From obscurity to ‘superbug ’ – The rise of Clostridium difficile

The anaerobic bacterium Clostridium difficile is a major nosocomial pathogen, the most commonly diagnosed cause of infectious hospital diarrhoea.1 C. difficile infection has a wide clinical spectrum, ranging from asymptomatic carriage, to mild-self limiting diarrhoea, and more severe pseudomembranous colitis (PMC). Antimicrobial exposure is the most significant risk factor for acquiring C. difficile and, of course, being exposed to the organism. Prior to the advent of antibiotics, PMC was a relatively rare disease, largely associated with colonic, pelvic or gastric surgery.2 As the use of antimicrobial agents becamemore common, PMCemerged as an important complication. Although C. difficile was first described in 1935, it was not identified as the aetiological agent of PMC and cases of antibiotic-associated diarrhoea (AAD) until the late 1970s. The observations that the toxi