Medical-data breach said to be major

A computer flash drive containing the names, addresses, and personal health information of 280,000 people is missing - one of the largest recent security breaches of personal health data in the nation.

"We deeply regret this unfortunate incident," said Jay Feldstein, the president of the two affiliated Philadelphia companies, Keystone Mercy Health Plan and AmeriHealth Mercy Health Plan.

The breach, which involves the records of Medicaid recipients, is the first such Medicaid data breach in Pennsylvania since at least 1997, according to the state's Department of Welfare, which has oversight.