Two of Palm Beach County’s largest hospitals were forced to return to paper record-keeping and make other adjustments in patient care this week as a result of what their parent company labeled a “cybersecurity incident.”

A spokesperson for Tenet Healthcare said computer systems and phone lines were back in operation at Good Samaritan and St. Mary’s medical centers Wednesday night after some were down for a week.

“All services at Good Samaritan Medical Center and St. Mary’s Medical Center are available to care for our community, and core systems are restored,” spokesperson Shelly Weiss Friedberg said in a statement.

While hospital giant Tenet acknowledged that other medical centers it owns were affected, it didn’t say how many. The Dallas-based company owns 450 healthcare facilities and 65 hospitals throughout the country, including five in the county.

None of the other Tenet hospitals in the county — Delray Beach, West Boca Raton and Palm Beach Gardens medical centers — were affected, Friedberg said.

Both the company and Friedberg declined to say how the security breach occurred or detail the impacts it had on hospital operations. They didn't say whether any patient records were compromised. 

“While there was temporary disruption to a subset of acute care operations, the company’s hospitals remained operational and continued to deliver patient care safely and effectively, utilizing well-established back-up processes,” Tenet said in a statement.

 It blamed the computer and phone problems on “unauthorized activity.” It said an investigation was ongoing.