For weeks, as the coronavirus spread through the Cook County jail and state prisons, Chicago’s downtown federal lockup continued to report no cases of the virus among its detainees.

That’s changed.

Six inmates in Chicago’s Metropolitan Correctional Center have now tested positive for the coronavirus, according to John Murphy, executive director of the Federal Defender Program in the Northern District of Illinois. That’s a sharp uptick from Tuesday, when the Federal Bureau of Prisons confirmed one inmate had tested positive for the first time.

It could also lead to renewed scrutiny about who is held there. Before the first positive test, Chicago’s federal judges did not appear inclined to release inmates for fear of the virus alone. But Wednesday afternoon, defense attorneys began making new bids for release on behalf of individual clients, citing the new number.

“Once it gets started it seems to accelerate fairly quickly,” Murphy said of the virus in an interview.

In its daily tally of coronavirus cases Wednesday, the BOP reported just one inmate with coronavirus at the MCC. It also said eight staff members there had tested positive. Officials have said at least seven of those staff members have had limited contact with inmates.

The most high-profile defendant held at the MCC is R&B singer R. Kelly, who faces child pornography and obstruction of justice charges in Chicago, as well as a racketeering indictment in Brooklyn. The judge presiding over Kelly’s case in Brooklyn already denied Kelly’s bid to get out of jail for fear of the coronavirus.

The first positive test of an MCC inmate was revealed in a filing by a federal prosecutor Tuesday. Assistant U.S. Attorney Sean Franzblau wrote that the person had been housed on a floor with other inmates who had already been sentenced and designated to other federal facilities. Franzblau wrote that the person who tested positive did not have any contact with inmates who had yet to be sentenced.

Defense attorney Holly Blaine wrote in a motion for release in a separate case Wednesday that “one inmate was reported to be in precarious shape, while the others were described as ‘recovering.’” In yet another case, attorney Damon Cheronis filed a motion that said the six inmates who tested positive “were previously housed on three separate floors of the facility.”

“It is no longer a question of when COVID-19 will infect the inmate population at the MCC, but how bad it will be,” Blaine wrote.