Crowded U.S. jails drove millions of COVID-19 cases, a new study says

Inmates do a deep cleaning in a cell pod to prevent the spread of COVID-19 at the San Diego County Jail on April 24, 2020. A new study says crowded jails may have contributed to millions of COVID-19 cases across the U.S.
Sandy Huffaker/Getty Images

If the U.S. had done more to reduce its incarceration rate, it could have prevented millions of COVID-19 cases.

That's the conclusion of researchers who conducted what they say is the first study to link mass incarceration rates to pandemic vulnerability. Many of those preventable cases, they add, occurred in communities of color.

The U.S. jail and prison system acts as an epidemic engine, according to the study from researchers at Northwestern University and the World Bank.

That engine is driven by a massive number of people who, despite some counties' efforts to trim jail populations, have been cycling between cramped detention facilities and their home communities.

Turn Up Your Support

MPR News helps you turn down the noise and build shared understanding. Turn up your support for this public resource and keep trusted journalism accessible to all.

How many cases could have been prevented?

After analyzing data from 1,605 counties, the researchers linked an 80 percent reduction in the U.S. jail population to a 2 percent drop in the growth rate of daily COVID-19 cases.

Such a substantial drop in the incarceration level could have been achieved by instituting alternatives to jail for non-violent offenses, according to the researchers — Dr. Eric Reinhart of the Northwestern University Feinberg School of Medicine, and Daniel Chen of the Toulouse School of Economics and the World Bank.

That 2 percent reduction is a a conservative estimate, but it still represents a dramatic potential shift, Reinhart told NPR.

When compounded daily, Reinhart said in a Northwestern news release about the study, "even just a 2 percent reduction in daily case growth rates in the U.S. from the beginning of the pandemic until now would translate to the prevention of millions of cases."

Tens of thousands of deaths could also have been prevented, he said.

A "u201cRed Tag"u201d on a cell door signifies an active COVID-19 case for its inhabitants. The first medically vulnerable inmates in the state were vaccinated at Faribault Prison on Monday, Jan. 4, 2021 in Faribault, Minn. More than half of the state's roughly 7,000 inmates have contracted COVID-19 as of Monday and nine have died of the disease. — A "u201cRed Tag"u201d on a cell door signifies an active COVID-19 case for its inhabitants. The first medically vulnerable inmates in the state were vaccinated at Faribault Prison on Jan. 4 in Faribault, Minn. More than half of the state's roughly 7,000 inmates have contracted COVID-19 as of Monday and nine have died of the disease.
Aaron Lavinsky | Star Tribune | Getty Images

Hundreds of thousands of people cycle through 'infectious disease incubators'

The U.S. has long had the world's highest incarceration rate among industrialized countries reporting such statistics. During the pandemic, it has also reported more COVID-19 cases and deaths than any other country, despite having less than 5 percent of the global population.

The new research, published Thursday in the journal JAMA Network Open, suggests those circumstances are directly related.

On average, U.S jails currently host some 650,000 detainees every day, according to Reinhart. The dynamic also includes more than 220,000 full-time jail staff, who commute back and forth from their homes each day, the study said.

Many of those detainees are held in custody for only short periods of time, as they either await trial or serve short sentences. The U.S. jail population has a 55 percent weekly turnover rate, according to the study.

"This jail churn effectively produces epidemic machines that seed outbreaks both in and beyond jails, undermining public safety for the entire country," Reinhart said.

Citing crowded conditions and poor healthcare in jails and prisons, a summary of the study from Northwestern says the U.S. facilities "have effectively become infectious disease incubators," putting the country at a higher epidemiological risk.

Minority communities suffer an outsized impact

The link between prisons and public health is one of the reasons Black and Hispanic communities have been disproportionately harmed by the coronavirus, the study's authors state.

The spread of coronavirus between jails and communities "likely accounts for a substantial proportion of the racial disparities we have seen in COVID-19 cases across the U.S.," Reinhart said.

"Ultimately, this also harms all U.S. residents regardless of race, class or partisan affiliations, as disregarding the health of marginalized people inevitably causes harm — albeit unevenly — to everyone else in a society too," he added.

The benefits of cutting the jail population would be magnified, Reinhart and Chen wrote, in counties with high proportions of Black residents, as well as in urban areas with above-average population density.

How the study was performed

The study's findings are based on data from jails that reduced their populations at rates from 20-50 percent during the pandemic in response to health risks from COVID-19.

The researchers sought to predict what the results would look like if the U.S. dropped its jail population by 80 percent, which would bring the country closer to the average rates seen in peer nations.

The study relied on data gathered at the county level from January-November of 2020, representing 72 percent of the U.S. population.