Coronavirus - worldwide spread and control

I don't think what Vallance says puts herd immunity as the primary aim. It is a part of the mechanism they hooped would unfold but a relatively minor part. I think it has been latched on to when it is not the main issue.

The primary aim was to avoid the severe lockdown that was assumed would be needed to have any home of keeping infection rates low enough to track and keep genuinely under control - essentially a sociopolitical aim to avoid upsetting people of in the business world and to avoid expected social unrest. The hope was that the epidemic could be allowed to run its course without too much damage in short enough time to preserve business interests. Herd immunity would have helped a bit but in reality not that much since it would only kick in at about 80%.

Or put more simply the aim was to allow almost everyone to get infected, with the vague hope that the elderly and vulnerable could hide away for long enough to manage to escape infection.

 

I've found these two studies comparing chest CT scans to PCR tests, with the latter showing greater sensitivity, in about 1000 Chinese patients.
https://pubs.rsna.org/doi/pdf/10.1148/radiol.2020200642

https://pubs.rsna.org/doi/pdf/10.1148/radiol.2020200432

Do you happen to have any other decent studies on the sensitivity of PCR testing for COVID-19 at hand (or anybody else)?

 

https://www.theguardian.com/world/2020/mar/13/herd-immunity-will-the-uks-coronavirus-strategy-work

Dr David Halpern, a psychologist ...

 

Surprising...

https://twitter.com/user/status/1245467476831412227

 

Bearing in mind the y-axis is logarithmic, so the shapes of the graphs makes the numbers look much more benign than they really are.

 

Yes the CFR has been rising in Germany and it now seems to have passed 1%. The same is true in South-Korea where it has now passed 1.6%. About two weeks ago Ioannidis highlighted the low CFR in these countries, namely 0.2% and 0.7% (at the time). Things can change quite rapidly!

 

I heard a few infectious disease doctors say that once we get infected (produce antibodies) and recover, then we can't get reinfected. But who knows? It's a new virus.

 

It's not a "new" virus, it's simply a novel variant of known viruses. We know from SARS and MERS that immunity is maintained for a few years at least.

 

When I read the first stories and papers coming out of China a month or so ago, I seem to remember them saying ventilators were not that effective as the virus had caused changes in the lungs so oxygen couldn't be absorbed well. What made the difference was ECMO.

Source : https://www.ucsfhealth.org/treatments/extracorporeal-membrane-oxygenation

Since the virus has exploded in Europe and the US I have not heard anything about ECMO and I have no idea why that is??????????????? Anyone know?

The figures I saw quoted today in the US was that 80% of COVID-19 patients on ventilators die. I don't know if that is true or not, but if it is, shouldn't we also be using ECMO?

 

How Taiwan handled the virus. We didn't hear much about it because China has forbidden mention of it, and they clout at WHO.

http://www.dailymirror.lk/opinion/I...-to-COVID-19-possible-in-Sri-Lanka/172-185720

 

That the death rate is rising could mean two things, if I am not wrong:

• the virus now spreads more under vulnerable people
• the virus spreads faster than the testing is detecting positive cases

Until now it seems that Korea (wearing masks) and Germany (wearing no masks) had a comparable outcome, death rate wise. This may be from massive testing.

But now it may become to differ. What could it mean, that masks were slowing down the death rate?

I am still hoping that the amount of the first viral loads one has taken up is a parameter. This would go along - if it turns out to be so - that countries without a slowing down procedure (Italy, UK and others) had a worse death rate. It might though be not the case.

 

Mass testing as per the WHO guidelines may not be feasible for many european countries :

https://euobserver.com/coronavirus/147830

and may not be currently desirable :

Perhaps time for less emphasis on numbers and more on intelligent use of testing? :

https://www.spiegel.de/internationa...pacity-a-4d75e7bd-dd0e-41e3-9f09-eb4364c43f2e

 

More intelligent because of limited resources. The massive testing itself will hardly have been wrong, in terms of understanding and assessment, as well as in terms of dealing (comparing the outcome of countries having done massive testing with other countries).
---
Virologist Hendrik Streeck is carrying out an evaluation in Germany, Heinsberg, an area having been highly affected early on. Investigating how many people of the population have already been in contact with the virus, using some antibody test. They think also to get some information about how the virus may have spread (family, asf.). Sample size is 1500.

(Information from TV)

 

I think I recall that in China they discovered that the scans (CT?) could be used to quickly diagnose people --- 20 minutes? So when you turned up for testing they immediately scanned your lungs. As @Jonathan Edwards said images from scans of people who have coronavirus, and have begun to develop lung problems, are very characteristic. If your weren't diagnosed via the scan then presumably they took the nasal/throat swabs for the PCR/antigen test and 8 hours later the results from the test were available. If the results of the scan, or PCR/antigen test, were positive then you didn't go home - you were quarantined.

Scans presumably won't pick up people who haven't developed lung problems to some extent.

PCR/antigen test presumably have sampling errors (don't swab properly); don't know how accurate the Chinese PCR/antigen test was but that's also a source of error ---. So if there's scan data, and PCR/antigen test data, then that would be interesting i.e. is the PCR/antigen test missing some of the people diagnosed via the scan?

 

Not necessarily. There are negative consequences where you have a relatively small percentage of the population currently infected and a test with an approximate 10% error rate.

Imagine quarantining 10% of healthcare workers due to false positives or conversersely releasing 10% of infected cases back into the community due to false negatives.

A hypothetical example :

The perils of mass coronavirus testing

https://www.aei.org/articles/the-perils-of-mass-coronavirus-testing/

 

Our health minister kept on saying that he has ordered 10.000 ventilators in press conferences - as if that means anything until he actually has them delivered.

Everybody is ordering them now.

How are companies going to decide who will get them? The highest bidder? The country that needs them the most?

I was wondering about oxygen, too when the demand now is so high.

 

As @Jonathan Edwards has said this is a % game.

So if your 90% right, and R naught reduces to less than 1, then the outbreak cannot be sustained.

On the other hand sitting on your ass and doing nothing, since the test isn't 100%, well you can see the results in the UK.

Presumably you'd also pick up the positive health care worker*/positive member of the public via contact tracing --- oh if you did it!

*EDIT: The chances of two consecutive tests giving false negative (if the test is 90% accurate) would be 0.1 X 0.1 i.e. 1 in a hundred.