The Niagara Health System says the patient who died Wednesday had tested positive for hospital-associated C. difficile.
It's not immediately known if C. difficile is the cause of death for the patient, who is not being identified. Officials say the patient had multiple health issues.
It's the second death of a patient with the intestinal illness at the hospital since an outbreak was declared last month on Unit D.
Sue Matthews, interim president and CEO for the Niagara Health System, says the death has been reported to the coroner's office and will also be reviewed internally to determine if C. difficile played any part.
"We always have to remember that this is about a patient and a family who has lost a loved one, so our sympathies go out to that family ... especially at this time of year," Matthews said Friday.
Extra nursing and housekeeping staff have been added to help deal with the increased workload and "high burden" of dealing with C. difficile, Matthews said.
Staff are doing everything they can and the administration is supporting them, she added.
"It's always hard to lose a patient, whether to C. difficile or to anything."
The outbreak declared Dec. 8 came six weeks after another C. difficile outbreak ended.
During that outbreak, 102 people fell ill with hospital-associated C. difficile over a five-month period and 37 patients with the bug died.
C. difficile was determined to be the cause of death of seven patients and a contributing factor in another 11.
Currently, there are 20 cases of C. difficile at the hospital.