About 2,600 patients at Hennepin County Medical Center are being notified that they were treated with a medical device that wasn't properly disinfected, the hospital disclosed Tuesday.

The danger to patients is "remote," the hospital said, but the discovery nonetheless prompted the manufacturer of the disinfecting equipment, Plymouth-based Minntech, to issue an urgent recall on June 17. The alert warned customers that the problem was due to a misprint in the application guide, which could result in "inadequate high-level disinfection" and potentially spread infections to patients.

The hospital said the device was "fully cleaned" with a special detergent, but that because of an error in the manufacturer's instructions, part of the device was not included in the final "disinfectant soak."

Hospital officials say all the affected patients had a "very specialized type of gastrointestinal procedure" using the device, an endoscopic ultrasound, between June 11, 2007 and May 28, 2010.

"The risk to any of our patients is remote because the scopes were thoroughly cleaned," said Kathy Wilde, the hospital's chief nursing officer, in a statement released Tuesday.

The risk, she said, is that patients could have been exposed to germs that were missed in the disinfecting process. But she said the hospital notified state and federal health officials, and based on their advice, "there was no medical need to recommend specific testing, treatment or follow-up."

The letters, which were mailed to patients Monday, state: "We do not believe that there is any significant risk related to this situation, but felt that it was important to inform you."

Wilde said the hospital discovered the problem last month when it switched to an automated cleaning system for the ultrasound endoscope, which is used to view and treat areas inside a patient's abdomen. It is not used for routine colonoscopies, she noted.

In its letters, the hospital apologized to patients and invited them to call 612-873-2223 if they have concerns.

Maura Lerner • 612-673-7384