16th Street BART Plaza. Photo by Clara-Sophia Daly.

Rapid tests might hold “promising” possibilities to prevent the spread of Covid-19, according to the lead researcher of a University of California San Francisco/Latino Task Force study conducted in late September at the 16th Street BART Station. 

During the three days of the study, technicians tested 878 people and used both the common nose-swab PCR tests and Abbott’s BinaxNOW rapid tests. 

About 93 percent of the Binax rapid tests (14 out of 15) were able to detect covid-positive people, and about 99.9 percent were able to tell whether someone did not have high amounts of the virus, professor of medicine and chief of the UCSF HIV division Dr. Diane Havlir said at a press conference on Monday.

“We need some more experience, because we don’t want to give people inaccurate results,” Havlir said. “But I think that this is promising in terms of us even going further, which is finding people as soon as they’re infected and getting them into effective isolation.”

The Binax cannot detect people with low levels of virus, which is why generally the more sensitive nose-swab PCR tests are relied on more, and why they’re called the “gold standard” for coronavirus testing. Some medical experts surmise that overreliance on rapid tests led to the Rose Garden “super-spreader” event in which President Donald Trump and multiple others contracted covid. 

Still, the Binax’s near sure-fire ability to track viral loads according to the 16th Street study data could be a good thing Havlir said. “Depending on how it is used,” Havlir said, “this actually could be helpful.”

The Binax definitely wins out on speed. Presently, all PCR tests are being processed between one to three days, according to Dr. Jim Marks at the San Francisco Department of Public Health. On the contrary, Binax tests can show results within 15 minutes. 

If procedures for administering rapid tests are ironed out, this could be key to cutting the time between a diagnosis and quarantine, Havlir said. 

Even speeding up PCR test result turnaround at the 16th Street initiative reduced the time between diagnosis and quarantine. In an attempt to shorten the time between testing and isolation, the 16th Street study knew test results had to be delivered faster than it took at the 24th Street pop-up in July. Those results came back in approximately five days. 

So, for the 16th Street study, researchers reached a deal with the Chan Zuckerberg Biohub to prioritize and process results within 24 to 48 hours. By speeding this up, the isolation period began sooner, Havlir said. This effectively eliminated two days in which the infected person might have entered society and transmitted the virus. 

Using the Binax could improve the speed even more, since it can spit out results in a quarter of an hour. 

An equally important motivation to get test results out faster is to deploy care. The test-to-community-care model engineered by community wellness teams from organizations like the Latino Task Force demonstrated that providing relief like food boxes and quarantine funds can further incentivize low-income and essential workers to stay home. 

The Right to Recover program attempted to address this back in July by giving essential workers with no paid sick leave two weeks of San Francisco minimum wage ideally within a matter of days following diagnosis. 

However, red tape around the new program caused some people to receive the money up to six weeks later, Mission Local found

“To access the money took longer, and the money ran out, and there became a waiting list,” Valerie Tulier-Laiwa, the head of the Latino Task Force, said on Monday. “And so, it basically defeated the purpose that it was intended to have.”

However, the city and the Latino Task Force have been working on “expediting the bureaucratic process” Tulier-Laiwa said. Already, the 16th Street pop-up showed that most of the people referred to Right to Recover received their paycheck within 11 days, according to the study’s data. 

It’s a great improvement, but should be whittled down even more, Diane Jones, a former UCSF HIV nurse said. 

“Eleven days, this is good,” Jones said. “But it really needs to be one day. It needs to be at the moment that you tell someone to isolate.”

Though positivity rates lately have been at record lows throughout the city and among underserved communities, the study finds Latinx locals are still disproportionately affected by the coronavirus, Havlir said. 

Of the 878 people tested at 16th Street, only 3 percent were positive and 42 percent of those were asymptomatic. 

Breaking it down by race, about 69 percent of total test takers were Latinx. Out of residents who were positive, 81 percent were Latinx, 8 percent were white, 4 percent were Asian, 4 percent Pacific Islander. Results also confirmed that essential workers continue to be at higher risk for contraction. 

More specific questions about masking and social functions were also asked during the September pop-up. About 82 percent of those who worked outside of the home wore a mask at work or during errands, 51 percent of people said they put one on during social functions and 10 percent donned one at home. 

As other UCSF studies have demonstrated, many people who test positive also use public transport. Out of all the people tested at 16th Street, about 58 percent used public transit that same day and, out of those who were positive, 56 percent reported using transit. 

“We feel like we’re really contributing to the knowledge,” Havlir said. 

Although more information is needed before deploying the rapid tests, she said, the experience will allow them to write guidance on how test takers should use and read the tests. Already local, state and out-of-state authorities are looking at the study’s results and asking advice on deploying their own rapid tests, she said. 

“I think this is another example of how our collaboration with the Latino task force is really helping,” Havlir said.

Annika Hom

Annika Hom is our inequality reporter through our partnership with Report for America. Annika was born and raised in the Bay Area. She previously interned at SF Weekly and the Boston Globe where she focused...

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