Source: SA Coronavirus
South Africa’s COVID Alert SA app was released yesterday. Here’s all you need to know about SA’s new Bluetooth-based contact tracing app:
- You can download the app from the Apple App Store or Google Play. It’s under 3 MB in size
- The app is free and does not feature in-app purchases.
- You will not have to pay for mobile data when you use the app – the data to use the app has been zero-rated by all of South Africa’s mobile network providers
What is contact tracing?
Contact tracing is the process used by public health authorities to control the spread of epidemics and pandemics. It’s been integral to containing outbreaks such as that of the Ebola virus in 2014, of the 2003 severe acute respiratory syndrome (SARS) outbreak, and of tuberculosis (TB) and other infectious diseases that are highly contagious.
Contact tracing means healthcare workers identifying and interviewing those who have contracted a disease to identify their ‘close contacts’ – those they have been in close proximity to in the recent past and therefore possibly infected as a result of their close contact.
Why do we need apps to assist with the contact tracing process?
Manual contact tracing is a time-consuming, process that has its limits. The person who tests positive for COVID-19 needs to remember all the people they have been in close contact with for the past two weeks and their contact details, which is not possible for people they come into contact with in public places such as the grocery store or public transport.
Bluetooth contact tracing apps, like COVID Alert SA, replace the need for us to remember and identify close contacts by simply letting app users’ smartphones “say hi” to each other and keep a record of every time this happens.
And, really importantly, every app-user’s identity is kept private at all times.
How the COVID Alert SA app allows for Bluetooth contact-tracing
- COVID Alert SA app uses Bluetooth signals to exchange ‘random codes’ (these are just random numbers that change several times a day) with other COVID Alert SA app users. That’s how the phones “say hi” to each other.
- This happens when app users’ smartphones are within two metres of each other for more than 15 minutes.
- This process happens whether app users are near to people that they know – such as when near to friends, family or colleagues – and people that they aren’t acquainted with – such as at the shops in a queue, or on public transport.
- As long as the COVID Alert SA app is running on smartphones that are near enough to each other, they will share random codes – saying “hi” and giving each other a digital handshake.
- The random codes exchanged at the time of the ‘digital handshake’ are stored in a log on each phone for 16 days.
- At no stage is the identity and location of the device users required for this exchange to happen. All that the COVID Alert SA app tracks is the proximity of smartphone devices to one another and how long they are in contact for.
- Then, when an app user contracts COVID‑19 and a test shows they have the disease, they can choose to anonymously report this information to the app community. That kicks off the Bluetooth-based contact tracing process.
- Their smartphone uploads the random codes that it has on record from the past 16 days to the Exposure Notification Server.
The Server sends these random codes to all of other app users.
- Each app user’s device runs through these random codes to check for a match between these codes and the codes it has stored in the past 16 days (every time it has come into contact with another device using the COVID Alert SA app).
- If there is a match, the device notifies the user that there they have potentially been exposed to COVID‑19, with the date on which they were in contact with someone who has tested positive.
- App users also receive information on what to do next to self-quarantine (for 14 days), watch for symptoms of COVID-19, and to optimise their health and wellbeing.
- This all happens in a way that preserves the privacy of every app user at all times.
By joining other COVID Alert SA app users, we can work together to stay safe, save lives and turn the tide on COVID-19 in South Africa.