WINNIPEG -- Manitoba's only federal prison is battling a surge in COVID-19 cases within its walls.

About half of the inmates at Stony Mountain Institution have tested positive for the virus.

The 140-year-old building’s open bar set up makes containment nearly impossible, according to James Bloomfield, the prairie regional president of the Union of Canadian Correctional Officers.

"When it comes into the facility at that point, we are just trying to rapid test as fast as possible," said Bloomfield. "We do have all that within the facility, so we can get the results back in half an hour, and we isolate and test everybody."

The prison now has 340 cases among inmates, with 274 listed as recovered and 65 as active. On December 27, it is one of three federal institutions to record an inmate death due to the virus.

To try to curb the spread Correctional Services Canada has limited the movement of inmates, meaning they are stuck in their cells almost all day - a concern for prison advocates.

"Segregation and solitary confinement were the subjects of numerous court cases because of the permanent, irreparable damage that can be done to people," said Kim Pate, an Independent Ontario Senator. "We should be very much concerned." 

Bloomfield says other than isolation, there aren't many options due to it being a jail.

"We can't just bring everybody into one room and call it the COVID room. If we do that, we will end up having people killed," said Bloomfield. 

Bloomfield said correctional officers are burnt out and worried. He said 44 staff have tested positive for the virus.

Correctional Services Canada told CTV News in a statement: 

"The health and safety of our employees, offenders and the public remains our top priority during this public health pandemic. We are working closely with our public health partners, unions, and stakeholders to do everything we can to contain any spread, make decisions based on sciences and implement measures with everyone's safety in mind."

Senator Pate said federal prisons should follow the lead of provincial institutions. 

"What some provincial jurisdictions have done which is to provide releasing options and prevent people coming into the prisons in the first place and provide other safe ways for them to be held accountable in the community," she said. 

Bloomfield admitted that if the prison stayed locked down like it did during the first wave, the outbreak would not have happened.

Since the virus is already ravaging Stony Mountain, Bloomfield said all officers can do now is to keep following protocols and wait it out.

"The environment itself, we are doing our best within this," he said. "There is no playbook for this at all, and as the officers, we are going to keep it as safe as possible for the inmates."