Covid-19 Contact Tracing

What is Contact Tracing?

Contact tracing is a technique used by public health authorities to measure and slow the spread of infectious diseases by identifying people who may have come into contact with an individual with an infectious disease, in this case COVID-19.

Methods of Contact Tracing

There are two primary methods of contact tracing. The conventional method involves manually gathering information from infected individuals about the people they’ve previously been in contact with. These people can then be notified by public health authorities to take appropriate safety measures, such as undertaking self-quarantine and getting tested to break the chain of transmission. There are some challenges with this conventional method though. First, there is a significant organizational burden due to the manual nature of the process, as many public health workers are needed to perform these tasks. Second, the process can be slow as it requires finding and interviewing infected individuals and then reaching out and talking to their high risk contacts – all of whom may not be able to remember or know all of the people that they came in contact with in the past days to weeks. Third, some people are distrustful of the medical professionals performing the follow up surveys for those that test positive and are either refusing to give out the contact information for those that they have been in contact with or are simply withholding some of that information.

The second, modern, method involves augmenting the process with mobile devices in an automated and scalable way to help determine who has been exposed to a person that later reports a positive diagnosis of COVID-19. For example, they can be used to send a rapid notification to the exposed person with instructions on next steps. These notifications may be beneficial by alerting an exposed individual faster than they would be notified via conventional contact tracing. They will enable public health authorities to contact and provide guidance to the individual and, where appropriate, include them in conventional contact tracing efforts. Using digital exposure notifications is new and individual health authorities are determining how they best fit into their own public health systems. This solution too has its own challenges. First, the fact that the mobile solution is opt-in and not opt-out, it’s not entirely useful if not everyone is using it so that those whom they come into contact with can be notified. Second, there is no universal implementation of Contact Tracing, so applications that aren’t the same as the others may not be sharing the same information with authorities in a given jurisdiction.

Implementation

To date, the most significant implementation was created between a partnership with Google and Apple, due to their massive mobile user base. The result was an Application Programming Interface (API) released in May for both Android and iOS devices which leverage the power of Bluetooth technology to aid in COVID-19 exposure tracing and notification. If enabled, users’ devices will regularly send out a beacon via Bluetooth that includes a random Bluetooth identifier not tied to a user’s identity and which changes every 10-20 minutes for additional protection. Other phones will be listening for these beacons and broadcasting theirs as well. When each phone receives another beacon, it will record and securely store that beacon on the device. At least once per day, the ‘system’ will download a list of the identifiers for the beacons that have been verified as belonging to people confirmed as positive for COVID-19. Each device will check the list of beacons it has recorded against the list downloaded from the ‘system’. If there is a match between the beacons stored on the device and the positive diagnosis list, the user may be notified and advised on steps to take next. To power this solution, mobile application developers can tap into this API when writing apps for public health authorities. These will be distributed via Google Play and Apple’s App Store. Once the app is launched, the user accepts the terms and conditions before the program is activated. Soon, this API will be embedded at the operating system level of mobile devices to help ensure broader adoption, which addresses one of the aforementioned issues with this method of Contact Tracing. After the operating system update is installed and the user has opted in, the system will send out and listen for the Bluetooth beacons as in the first phase, but without requiring an application to be installed. If a match is detected the user will be notified, and if the user has not already downloaded an official public health authority application they will be prompted to download an official app and then advised on next steps. Only public health authorities will have access to this technology and data, and their apps must meet specific criteria around privacy, security, and data control.

Privacy Concerns

Despite these assurances, both Google and Apple have maintained that they are putting user privacy at the forefront of this exposure notification technology and have established strict guidelines to ensure that privacy is safeguarded during its implementation. Mobile users have to explicitly enable the functionality on their devices. It can also be turned off by the user at any time after that. Despite this, people and organizations alike (e.g. the ACLU) are concerned of the potential privacy implications. Furthermore, people are concerned about the accuracy of the technology due to Bluetooth’s range.

Hopefully the technology at our nation’s disposal will allow us to better address this ongoing epidemic, but not everyone is on board with that.