A ninth patient has died after developing severe respiratory symptoms at a long-term-care center in New Jersey.

Eight of the nine were confirmed to have been infected with an adenovirus — a dangerous type of microbe for such patients, who are dependent on ventilators and have weakened immune systems.

The ninth death was announced Sunday by the state Department of Health. The cause of infection in the eighth death, announced Friday, remains to be identified.

All nine were in the pediatric unit of the Wanaque Center for Nursing & Rehabilitation in Haskell, Passaic County. Most were children, though at least one was a young adult; state officials have revealed minimal details to protect patient privacy. During a site visit last week, inspectors identified "hand-washing deficiencies," and state health officials have barred the center from admitting new patients until the outbreak is past.

"This is a tragic situation, and our thoughts are with the families who are grieving right now," Health Commissioner Shereef Elnahal said in a statement. "We are working every day to ensure all infection control protocols are continuously followed and closely monitoring the situation at the facility."

In all, 25 patients have been confirmed as being infected with the adenovirus. A staff member also became infected but has since recovered, the Health Department said.

All the infections occurred before Oct. 22.