TORONTO - A spate of C. difficile outbreaks that has struck at least eight hospitals in Ontario is "par for the course" in the province, an infectious diseases expert said Friday.

"We always have a baseline of outbreaks in the province," said Dr. Michael Gardam, medical director of infection prevention and control for the University Health Network in Toronto.

The dangerous bug can be found in every hospital and is notoriously hard to kill, so "we will continue to have outbreaks of C. difficile for a very long time," he said.

His comments came as health officials in Niagara Region announced three more deaths linked to the bug, bringing the province's toll to 20 since late May.

While outbreaks typically fly under the radar, Gardam and other observers said a public outcry against some of the hospitals struggling to contain the bacterial disease has put a spotlight on hospital-acquired infections.

Dozens of people took to the streets earlier this week to show their frustration with health care in the Niagara region following C. difficile outbreaks at centres run by the Niagara Health System.

The disease, which causes severe diarrhea, generally affects vulnerable patients who have taken antibiotics. C. difficile is typically spread in hospitals through contact with bodily fluids.

Two patients in St. Catharines and one in Niagara-on-the-Lake died Thursday night, Dr. Sue Matthews of the Niagara Health System said Friday in a conference call from Welland.

The hospital in Niagara-on-the-Lake has not declared an outbreak, she said.

Ten Ontario hospitals reported outbreaks earlier this week, but health officials Friday said it was down to eight.

Michael Hurley, president of the Ontario Council of Hospital Unions, said deaths related to infections caught in hospital are usually "swept under the rug" and handled through settlements and class-action lawsuits.

"What we're seeing now is a new phenomenon, which is demanding proactivity," said Hurley, who has led a campaign to raise awareness of hospital-acquired infections for several years.

"It's not asking for restitution, it's asking for the government, for the Niagara Health System, to deal with the problem," he said.

The organization is calling for mandatory reporting of deaths linked to C. difficile, saying it's not enough to force hospitals to track and report outbreaks of the infection.

Many patients might have chosen different hospitals had they known about deaths associated with the disease, Hurley said.

The province extended mandatory reporting of C. difficile and other hospital-acquired infections after an outbreak that caused or contributed to dozens of deaths in Ontario hospitals in 2007 and 2008.

Ontario's associate chief medical officer of health, Dr. David Williams, said determining the bug's role in a person's death is "a guessing game" since most hospital patients suffer from a number of conditions.

"If we did develop a test or technology that would definitively note that for us, then we could speak to that issue, but until then it would not be accurate" to report that deaths were directly caused by the infection, he said.

Williams previously said an outbreak could be as few as two cases in a ward, and there are regularly four to six outbreaks happening in the province's hospitals.

Though it may be impossible to wipe out the bug, Gardam said there's always more health officials and workers can do to limit its impact.

Outbreaks are "the norm for the province, but it doesn't mean I'm happy with that norm," he said. "I think we can continue to improve on our record with (C. difficile)."