One of [infectious disease specialist Diane] Havlir’s motivations for the testing was to understand how the virus was being transmitted even after the city had been locked down for six weeks. Questionnaires administered with the tests gave her an answer: 90% of those who tested positive could not work from home. Most were low-income, and most lived in households with three or more people.
“What really comes out of these data is that low-wage essential workers are victims of this disease,” Havlir said. Many of those infected were working in food service, making deliveries, or cleaning offices despite shutdown orders. “These people were out working the entire time,” she said.
“Anecdotally, we knew this, but the hard data is heartbreaking,” said Susana Rojas, executive director of the Calle 24 Latino Cultural District and a leader of the Latino Task Force for Covid-19 that partnered with UCSF to run the study. “Our community was out working, keeping the city moving and fed. Of course they were more exposed and getting sick.”
The study also found that 53% of those who tested positive were asymptomatic, possibly transmitting the virus to others without realizing they had it themselves. This asymptomatic transmission is something Havlir calls the “Achilles’ heel of Covid-19 pandemic control.”
The results have led elected officials to call for changes in the city’s response to the coronavirus. San Francisco Supervisor Hillary Ronen, whose district includes the Mission, is pushing for the city to provide replacement wages, food, supplies, and hotel rooms for those who need assistance to self-quarantine.
“This study shows us that it actually takes resources to quarantine,” said Kirsten Bibbins-Domingo, a physician, epidemiologist, and vice dean of population health and health equity at UCSF who has been treating Covid-19 patients, a majority of them Latinx restaurant, delivery, custodial, and construction workers. “It speaks to the many ways risk happens in this pandemic.”