[stone]

Stone - maybe you can answer a question for me. I’ve seen a couple of papers showing that saliva tests are as effective - and have lower false positive rates - than the nose and throat swabs we currently use.

Less invasive and not an aerosol generating procedure too.

Is it possible to switch to saliva based testing without retailing the test equipment in labs?

I'll check out those papers. That sounds great. Our floor coordinator was saying on Tues (when I was last called in) that she was spooked at having seen swabbing being done on the TV just in people's mouths rather than the normal deep-nose, deep-throat regime. What you are saying explains that. It would be even easier if people could just spit in a tube I guess.

The "equipment" for the first step going from a swab tube to scanning the barcode  and getting the samples in a 96well plate -is just a minion such as myself with a pipette in my hand. That's why it is by far the biggest bottleneck. Dealing with spit in a tube might be much easier to automate than dealing with an often broken and wonky swab in a tube.

I saw something yesterday saying that the virus could be heat inactivated and still be just as good for RT-PCR.  testing. That would be transformative I guess.

[tomtom]

Will - scan the paper I linked to clearly showing that all children had a similar viral load to adults.

[tomtom]

Will - scan the paper I linked to clearly showing that all children had a similar viral load to adults.

As now picked up by the Guardian

https://www.theguardian.com/world/2020/apr/30/coronavirus-scientists-caution-against-reopening-schools?CMP=Share_iOSApp_Other

[tim palmer]

Ace2 receptors (the 'receptor' for SARS-CoV-2) are expressed in foetal tissues.

Kawasaki disease is an inflammatory condition of unknown cause made on the strength of a combination of clinical and radiological findings.  No consistent link to a specific infectious aetiology has been made (I think). The issue with the diagnosis is it requires specific treatment to avoid severe cardiac sequelae (coronary artery aneurysm).  I think the concern is that the symptoms between this covid- related syndrome and Kawasaki maybe similar and care is required to make the correct diagnosis I.e. treat the Kawasaki disease if that is the clinically appropriate thing to do.  I believe some children have had a delay in their Kawasaki diagnosis.

Whether these covid related things are a variant of Kawasaki and need to be treated as Kawasaki seems like a difficult ball of string to untangle. 

On the subject of swabs I thought false negatives was more the problem?
I hear the serology had a high rate of false pos??

[Stu Littlefair]

You’re right Tim - I meant false negatives when I wrote positives.

Here’s the better of the papers I saw looking at saliva tests: https://www.medrxiv.org/content/10.1101/2020.04.16.20067835v1

Looked convincing to me (usual out-of-field disclaimers apply) - esp figure 2.

I’d certainly rather spit in a tube than have someone scrape away at the back of my skull whilst wearing a full hazmat suit. And would seem to massively simplify the logistics of getting tests where they are needed - just post in your tube o’ spit. I’m a bit puzzled that there hasn’t been more made of it.   

[tim palmer]

I can say from personal experience the throat and nose swab is a very unpleasant experience.   Being asked "What is your gag reflex like?"  Is never a good sign.

[SA Chris]

Are priests doing the tests then??

[tomtom]

We turned down the opportunity for 100k saliva tests from the USA earlier in the month apparently...

[tomtom]

Hopefully the above works. Really nice animated gif of the results from the CV19 app that 2.8 million people are reporting symptoms (or not) on in the UK.

Link to page below if image above doesn’t work.

https://covid.joinzoe.com/data#levels-over-time

[galpinos]

I can say from personal experience the throat and nose swab is a very unpleasant experience.   Being asked "What is your gag reflex like?"  Is never a good sign.

My wife and I did it to ourselves at a drive in centre. I nearly threw up in the car and my eyes were streaming. I couldn't drive the car straight away and had to sit their a while to let them recover. The discomfort in my nose/sinus persisted for a good half a day.

My wife then had to do it on our 7yo. It was an experience neither of them enjoyed........

[Fultonius]

Good to finally see some leadership amongst the UK's leading politicians with a clearly thought-through lockdown exit strategy.

https://www.gov.scot/publications/coronavirus-covid-19-test-trace-isolate-support/pages/1/

You're welcome, Scotland.

[tomtom]

Ok so details of the govts app are release now... seems like all you need to do is switch on Bluetooth for the app and enter the first part of your postcode.

Now - maybe I have a devious mind - but remember this?

https://www.google.co.uk/amp/s/www.wired.com/story/99-phones-fake-google-maps-traffic-jam/amp

Where an artist dragged a bag of 99 smartphones around some streets at walking pace - which tricked google maps into saying there was a traffic jam there - and no cars went down there accordingly.

Well - what’s to stop some arsehole signing on to the app - then going to various supermarkets, parks, tube trains whatever - with their phone on - registering contacts all the way. Then next day saying they have the symptoms - and all the people they’ve been near the day before have to go into isolation... or what happens if you work on a building site or amazon warehouse etc.. and want to fuck over the company? Do the same... everyone you’ve worked with has to take the next two weeks off. So much opportunity for abuse...

[petejh]

Wouldn't it need to rely on a positive test result before you could be flagged on the app as a source of virus?

[abarro81]

Then they'd need to identify you though - which is one of the things everyone wants the app to avoid doing...

[ali k]

Wouldn't it need to rely on a positive test result before you could be flagged on the app as a source of virus?

Not so apparently. You just register that you have symptoms via the app and then everyone who’s been in contact is alerted. So as tomtom says, unless I’m missing something it’s open to abuse.

[petejh]

Yeah seems to be. What do they do in other countries?


Couldn't there be a process where you attached an anonymous 'tag' generated by your NHS app, to a test result, which signalled back to the relevant app that it was 'positive' to keep things anonymous..? Dunno just thinking out loud.

[abarro81]

Random anecdote:
Just went to one of the international supermarkets quite close to us. A very different experience from going to Sainsbury's, Tesco or Aldi! No control over numbers, staff and shoppers didn't really give a fuck about distancing. Makes you wonder if this, and/or the underlying attitude, partly accounts for the disproportionate impact on BAME groups? (Probably 80%+ of staff/shoppers seemed to be BAME)

[TobyD]

Amazon are unsurprisingly doing pretty well.

https://www.newstatesman.com/politics/business-and-finance/2020/05/amazon-jeff-bezos-finances-coronavirus-pandemic-effect-AWS

The numbers are almost incredible:

The company as a whole is taking in $9,602 per second.

Following the results, Bloomberg’s Billionaires index updated the personal wealth of Amazon’s founder and CEO, Jeff Bezos, to $149 billion. In three months — a period in which US economy has contracted by 4.8 per cent and more than 30 million Americans have filed for unemployment — his personal wealth has grown by of $34.2 billion, an overall growth rate of more than $15 million per hour. Were his wealth to grow at this rate for a year, Bezos would make more money in 2020 than Morocco, a country of almost 36 million people. 

[remus]

Then they'd need to identify you though - which is one of the things everyone wants the app to avoid doing...

No idea how the gov app is meant to work, but in theory you wouldn't necessarily need to identify anyone. You could do something like

• 1. Get tested
• 2. Result comes back positive, including a one time code from the trusted authority running the test saying it is indeed a positive test (could come in the form of a QR code)
• 3. Mark yourself as positive by scanning the QR code in the app in the presence of the trusted authority

It's certainly not foolproof (The people running the tests could keep a record of who gets which codes so no anonymity) but it seems like a significant improvement over bob downloading the app, getting cuddly with half of london and then self diagnosing as positive.

This scheme would also rely on an abundance of tests being available, which is not necessarily a reality.

[Stu Littlefair]

Remus’ suggestion is almost exactly how the Google/Apple plan is supposed to work. The downside is that someone has to test positive before they can alert contacts which adds some delay and will miss people.

But if you allow people to self-report you’ll get all sorts of jokers spamming the system.

This is one of the few advantages of the centralised system; you can do quite a lot to filter out malicious self reports at the database level by looking for unusual patterns.

There’s a long and technical description of how the NHS app will work in principle by the NCSC director Ian Levy.

https://www.ncsc.gov.uk/blog-post/security-behind-nhs-contact-tracing-app

It looks OK in principle. The app doesn’t store much data about you - a random ID, your phone model and the first but of your postcode.

Hard to imagine hackers doing much damage with that if they gain access to the DB.

My concern would be what happens when you submit symptom data. The information that ID 123456 is Alex Barrows will he stored somewhere in the NHS, so that the alerts sent out can be tweaked if Alex tests negative. In theory no single person has the access to link that data together, but we’ve heard those sorts of things before.

[Oldmanmatt]

I wonder how many more of these will crop up around the globe.

Europe’s infection date keeps being pushed back and not by days, by months.

https://www.theguardian.com/world/2020/may/04/french-hospital-discovers-covid-19-case-december-retested?CMP=fb_gu&utm_medium=Social&utm_source=Facebook#Echobox=1588663411

[Offwidth]

I'm not sure this matters very much except for conspiracy theorists.  These unusually early cases obviously didn't cause a outbreak unless the virus mutated as the minimum mortality rate seems to still be more than 0.2% and the unfettered infection growth rate (with no social distancing) was similar across the world.

In the meantime the euromomo stats on real data on excess deaths on England versus everyone else in Europe are shocking. People say the 'hidden deaths' would be the same everywhere, they clearly were not.

https://www.euromomo.eu/graphs-and-maps/

[Oldmanmatt]

I'm not sure this matters very much except for conspiracy theorists.  These unusually early cases obviously didn't cause a outbreak unless the virus mutated as the minimum mortality rate seems to still be more than 0.2% and the unfettered infection growth rate (with no social distancing) was similar across the world.

In the meantime the euromomo stats on real data on excess deaths on England versus everyone else in Europe are shocking. People say the 'hidden deaths' would be the same everywhere, they clearly were not.

https://www.euromomo.eu/graphs-and-maps/

Oh, my bad.

Of course, the early cases simply weren’t infectious...

Don’t be so bloody silly, of course it’s important. Just because it doesn’t fit your chosen narrative (at the risk of sounding like Pete, you are stuck in a certain groove).

If this has been spreading for a month longer than was first assumed (in both Europe and China, since there are reports of unusual cases of pneumonia there from November) then it will be significant. Or are you simply accusing the French of lying?

Spread to vulnerable populations (those prone to severe symptoms) is  random. The possibility of an infection spreading for some time, without hitting a susceptible host, is more than a remote chance. Just as it’s entirely possible that here in the UK, we have as yet unidentified early casualties, who were simply described as pneumonia or otherwise (given we now know of some other, diverse, symptoms and complications).

Early diagnosis was primarily based around travel history and contact tracing. The French example, shows the shortcomings of that. And somewhat proves (or adds significant circumstantial evidence for) the last paragraph.

Oh, and see this:

This is good news, surely?

If I understand the post correctly, approximately 1:10 people have the virus (within the setting context) but are asymptomatic?
(You didn’t say what the total, symptomatic and asymptomatic numbers were).

I don’t see a huge argument that a tertiary cancer clinic, should be significantly different in infection incidence than the general population? Unless there is a Covid ward within the same building and communication of people and services between the two (ventilation, cleaning staff etc).

To be clearer, symptomatic patients had already been tested, symptomatic staff were off work so the 9/10% positives were all asymptomatic at the time of the test.

The setting is a tertiary cancer hospital, i.e. it has in patients. They have a Covid positive ward but this testing has shown that there are staff and patients on the non Covid wards that are Covid positive, so will be shedding virus to currently Covid negative patients.

[Offwidth]

Of course, the early cases simply weren’t infectious...

Don’t be so bloody silly, of course it’s important. Just because it doesn’t fit your chosen narrative (at the risk of sounding like Pete, you are stuck in a certain groove).

If this has been spreading for a month longer than was first assumed (in both Europe and China, since there are reports of unusual cases of pneumonia there from November) then it will be significant. Or are you simply accusing the French of lying?

Spread to vulnerable populations (those prone to severe symptoms) is  random. The possibility of an infection spreading for some time, without hitting a susceptible host, is more than a remote chance. Just as it’s entirely possible that here in the UK, we have as yet unidentified early casualties, who were simply described as pneumonia or otherwise (given we now know of some other, diverse, symptoms and complications).

Early diagnosis was primarily based around travel history and contact tracing. The French example, shows the shortcomings of that. And somewhat proves (or adds significant circumstantial evidence for) the last paragraph.

To be clearer, symptomatic patients had already been tested, symptomatic staff were off work so the 9/10% positives were all asymptomatic at the time of the test.

The setting is a tertiary cancer hospital, i.e. it has in patients. They have a Covid positive ward but this testing has shown that there are staff and patients on the non Covid wards that are Covid positive, so will be shedding virus to currently Covid negative patients.

The world is a highly connected place so since it was present in China then I'm not surprised there were earlier cases in Europe. The particular French case had no contacts other than his wife (they checked).

In hospitals testing has been good so you would expect people to be tested where local cases have cropped up before  the staff show symptoms. So yes that also means I don't think anything like 9/10  remain asymptomatic with C19 from any mass of evidence. A BMJ report of 75% is the highest I've been aware of but it contradicts earlier data that ranges from 10 to 33%. Also WHO still say peak infectiousness is most common a few days after symptoms show (asymptomatic transmission has been tracked but at much lower numbers).

My argument is not a 'narrative' as the disease infomation simply points with very high probability to particular characteristics that mean a mass world spread in December is highly unlikely, unless the virus subsequently mutated to become more infectious/dangerous.  If we assume it has been around longer with an exponencial growth giving many asymptomatic cases and the mortality a tenth lower than currently thought ( 0.05% or below) then the per capita mortality  rates would be expected to self limit at 500 per million (unless there are a lot of interconnected unknowns, like no immunity from having it and/or a big correlation of mortality vs dose). NY is already at 1270 per million and the US experts don't think everyone there has had it. Also those countries who were successful with track and trace don't fit an older, more slowly spreading less lethal C19.

[galpinos]

If this has been spreading for a month longer than was first assumed (in both Europe and China, since there are reports of unusual cases of pneumonia there from November) then it will be significant. Or are you simply accusing the French of lying?

I would have thought that if it had been around that much earlier, the "excess deaths" number would have started creeping up before the "Covid deaths" number, however, they seem to correlate pretty well in the UK.

The stats showing excess deaths by location and the fact the increase in excess deaths seems to have occurred in areas of the UK with high Covid deaths indicates that the FT estimate of currently approx 50,000 deaths attributable to Covid-19 is probably pretty accurate.