COVID-19 Exposure Alert – There’s an app for that!

By: Grace Martin

We have an app for everything – ordering food, listening to music, watching videos, and buying just about anything – right at our fingertips. Now, we have an app where people can be alerted of possible COVID-19 exposures. COVID Alert, an app released by Health Canada on Friday July 31st, 2020 is currently linked to the Ontario health system and available for public use throughout Canada. The hope is that the other provinces will be joining shortly. It took me 47 seconds (yes, I did time myself) to download and set up the app on my phone.

With new emerging technology, there are always valid concerns about privacy and how consumer data will be used. So, here is a breakdown of how the app works:

The app uses Bluetooth to exchange random codes with nearby phones. Whenever you are near someone else with the COVID Alert app, both phones exchange random codes every five minutes. The random codes change often and cannot be used to identify your location, name, address, or health information. However, if you are an Android phone user, location services are needed to utilize Bluetooth, and while COVID Alert itself has no way of accessing your location, Google might.

If someone with the app is diagnosed with COVID-19, they will receive a one-time key from public health officials or healthcare providers. They can then voluntarily decide to enter this one-time key into the app and share the random codes from their phone to a central server operated by the Government of Canada – it does not receive any personal information about the individual. It should be noted that nothing is shared without explicit permission.

Every day, the app will check a list of random codes from people who have tested positive, and if you as a user have had close contact with such an individual (classified as closer than two meters and for longer than 15 mins), the app will notify you of the exposure and explain what to do next (e.g., getting tested).

It is critical to remember that this is just one tool that can be used to combat the COVID-19 pandemic. The hope is that this app will be used in conjunction with other measures such as contact tracing, existing public health measures (e.g., mask use, social distancing, hand washing), and evolving scientific research.


1. Public Health Agency of Canada. COVID Alert: Exposure notification application privacy assessment – [Internet] 2020. Available from:

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