On Tuesday, Mayor Muriel Bowser (D) announced the DC COVID Alert Notice (DC CAN), the official COVID-19 exposure notification app for the District, and urged DC residents who use iPhone or Android smartphones to opt-in.
The system was designed to assist the District’s contact tracing efforts. It allows mobile device users to receive an alert when they may have been exposed to someone who has tested positive for COVID-19.
Once a user opt-ins to the notification system, the Exposure Notifications System will generate a random ID for your device which change every 10-20 minutes. The user’s phone and the phones surrounding it will work in the background to exchange these privacy-preserving random IDs via Bluetooth.
On a daily basis, DC CAN downloads a list of all the random IDs associated with positive COVID-19 cases and checks them against the random IDs users have encountered in the last 14 days. If there is a match, the system notifies users of the day of exposure, how long it lasted, and the Bluetooth signal strength of the contact. No other information about exposure will be shared.
“We are encouraging all District residents, and those who spend time in the District, to opt into DC CAN,” said Mayor Bowser. “Using the DC CAN system is a quick and easy way to know if you might have been exposed to COVID-19. Opting in is one more way you can protect yourself, your friends and family, and our entire community.”
Beginning Tuesday, Oct. 20, DC residents with iPhone or Android smartphones will receive a push notification inviting them to opt into exposure notifications, the District said in a press release. On iOS, users will be able to opt into exposure notifications through settings without having to download an app. On Android, users will be prompted to opt in and install the DC CAN app from the Google Play Store. Users can also go directly into their iOS settings to enable the system or go to the Play Store to download the DC CAN app.
“This technology was created for the sole purpose of helping us stop the spread of COVID-19. Knowing your exposure history allows you to self-quarantine quickly, seek medical attention, and reduce the potential of exposing others,” said Dr. LaQuandra S. Nesbitt, Director, DC Health. “DC CAN is another tool helping our contact tracing efforts in the District. The Exposure Notifications System will be disabled once the pandemic reaches a point that no longer necessitates the use of this technology.”
The app does not need to be open for this process to take place. The phone periodically checks all the random IDs associated with positive COVID-19 cases against its own list. If there is a match, you will receive a COVID-19 exposure notification, with further instructions from DC Health on how to keep you and the people around you safe.
For COVID-19, a close proximity is anyone who was within six feet of an infected person for at least 15 minutes. An infected person can spread COVID-19 starting from 48 hours (or two days) before the person had any symptoms or tested positive for COVID-19.
The District said that DC CAN protects users’ privacy and data security, and that the Exposure Notification System does not track the users’ location, only their proximity to other phones with the app. Officials also reassure users that Google, Apple, or other users cannot see the user’s identity and only public health authorities can use this system, which will not be shared with any other agencies, including law enforcement or immigration. Users can choose to share their information for public health purposes only and can optionally provide a phone number so that a contact tracer may follow-up.