Coronavirus: How does contact tracing work through app?

Millions of people in the UK will soon be asked to track their movements to limit the spread of coronavirus.

The government is deploying 18,000 people to trace the contacts of those infected, and the wider public will be asked to get involved too.

So how does contact tracing work, who will have to take part in it - and what happens to the participants' data?

What is contact tracing?
Contact tracing is a method used to slow down the spread of infectious outbreaks. It is commonly used in sexual health clinics, when infected patients are told to contact anyone with whom they have been intimate.

In the coronavirus pandemic, it means tracking down anyone sufferers have been in prolonged contact with, to potentially ask them to self-isolate.

This is often done through phone calls to the friends and family of coronavirus sufferers, complemented by an automated location-tracking mobile app.

Contact tracing is already being used extensively by various countries hit by coronavirus, including Hong Kong, Singapore and Germany.

The UK is planning to roll out its contact tracing app and phone team by the middle of May, in the hope that weeks of social distancing will have made new outbreaks easier to track.

What will contact tracing look like in the UK?

The 18,000-strong team will feature about 3,000 civil servants and health workers, and 15,000 call handlers. They will ask coronavirus patients about their recent movements, and then contact anyone with whom they have had extended contact.

This telephone system will be used in tandem with a tracing app, available to download on smartphones in the next few weeks.

Using Bluetooth, the free app tracks when its users come into contact with each other, automating the laborious contact tracing process. If a user develops coronavirus symptoms, it is up to them to let the app inform the NHS.

Their disclosure may trigger an anonymous alert to users with whom they recently had significant contact, again potentially asking those people to go into quarantine or be tested.

For those without smartphones, an alternative could be a Bluetooth-enabled wristband, like those being used in other countries to detect lockdown breaches.

(Source: BBC)