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Clostridium difficile is a Gram-positive, sporulating, obligate anaerobe. It was first described in 1935 by Hall and O’Toole and is now a leading cause of Healthcare Associated Infection. It can be present in healthy individuals without consequence. However, when the balance of the commensal gut flora is disrupted, a C. difficile infection (CDI) can become established in the colon.


People in good health usually do not get CDI. Increased risk is associated with:

  • Prolonged use of antibiotics
  • Advanced age (Usually over 65)
  • Gastrointestinal surgery
  • Immunologically compromised


Although some people can be healthy carriers of C. difficile, in most cases the disease develops after cross infection from another patient, either directly, via healthcare staff, or via a contaminated environment. A patient who has CDD excretes large numbers of the spores in their liquid faeces, which can contaminate the environment for a long time.


C. difficile causes disease by the production of two toxins: Toxin A, an enterotoxin promoting fluid accumulation in the bowel and Toxin B, an extremely lethal (cytopathic) toxin.

The severity of infection can range from a mild,
Clostridium difficile associated diarrhoea (CDAD) to life-threatening pseudomembranous colitis (PMC): ulceration and bleeding from the colon (colitis) and, at worst, perforation of the intestine and peritonitis.


Strains of C. difficile are commonly resistant to several antibiotics hence its association with antibiotic treatment. However, at present, it is still possible to treat most CDI with metronidazole and vancomycin.


Spores of C. difficile are resistant to heat and many chemical treatments. Consequently, it is extremely difficult to eradicate C. difficile from the hospital environment.

There are three important components to the prevention and control of CDI:

  • Prudent antibiotic prescribing to reduce the use of broad spectrum antibiotics.
  • Isolation of patients with CDAD and good infection control nursing
    - handwashing (not relying solely on alcohol gel as this does not kill the spores)

    - wearing gloves and aprons, especially when dealing with bed pans etc.
  • Enhanced environmental cleaning and use of a chlorine containing disinfectant.

When CDI were first recognised in the late 1970s, laboratory diagnosis was difficult and case numbers were not monitored. UK reporting to the Health Protection Agency (voluntary from 1990, mandatory since 2004) shows a massive increase, from less than 1,000 in the early 1990s to 55620 cases in 2006. In 2007 C.difficile contributed to five times more deaths than MRSA. Other countries report similar trends. Some of this is due to improved testing and reporting, but there has clearly been a real and significant increase.

Reasons for the increase have been suggested:
  • Increasing age of the population and therefore the number at risk.
  • Increased antibiotic resistance.
  • Emergence of hypervirulent strains.
  • Lower standards of hygiene
  • Overcrowding in hospitals.

Whatever the reason, it is clear that CDI pose a major and escalating health problem which needs to be addressed.

To see Panorama Special "How Safe is Your Hospital?" (26/04/08) click here BBC

To see TV news item "More Deaths Linked to Bug"(04/08/08) click here BBC