At least 2,300 people died in 2006 as a result of an MRSA superbug and nearly 12,000 new patients were infected, as rates of the antibiotic-resistant bacteria continue to climb in Canadian hospitals, according to figures released by the federal government.

Methicillin-resistant Staphylococcus aureus bacteria, magnified nearly 10,000 times by an electron microscope.
(Canadian Press)

A national surveillance program using data from 48 hospitals in nine provinces found 5,787 new cases of infection by methicillin-resistant Staphylococcus aureus bacteria in 2006, a 2.7-per-cent increase over 2005 figures, which translates into 8.04 cases per 1,000 hospital admissions.

Dr. Andrew Simor, who co-chaired the surveillance program, extrapolated those figures to estimate the number of MRSA-related deaths in Canadian hospitals.

As well, he calculated there were 29,000 new patients carrying MRSA bacteria in 2006, of whom 11,700 had new infections.

Hospitals main source of infections

Of the cases recorded from the nine provinces, 62 per cent were thought to have been acquired in network hospitals and seven per cent in other acute care hospitals.

But 15 per cent were believed to be community-acquired, a rate that has doubled in Canada over the last five years, Simor said.

The remaining cases would have been acquired in long-term care facilities, hospitals outside the network or were of unknown origin. They accounted for seven per cent of cases.

MRSA usually causes only mild infections, but can progress to large boils, hemorrhagic pneumonia or flesh-eating disease in rare cases. It rarely affects healthy people and is most often seen in hospitals and nursing homes, where it is considered a problem because it is resistant to the antibiotics penicillin and methicillin.

It must be treated with vancomycin, an antibiotic that is only used as a last resort because it is extremely irritating to human tissue.

Infection rate slower than in U.S.

Simor said the 2006 figures show a slow and steady increase over previous years.

"I think it's a mixed story. There's good news and there's bad news," Simor, chief microbiologist at Toronto's Sunnybrook Health Sciences Centre, told the Canadian Press.

"The good news is our rates remain substantially less than what is seen in the United States and many other parts of the world. No question about that — that's good news.

"The bad news is despite our best efforts, we've not yet been able to control the spread of MRSA in our hospitals, and there is a continued and steady increase that has taken place, albeit at a slower rate than is seen south of the border. Nonetheless, this is of concern."

Dr. Donald Low, head of the department of microbiology at Mount Sinai Hospital in Toronto, said the results are not surprising.

"We've expected that because we've seen what's happened in the United States over the last five to 10 years where it's really gotten out of control," Low told CBC News.

Low said people in hospital are sicker as opposed to 10 to 15 years ago when patients had milder illnesses and were in hospital for longer periods of time, allowing them to recuperate.

"The density of sick patients in hospitals has increased quite dramatically, so that's one of the major reasons for such an increase," Low said.

With files from the Canadian Press