Possible hantavirus case at San Quentin prompts testing, decontamination

San Quentin Rehabilitation Center is awaiting state and federal test results after an incarcerated person showed symptoms that could be consistent with hantavirus, according to the California Department of Corrections and Rehabilitation.

CDCR said there is no confirmed case at the prison. As a precaution, the housing area where the person was held was thoroughly decontaminated, and medical staff are monitoring incarcerated people and staff for symptoms.

The San Francisco Chronicle first reported the case on June 10, 2026. ABC7 reported that the person being evaluated is a 38-year-old male inmate who was in stable condition.

What officials have said

CDCR said testing was sent to the state public health laboratory, with additional testing to be sent to the U.S. Centers for Disease Control and Prevention.

The agency has not said what specific symptoms prompted testing, when they began, or whether any rodent exposure was identified inside the prison.

San Quentin Rehabilitation Center is a large state prison in Marin County with a design capacity of 3,084 people, according to CDCR.

Why officials are being cautious

Hantavirus can cause hantavirus pulmonary syndrome, a severe and potentially deadly lung disease. The CDC says hantaviruses are spread mainly by rodents, especially through contact with urine, droppings or saliva.

The CDC says early symptoms can resemble the flu, which can make the illness difficult to identify early. In the United States, the most common hantavirus causing HPS is spread by the deer mouse.

CDC also says the Andes virus is the only hantavirus known to spread from person to person.

What happens next

Lab results from California and the CDC will determine whether the prison is dealing with a confirmed hantavirus infection or another illness.

Until then, CDCR says it will continue monitoring people in custody and staff for symptoms consistent with possible exposure.