With early reports suggesting Latinos in San Francisco were being disproportionately affected by COVID-19 and the Mission District having the highest number of positive cases, free testing for the coronavirus began on the morning of April 25 and continued through April 28 for residents living in the section of the neighborhood between 23rd Street to Cesar Chavez and South Van Ness to Harrison Street. 

The results are in, and they tell a tale mired in privilege and inequality. 

Over four days of testing 4,160 people, 74 were PCR (Polymerase chain reaction) positive for COVID-19, but “Hispanic or Latino/Latinx” participants overwhelmingly accounted for 95.1 percent of those positive cases for COVID-19.

“We can see very clearly even within this census tract, that ongoing active infections are not evenly distributed across the community,” said Diane Havlir, MD, chief of the Division of HIV, Infectious Diseases and Global Medicine at UCSF. “That low wage, essential workers in the Latinx community, living in crowded households are bearing the highest burden and are most affected. And this is in part driven by the challenges, for example, of doing shelter in place.”

The testing was carried out by Unidos en Salud, a partnership between San Francisco General Hospital and University of California, San Francisco (UCSF) and the Latino Task Force for COVID-19. The study aimed to screen a specific section of the community (designated by a census tract) after the Mission District’s 94110 zip code accounted for the top number of confirmed cases in San Francisco and with early reports showing that 84 percent of people hospitalized with COVID-19 at San Francisco General were Latinx. Testing relied  heavily on medical and community volunteers, with over 450 being trained and recruited. 

But trying to test everyone in the second most dense area of San Francisco didn’t come without “enormous obstacles,” including the challenges of finding a testing site, volunteers and protocols for how to handle sick patients. “Think of the paradox of this,” Havlir said. “We’ve told people to shelter in place and please stay home. And now we’re saying, ‘Oh no, please come out and test. Test in a place that we feel will be safe for you.’ People, for any disease, often don’t want to test for it when they’re feeling OK.” 

The census tract where the testing took place—according to 2018 data—noted a population that is 58 percent Latinx, and 34 percent of households earning incomes less than $50,000. 

The study was broken up into three categories—Residents and Workers (2,959), Expanded Community Residents (800) and Other (401). Of the Residents and Workers who were tested, 44.1 percent were Latinx, and 2.1 percent (62) were PCR positive. But within that same Residents and Workers category, the study showed a higher rate of PCR positive cases in people who worked in the area (6.1 percent) as opposed to those who lived there (1.4 percent). But of everyone who tested positive, 90 percent said they couldn’t work from home during shelter in place. 

“These were frontline workers, they had to work outside of the home. Either that or they were furloughed or unemployed,” Havlir said. “In other words, people who cannot sustain their income while sheltering in place, are disproportionately represented in the PCR positive cases.”

These findings, while not completely unexpected, were disturbing to District 9 Supervisor Hillary Ronen. 

“I don’t believe the study asked about immigration status, but if there is a large number of undocumented workers who aren’t eligible for state unemployment programs, they’re not getting the $1,200 check in the mail from the federal government, there really is no way of keeping food on their own plates or their families plates if they don’t take that risk and go to work,” she said.

Ronen said she will be introducing legislation that would support San Francisco residents who test positive with access to a hotel room should they not have a safe place to self quarantine, access to replacement wages and access to food and other essential items during for the 14 days of quarantine should they have no access to those items. 

Nearly everyone who tested positive has been contacted and put in touch with Clinical Response Teams and Community Wellness Teams. But the study showed that only 15 of 67 people who tested positive had a primary doctor.  

The Chan Zuckerberg Biohub did “massive and rapid” turnaround of the tested specimens. But aside from the actual testing itself, the study revealed that there is a high demand for testing. In four days, Unidos en Salud increased the City’s total COVID-19 tests by 29 percent. Before the Mission’s testing began on April 25, San Francisco had tested 14,570 people for COVID-19. 

The study also revealed that correlations between PCR positive cases and household size and income. Although—according to census data—39.3 percent of households earned less than $50,000, those households accounted for 88.9 percent of positive PCR cases. Larger households also were associated with PCR positive cases. Households with a size of 3-5 accounted for 59.6 percent of PCR positive cases, and households larger than five accounted for 28.8 percent of PCR positive cases. 

“What we have particularly here in San Francisco is a very expensive city, something that requires more laborious work, that requires more money for rent, and what we’re seeing is more people having to live together in order to survive,” said Jon Jacobo, the chair of the UCSF study committee and a member of the Latino Task Force on COVID-19. “And I think that the numbers that we saw absolutely highlight and magnify the inequities that exist within the system.”

One key question researchers looked to answer with the study regarded relying on symptoms for testing. “What we found in this study, and this is consistent with what we know about COVID-19, is that people have high viral titers before they get sick, and some people never feel sick from this disease,” Havlir said.

 Of those tested in the study, 53 percent of all PCR positive participants reported no symptoms, and of those that did report symptoms, 33 percent reported coughs, 17 percent reported muscle aches, and 11 percent reported fevers. 

“I think it’s really important when we share these results, is what we’re saying is that this positivity rate was in the people that we reached during this four-day time period. And one has to be extremely cautious about generalizing when you’re missing certain people,” said Havlir. “There’s reasons why we could have underestimated how much PCR…because PCR actually probably only detects 80-90 percent of the cases. We could have underestimated because people who are most fearful to get testing and who might be at the highest risk to be PCR positive didn’t come to get tested. On the other hand, we could have overestimated if people who were most worried and the ones who were likely to have symptoms were the ones who came to this particular testing campaign.”

A repeat study is being currently planned in the next three to six months. 

“The findings here don’t mean that the Mission is a less safe place to be in the city than anywhere else,” said Susan Philips, Director of Disease Prevention and Control from the Department of Public Health. “We consider the entire city of San Francisco to be a place where community transmission is happening. And we all need to take the precautions that we’ve been hearing about.”  

“With any disease, if one doesn’t know they’re infected, you can’t do anything. If a person knows they’re infected, the person can do something. Our community can help that person,” said Havlir. “We all wish we had a vaccine, we all wish we had treatment. But we don’t right now.”