Digital contact tracing for COVID-19 is now in full swing in many countries like Australia, Germany, Ireland and South Korea.
Digital contact tracing for COVID-19 is now in full swing in many countries like Australia, Germany, Ireland and South Korea (although the latter is not through a mobile app as such, but credit card transactions and mobile phone data).
There is plenty of debate around the best methods to be used and, of course, privacy of data is a big discussion point.
Digging into the tech helps to better understand what works and what limitations there are to digital contact tracing.
Bluetooth
If you’ve ever used Bluetooth headphones (i.e. Airpods), you’ve likely had problems setting up a connection, with drop outs, or found they are just that little bit less reliable than the old corded versions.
If a contact is considered to be someone who passes within one metre of you, then that’s really difficult to record with standard Bluetooth technology.
It’s quite a tight radius and, for it to work, the Bluetooth must be switched on 100 per cent of the time and working perfectly at the exact moment the other person passes by.
Things like crossed signals, or even a metal roof (as personally experienced in a conference venue) can prevent Bluetooth from operating perfectly.
Although, it has vastly improved and is still very useful technology.
Battery drain
Nobody enjoys seeing the dreaded 10 per cent battery warning on their phone, as you make a beeline towards your phone charger.
However, anything that constantly runs processes in the background will drain your battery.
This has been the big question for many potential corona tracing app users.
All COVID apps, including Australia’s COVIDSafe, use Bluetooth technology to essentially search and respond to signals sent out by another person’s mobile device.
It’s like little people in your pocket whispering to each other while you go about your day.
The good news is that Bluetooth Low Energy (BLE) doesn’t actually use a huge amount of battery.
If you’re concerned about it, reducing your screen brightness or putting your phone on low power mode will save significantly more power than turning off BLE.
Definition of contact
Most of the debate around tracing apps has been centred around privacy, but there hasn’t been much discussion about what defines ‘contact’ according to each app.
The World Health Organisation defines it in a COVID-19 contact tracing guidance document as being within one metre of an infected person for more than 15 minutes.
It would be helpful to know how those parameters are treated by each of the tracing applications.
Looking at apps in use around the world, it really isn’t clear what each of them define as a ‘contact’.
As a result, it is almost impossible to assess the accuracy of each of the apps and the likelihood they will successfully record a ‘contact’.
Volume of users
Like many mobile applications, what makes a contact tracing app successful is a high volume of users.
A study conducted by Oxford University simulated the impact of such an app on a city of 1 million people.
Researchers estimated that about 60 per cent of the population would need to use the app for it to serve its purpose and stop the epidemic.
However, they reported it would still help to slow the spread of the virus if there were fewer people using it.
Privacy
Privacy is one of the main reasons people give for refusing to download tracing apps.
If you’re in China, it’s mandatory.
If you’re one of the 16 million downloaders of Corona-Warn-App in Germany, your privacy is protected, but the data is less impactful.
The more sensitive the data, the more useful it is from an epidemiological point of view.
Many countries, like Italy, are building their apps on a privacy-first platform built by Google and Apple in an unlikely collaboration between the two tech giants.
The Exposure Notification Framework was released in May, and the Australian government reportedly won’t be implementing it any time soon.
A spokesperson for the Government Services Minister Stuart Robert, said: “It is important to note, the COVIDSafe app is designed to supplement manual contact tracing.
“The current Apple and Google tracing platforms are structured very differently. They rely on the individual who tests positive to initiate sending the alert to the close contacts, and those people reacting to automated notifications, isolating and getting tested.”
In simple terms, there are two key ways data is handled through a data tracing app–centralised or decentralised.
Rather than your identity and device location being sent to a central server, a decentralised system uses an opt-in system, the data is handled locally on your device and you choose when to share your information.
While this might be less effective at mapping and tracking the spread of the virus, it is likely to encourage a higher number of users.
Taking everything into consideration–Bluetooth reliability, how a contact is defined in an app’s code and privacy concerns largely deterring mass downloads of these types of apps, I have some concerns about how effective they can truly be.
However, in my opinion, if a simple download prevents just one infection, then that should be considered a success and we should all do our part to help protect the greater collective.
