Introduction

Abstract

The anaerobic bacterium Clostridium difficile is a major nosocomial pathogen, the most commonly diagnosed cause of infectious hospital diarrhoea. There is now evidence that C. difficile is also causing diarrhoea in the community, both as a result of exposure to hospitals and de novo. The clinical spectrum of cases presenting with C. difficile disease can be wide, ranging from asymptomatic carriage, to mild self-limiting diarrhoea, and more severe pseudo-membranous colitis. Antimicrobial exposure remains the most significant risk-factor for acquiring C. difficile. There is great concern worldwide following the recent emergence in Canada, the USA, and now Europe, of a new highly virulent strain of C. difficile (called PCR ribotype 027 in Europe and NAP1 in the USA). Rates of detection of C. difficile have risen dramatically, C. difficile disease has been more severe, and attributable mortality is high. While C. difficile disease was once viewed by some as more of an annoyance than a serious hospital-acquired infection, many hospitals are now moving rapidly towards implementing a range of infection control measures to stem the tide. The value of sensible policies regarding antibiotic use, as well as good infection control procedures implemented by responsible personnel, cannot be over-emphasised. Antibiotic restriction can be effective in reducing C. difficile-associated diarrhoea. In response to the outbreak in Canada, the Quebec government provided Can$30 million to hospitals in the province to buy additional equipment and hire infection control staff. In the long term, such initiatives are likely to impact not only on C. difficile-associated diarrhoea but also on methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci and other organisms that pose a challenge to infection control programmes. Money alone will not solve this problem. What is also required is good-quality research in the fields of hospital epidemiology and infection control, to allow formulation of policy and practice. Such research should comply with the principles espoused in the ORION statement. In this supplement to Clinical Microbiology and Infection, the current state of knowledge about C. difficile as a cause of diarrhoeal illness is reviewed so that healthcare institutions and jurisdictions can develop evidence-based guidelines to limit the spread of C. difficile.