http://www.amm.co.uk/newamm/files/factsabout/fa_cdiff.htm
Clostridium difficile infection
anonymous Association of Medical Microbiologists.
1998

Clostridium difficile (so called because when it was first discovered it was difficult to grow in the laboratory) is a cause of diarrhoea, which is usually acquired in hospital. Although in most cases it causes a relatively mild illness, occasionally and particularly in elderly patients, it may result in serious illness and even death. The bacterium produces two toxins which are responsible for the diarrhoea and which damage the cells lining the bowel. However, not all strains of C. difficile produce toxin; these strains are unlikely to cause disease and patients colonised by them remain healthy. In addition, the bacterium can form spores which enable it to survive in the environment outside the body and which protect the organism against heat and chemical disinfectants. ...

C. difficile infection is usually acquired in hospital , and almost all patients who develop C. difficile diarrhoea are taking, or have recently been given, antibiotic therapy. Diarrhoea is the most common symptom but abdominal pain and fever may also occur. In the majority of patients, the illness is mild and full recovery is usual, although elderly patients may become seriously ill with dehydration as a consequence of the diarrhoea. Occasionally patients may develop a severe form of the disease called 'pseudomembranous colitis' or 'antibiotic-associated colitis' which is characterised by significant damage to the large bowel. This may lead to a grossly dilated bowel possibly resulting in rupture or perforation. Unlike some other causes of diarrhoea, it is rare for C. difficile to spread to other parts of the body such as the blood stream. ..

Although the bacterium may be grown on special culture medium, its isolation alone does not conclusively prove that the diarrhoea is due to this organism, as strains of C. difficile which do not produce the toxin are unlikely to cause diarrhoea. Direct examination of the bowel by sigmoidoscopy and taking small biopsies for analysis may also help in confirming a diagnosis, especially in suspected pseudomembranous colitis, but these procedures are not always available. X-ray investigations are sometimes helpful. ..

Fortunately, most patients develop only a mild illness and stopping the antibiotics, if clinically possible, together with fluid replacement, either by mouth or intravenous drip, usually results in rapid improvement. Sometimes, however, it is necessary to give specific therapy against C. difficile itself. Two antibiotics are known to be effective in treatment. Metronidazole taken by mouth is often prescribed as the first choice; if this is not effective then another antibiotic, vancomycin, also taken by mouth, can be tried. There is a risk of a relapse of symptoms in about 20-30% of patients and further courses of these antibiotics may be required. ..

The sensible use of antibiotics is the key to the prevention and control of C. difficile infection. Where possible, short courses of antibiotics of only three to five days are preferred to longer courses. In addition, narrow-spectrum antibiotics e.g. penicillin, which only kill a small range of bacteria are preferred to broad-spectrum agents which can have an effect on a wide range of bacteria. Both of these features of antibiotic therapy will minimise the alteration of the normal bacterial flora of the bowel which is a key factor in the development of this condition. A short course of a narrow-spectrum antibiotic is particularly advisable when the precise cause of a bacterial infection is known. Finally when a patient is identified as having C. difficile diarrhoea the infection control measures already described will minimise the risk of spread to others.

2