An unencrypted computer hard drive containing thousands of personal and sensitive images is missing from Edmonton's Misericordia Hospital.

The 3,600 images on the hard drive were recorded between 2002 and 2010.  Covenant Health, the operator of the Misericordia Hospital, is now contacting the 233 patients believed to be affected.

"On behalf of Covenant Health, I personally want to apologize for the emotional distress this lost hard drive may cause those patients," said CEO and president Patrick Dumelie.

The hard drive was last seen on Jan. 17 when a staff member was moving offices. The loss was noticed on Jan. 28 and reported to Alberta's privacy commissioner on Feb. 3, after attempts to find the hard drive were unsuccessful.

There is no reason to believe the hard drive was stolen, Dumelie said.

Hospital staff started calling patients on the weekend and psychologists and chaplains were made available to help. About 147  patients have been contacted so far, Dumelie said.

The images were stored separately from health records. While patient names were on the images, other personal information like addresses and Alberta Health numbers were not included on the majority of the files.

Material on the missing hard drive included lab specimens, pictures of infants who died at the hospital, and information about patients who used the hyperbaric oxygen chamber.  

The information on the hard drive are copies. The originals are stored securely in the hospital.

Patients who believe their information might be on the missing hard drive can contact the hospital at 1-855-735-9900 from Monday to Friday between 3 to 8 p.m.