In the year since Quebec has been tracking cases of Clostridium difficile, about 8% of those infected, or 409 people, died.
Quebec Health Minister Philippe Couillard and Dr. Alain Poirier, the province's director of public health, released the statistics at a provincial health conference in Montréal in October.
The province's preliminary statistics recorded 8673 cases of C. difficile from August 2004 to August 2005. The vast majority, 73% of patients, acquired the bacteria during hospital stays.
An examination of 5113 cases indicated a death rate, on average, of 8%, or 409 people. C. difficile was the principal cause of death in 3.2% of the cases and a contributive cause in the remainder, says Rodica Gilca, an infectious disease specialist with the province's Public Health Institute.
Quebec's official figures and mortality rate contrast with what Dr. Jacques Pépin, an infectious disease specialist, tracked at the Centre Hospitalier Universitaire de Sherbrooke from 2003 to 2004. In a cohort study, Pépin found a cumulative 1-year mortality rate of 16.7% at the height of the outbreak. He estimated that about 2000 people died across Quebec during that period, a number that Poirier disputes (CMAJ 2005;173:1037-41). The province does not have official figures for that period, however, because it didn't begin tracking the infection until August 2004.
Quebec has made “significant” progress in stabilizing the infection, Couillard told reporters at the conference.
“If you ask other provinces or other countries, they cannot tell you how many cases they have because they don't measure it, but they know they have a lot,” Couillard said. “We know exactly how many we have from month to month to month.”
But Gilca says it's premature to quantify Quebec's progress in reducing infections because the disease has important seasonal variations, and the province has only 1 year of surveillance figures to examine.
“At this point we are able only to compare our data with the data predicted by [a] model,” says Gilca. Incidence rates fell by 30%–40% from March to August this year — more than the seasonal rate predicted by the model — but it's too soon to say whether that decline will continue.
“We see an important trend of dropping incidence rates, but we can't quantify it because we have no comparison period,” she says.
“Starting the second year we will be able to compare our incidence rates.”
But Dr. Vivian Loo of the McGill University Health Centre said the institution still has an incidence rate of about twice its baseline target of C. difficile cases (6–8 per 1000 admissions).
“We do have an overall trend that this year, and even the last fiscal year was lower than the previous fiscal year by 50%, says Loo, the chief of microbiology. “We're waiting to see what happens over the next coming months. We're still vigilant.”