An inmate at Moose Lake prison and a corrections officer at the Red Wing juvenile facility each tested positive for COVID-19 over the weekend, marking the first signs of an outbreak behind bars in Minnesota.

The inmate remains in isolation alongside three other prisoners he had close contact with in recent days, while the officer is recovering at home. Both infections have produced mild symptoms and don't require hospitalization.

In an e-mail to employees Sunday evening, Corrections Commissioner Paul Schnell said an unidentified staff member tested positive for the respiratory disease. He explained that they had developed a fever outside of work and sought medical attention. Although three colleagues and three minors who closely interacted with the officer are not exhibiting symptoms, they are all on a 14-day quarantine.

Early Monday morning, he announced that an inmate at another facility 2½ hours north also tested positive.

"We fully expect to see more confirmed cases among both staff and the people we serve," Schnell wrote. "We are working with the Department of Health to conduct contact tracing for this case and make sure we are mitigating the risk of exposure in the facility — especially for those people who are medically most at risk."

So far, the department has tested 22 prisoners across the state who have fallen ill with flu-like symptoms; 17 of those came back negative, while four others are awaiting results.

Moose Lake Warden William Bolin placed the unit where infected inmate lived on indefinite lockdown pending further instructions from medical professionals, according to an e-mail obtained by the Star Tribune.

The development comes nearly three weeks after Schnell closed all 11 Minnesota prisons to visitors to try and protect inmates and workers from the virus.

Since then, the state agency has scrambled to sanitize jail cells, stockpile medical supplies and develop daily screening practices for staff.

Schnell's executive team has met daily to outline mitigation measures, such as providing extra soap and transferring some prisoners to county jails to reduce the number of double-bunked cells. The department also waived the $5 copay for prisoners who seek medical treatment, granted inmates two free 5-minute phone calls per week and, starting Wednesday, will offer free 15-minute video chats to help maintain communication with their families.

As local jails move to release dozens of nonviolent inmates — especially those held before trial — pressure has been mounting for Schnell to follow suit. Criminal justice advocates have peppered Schnell's office with phone calls and demonstrated in front of the governor's residence in St. Paul. They see this as a potential life-or-death issue for individuals with chronic health issues trapped inside historically unhygienic facilities.

The Legal Rights Center believes the issue is particularly imperative for incarcerated juveniles and is leading the effort to discharge hundreds of youths to caregivers who can provide a safe home during the pandemic.

"Imagine being a kid … in recent close proximity to someone with the disease" and only having limited contact with loved ones, said Michael Friedman, the organization's executive director. "Isolating children from the parents/guardians is cruel and developmentally inappropriate."