Can somebody please explain what contact tracing is?

[ladypete]

Apologies if I seem dim. How does it work? I though some of you may be in a country that is doing it currently or just understands the concept better than I do?

I understand that you need to trace anyone you had contact with for over 15 mins in close proximity. So an entire train carriage perhaps? Everyone in a meeting at work? A long queue? A school classroom?

What happens if people are asymptomstic, but managed to infect you? Does everyone you say you’ve been in contact with get tested or would they just find the link by working out who also has other people within their circles fallen ill? Surely the latter wouldn’t be reliable. Is it left to an app like other countries have used (South Korea I believe)

I live in London, and will be using public transport when I eventually go back to work so I am intrigued to see how this next phase is meant to work. I’m wondering whether we’ll get messages asking whether we were on the 9.48am to Waterloo in Carriage 3 last Thursday...etc.

It seems like a very hard thing to do, but I’m sure that’s because I don’t understand the logistics.

Thanks in advance for any clarity!

You're quite right that it's extremely complicated to do it manually. This is a nice article on how app-based tracking works on a broad scale:
www.theregister.co.uk/2020/04/14/coronavirus_phone_app/
The most likely way it will be accomplished in the UK is via the bluetooth method, probably following the same methods as the EU:
www.theregister.co.uk/2020/04/17/european_contact_tracing_app_spec/
I don't expect the specific location would be mentioned in a notification, for privacy reasons. In addition to the above, the UK ICO has also provisionally approved the collection of location data but that doesn't mean it will definitely be implemented:
www.theregister.co.uk/2020/03/29/ico_anonymised_location_data_coronavirus/

In short, Bluetooth-based contact tracing is the best option for privacy, because it's location-agnostic while adding in location data reduces privacy but may prove helpful in larger containment efforts. Bluetooth also has the issue that it requires the latest low energy version (since standard Bluetooth would drain a phone battery rather quickly).

Trouble with contact tracing is that it doesn't protect you - you're still going to get it if you're going to get it - it just gives you a heads up you may have got it, sooner than symptoms appear, so you can social distance and isolate to protect others. That means a lot of people won't be interested as they're not bothered about protecting others once they've got it themselves. It's why so many people carried on their normal lives and spread it around despite having symptoms and why the lock down was necesssary!

You’d get an alert on your phone that you we’re in close proximity with somebody who has tested positive, telling you to either isolate or get tested.

If you develop symptoms or get a positive test then everybody who’s been in close contact with you gets a message.

Etc etc.

Thanks so much for that info. Very useful indeed.

So do we think 60% of people have a Bluetooth enabled phone and carries it with them 24/7? I would say so but I’m very aware it’s easy to just know your circle and demographic etc. I guess it’s like vaccinating - everyone Who can use an app would need to step up for the people that can’t in order for it to work.

I wonder if they’ll add a function to show how long you spent in contact with people. Again I’m just imagining how many phones pass other phones in quick concession on say a TFL escalator

@Kazzyhoward you’re right about people possibly only wanting to protect themselves, and that’s very unfortunate.

@8by8 Of course I knew, but reading that has again confirmed just how long we’re going to be fighting this.

If the virus is as widespread as they think, you’d be constantly isolating/testing? I can imagine isolating for 2 weeks, then going to Tesco and bam, another text comes through that I have to stay in for another fortnight.

In Iceland, there is now an app. But originally they just asked people who were diagnosed with the virus to tell them everyone they had been in contact with recently and everywhere they remember being. The contact tracing team then contacts people who could have been exposed and they are ordered to quarantine for 2 weeks (followed up with fines for non compliance).

This has been pretty successful, with just over 50% of new cases diagnosed in people who were already in quarantine (meaning they didn't spread it further).

This is one of the ways Iceland has been so successful in slowing the spread of the virus.

it will be utter chaos if people have to isolate every time they think they’ve been in enough proximity. I don’t know what parameters they’d set for the app. A half hour bus journey next to someone who had it? And you might have had it already and not even known.

Anything relying on people "doing the right thing" will fail.

Right at the start of Covid, people were told to self isolate if they had symptoms - many didn't. Cafes/pubs were told to close if they couldn't social-distance, they didn't. Shops and other businesses were told they could stay open if they could social-distance, many didn't. Unfortunately, far too many people think they know best, which is why a hard lock down was eventually necessary. Even with the lock down, many people still think they know best and are flouting it.

So, no, any system that relies on people doing what they're told, won't work.

So I’m in a country with pretty thorough contact tracing. One of the dc is at uni and was in contact with someone who tested positive. That girl had to tell the health authorities everyone she had been in close contact with for the previous 2 weeks and every one of those people was contacted by the health authorities. My dc was called on a Sunday morning so I presume they are working 24/7. She was then asked all about her health but since she had no symptoms she didn’t need to trace her contacts but was still tested within 24 hours. The health authority then followed up at 9.30pm to check she was staying home till the results came through and that she still felt ok. It was thankfully negative but I was very impressed with the service. And also amazed at the manpower involved in doing it so thoroughly

@PuffinShop in Australia apparently they did the same thing. They traced people and they only really get concerned where people went to large events.

In Germany they also do contact tracing. However as we don't do it, all they could do is ask the UK press to publish stories of people who flew in from the UK who were knowingly infected.

Certain "incentives" for using the app have been mentioned, though they haven't confirmed which (if any) they'll actually go ahead with. You might not be allowed to use public transport without it, for instance. In China, their equivalent (a QR code, coloured based on your exposure) was a pre-requisite to even enter a supermarket.

@Kazzyhoward if you ran a pub, cafe, restaurant or gym where you employed people and the government didn't give you a direct instruction to close would you? Particularly when you know you didn't have the money to fund those people's wages, pay your rent and other fixed costs if you closed? Or couldn't claim from your business interruption insurance unless the government gave a direct instruction?

The principles of contact tracing, in essence, have remained unchanged for centuries. Find a case. Quarantine them. Work out who they have been in contact with. Quarantine them, too.

www.thetimes.co.uk/article/17c815ae-8667-11ea-b876-ef9d21d57c48?shareToken=26f195e0ba71f195d2da0d444e5dc580

if you ran a pub, cafe, restaurant or gym where you employed people and the government didn't give you a direct instruction to close would you?

Lots did just that. Our village pub closed on the Wednesday, immediately after they were told to close if they couldn't social-distant. Our village pie shop was allowed to stay open as per the rules, but chose to close because of shortage of customers. Our local chip shop closed because they couldn't easily socially-distant the staff behind the counter and in the kitchen, again, despite being allowed to stay open as per the rules.

Power slide “ You might not be allowed to use public transport without it, for instance”

Has this been mentioned in the UK?

Lots of places in London closed before lockdown.

Power slide “ You might not be allowed to use public transport without it, for instance”

Has this been mentioned in the UK?

Yes - it was in one of the earliest articles I saw about the UK app - 2 or 3 weeks ago now. I've not heard mention of it since though, so who knows what their plans are.

Thanks Powerslide

Wonder what they’ll do about people with dumb phones or no phones etc.

It probably will be hard to make it work and people may not want to stay at home for 2 weeks without pay because they might have passed someone who thinks they might have had it but never got a test so might just be wrong. I just cannot see it working and many people don't have a phont it will work on (and I don't even take my blackberry out on most journeys). My neighbour doesn't even have a mobile never mind a computer.

Xenia it seems like a really bonkers idea.

It obviously only works based on confirmed cases, so in conjunction with a good testing programme, and with measures in place to ensure that people receive compensation from the government if they can't work in quarantine. And they realustically won't catch 100% of cases, but around 50% seems to work to significantly slow things down.

These things enable most of society to continue more or less functioning without such severe blanket restrictions on the whole population. More of a targeted approach rather than a sledgehammer to crack a nut.

But surely if you’re confirmed as an active case, you quarantine yourself?

The app pnly helps with....making someone money.

But surely if you’re confirmed as an active case, you quarantine yourself?

In Iceland you would then be in isolation with daily contact from healthcare workers. That's a bit more restrictive than quarantine.

Quarantine is for people who may have been exposed but are currently healthy. If you've been ordered to quarantine by the Directorate of Health, this is followed up. It's more formal than just asking people to follow a set of guidelines.

Puffin - quarantine for a confirmed active case, with doc checking, okay.

Quarantine because you’ve been in contact with someone who has it and the app said so? Who’s going to go along with that - unless they’re paid?

This whole thing is so OTT.

Our app definitely doesn't make any money. Who would be profiting? I mean I assume the programmers received a wage but other than that what do you mean? It's just for helping the contact tracing team do their jobs, because it can be difficult for people to remember everyone they've been in contact with.