Berkeley city workers become sleuths to track down COVID-19 cases

The public health division uses contact tracers to figure out who has become exposed to the novel coronavirus. Then those people are asked to self-isolate to stop further spread.

Berkeley has set up a COVID-19 testing site in West Berkeley. As part of containing the spread of the virus, city workers are tracing people who have come into contact with someone who has tested positive. If they have symptoms, they are encouraged to be tested. Photo: Pete Rosos

Immediately after Berkeley’s first reported COVID-19 case, on March 3, city health workers started sleuthing. Their goal: to track down each person this patient could have exposed to the virus, and tell them to self-quarantine.

They asked the patient when they first felt sick. Who they lived with, shared meals with. Where they had traveled or shopped.

This process, called contact tracing, is set into motion for each of the city’s confirmed COVID-19 cases — 67 people so far. Hundreds of people have been contacted. Going forward, it’s expected that Berkeley will need to contact hundreds or thousands more.

Contact tracing is a buzzword used during today’s pandemic. But Dr. Lisa Hernandez, Berkeley’s public health officer, is quick to say that contract tracing isn’t new for Berkeley but is a standard prevention tool of public health. Stopping the spread of contagious conditions depends on preventing exposures, whether it’s COVID-19, measles, tuberculosis or HIV. For an infectious virus without a vaccine or cure, quarantining those exposed is especially critical.


“It’s not a new activity. We do this all the time for most diseases reported with us and we have over 80 diseases reported to us. It’s the core of public health disease control,” Hernandez said. “We interview every case. The difference now is the scale of contacting tracing.”

Ramping up trained staff

Normally, the city’s public health nurses do contact tracing along with their other duties. But in the pandemic, Berkeley, like most health departments, is expanding its force of contact tracers. This means training and repositioning existing city staff and adding new workers, including nursing students and disaster volunteers.

The city’s goal is to have at least 20 designated contact tracers on the job. Whatever it takes, Hernandez said.

This week, the city started reassigning and training city employees from other departments for contact tracing. So far, 37 staff are preparing to become contact tracers, which allows for attrition, Hernandez said. They’re mainly from health, housing and community services, but also from the library.


“We’re phasing in the staffing, so we’re able to respond to the anticipated increase in cases,” Hernandez said.

Some of those trained might eventually be shifted to other, related roles, such as offering additional support to people to help them maintain their quarantine, said Matthai Chakko, the city spokesperson. COVID-19 case management includes making sure patients have the services and resources they need to self-isolate.

The city is not looking for volunteers for contact tracing, he said.

Self-isolation for those exposed

As soon as the city gets a positive COVID-19 patient, that person is asked to self-isolate and is monitored by the health department until they have recovered, meaning they test negative and feel healthy. As of this week, 51 of the city’s 67 COVID-19 patients had recovered. One has died.

At the same time, tracing is done of the person’s contacts when they were sick — people who were within six feet of the patient for at least 15 minutes

At-risk contacts are asked to self-isolate for two weeks. If they develop symptoms, they’ll get tested, Hernandez said. If they test positive, tracing starts on their contacts. Webs of contacts grow new webs of contacts. Over time, the early webs fade away as the virus disappears.

Berkeley patients average eight contacts each, or people potentially exposed to the virus, and tracked by the city, she said.

“The biggest thing we want is that someone who is exposed is quarantined, so they’re not exposing other people.” — Dr. Lisa Hernandez, Berkeley’s public health officer

Contacts without symptoms can also get tested. But in the days after possible exposure, testing isn’t particularly helpful because it takes a while for the virus to incubate or become detectable, Hernandez said.

“The biggest thing we want is that someone who is exposed is quarantined, so they’re not exposing other people, said Hernandez. “That’s the most important thing. We wouldn’t require someone to get tested just to get tested.”

Contacts need to self-isolate regardless of test results.

The city can legally require people who test positive to self-quarantine under the health order, subject to misdemeanor charges. But so far, Berkeley is using the lighter touch of asking for voluntary compliance, Hernandez said. And, so far, she said, it’s working.

“If you’re diagnosed with COVID-19 then you’re by law, under the health officer, ordered to isolate or subject to fines or imprisonment,” she said. “We have the facility to do that, but I haven’t yet. I’ve considered it, but I haven’t done it.”

The health officer can also order someone to take a COVID-19 test, which she also hasn’t done.

“We assume people can be compliant. We try to link them to resources, food, shelter and whatever smaller issues, making sure they get the medication they need.”

Testing and contact tracing go hand in hand

Testing and contact tracing are key to determining the city’s COVID-19 prevention strategies, including where, when and how to loosen shelter-in-place requirements, Hernandez explained.

Ramped up testing paired with ramped up contact tracing establishes a road map for easing sheltering.  The more people tested, the more contacts traced, the more people with or exposed to the virus are isolated, the greater the safety for the public.

“The more we can test, the more we can follow-up with contact tracing, and use these tools to limit the spread,” Chakko said.

Studies indicate that people can have COVID-19 without showing symptoms — an area of aggressive research as experts strive to better understand the virus. This is a reminder of the importance of testing even for those with mild symptoms.

This is the strategy being used globally. It’s also spelled out in Governor’s Newsom’s guidelines for relaxing sheltering, which are based on communities meeting specific goals.

One of the state’s six indicators for modifying the stay-at-home order is “the ability to monitor and protect our communities through testing, contact tracing, isolating, and supporting those who are positive or exposed.”

Berkeley is now testing any resident who exhibits symptoms. Appointments can be set up by calling the city’s test screening line at 510-981-5380, Monday through Friday, from 9 a.m. to 4 p.m. As of this posting, 1,586 Berkeley residents have been tested for the virus.

Studies indicate that people can have COVID-19 without showing symptoms – an area of aggressive research as experts strive to better understand the virus. This is a reminder of the importance of testing even for those with mild symptoms.

“Our hope is to have capacity one day to test everyone who wants to be tested,” Hernandez said. “That’s part of our goal. We know that’s one of the ways we’re going to be able to control this disease.”