Coverage of the COVID-19 pandemic, criminal justice and immigration.

Note: The data in this story was compiled on April 24, 2020. Our latest numbers of COVID-19 cases in federal and state prisons are updated weekly here.

For weeks, lawyers, criminal justice reform advocates and families of the incarcerated have worried about what was happening in prisons across the nation as coronavirus began to take hold in the communities outside. Their fears seem justified.

We now can see, through data collected by The Marshall Project, that thousands of prisoners have caught the illness, and the number of cases has grown more than threefold in the last week alone. Thousands more workers, correctional officers and medical staff have been sickened. And more than 140 people—most of them incarcerated—have died thus far.

There have been at least 9,437 cases of coronavirus reported among prisoners. Each represents 10 new cases Source: State and federal prison agencies

For the past month, The Marshall Project has collected data from prison systems in all 50 states and the federal Bureau of Prisons to track how the virus has spread and how prisoners and corrections workers are succumbing to it.

By Wednesday of this week, at least 9,437 people in prison had tested positive for the illness. The number of new cases among prisoners is more than doubling each week, showing that the curve used to measure when the virus is under control is still soaring in prisons even as some parts of the country are starting to flatten the curve through social distancing.

As startling as these figures are, they are almost certainly an undercount. While most prison systems are releasing information about the number of positive tests and prisoner deaths in their facilities, far less is known about how many people are being tested. Sixteen prison systems are not releasing information about how many prisoners they are testing, including the Federal Bureau of Prisons, which has seen several major outbreaks of coronavirus in its institutions. Of the rest, only eight systems had tested more than 400 of the people in their custody by this week.

In many communities there have been efforts to bail people out of local jails—or to avoid arrests or bail decisions that would land people in jail in the first place. Similarly, several states have announced plans to release people early from prisons, where people are sentenced for more serious crimes for years or even a lifetime. But little is known about how many people have actually returned to life outside as a result of the policies prompted by the pandemic. Of those who have been released, we don’t know whether they’ve been tested before they left prison.

Indeed, much of the remarkable growth in coronavirus cases in the last several weeks is due to a small handful of states—Ohio, Tennessee, Arkansas, Michigan, North Carolina among them—that have begun aggressively testing nearly everyone at prisons where people have become sick. This new spate of testing would suggest that coronavirus has been circulating in prisons in much greater numbers than known in past weeks, and that in the many states where tests have not been prevalent, far more people may be carrying it than are being reported.

Not all states are testing their prisoners as rapidly. While Ohio has tested more than 5,000 people in its state prisons, Arizona, with a prison population similar to Ohio’s, had tested just 172 people by Wednesday.

The patchwork of testing across the country is inevitable, said Nancy La Vigne, the vice president of justice policy at the Urban Institute.

“It’s hard to attribute the level of testing—whether sufficient or lacking—solely to the prison system. It’s also about the context of the state government and the governors,” La Vigne said. “Some states don’t have the resources to purchase enough tests, or they don't make it a priority that the tests get into the prisons.”

Epidemiologists and public health experts suggest that given the uneven amount of testing happening within our nation’s prisons, a better way to gauge the spread of the virus is by examining the number of people who have been killed by COVID-19. Such deaths are less likely to go unnoticed than people who are asymptomatic and thus have not been tested.

The first prisoner known to have died of coronavirus was Anthony Cheek, who died in Georgia on March 26. Cheek, who was 49 years old, had been held in Lee State Prison near Albany, a hotspot for the disease. Since Cheek’s death, at least 130 other prisoners have died of coronavirus-related causes.

There have been at least 131 deaths from coronavirus reported among prisoners. Each represents one new death Source: State and federal prison agencies

The first cases of COVID-19 among prisoners were diagnosed in Georgia and Massachusetts on March 20. By that point, two months after the first reported case in the country, states were beginning to institute orders for people to remain in their homes and distance themselves from their friends and neighbors.

The Marshall Project compared the spread of coronavirus among prisoners to the nation as a whole. In the first weeks that COVID-19 made its way into prisons, the infection rate lagged well behind the country overall. In the past two weeks, that has changed dramatically. The prison infection rate now eclipses the spread among the general population by more than 150 percent.

The week of April 22, the estimated rate of infection among prisoners more than tripled from the previous week. A small handful of states began aggressively testing nearly everyone at prisons where people have become sick. In prisons across the country, there were an estimated 696 confirmed cases per 100,000 prisoners the week of April 22. Among the overall U.S. population, there were about 250 confirmed cases per 100,000 people on April 22. Note: Estimates of the U.S. rate of infection use case counts from The COVID Tracking Project , which are reported on a daily basis. The Marshall Project's estimate of the rate of infection among people in prison uses reported cases collected on a weekly basis and prison population figures from the corrections agencies.

Part of this difference may be explained by the recent burst in testing in key states. We know there are many more cases now in Ohio and Tennessee because they’ve tested more people. But it could be because infection spreads differently in a prison than in a community where people freely move from room-to-room of their homes, from work to school to the store and back, interacting with whomever they please. It also appears that the mortality rate in prisons, at least thus far, is lower than in the greater population.

While we know considerably more about how many prisoners are getting sick, another group of people is at risk in these facilities: correctional officers and other workers. We know even less about how the virus is affecting them, though they have the potential to carry the virus both into facilities and back into their communities. It’s difficult to assess how prison workers are being affected because many aren’t being systematically tested.

Only five states—Idaho, New Mexico, Pennsylvania, Texas, Wyoming—are releasing information on the number of staff members tested for coronavirus. Where we do know about positive cases, most state corrections departments stress the numbers count only the staff members who voluntarily report a diagnosis, often in the course of calling out sick.

While nearly 4,000 prison staff members have tested positive, only 13 deaths have been publicly reported. Because we know so little about how many staff are tested, and in many states it’s not clear how many people are working in prisons right now, it’s impossible to say if their mortality rate is lower than would be expected.

There have been at least 3,950 cases of coronavirus reported among prison staff. Each represents 10 new cases There have been at least 13 deaths from coronavirus reported among prison staff. Each represents one new death

However, our data show prisoners who are diagnosed with COVID-19 are dying four times as often as prison staff who test positive. The different death rates may be attributed to the difference in the age distributions among prison staff and those they guard, said David Rosen, a professor of medicine at the University of North Carolina at Chapel Hill.

“In the incarcerated population, there is a bulk of people who are young, then you have a tail-end of people who are older, who are just at more risk of mortality,” said Rosen, who studies infectious diseases in the prison system. “There are greater percentages of correctional officers in their 40s than the incarcerated population. But I don’t imagine you’ll have officers who are older than 65."

The availability of testing inside and outside of prison walls may also make a huge difference in the mortality rate, Rosen said. Correctional officers, who are essential workers, may get more access to COVID-19 tests at earlier stages of their illness, which means they are also more likely to get timely treatment. Prisoners, Rosen said, may only get tested when they are at later stages of COVID-19, when they are much sicker.

In collecting this data, it’s clear there is still more we need to know to understand this pandemic in our prisons. In the weeks ahead, The Marshall Project will continue to track data on coronavirus and assess its effects in our prison systems.