The Cook County sheriff’s office announced Saturday that 89 detainees at the Cook County Jail have tested positive for COVID-19, an increase of 51 cases from the day before.

Additionally, 12 sheriff’s office employees have tested positive for the coronavirus.

A total of 190 inmates have been tested, the sheriff’s office said. Nine have turned out negative, while 92 are still awaiting results of the test.

The rapid spread of COVID-19 at the jail has happened in less than a week. The first two cases among inmates were announced Monday.

Later in the week, the jail’s population dropped to about 5,000, its lowest level in decades, as judges began to review bail in mostly non-violent cases in an attempt to stem the spread of the coronavirus.