COVID-19: Can smartphone contact-tracing apps replace lockdown?

With COVID-19 showing no signs of slowing its spread across the globe, public debate is moving on from how to stop the virus in its tracks, to how we can adapt and live through this outbreak.

Societies have been enormously altered by the efforts to control the epidemic, with long-lasting repercussions for the economy and for individuals. As a widely available vaccine for coronavirus is still more than a year away, governments worldwide are considering ways to bring some semblance of normality back to the world a little sooner.

One option coming under close scrutiny is using mobile technology to trace people thought to have COVID-19, and those they may have passed the disease on to.

Contact-tracing apps follow the movements of a person’s smartphone using technology such as Bluetooth low-energy sensors. The Bluetooth sensors in mobile phones would “see” when someone came within close proximity of anyone who reports that they have the symptoms of COVID-19, or who has tested positive for the virus. If a user spent more than a certain amount of time next to someone who thinks or knows they’re positive, they would be warned.

Another key benefit of the apps is that they could be a way to warn people retrospectively when they have had contact with someone who was asymptomatic or didn’t know they had COVID-19 at the time. It Is possible to do contact tracing the old-fashioned way, through interviews with the patient, but this is time consuming, laborious, and relies on fallible human memory. Then there is the additional problem that a person won’t remember or know how to identify a stranger they passed in a shop, for example.

If contact-tracing apps fulfilled this potential, then there could be the potential to ease lockdown, largely limiting it to those who have symptoms, the people who have had contact with them and those at particularly high risk of death from the virus. In theory, life could start to look more normal again for everyone else.

Lifting lockdown

Bluetooth is being used rather than location data, powered by GPS, the global positioning system, because GPS is not possible to use without breaching privacy laws in most democracies. It is also a significant drain on mobile phone batteries and, more fundamentally, isn’t accurate enough based on what we think we know about the transmission of COVID-19. “There are lots of problems with it,” says Michael Veale, lecturer in digital rights and regulation at University College London. “It doesn’t work in multi-storey buildings, for one thing.”

Whereas Bluetooth low-energy records “contacts” between people (or their phones), rather than their location at all times, and is more precise.

Source: BBC health news