Clostridium difficile-associated diarrhoea rates and global antibiotic consumption in five Quebec institutions from 2001 to 2004.

A massive outbreak of a new Clostridium difficile clone affected the province of Quebec between 2002 and 2004. There are several theories as to the exact cause of the emergence of this new clone, including the overuse of some classes of antibiotics. Antibiotic prescription is associated with C. difficile-associated diarrhoea (CDAD), but which class has the highest risk is still the subject of debate. We analysed the global antibiotic consumption patterns in five institutions in Quebec, three in the area affected by the 2002-2004 CDAD outbreak and two in non-affected areas. We showed that there is no correlation between the type and amount of antibiotics used at the institution level and the magnitude of the outbreak. Deficient infection control measures likely led to the rapid spread and dissemination of this newly characterised clone within some parts of Quebec.