SALEM, Ore. — An inmate at Oregon's maximum security State Penitentiary has died after testing positive for the new coronavirus, according to the Oregon Department of Corrections (DOC).

The unidentified man was between the ages of 50 and 60 years old and died on May 20. His next of kin has been notified.

"As with all in-custody deaths, the Oregon State Police have been notified and the Medical Examiner will determine cause of death," the DOC said in a statement.

According to the agency, 38 DOC employees and 148 inmates have tested positive for COVID-19 throughout the state since the outbreak began. The vast majority of those cases — both for inmates and staff — has been at the Oregon State Penitentiary. Almost 2,000 inmates of the prison have been quarantined as a result, and 45 placed in medical isolation.

"Medical isolation refers to confining a confirmed or suspected COVID-19 case," the DOC says. "Ideally, to a single cell with solid walls and a solid door that closes, to prevent contact with others and to reduce the risk of transmission."

The DOC says that its institutions are cleaned numerous times a day, and inmates are encouraged to wash their hands frequently.

Last week the agency reported a lockdown at the State Penitentiary after fights broke out in the yard, prompting one of the tower officers to fire "a warning shot." There were only minor injuries to inmates reported, but prison staff halted phone calls for inmates "until normal operations return."

In early April, the Associated Press reported that a group of inmates concerned about contracting the coronavirus filed a lawsuit against Governor Kate Brown and leaders at the DOC, alleging that they had not taken the necessary steps to slow the spread of COVID-19 at state correctional institutions.