Ngunnawal Country Posts: 71,117	Moving to Stage 3 this quickly is pretty impressive. It's important to remember that the first vaccines approved for general use are unlikely to be the most effective. But they'll be better than nothing.
	__________________ We will meet them on the beach, we will meet them on the phone hook-ups. - Scott Morrison, probably

14th July 2020, 09:46 PM	#411
Aridas Crazy Little Green Dragon Join Date: Sep 2011 Location: East Coast, US Posts: 7,603	Originally Posted by The Atheist Uh-oh. That "can you catch Covid again" question may have been answered in the positive. https://www.vox.com/platform/amp/202...-herd-immunity tl;dr version: Guy has mild Covid, recovers & tests negative twice. Then gets a bad dose, requiring multiple hospital visits. This would be unbelievably bad news for a second wave, considering the overwhelming majority of people having a very mild/asymptomatic dose in the first wave. Those shades of 1918 just went up a notch. He wouldn't be the first, by a long shot? There have been reports of people with repeat cases for quite a while, now, beyond just testing positive again, IIRC. Still, when it comes to concern related to reinfections during a second wave, I would think that the seemingly probable lung scarring from the first case (even in asymptomatic cases) would likely be something to focus on more as a reason for likely worse symptoms if the body's defenses don't remain strong.
	__________________ So sayeth the crazy little dragon.

14th July 2020, 10:29 PM	#412
Puppycow Penultimate Amazing Join Date: Jan 2003 Location: Yokohama, Japan Posts: 25,909	Originally Posted by GodMark2 According to Wikipedia, you are exactly incorrect. False positive rate^WP This would go a long way toward explaining many misunderstandings earlier. Originally Posted by marting Seems to me the difference between the expected value of 1840 (by calculation assuming TFN rate=0 as it's not given) and the 2000 false negatives in Puppycow's example is quibbling. IE: 18.4% v 20%. Thank for clarifying that. My statement was incorrect. You have to subtract the true positives from the denominator. However, it still means a larger number than 2% of the positive results. As you say, in my hypothetical example, that would result in 1840, not 2000 false positives.
	__________________ A fool thinks himself to be wise, but a wise man knows himself to be a fool. William Shakespeare

14th July 2020, 10:43 PM	#413
arthwollipot Observer of Phenomena Pronouns: he/him Join Date: Feb 2005 Location: Ngunnawal Country Posts: 71,117	Quote: Police in the ACT have politely been requesting that people in Canberra stop answering the door in the nude during Covid-19 compliance requests. In a press conference this morning detective superintendent, Jason Kennedy, said those in isolation had been offering police a “warm reception”. But, as News.com.au reports, some of the welcomes were a little too friendly; “Some of them may need a reminder to put some clothes on before they open the door for a compliance check,” he said. “We did get a few surprises on the weekend. The ACT has again recorded no new cases of Covid-19 on Wednesday. Source Go Canberra!
	__________________ We will meet them on the beach, we will meet them on the phone hook-ups. - Scott Morrison, probably

14th July 2020, 11:55 PM	#414
The Don Penultimate Amazing Join Date: Nov 2002 Location: Sir Fynwy Posts: 31,629	Some more data about people with Covid-19 who are asymptomatic Quote: And the study showed 69% of those who did test positive reported no symptoms on the day of their test or the previous week, though they may have developed symptoms later. https://www.bbc.co.uk/news/uk-53414363

15th July 2020, 12:13 AM	#415
rjh01 Gentleman of leisure Tagger Join Date: May 2005 Location: Flying around in the sky Posts: 26,638	Originally Posted by arthwollipot Source Go Canberra! I wonder why the police were calling on those houses for? Had they just had a test? What made the residents answer the door in the nude? Was it a show of disrespect or something?
	__________________ This signature is for rent.

15th July 2020, 03:19 AM	#416
ohms Graduate Poster Join Date: Apr 2005 Posts: 1,328	Originally Posted by The Atheist More good news on vaccines: https://www.nzherald.co.nz/world/new...ectid=12348208 Still needs more work, but we're making quick progress. And some more: https://www.itv.com/news/2020-07-15/...-robert-peston The vaccine is currently in Phase III trials in the UK, Brazil and S.Africa with a large trial due to start in the USA next month.
ohms Graduate Poster Join Date: Apr 2005 Posts: 1,328	__________________ Long time lurker

15th July 2020, 07:20 AM	#417
Arcade22 Philosopher Join Date: Aug 2007 Location: Sweden Posts: 6,823	Quote: This report is a comparison between Finland and Sweden, two in many ways similar countries who applied different measures regarding schools during the covid-19 pandemic. There is no difference in the overall incidence of the laboratory confirmed covid-19 cases in the age group 1-19 years in the two countries and the number of laboratory confirmed cases does not fluctuate with school closure or change in testing policy in Finland. In Sweden, the number of laboratory confirmed cases is affected by change in testing policy. Severe covid-19 disease as measured in ICU admittance is very rare in both countries in this age group and no deaths were reported. Outbreak investigations in Finland has not shown children to be contributing much in terms of transmission and in Sweden a report comparing risk of covid-19 in different professions, showed no increased risk for teachers. In conclusion, closure or not of schools had no measurable direct impact on the number of laboratory confirmed cases in school-aged children in Finland or Sweden. The negative effects of closing schools must be weighed against the positive indirect effects it might have on the mitigation of the covid-19 pandemic. https://www.folkhalsomyndigheten.se/...d-children.pdf
	__________________ We would be a lot safer if the Government would take its money out of science and put it into astrology and the reading of palms. Only in superstition is there hope. - Kurt Vonnegut Jr And no, Cuba is not a brutal and corrupt dictatorship, and it's definitely less so than Sweden. - dann

15th July 2020, 11:51 AM	#418
The Atheist The Grammar Tyrant Join Date: Jul 2006 Posts: 28,610	Originally Posted by Aridas He wouldn't be the first, by a long shot? There have been reports of people with repeat cases for quite a while, now, beyond just testing positive again, IIRC. Yes, the defence that the test was faulty the first time is getting pretty hard to accept. Originally Posted by Arcade22 https://www.folkhalsomyndigheten.se/...d-children.pdf Not to mention, none of the studies on schools have taken into account the immense harm done by having kids not at school.
	__________________ The point of equilibrium has passed; satire and current events are now indistinguishable.

15th July 2020, 04:54 PM	#419
Puppycow Penultimate Amazing Join Date: Jan 2003 Location: Yokohama, Japan Posts: 25,909	Originally Posted by The Atheist Yes, the defence that the test was faulty the first time is getting pretty hard to accept. Why? If I'm right about this, it seems highly likely that there would be multiple examples of apparent reinfections due to false positive test results. Of course, it's just speculation on my part, but the hypothesis has to be ruled out somehow, and I don't see how it is ruled out. Anyway, seems like something that could be studied. Can samples be retested by another lab or are they immediately destroyed after being tested?
	__________________ A fool thinks himself to be wise, but a wise man knows himself to be a fool. William Shakespeare

15th July 2020, 05:37 PM	#420
The Atheist The Grammar Tyrant Join Date: Jul 2006 Posts: 28,610	Originally Posted by Puppycow Why? If I'm right about this, it seems highly likely that there would be multiple examples of apparent reinfections due to false positive test results. Of course, it's just speculation on my part, but the hypothesis has to be ruled out somehow, and I don't see how it is ruled out. I'm going on the now numerous cases of claims of reinfection. People have been trying to explain them away as false positives and/or false negatives, but the more cases there are, the more likely it is actually being reinfected. Originally Posted by Puppycow Anyway, seems like something that could be studied. Can samples be retested by another lab or are they immediately destroyed after being tested? They wouldn't be kept either way, mainly for logistical reasons. Whether they could be re-tested I don't know, but I'm presuming not, because the virus will break down if it gets dry, so you'd be faced with keeping millions of tests and cost would be prohibitive. It's just something else we need to wait for more work.
	__________________ The point of equilibrium has passed; satire and current events are now indistinguishable.

15th July 2020, 05:46 PM	#421
arthwollipot Observer of Phenomena Pronouns: he/him Join Date: Feb 2005 Location: Ngunnawal Country Posts: 71,117	Originally Posted by rjh01 I wonder why the police were calling on those houses for? Had they just had a test? What made the residents answer the door in the nude? Was it a show of disrespect or something? You know exactly as much as I do. The only time I've ever answered the door in the nude it was someone who was wondering whether I was the owner of the car that had parked him in.
	__________________ We will meet them on the beach, we will meet them on the phone hook-ups. - Scott Morrison, probably

15th July 2020, 08:14 PM	#422
GraculusTheGreenBird Critical Thinker Join Date: Apr 2004 Posts: 344	Originally Posted by The Atheist I'm going on the now numerous cases of claims of reinfection. People have been trying to explain them away as false positives and/or false negatives, but the more cases there are, the more likely it is actually being reinfected. Why? Why, as more cases occur, is it more likely to be actual reinfections, rather than false positives which we know for a fact happen?

15th July 2020, 08:36 PM	#423
pipelineaudio Illuminator Join Date: Feb 2006 Posts: 4,863	Originally Posted by The Atheist I'm going on the now numerous cases of claims of reinfection. People have been trying to explain them away as false positives and/or false negatives, but the more cases there are, the more likely it is actually being reinfected. I doubt these are reinfections, I think they are Long Haulers
	__________________ Don't fear the REAPER, embrace it

15th July 2020, 08:39 PM	#424
GraculusTheGreenBird Critical Thinker Join Date: Apr 2004 Posts: 344	Wouldn't these claims of reinfection have to exceed the false positive rate for it to be more likely that they were real rather than false positives in the first place?

15th July 2020, 10:46 PM	#425
The Atheist The Grammar Tyrant Join Date: Jul 2006 Posts: 28,610	Originally Posted by GraculusTheGreenBird Why? Why, as more cases occur, is it more likely to be actual reinfections, rather than false positives which we know for a fact happen? Simple maths. If more and more people get reinfected, and the longer period between infections, we can be more confident of what's happening. It will be solved one way or the other in the next few months.
	__________________ The point of equilibrium has passed; satire and current events are now indistinguishable.

15th July 2020, 11:02 PM	#426
RoMo New Blood Join Date: Nov 2019 Posts: 7	Originally Posted by The Atheist They wouldn't be kept either way, mainly for logistical reasons. Whether they could be re-tested I don't know, but I'm presuming not, because the virus will break down if it gets dry, so you'd be faced with keeping millions of tests and cost would be prohibitive. The swabs are sent in viral transport media so they don't dry out. (We do keep ours).
RoMo New Blood Join Date: Nov 2019 Posts: 7

16th July 2020, 12:17 AM	#427
pipelineaudio Illuminator Join Date: Feb 2006 Posts: 4,863	Lots on Long Haulers at the beginning of this episode, including some who seemed to be PCR negative for a bit https://www.microbe.tv/twiv/?fbclid=..._5oMB1C0P7fXxs
	__________________ Don't fear the REAPER, embrace it

16th July 2020, 07:38 AM	#428
Giordano Penultimate Amazing Join Date: Apr 2011 Posts: 17,646	A good NY Times article comparing the various COVID-19 treatments and what is known about their efficacy: https://www.nytimes.com/interactive/...gtype=Homepage

16th July 2020, 10:51 AM	#429
TellyKNeasuss Master Poster Join Date: Oct 2006 Posts: 2,658	Originally Posted by Giordano A good NY Times article comparing the various COVID-19 treatments and what is known about their efficacy: https://www.nytimes.com/interactive/...gtype=Homepage Or a different way of looking at the data: https://www.bio.org/policy/human-hea...peline-tracker Neither article includes a mention of the Japanese drug nafamostat mesylate, which has performed well in lung cell culture trials but which doesn't seem to be a priority for clinical trials.
	__________________ "Facts are stupid things." Ronald Reagan

16th July 2020, 11:06 AM	#430
Chris_Halkides Penultimate Amazing Join Date: Dec 2009 Posts: 10,050	serine protease inhibitors Originally Posted by TellyKNeasuss Neither article includes a mention of the Japanese drug nafamostat mesylate, which has performed well in lung cell culture trials but which doesn't seem to be a priority for clinical trials. This compound is an inhibitor of serine proteases; acting as a very slow alternate substrate in a model system. The acyl enzyme is very slow to hydrolyze. The target is the serine protease TMPRSS2.
	__________________ It is possible both to be right about an issue and to take oneself a little too seriously, but I would rather be reminded of that by a friend than a foe. (a tip of the hat to Foolmewunz) Last edited by Chris_Halkides; 16th July 2020 at 11:21 AM.

16th July 2020, 11:08 AM	#431
Skeptical Greg Agave Wine Connoisseur Join Date: Jul 2002 Location: Just past ' Resume Speed ' . Posts: 17,010	Originally Posted by arthwollipot You know exactly as much as I do. The only time I've ever answered the door in the nude it was someone who was wondering whether I was the owner of the car that had parked him in. How did that turn out?
	__________________ " The main problem I have with the idea of heaven, is the thought of spending eternity with most of the people who claim to be going there. "

16th July 2020, 11:13 AM	#432
Darat Lackey Administrator Join Date: Aug 2001 Location: South East, UK Posts: 97,852	Originally Posted by Skeptical Greg How did that turn out? They've been married for 30 years......
	__________________ I wish I knew how to quit you

16th July 2020, 11:47 AM	#433
The Atheist The Grammar Tyrant Join Date: Jul 2006 Posts: 28,610	Originally Posted by RoMo The swabs are sent in viral transport media so they don't dry out. (We do keep ours). Ok, thanks. How long are they viable for? How long are they kept?
	__________________ The point of equilibrium has passed; satire and current events are now indistinguishable.

16th July 2020, 02:55 PM	#434
Skeptic Ginger Nasty Woman Join Date: Feb 2005 Posts: 87,928	Originally Posted by The Atheist I'm going on the now numerous cases of claims of reinfection. People have been trying to explain them away as false positives and/or false negatives, but the more cases there are, the more likely it is actually being reinfected.... No it is not. These claims don't stand up to epidemiological standards. Who were they exposed to the second time? Is that data even being collected? Are the people who test positive after testing negative experiencing relapse in symptoms? Is that data even being collected? We have seen people experience weeks of symptoms without testing negative.

16th July 2020, 03:01 PM	#435
Skeptic Ginger Nasty Woman Join Date: Feb 2005 Posts: 87,928	Originally Posted by The Atheist Ok, thanks. How long are they viable for? How long are they kept? Most commercial labs don't keep specimens more than a week. The storage would need to be immense. Research labs may keep specimens longer. And AFAIK the only way to see if the virus is viable would be to infect an animal model or at least infect a cell culture where reproduction could be detected. Not sure who would be funding that research, maybe a university?