Thousands of Texas prisoners still have the coronavirus. More than 25% of inmates at four units are infected.

Two Texas prisons each have more than 670 inmates with active coronavirus infections, according to the Texas Department of Criminal Justice, the highest counts seen at any state lockup since the pandemic began.

As of Monday, 672 men incarcerated at the Stiles Unit near Beaumont had active infections — a quarter of the lockup’s population, according to the most recent figures. At the massive Coffield Unit in East Texas, 753 inmates recently tested positive — 19% of prisoners there, according to TDCJ data.

Aside from Stiles, three other state-run prisons and jails had at least 25% of their inmates with active coronavirus infections Monday. Dominguez State Jail in San Antonio had 472 inmates with the virus. The Daniel Unit in Snyder and the Hamilton Unit in Bryan each had about 250 cases.

The new high infection counts at several prisons indicates the virus is still very active inside TDCJ. And although some of the hardest-hit prisons in May and June are now reporting very few active cases, their inmates also haven’t been tested recently on a large scale.

Since March, more than 12,000 Texas prisoners and 2,100 TDCJ employees at dozens of prisons have had confirmed infections of the new coronavirus. At least 94 inmates have died with the virus — the most of any state prison system in America — along with 10 people who worked in Texas prisons.

The jump in positive cases at some units follows a new round of mass testing at some prisons. TDCJ began testing all inmates at dozens of units in mid-May, with more than 100,000 coronavirus tests on inmates completed by June 10, according to agency reports. The tests led to a sharp increase in reported cases of the virus, followed by a period of fewer active cases reported after the first round of testing was finished.

The Michael Unit, next to Coffield prison in Anderson County, reported zero inmates with active cases of the virus Monday, with 429 men having recovered from it. But TDCJ only tested all of the inmates at the prison once, on May 13, according to TDCJ testing data provided to The Texas Tribune on Monday.

A Texas epidemiologist said one-time testing sweeps provide snapshots but don’t tell the full picture of how the virus is affecting the prison system.

“You get these windows … but if you don’t follow up to see if it’s grown or decreased, you’re kind of just playing out those cases you had at that time,” said Ben King, a clinical assistant professor of public health at the University of Texas at Austin. “It’s kind of like turning on the lights for just a second.”

Aside from mass testing, TDCJ also tests symptomatic inmates for the coronavirus — though prisoners say not everyone who reports symptoms is tested. Mass testing is done to capture those without symptoms who can still spread the illness, a group King said could account for a large percentage of those infected.

TDCJ spokesperson Jeremy Desel said Monday that most of the recent reported upticks in positive tests at places like Stiles and Dominguez are because of asymptomatic inmates. He added that some inmates the agency reports as actively infected are also likely no longer contagious because TDCJ’s process to medically clear inmates and count them as recovered is more stringent than the guidelines issued by the U.S. Centers for Disease Control and Prevention.

The CDC advises that those who test positive for the coronavirus be isolated until they have been fever-free for at least three days and at least 10 days have passed since symptoms first appeared, or since the date of the positive test if the person is asymptomatic. Desel said by the CDC’s definition, all of the asymptomatic inmates at Dominguez would now be considered recovered, since their mass testing was completed June 26.

“Under the CDC guidelines, they should be considered recovered, but they’re not because our protocols suggest they need to be signed off on by … a medical provider at the facility,” Desel said. “Sometimes that takes longer than six weeks in some cases just because of the mass numbers.”

The recent surges at Coffield, Stiles and Dominguez make them the three Texas prison units with the most reported inmate coronavirus cases, with almost all of them counted by TDCJ as actively infected.

Estelle, Michael, Jester III and the Pack Unit all have more than 400 inmates each who have tested positive as well, though the majority of their cases are counted as recovered.

At Pack, a geriatric prison near College Station, attorneys told a federal judge Monday that 487 inmates have been infected in the pandemic and 19 men have died from the virus. It was the first day of a trial over TDCJ’s handling of the pandemic after two older inmates filed a lawsuit at the unit in late March arguing for protective gear and more cleaning supplies.

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