State corrections officials have temporarily halted all in-person visits at Minnesota prisons and jails due to heightened concerns over the novel coronavirus outbreak.

Although there have been no reports of COVID-19 inside U.S. penitentiaries, health experts warn it is only a matter of time before the respiratory disease spreads to the incarcerated — populations that suffer from disproportionately high rates of chronic illness.

"We have to expect that we're going to see this in our facilities," said Corrections Commissioner Paul Schnell, who is preparing for the worst-case scenario. "These prisons are petri dishes, because they're a contained environment."

For the sake of staff and inmates, Schnell said he was forced to act quickly to stave off potential infections. Volunteers will be barred from all 11 prisons until further notice and visitation is canceled for a minimum of two weeks — or until the Minnesota Department of Health advises that it's safe to resume normal operations. Until then, the state agency is exploring how to expand video visitation and increase phone privileges so prisoners can maintain communication with their families at a reduced cost.

"We recognize the importance of community connection and recreational activities," Schnell said, but "we're trying to manage spread."

Outbreaks are common in prisons and jails, where inmates share tiny cells, use toilets beside their beds and spend hours in close contact with one another. Practicing basic hygiene, like consistent hand washing, is not always easy, because inmates' movements are restricted and alcohol-based hand sanitizer is considered contraband.

In February, a strain of influenza A swept through the prison system, sickening 170 inmates around the state — as many as 70 at Lino Lakes alone.

But health officials say the flu has proved easier to control than COVID-19, which often produces such low-grade symptoms that people who are infected may pass on the virus without ever knowing they're sick. On Wednesday, the World Health Organization announced that the disease has reached pandemic proportions around the world.

"We've never seen anything like this before," said Tyler Winkelman, a primary care physician at Hennepin Healthcare who treats individuals housed at the county jail. "It's particularly dangerous in contained spaces with lots of people. … In places like prisons and jails, you can go from your first case to a very large outbreak in a relatively short amount of time."

At the Hennepin County jail, deputies have dusted off public health plans written during the earlier SARS and H1N1 outbreaks and are screening incoming inmates for signs of infection. So far, none has been identified and visitation remains unaffected. However, officials indefinitely suspended volunteers and programming inside the facility.

"At present, the public shouldn't see any big difference in the way [the jail] operates," Sheriff Dave Hutchinson said in a statement. "That said, conditions are continually changing. … We are confident in our ability to serve the public, provide appropriate medical care to the inmates in our jail, and to ensure that our staff has access to the best precautions available to avoid contracting this illness."

In St. Paul, Ramsey County Sheriff Bob Fletcher has ordered daily temperature checks on several hundred inmates and even instructed jail staff to screen visiting clergy members. Personal visits were called off Tuesday and are now conducted only through virtual monitors.

Beginning Thursday, lawyers were barred from face-to-face meetings with clients. Ramsey County Chief Public Defender Jim Fleming said he worries about whether inmates will receive adequate medical treatment if corona­virus infiltrates the facility.

"Jails are going to be a cesspool," Fleming said. "This thing could shut down the whole court system."

Even before Minnesota announced its first presumptive positive case last week, preparations were underway at area prisons to prevent the virus from creeping behind bars. Wardens scrambled to sanitize jail cells, stockpile medical supplies and develop screening practices for staff.

Since then, Schnell's executive team has met daily to weigh their options. Initial plans included educating staff and inmates on proper hygiene practices, providing extra soap and transferring some prisoners to county jails to reduce the number of double-bunked cells. The department has also canceled all out-of-state travel other than prisoner transport, suspended hands-on training exercises and waived the $5 copay for prisoners who seek medical treatment when exhibiting flu-like symptoms.

The Twin Cities Incarcerated Workers Organizing Committee, a group of activists inside and outside of prison, applauded the DOC for suspending medical copays but called on the agency to broaden that move to include free phone and video calls.

"Losing visits is like losing your world," organizers said in a statement.

The group pointed to recommendations by the Prison Policy Initiative, a Massachusetts-based public policy think tank, which calls for U.S. jail operators to release the elderly and other high-risk individuals to reduce overcrowding and ease staffing pressures.

Iran did that and more last week, temporarily releasing more than 50,000 prisoners as the virus swept the country. Meanwhile, in Italy, corrections officers have struggled to quash prison riots that erupted after administrators suspended family visits. At least six inmates broke into the prison infirmary and fatally overdosed on methadone during the unrest, while several others escaped.

Schnell intends to avoid a similar fate in Minnesota, where his staff is focused on ensuring the continued delivery of food, water and public health services to state facilities.

"Public safety is going to be paramount," he said.

The Associated Press contributed to this report.

Liz Sawyer • 612-673-4648