Here's how California's smartphone COVID-19 alert tool works

SAN FRANCISCO (KGO) -- Governor Gavin Newsom announced Monday that the state will be rolling out a voluntary smartphone tool to alert people if they spent time near someone who tests positive for the coronavirus.

This comes as California deals with a surge in cases and hospitalizations that has pushed some regions to implement a stay-at-home order.

RELATED: 'Vast majority' of California under stay-at-home order as ICU capacity reaches critical levels, Newsom says

The tool Newsom mentioned in Monday's news conference was first tested and used in the University of California system.

The tool doesn't track people's identities or locations but uses Bluetooth wireless signals to detect when two phones are within 6 feet (1.8 meters) of each other for at least 15 minutes, officials said. Newsom said it will be ready for use on Thursday.

Berkeley's Assistant Vice Chancellor for University Health Services Guy Nicolette joined ABC7 News 3 p.m. show "Getting Answers" to explain how the app works and how it's different than contact tracing.

RELATED: California to expand smartphone COVID-19 alert tool statewide

"Traditional contact tracing is really heavily reliant on skillful questions and kind of relying on or trusting the veracity of the answers given and then just diligent work, kind of following the timeline and contacting those with significant exposure," said Nicolette. "The app adds a kind of a layer on top of it and the value comes really in my opinion from contact tracing the folks that the case doesn't know basically strangers. So it's helping identify those that couldn't be identified in a typical case investigation in the three weeks."

Watch Nicolette's entire interview in the media player above.


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