TraceX is an iOS application that empowers you to slow the spread of COVID-19 in your community via digital contact tracing. It provides early and anonymized alerts if someone has a high-risk exposure so that they can get testing or self-quarantine to help protect their friends and family members.
What is contact tracing? How does TraceX help?
Contact tracing is part of the process used to identify people who may have been exposed to someone with a confirmed or suspected infection. The exposed individuals, or contacts, are then given instructions to monitor for symptoms or self-quarantine in order to prevent further transmission. Symptomatic contacts may referred for testing and medical care.
TraceX can provide a huge advantage to manual contact tracing since infected people may not remember everyone that they have been in contact with. It provides a seamless way to notify any of your previous points of contact without storing or sharing any personal information.
Users who receive exposure alerts from TraceX should follow CDC guidelines and consult with their health care provider for detailed information on what to do next.
Why should I download the app?
By downloading TraceX and reporting your health status, you can play an active role in preventing further transmission to your family, friends, and close contacts.
If you encourage and assist others to download the app, the technology can have a significant impact on slowing the spread in your community and can keep you aware of any COVID-19 exposures so you know when to get tested or self-isolate.
What kind of phone will work to use this app?
The app requires an iPhone with iOS version 10 or above.
An Android version is under development.
So what happens when I download TraceX?
When the app is downloaded, you will be asked to enable the use of Bluetooth and allow notifications.
On the home page, you will be asked if your status is healthy, having symptoms suggestive of COVID-19, or recently tested positive for COVID-19.
Later on, if you change your status from healthy to symptoms or positive test, your contacts will be anonymously notified.
At any point, you can view any exposures you've had to people who are symptomatic or COVID-19 positive from the past 14 days.
Will it drain my battery? Can I still use my bluetooth headphones?
TraceX uses low-frequency bluetooth beacons to avoid consuming significant battery and only broadcasts bluetooth signals when in the foreground. The app will work fine if used simultaneously with bluetooth headphones or any other nearby bluetooth devices.
What data is collected through the app and how long is it stored?
In order to protect your privacy, TraceX only uses low-energy Bluetooth signals to detect other phones and never tracks your location.
The only data stored on your phone is a randomly hashed key that your app exchanges with nearby TraceX users if you have had significant contact with them. No phone numbers, personal data, or location data is requested, stored, or shared.
The past 14 days of contact data are always stored directly on your phone.
Do I need to keep the app open in order for TraceX to work?
TraceX works best when one of two users that come in contact has the app open. It’s recommended that users open the app in the foreground when leaving home.
Aren't Google and Apple building an app for contact-tracing?
No, Google and Apple will be releasing programming libraries to allow health agencies and later developers to build contact-tracing apps with enhanced bluetooth functionality. We plan to use this once the consumer-facing API is released so that TraceX can always run in the background on any user's iPhone, as this is currently restricted by Apple.
Will nearby users be able to see if my current health status is symptomatic or COVID-19 positive?
No, the TraceX app on your phone and other users’ phones will record anonymous random numbers when the phones come into contact.
Notifications of an immediate exposure will be updated once daily at a later time.
How close do two phones have to be to log a contact event?
TraceX uses a smoothing function to reduce false positives by only exchanging hidden keys with phones within a certain threshold of distance and time (6-8 feet for several minutes), which is based off the smoothed value of the bluetooth signal strength. We adapted this function from the open-source Vicinity project, credits!
The thresholds for defining close contact are within 6-8 feet distance for several minutes.
How can I be sure that the exposure notifications are accurate?
TraceX depends on the users' voluntary reporting of symptoms and testing status.
Since testing is not verified by this app, false positive rates may be higher than contact tracing apps developed by health agencies in other countries.
Since the sensitivity, specificity, and availability of testing can vary, notifications about contact with people having symptoms is an important early warning that can help protect your friends and family.