Overcrowding, poor ventilation and outdated infrastructure accelerate the spread of COVID-19 in California state prisons, according to a UC Berkeley and UCSF report.

The report is part of the California Prison Roadmap for Targeting Efforts to Address the Ecosystem of COVID Transmission, or CalPROTECT, project by Amend at UCSF, a joint UCSF and UC Berkeley initiative. With a multidisciplinary team of researchers ranging from epidemiology to public policy, CalPROTECT conducted site visits to 10 state prisons and analyzed data from the California Department of Corrections and Rehabilitation, or CDCR, and California Correctional Health Care Services, or CCHCS.

“Prison settings are essentially super spreading environments that incarcerated people are living in and staff are working in,” said UCSF postdoctoral scholar Ada Kwan, a co-director of the report. “These settings have higher rates — up to 14-fold the case rate of the state populations.”

Due to these unique settings, prisons must take a “multi-layered” approach that includes improving ventilation and depopulating, according to Kwan. UCSF professor of infectious diseases David Sears, a co-director of this report, emphasized that all COVID-19 prevention strategies, such as masking and vaccinations, are “infinitely” more difficult in prisons as people are constantly around others and may not trust healthcare providers — a consequence of incarceration itself.

Sears said CDCR attempted to address crowding earlier in the pandemic by halting intake from county jails and releasing a few thousand people two to three months earlier than scheduled. However, he alleged these actions were short-term and left vulnerable people in jail.

“That did help some of the crowding and population reduction in state prisons, but did very little and left people in overcrowded county jails instead,” Sears said. “After those three months of releases, there was a decrease in releases, so it kind of made an impact but only for a couple months.”

Moreover, there is “incredible heterogeneity” among prisons, according to campus professor of public health Sandra McCoy. While some prisons are modern, others date back to the San Quentin era, which opened in the summer of 1852.

Incarcerated individuals may live in cells that house one to three people or dormitories with hundreds of occupants in the same room, McCoy added.

“The efficiency that the virus spreads depends on the number of people breathing the same air,” McCoy said. “In California and across the country during the pandemic, prisons were often hotbeds of COVID-19 spread because too many people were living in a congregate setting.”

The report also recommended prioritizing rapid antigen testing over PCR testing since they are more effective for isolating residents as early as possible, according to campus doctoral candidate Robert Schell.

For McCoy and Sears, this is an urgent call for decarceration.

“We incarcerate more people per capita in the world, and there’s so many significant health, societal, and economic impacts from that,” Sears said. “COVID-19 has, in a tragic way, brought that to attention.”