The breach at Jefferson is part of a national problem, experts say.
A federal database has documented 121 such lapses nationwide since September 2009, showing that medical or financial information had been exposed for more than 5 million people.
"There is almost no excuse for unencrypted data to be sitting on any computer at a hospital or any organization," said Scot Silverstein, a Drexel University expert on health information technology.
Such problems heighten the concern many people have about the move toward electronic health records.
Perhaps as a result, the U.S. Department of Health and Human Services has increased penalties for violations of patient privacy, including fines for up to $50,000 per violation and up to $1.5 million a year.
Still, such breaches occur every week.
A similar loss of private patient information occurred in December at Children's Hospital of Philadelphia when an employee's laptop with data including Social Security numbers on 943 patients was stolen from a car.
On Tuesday, Cooper University Hospital in Camden reported that a flash drive with Social Security numbers, addresses and phone numbers of medical residents and fellows was missing.
"The hospital is conducting a thorough investigation and has initiated an aggressive plan to protect any personnel who could be affected by this potential security breach," Cooper said in a statement.
Meanwhile, a nurse accessed records of 600 patients at Tomah Memorial Hospital in Wisconsin to get narcotics data for personal use, and 1.2 million patient records were stolen on a laptop owned by a Florida health insurer, AvMed Inc.
"We are seeing this all the time," said Paul Stephens, director of policy and advocacy at the California-based Privacy Rights Clearinghouse.
