CHICAGO (CBS) — The number of confirmed cases of coronavirus inside Cook County Jail has exploded in the past week, with 51 new cases among detainees, and three more cases among sheriff’s employees as of Saturday.

The cases among inmates more than doubled in one day. There were 38 cases as of Friday.

The Cook County Sheriff’s Office said a total of 190 inmates have been tested so far for COVID-19, and 89 have tested positive. Nine have tested negative, and 92 are awaiting test results.

“Cermak staff are closely monitoring the detainees on the living units where these individuals were housed and will test any detainees who are symptomatic,” the sheriff’s office said in a statement.

In addition, a total of 12 sheriff’s employees have tested positive for the virus.

The first reported case at the jail, a correctional officer, was confirmed on Sunday.

Cook County Sheriff Tom Dart said Friday there are currently about 5,000 inmates being held within the walls of the jail, the lowest population it’s ever had. He said will allow the jail to have every inmate in a cell of his or her own within the next couple days, except for inmates who face mental health issues that require them to have a cellmate for therapeutic reasons, or to reduce the risk of suicide.

Dart also recently reopened a shuttered barracks facility used for an old boot camp program, so it can be used as a hospital for inmates who test positive for COVID-19, or as an isolation facility for others who are being quarantined.

“This is beyond complicated,” Dart said. “This is a very complicated puzzle.”