With thousands of people arrested in Chicago amid massive protests of the killing of George Floyd, new research from the University of Chicago suggests such mass detentions could lead to a spike in coronavirus cases.

More than 3,000 people have been arrested in Chicago since May 29, detained for civil unrest, disorderly conduct and looting, police said.

A study released last week from researchers Eric Reinhart and Daniel Chen suggests the surge of people being taken to Cook County Jail to await court hearings carries a tremendous risk of spreading COVID-19 back into communities.

The study found nearly 16 percent of all documented cases of COVID-19 in Chicago as of mid-April were associated with people cycling through the jail — which has been a hotbed for infections.

County officials have worked for months to reduce the jail population and contain the spread of disease. But the study suggests despite those interventions, people entering and exiting the jail even briefly can introduce COVID-19 back into their neighborhoods.

Jail cycling is a much bigger predictor of COVID-19 community spread than demographic considerations like race, poverty, public transit utilization and population density, the researchers said.

“Those people are processed through closed, tight spaces in the jail,” Reinhart said. “So even if just one of them has COVID and may not even know it, by the time they’re done processing them … they have been made into a possible risk to their communities.”

At one point, Cook County Jail had one of the highest clusters of confirmed COVID-19 infections in the country, though prisons and jails in other states have since recorded more illnesses. Sheriff Tom Dart has said the high number of positive cases was due to his office’s rigorous testing practices.

At the peak of the outbreak in the jail, more than 300 detained people were sick with coronavirus at the same time. Seven detainees and two correctional officers have died from complications related to COVID-19.

As of June 7, 36 people detained at the jail were positive for COVID-19 and 39 correctional officers had the virus.

The Sheriff’s Office pushed back on that conclusion, saying in a statement the study was “a fantasy filled with assumptions bordering on lies.”

According to the Sheriff’s Office, the study fails to take into account the precipitous drop in coronavirus infections in the jail in the past month. Nearly all new COVID-19 infections come from incoming detainees who often come from communities hit hardest by the pandemic, officials said.

But Reinhart said the risk of community transmission is separate from the jail’s improved sanitation practices and dramatic reduction in COVID cases. The hundreds of arrestees entering the jail daily could infect each other even if they are released within the day, he said.

Given the racial disparities in COVID-19 infection rates and deaths, the study points to over-policing as a contributing factor to the disproportionate burden of the pandemic on Black communities. Reinhart said the infections are just one metric of the many, often unseen effects of mass incarceration.

“The real problem is not the internal conditions of the jail. It’s the structural conditions that are producing huge numbers of unnecessary arrests and producing this risk,” Reinhart said.

Hoping to prevent the unnecessary spread of the disease, the Chicago Community Bond Fund has posted bail for more than 75 people who were detained in the past week. Many of those released participated in the wave of protests against police violence.

The nonprofit has pushed to reduce the population of the Cook County Jail since the outset of the COVID-19 pandemic.

The Bond Fund and other civil rights advocates, including the MacArthur Justice Center, contend social distancing is impossible while incarcerated. An inability to afford bail can be a death sentence for those awaiting trial, they said.

More than 75,000 people have donated more than $3.5 million to the Chicago Community Bond Fund since May 28, helping its effort to post bail for activists and to stop the spread of COVID-19. The group aims to pay bail for each person arrested at the protests.

“We consider every single one of those arrests to be a political arrest,” said program director Matt McLoughlin.

McLoughlin said the organization’s current efforts hearken back to its origins.

The fund was founded in the aftermath of the murder of 17-year-old DeSean Pittman by Chicago Police officers. Days after the police killing in 2014, Pittman’s family and friends held a vigil that was interrupted by police, who allegedly shouted racial slurs and provoked mourners. Five people attending the vigil were arrested.

Those who were arrested were incarcerated because they could not afford bail. In response, community members raised around $30,000 in four months to secure their release from jail.

The fundraising project became the Chicago Community Bond Fund in 2015.

Pascal Sabino is a Report for America corps member covering Austin, North

Lawndale and Garfield Park for Block Club Chicago. Read more of his reporting at blockclubchicago.org.