Cellphone-based coronavirus alert becomes available to UC San Diego Health users

Philip Tajanko, an 18-year-old UC San Diego student
Philip Tajanko, an 18-year-old UC San Diego student, tested positive for the COVID-19 coronavirus in October and let people know of his diagnosis with a cellphone-based exposure notification system.
(K.C. Alfred / The San Diego Union-Tribune)

About two weeks after Philip Tajanko moved into his UC San Diego dorm room, he tested positive for the COVID-19 coronavirus.

He says he has no idea where he caught it.

Tajanko, 18, isn’t alone. Many people diagnosed with the virus don’t know where they came down with it, making it nearly impossible for county disease detectives to track down everyone who may have been exposed.

But Tajanko had another tool at his disposal. Before moving onto the campus, he chose to participate in CA COVID Notify, a pilot program that uses a smartphone’s Bluetooth capabilities to tell people when they’ve come in sustained contact with someone who tested positive for the coronavirus.

With the push of a button, Tajanko was able to send an alert to anyone else in the program he may have spent time with.

“It was definitely comforting in that I could notify people I didn’t even know,” he said. “I could inform a lot more people than I normally could have.”

Until this week, exposure notifications had only been available to students, faculty and staff members at eight universities across the state, including UC San Diego.

But now the program has been opened to all patients in the UC San Diego Health system, growing the user base by hundreds of thousands.

The expansion comes as San Diego County and other counties across the state grapple with an explosion of coronavirus cases leading up to Thanksgiving, a holiday known for close-knit gatherings at home — one of the most common places of possible infection, county officials say.

But many people who got sick also reported going to public places before symptoms started showing. They traveled, went to office buildings or visited bars or restaurants. While people may have no problem telling a contract tracer about the people they spent time with at a gathering among friends, listing everyone who was nearby at an airport would be much more difficult.

“Most people getting COVID now don’t know where they got it,” said Dr. Christopher Longhurst, chief information officer and associate chief medical officer at UCSD Health. “They don’t actually know where they were exposed.”

Exposure notifications are the solution to that problem, he said. “This is how you stop the spread.”

The pilot program was launched in September as a way to test Apple and Google’s Exposure Notifications System, and its expansion bodes well for an eventual statewide release.

For now, only the UC San Diego campus and health community have access to the program in San Diego County. The UCSD Health system includes the UC San Diego Medical Center, Jacobs Medical Center, Moores Cancer Center, Sulpizio Cardiovascular Center and express care, urgent care and clinic locations across the county.

Apple cellphone users who decide to participate will turn on the Exposure Notifications System built into iOS 14.2. Google cellphone users will need to download the CA COVID Notify app from the California COVID Notify website. (It is not yet available through the Google Play store.)

UC San Diego officials estimate that 25,000 people have turned on exposure notifications since the pilot launched, and they hope to see that number grow, since the technology relies on participation to be effective.

So how does the system work?

Bluetooth technology uses radio waves instead of internet connections or cables to connect to other gadgets, including other phones.

Smartphones will harness that technology to regularly broadcast an anonymous, constantly changing code that can be picked up and logged by other phones nearby.

The strength of the signal helps approximate how close people are. When phones come within six feet of one another for at least 15 minutes, they log one another’s code.

If someone later tests positive for the coronavirus, a health official who has verified the diagnosis will provide an exposure notification key for the infected person to enter into his or her phone. This gives the system permission to alert everyone the infected person made contact with in the 14 days before getting sick.

Technically, anyone with the latest iPhone operating system or the Google app can turn on the exposure notifications. But only approved health systems can issue the keys that allow those programs to share test results.

UC San Diego has issued more than 20 of those keys since the program launched. One of the keys sent an alert to B.C., a freshman at the university who asked to be identified only by her initials to protect her privacy.

The 18-year-old psychology student had been on campus for about a month when the notification popped up on her phone.

“A person you were recently near has reported they tested positive for COVID-19,” the message read. “Based on the strength and duration of the signals between the two phones, there is a good chance you were exposed to the virus.”

B.C.'s roommate had already told her that someone the two of them hung out with at the beach the day before had tested positive. But she wasn’t sure what to do next.

Getting the notification was a relief, she said, because it gave her a plan. The message told her to immediately self-isolate and it gave her a number to call. She spoke with campus officials who assured her she would be taken care of, and they explained how to get tested. Several hours later, she was moved into quarantine housing on campus, where she lived for two weeks.

She never tested positive.

“They weren’t condescending or judgmental. Instead they were like, ‘This is a pandemic. This is what we expected. We’re prepared for this. We just want everyone to be safe,’” B.C. said. “It made me feel so much safer.”

UCSD’s prevention plan also includes face-covering requirements, increased sanitation, wastewater testing and public health interventions like case isolation. ◆