GREENVILLE, S.C. (AP) _ Officials say a rare infection at Greenville Memorial Hospital may have been a factor in the deaths of three patients.

Fifteen patients have tested positive for the infection linked to surgical equipment.

Greenville Health System medical quality director Dr. Robert Mobley Jr. said all three patients who died also suffered from other serious health conditions.

Mobley says the hospital is working to monitor the patients who have tested positive for the infection.

Officials said June 20 that 14 patients tested positive for atypical Mycobacterium abscessus. Most of them had cardiac surgery, while two had abdominal surgery and one a neurological operation.

Another case was confirmed this week. The first patient recognized with the infection tested positive in March. Six of the patients are being treated at home.