The contact tracing challenge
State’s strategy for curbing the pandemic is hampered by a surge in cases, lag in testing and results
Contact tracing — a key piece of the public health strategy for controlling the coronavirus pandemic — is straining to keep up with California’s summer spike in COVID-19 cases.
The time-tested tactic of asking the newly infected about family, friends and acquaintances they might have exposed so those people can be notified to self-quarantine and get tested is being hampered by the surge in cases across the state’s urban areas and related delays in getting timely testing and results.
Though California has reached its overall staffing goals — a statewide force of 10,000 contact tracers — and some counties such as Santa Clara have far exceeded the state’s personnel benchmark, Health and Human Services Secretary Dr. Mark Ghaly said this week that those goals didn’t assume today’s surge. “Contact tracing with this level of transmission is much, much more difficult,” Ghaly said Tuesday. “We did not build the current contact tracing program on this level of transmission.” Limited testing availability and lags in getting results are causing crucial delays in reaching the newly infected and their close contacts, adding to the number of people they may have exposed.
Even in Santa Clara County, which has amassed a contact tracing force of more than 700 — about three times the minimum recommended by the state of 15 per 100,000 people — health officials cannot say with confidence how well tracing is working.
“I don’t have an answer,” Santa Clara County Assistant Health Officer Dr. Sarah Rudman, who is overseeing the county’s contact tracing effort, flatly acknowledged when she was asked recently whether the system is proving effective against the stealthy coronavirus, which people can spread for days before they show any symptoms.
“I think it is definitely effective in the best of circumstances,” Rudman said. “But there are many moving parts to us being able to achieve those circumstances here in Santa Clara County.”
Other counties such as Alameda remain far from the state’s minimum contact tracing staffing goal. Alameda County has 93 tracers, fewer than half the roughly 250 the state has suggested are needed to have 15 for every 100,000 residents. An additional 40 have completed training.
“The recent spike in cases has made this work additionally challenging,” Alameda County spokeswoman Neetu Balram said. “But we are expanding our efforts through internal recruitment to bring more county staff on to do this work.”
“It’s spreading not because contact tracing is failing, but because people are acting like the pandemic is over.” — Perry N. Halkitis, dean of the Rutgers School of Public Health
Contra Costa County did not respond to questions Wednesday about its current staffing.
State Sen. Steve Glazer, D-Orinda, said the lack of performance data on the statewide contact tracing effort is troubling as cases surge.
“Beyond the goal that Gov. Newsom had set to train 10,000 new contact tracers, I’m not aware of any other data or any other facts that demonstrate that we’re doing it successfully,” Glazer said Wednesday.
Glazer said the state and most counties have not indicated how many people contact tracers reach within 24 hours, the amount of time that the U.S. Centers for
Disease Control and Prevention recommends in order to effectively isolate new infections and contain the spread. They also haven’t indicated how successful they are in reaching the close contacts of new cases.
And he said they haven’t provided case data being collected on the infected that can be useful in assessing public risk — were they medical staff or other workers deemed essential during the outbreak, such as grocery and food production employees? Were they avoiding going out in public or did they go to parties? Did they regularly wear masks?
“We don’t have any data to understand our circumstances,” Glazer said. “Yet without it, we can’t expect to contain the virus.”
In the Bay Area, doctors in Alameda and Santa Clara County have voiced concerns about cases and contacts not being reached by public health contact tracers and the lack of disclosure about how well tracing is working and what it reveals about outbreaks.
In Alameda County, Dr. Nicholas Moss, interim director of the public health department, said in a recent interview that while contact tracing has been used for years to control infectious diseases ranging from measles to HIV, the sheer number of COVID-19 cases has made it more of a challenge.
“It’s orders of magnitude more cases than what we’re used to, so it’s really strained our legacy systems,” Moss said.
Santa Clara County’s rapid scaling up of its contact tracing force through reassigned county employees, volunteers and a contractor has been one local success story.
But little has been made public about how effective the program has been. One Santa Clara County tracing volunteer responded Wednesday to Glazer on Twitter and described the effort as a “(expletive) show.”
Rudman said last week that Santa Clara County tracers were reaching “about 70-75% of all cases and 65% of contacts” and that “the vast majority are reached within 48 hours.” But exact figures weren’t available.
Perry N. Halkitis, dean of the Rutgers School of Public Health who is advising New Jersey on its contact tracing program, said that goals vary by disease. But for COVID-19, which spreads easily and stealthily, tracers ideally should reach three out of four cases and exposed contacts within 24 hours. Reaching them within 48 hours, he said, is “not great,” and beyond that, the effectiveness is limited.
Gonzalo Riccombeni, a Santa Clara County public health contact tracer, said he’s found people he’s reached to be cooperative and helpful but that testing availability and turnaround times for results have been a concern.
Balram said that while Alameda County is meeting its goal of testing 3,100 persons per day, “We too are experiencing increased lag time for testing results.”
Labs across the country have reported that turnaround times on tests have doubled with lags of several days and in some cases delays of more than a week. Ghaly on Tuesday announced that given the limitations, the state will be prioritizing testing for those with symptoms.
“We’d like to be able to refer everybody to a test,” Riccombeni said. “Testing is definitely to me my biggest obstacle.”
Despite the obstacles, health experts maintain that contact tracing still is the most effective tool in containing outbreaks and allowing businesses and schools to reopen and that the nation’s summer COVID-19 surge isn’t a result of tracing failures.
“It’s spreading not because contact tracing is failing,” Halkitis said, “but because people are acting like the pandemic is over.”