A man incarcerated at a state prison in Lancaster and five employees at corrections facilities in Chino, Sacramento and Folsom had tested positive for the novel coronavirus as of Sunday, March 22, prison officials said.

The Lancaster case is the first to be reported among inmates in California’s prison system.

The first three confirmed cases of the virus in the prison system involved two employees at the California Institution for Men in Chino and another at California State Prison, Sacramento, officials for the California Department of Corrections and Rehabilitation wrote in a statement issued Saturday, March 21.

The agency reported Sunday that an additional employee in Sacramento, one other at Folsom State Prison, and an inmate at California State Prison, Los Angeles County in Lancaster had also contracted COVID-19.

CDCR officials noted that a San Quentin State Prison employee had previously tested positive, but ultimately was not diagnosed with the illness.

The inmate who tested positive for the virus has been in isolation since he notified staff of his symptoms on Thursday, March 19, CDCR officials said. A sample taken from him the following day was examined and returned a positive result Sunday.

Movement will be restricted at the Lancaster facility while officials attempt to determine when, where and how the inmate became infected. Those deemed at risk in light of his diagnosis will be placed under quarantine.

Officials also said that any inmates arriving at a prison’s Reception Center from county jail will be quarantined for 14 days.

The agency’s statements did not mention what jobs the infected employees held, or whether they had been in contact with the prison’s population.

Throughout the past several weeks, CDCR has made sweeping changes throughout its prison system to address the coronavirus pandemic.

On March 12, officials announced they would cancel all visitations to state prisons to prevent the spread of the disease to its inmate population and employees.

“CDCR recognizes the value of visitation in maintaining important connections with family,” spokesperson Dana Simas wrote in a news release. “However, at this time the Department must do all it can to protect the health of those who live in, work in, and visit state institutions. This measure is taken as part of CDCR’s comprehensive enhanced precautions related to COVID-19.”

The visit ban was followed by the suspension of rehabilitation programs, postponement of parole hearings until March 30, and halting all out-of-state transfers for 30 days, which officials announced on Tuesday.

Spread of the potentially lethal coronavirus among state inmate populations, who are largely housed in overcrowded facilities, has been a concern for civil rights activist groups.

In a letter sent to Gov. Gavin Newsom’s office on March 13, a coalition of advocate groups listed seven demands to protect state prison inmates from COVID-19.

Among their demands was the release of all medically fragile adults and adults over the age of 60 and the release of all people who have an anticipated release dates in 2020 and 2021 to parole supervision.

The letter was cosigned by groups such as Justice Collaborative, American Civil Liberties Union, California Public Defender’s Association and Los Angeles County Public Defenders.

“This overcrowding and unsanitary conditions will contribute to the spread of COVID-19 within California’s prison system,” the letter said. “Moreover, it threatens the public at large, as thousands of individuals and correctional, medical, and other staff interact with the incarcerated population and return to their communities.”

The prison in Chino is among many state prisons that have struggled with overcrowding in recent decades.

The facility was designed to house 2,976 inmates, according to a weekly population report released by CDCR. Currently, the Chino prison houses 3,537 inmates, 118.9 percent of its capacity, the report said.

In San Bernardino County there have been 17 confirmed cases of the coronavirus as of Sunday evening.