UK Contact Tracing APP Failed to Warn People of Covid-19 Exposure

The contact tracing app used in England and Wales failed to warn people that they were exposed to COVID-19 patients and should quarantine.

Just because you have a COVID-19 contact tracing app on your phone doesn’t mean you can take the virus lightly. A new report said that the app used in England and Wales failed to do its job. The error caused thousands of people not to enter quarantine when they should have. 

COVID-19 Contact Tracing Apps

The Verge said that the app failed to tell these people to quarantine. Moreover, the Sunday Times said that the app didn’t warn people that they had close contact with COVID-19 patients. 

UK contact tracing app failed to flag people exposed to COVID-19 https://t.co/dpecalslqc pic.twitter.com/n10tnhgwL2

— The Verge (@verge) November 2, 2020

England and Wales launched the app on September 24. Since then, 19 million people have downloaded it. The app also uses Google and Apple’s system, which monitors phones nearby. If you interact with a person who later tests positive for COVID-19, the app will ping you. 

Flaws in the App

The Sunday Times reports that the app flagged only a few users since its launch. Last week, engineers found the flaw. Spending over 15 minutes at closer than 2 meters with a person who tests positive should be enough to flag you. However, they changed the app to include the start of the symptoms. 

Why Was it a Flaw?

Studies show that people are more contagious a day before they start showing symptoms. They also tend to have high levels of virus in their nose and throat on that day. These virus levels stay high for a few days. After that, they drop off. 

If you talked to someone outside of that window, the app said you were safe. So, you could spend about 40 minutes with a sick person outside this window. The app would not alert you.