COVID-19 infections at two federal prisons in Minnesota are rising, with nearly half the inmates at one facility testing positive for the disease, raising concerns the virus could spread beyond prison walls.

Nearly 300 of the 600 inmates at the women’s prison in Waseca have contracted the virus, most in the past few weeks. Nine staff members also have tested positive.

“People are scared,” said Ryan Burk, president of the union that represents 150 prison staffers. “The concern is that we’re going to bring it home to our families, our parents and to the community.”

The prison reported its first three COVID-19 cases among inmates in July but had no new cases until a busload of new prisoners arrived in late August, Burk said.

Daily numbers released Thursday by the federal Bureau of Prisons showed 187 inmates and two staffers at Waseca currently have COVID-19. The data also showed 108 inmates and seven staff members have recovered from the illness.

Jails and prisons are the likely sources of 1,063 of the state’s 93,012 lab-confirmed infections with the novel coronavirus that causes COVID-19. The state’s COVID-19 death toll as of Thursday was 1,988.

While there are some hopeful signs amid the pandemic, including a positivity rate of diagnostic testing that is below the 5% threshold that signifies broad spread of the virus, state health officials are concerned about individual hot spots such as Waseca leading to another statewide wave of cases.

Waseca County has had one of the nation’s fastest-growing surges of COVID-19 over the past month, in part because of the prison numbers. The number of lab-confirmed infections increased from 127 on Aug. 1 to 612 by Thursday. All eight COVID-19 deaths in the county have been reported since Aug. 1.

The Waseca public school district switched to distance learning for grades 7-12 on Sept. 14 after 70 students were exposed to the virus, said superintendent Eric Hudspith. Four students tested positive, he said, adding that community cases were ticking up before the prison outbreak.

County-level data released Thursday showed a rate in Waseca of 85 new infections per 10,000 people over the 14-day period ending Sept. 12 — well above the state threshold of 50 by which it recommends distance learning for all K-12 students.

Meanwhile, viral infections at the federal prison in Sandstone, Minn., also have spiked.

Federal officials reported Thursday that the prison had 95 active infections among the nearly 1,000 men housed there. Nine inmates had recovered, and no staff infections were reported by the bureau.

The number of cases in Sandstone has grown “exponentially” in the past three weeks, said Sandra Freeman, who represents an inmate there.

By Sept. 10, six inmates had been infected, said Freeman, who has been tracking the published numbers from the Bureau of Prisons. Less than a week later, that number jumped to 51, she said.

With infections increasing, Freeman recently filed a motion in federal court asking that her client, Michael Markus, be released to home confinement because underlying health conditions make him more vulnerable to the virus.

Markus, who was arrested during the 2016 Standing Rock pipeline protests and has seven months remaining of his 36-month-sentence, is also asking the court to reduce his sentence to time served.

Freeman said Markus reported having a fever in August and was told to take Tylenol. He was not tested for COVID-19, she said. Freeman said she and her client believe the number of cases in the prison likely is underreported because not everyone is being tested.

“They’re remaining willfully ignorant in order to not make the numbers look bad,” she said. She added that it appears the prison is not following protocol set by the CDC or the protocols the bureau said it’s using.

In a written statement, the Bureau of Prisons said it carefully monitors COVID-19 in its facilities and implements measures to mitigate spread.

“The BOP follows CDC guidance the same as community doctors and hospitals with regard to quarantine and isolation procedures, along with providing appropriate treatment,” the statement said.

Meanwhile, until a few weeks ago, the federal prison in Waseca seemed to be succeeding at keeping the number of COVID-19 cases to single digits. But then the virus spread like “wildfire,” Burk said, after 22 inmates arrived by bus in late August.

Those inmates came from county jails or other facilities that may not follow the same COVID-19 protocols that federal prisons use in moving prisoners, he said. For example, before federal prisoners are moved, inmates are quarantined and tested for COVID-19, Burk said, and contact with prison staff is limited.

“We had zero cases [in August] until we received that shipment of inmates,” Burk said. “We can’t just lock the door to the facility and say we’re no longer accepting more inmates.”

As a precaution, the newly arrived inmates were isolated from the general population, he said. Eventually, most of them tested positive for the virus. Within 10 days, it began spreading through the prison population.

“Unfortunately, this stuff spreads through the air,” Burk said. “I’ve talked to the warden and all we can do is find the best way to manage it.

“The genie is out of bottle. It’s just a bad situation. I hope the staff doesn’t bring it into the community.”

State health officials are keeping tabs on the outbreaks.

“There’s always concern when we see numbers continuing to increase,” said Jennifer Zipprich,, an epidemiologist at the Minnesota Department of Health, which has contacted the medical staff at both prisons.

“Continued diligence is needed to keep COVID at bay,” she said. “COVID can be challenging and unpredictable.”