How does coronavirus track and trace system work to stop spread of Covid?
THE TRACK and trace system is just one of the ways the Government plans to pull us out of lockdown.
The theory goes that you can stop Covid-19 in its tracks, if you seek out and isolate those infected asap.
⚠️ Read our coronavirus live blog for the latest news & updates
The Government has been widely criticised for abandoning track and trace on March 12 - when they moved tactic from containing coronavirus to delaying the peak.
They argue it has worked in other countries like Singapore and South Korea, helping to keep infection and death rates down.
Now, Boris Johnson has pledged to have a "world class" system in place by June 1, to help ease lockdown measures further.
There are two key strains to the operation - human tracers, and the NHS app.
So far, 25,000 contact tracers have been hired to manually track down people who have been near others who have contracted Covid-19.
How does track and trace work?
Contact tracing works by stopping the spread of coronavirus through a community.
The idea is that by isolating an infected person you can stop the chain of transmission.
Experts have explained the premise using persons A, B, C, D and E as an example.
Professor Keith Neal, from Nottingham University, has 30 years experience of contact tracing and infectious diseases and says such programmes are in place to disrupt chains of transmission.
“We're already doing that in part by people working at home, people are actually socially distancing," he told Radio 4's Today Programme.
"If anybody is infected, they are meeting less people.
“Once we find somebody who has been infected the whole point of the contact tracing is identifying person A who has the infection, who will have passed it on to person B.
“Then B will have passed it on to C, C to D and so on.
“The idea is we identify B from A to stop C, D and E becoming infected and it all adds up to reducing the rate of infections across the country.”
Professor Neal added that if most people have followed the rules and have successfully been social distancing, then the tracing shouldn’t be “particularly difficult”.
He said person B is the key, and that by identifying them quickly - and asking that they self-isolate for 14 days - you can bring the virus under control.
High risk contacts are the priority
So far in the UK more than 36,000 people have died from the coronavirus, while more than 250,000 Brits have tested positive for Covid-19.
When the Government abandoned contact tracing in March, they quickly moved to introduce measures including social distancing to help delay the peak of the epidemic, and stop the spread.
Social distancing and hand washing remain the best tools in fighting the virus, scientists agree.
Prof Neal said social distancing can also help speed up contact tracing.
He said given the lockdown, most Brits are very aware of who they are mixing with - and in most cases it is just their household.
So, in most cases person B will be quickly identified as a family member, or house mate.
The NHS app, which is unlikely to be ready for June 1, is only really needed when people don't know who they've been in contact with.
Prof Neal said: "If you have gone to a supermarket that's where the app comes in.
"It will help to identify who you've been in contact with, when you don't actually know their name or phone number.
“The (the two strains of contact tracing) complement each other."
Prof Neal said track and trace can be done without the app.
Downing Street had originally planned to hire 18,000 tracers, but the opposition criticised the figure, saying it would be too small a team.
The app that will accompany the tracing is not yet ready and questions have been raised as to how the tracers can successfully do their job if the app is not yet up and running.
Downing Street said any contact tracing that requires clinical expertise will be carried out by staff with specific training if they have never worked in the healthcare sector.
"We are ensuring everybody gets all the relevant training they need before they start work."
They added that the aim to boost tracing to 200,000 a day by the end of the month "coincide" with the Prime Minister's promise of "having an effective track and trace system in place by June 1".
As part of the roll out 20,000 households will be recruited and routinely tested over 12 months.
Ultimately, 300,000 participants will be involved in the study.
"High accuracy" antibody tests will be used to understand how immunity could work in those recovering from the disease.
Those taking part will be swab-tested and asked questions by a health worker during a home visit.
The tests will be repeated every week for five weeks, and then monthly for a year.
How does the app work?
On May 8 the first app was launched on the Isle of Wight with a second app on its way.
The pilot on the Isle of Wight is still ongoing, Number 10 said today.
The app monitors when users come into contact with people who may have Covid-19.
It is able to identify people that the person using the app may not know personally, such as a bus driver, postal worker or supermarket staff.
Professor Neal added: "We can do contact tracing even without the app because that's the matter of finding the most high risk contacts - it's close and prolonged contact and you tend to and should only have close and prolonged contact with people you actually know".
The app will work by using Bluetooth to log when another user’s smartphone has been in close proximity.
If a person develops Covid-19 symptoms, they can report their symptoms to the app and immediately organise a test.
The tech automatically sends out an anonymous alert to other users they may have infected, urging them to self-isolate if necessary – thus stopping further spread.
They will then have the ability to book a coronavirus test.
Health Secretary Matt Hancock had previously said the Isle of Wight was chosen for the trial of the app due to it's population size.
On initial launch of the app residents complained of issues such as the app notifying them with multiple alerts and download difficulties.
Number 10 said they were still working on ironing out the issues and a spokesperson for the Prime Minister said: "The intention is to roll the app out in the coming weeks but I've also said there is certainly no requirement to have the app in order to have an effective trace and system, which the PM spoke about, in place by June 1."
CORONAVIRUS CRISIS - STAY IN THE KNOW
Don't miss the latest news and figures - and essential advice for you and your family.
To receive The Sun's Coronavirus newsletter in your inbox every tea time, sign up here.
To follow us on Facebook, simply 'Like' our Coronavirus page.
Get Britain's best-selling newspaper delivered to your smartphone or tablet each day - find out more.