A Cyberattack Has Disrupted Hospitals and Health Care in Five States

A cyberattack has disrupted hospital computer systems in several states, forcing some emergency rooms to close and ambulances to be diverted, and many primary care services remained closed on Friday as security experts worked to determine the extent of the problem and resolve it.

The “data security incident” began Thursday at facilities operated by Prospect Medical Holdings, which is based in California and has hospitals and clinics there and in Texas, Connecticut, Rhode Island and Pennsylvania.

“Upon learning of this, we took our systems offline to protect them and launched an investigation with the help of third-party cybersecurity specialists,” the company said in a statement Friday. “While our investigation continues, we are focused on addressing the pressing needs of our patients as we work diligently to return to normal operations as quickly as possible.”

In Connecticut, the emergency departments at Manchester Memorial and Rockville General hospital were closed for much of Thursday and patients were diverted to other nearby medical centers.

“We have a national Prospect team working and evaluating the impact of the attack on all of the organizations,” Jillian Menzel, chief operating officer for the Eastern Connecticut Health Network, said in a statement.

Elective surgeries, outpatient appointments, blood drives and other services were suspended, and while the emergency departments reopened late Thursday, many primary care services were closed on Friday, according to the Eastern Connecticut Health Network, which runs the facilities. Patients were being contacted individually, according to the network’s website.

Similar disruptions also were reported at other facilities system-wide.

“Waterbury Hospital is following downtime procedures, including the use of paper records, until the situation is resolved,” spokeswoman Lauresha Xhihani, said in a statement. “We are working closely with IT security experts to resolve it as quickly as possible.”

In Pennsylvania, the attack affected services at facilities including the Crozer-Chester Medical Center in Upland, Taylor Hospital in Ridley Park, Delaware County Memorial Hospital in Drexel Hill and Springfield Hospital in Springfield, according the Philadelphia Inquirer.