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Gov. Newsom Announces Phone-Based Virus-Exposure Tracking System

A contact tracing app is seen on a cell phone screen, Friday, May 22, 2020.
Stephen Groves / AP
A contact tracing app is seen on a cell phone screen, Friday, May 22, 2020.

Gov. Gavin Newsom Monday announced a statewide cell-phone-based system designed to notify residents when they've been exposed to COVID-19.

The CA Notify system was originally developed at UC San Diego and UC San Francisco, and it has been deployed on a trial basis on seven UC campuses, with an estimated 250,000 people opting in to participate, Newsom said.

Gov. Newsom Announces Phone-Based Virus-Exposure Tracking System
Listen to this story by Matt Hoffman.

The system relies on Bluetooth technology that detects when a person is in close proximity to others, thanks to anonymous signals transmitted among cell phones. When a person who has opted into the program tests positive for COVID-19, the person can then consent to have all of their recent close contacts notified by cell phone.

RELATED: Tracking COVID-19 In San Diego

VIDEO: Gov. Newsom Announces Phone-Based Virus-Exposure Tracking System

Those contacts then receive a notification on their phone, alerting them that they have recently been exposed to someone who has tested positive for the coronavirus. The idea is to more rapidly reach people who may have unknowingly contracted the virus and could be passing it along to others, giving them a chance to get tested and go into quarantine.

The program will not replace traditional contact-tracing efforts, but Newsom described it as "another tool in the toolbox" to supplement those efforts.


The city and county of Los Angeles announced a similar program earlier this year, partnering with the Citizen crime-tracking app. That program also required participants to opt-in, since it requires constant tracking of a person's location to determine if they were in an area where virus exposure may have occurred.

The CA Notify program conducts similar tracking through the Bluetooth system, but Newsom stressed that the information is not collected or made public.

The program will begin on Thursday.

RELATED: Tracking Coronavirus Hospitalizations In California By County

UC San Diego has been testing the platform since September and has more than 25,000 users signed up.

“We got great feedback from students, some who tested positive and said this took a weight off their shoulders,” said UC San Diego Health’s Dr. Chris Longhurst. “They could launch this anonymous app and keep people around them safe.”

Longhurst said nearly two dozen other states are using similar technology. He said this is not a replacement for physical distancing or wearing face coverings, and for it to work best, users have to enter positive test results into the platform.

“The more people who adopt it, the more effective it will be,” Longhurst said.

UC San Diego has been contracted by the state to provide some technical support to users on the CA Notify platform.

Android phone users will need to download the CA Notify app to take part in the program. Apple iPhone users will not have to download and app. The notify program will be available in the phone's Settings menu, and users can opt-in to receive notifications of possible exposures.

Cell phone users across the state will receive a notification on their phones prior to Thursday, notifying them of the availability of the system and the need to opt-in.