The Prince George’s County Department of Corrections has reported six new cases of the coronavirus after completing 521 tests over three weeks.

As of Tuesday morning, the six inmates, who the department said were asymptomatic, had returned to the general population after completing quarantine.

Department of Corrections Director Mary Lou McDonough said she was glad to see the infections in the facility were not more widespread.

“We were not sure what to expect,” McDonough said. “We had been testing for symptoms, but once we knew the virus could be asymptomatic, we were concerned that there could be a large percentage of infections.”

The update comes more than two weeks after a federal judge ordered the county’s jail to submit plans to ensure proper testing for the coronavirus and to improve health care at the jail to protect medically vulnerable inmates. The judge intervened after activists filed a lawsuit on behalf of inmates on April 21 describing unsanitary conditions and lack of medical care at the facility.

U.S. District Judge Paula Xinis mandated that the facility improve its practices after she found subpar procedures at the jail during the height of the pandemic, specifically referencing the low total of tests during the outbreak. The judge found an outbreak at the end of March, which began in a dining room for correctional officers and spread to at least four housing units. In late May, the jail had reported 18 inmates who had tested positive for the virus, which is the same total going back to April 23, an indication that the spread had been halted.

“The significant presence of covid-19 at the facility, in combination with the scores of detainees who described experiencing distinct covid-19 symptoms (e.g. fever, chills, shortness of breath, loss of smell and taste) yet were never tested, spoke to substantial under-testing at the facility,” she wrote in the 33-page opinion on May 21.

The county appealed the judge’s injunction order on the grounds that they did not require the department to adopt any new practices. Xinis denied the request to stay the order on Wednesday.

“Defendant’s arguments regarding the overly burdensome expenditure of additional resources to memorialize a plan she claims to have crafted already lacks credulity,” the judge wrote.

Xinis had earlier credited the jail for taking steps that helped curb the spread of the coronavirus, and she noted that the jail appeared to be complying with detention center guidelines established by the federal Centers for Disease Control and Prevention.

The Prince George’s County Department of Corrections has submitted its plans to protect inmates from the spread of the coronavirus, according to Andrew Cephas, the department’s spokesman.

Katie Chamblee-Ryan, who filed the lawsuit on behalf of Prince George’s inmates, said the plans that the Department of Corrections has put forth have not translated into real changes in the jail. She urged officials to increase vigilance to ensure a second wave of infections does not sweep through the facility.

“The jail is interpreting this as a sign of their success. Unfortunately, it could just as easily be a sign of the failure to contain the virus because most people in the jail have already been infected,” Chamblee-Ryan said in an interview. “We hope the jail uses this time wisely to protect people so there will not be an outbreak in the fall.”

McDonough said the department will begin universal testing of its staff next week.