'Although cleaning and hygiene are important the main problem is antibiotic use. People are given antibiotics when they don't need them and when they need them they are given the wrong ones.'

Clostridium difficile is the commonest cause of diarrhea in hospitals and can lead, in severe cases, to inflammation of the gut similar to gas gangrene. Unlike MRSA, it is not resistant to antibiotics but some patients are difficult to treat. Cases of C. difficile are rising rapidly while cases of MRSA have begun to fall.

The bacterium is present naturally in the intestines of healthy individuals where it is kept under control by the presence of other bacteria. When antibiotics are given as part of other routine hospital treatment they may knock out some bacteria, allowing C. difficile to take advantage of the weakness in the defense. Thus drugs given to protect patients against infection may make them more vulnerable to it.

Overuse of antibiotics is thought to be key reason for the dramatic rise in cases of C. difficile. It mainly attacks the elderly and vulnerable but the new more virulent strain identified at Stoke Mandeville hospital has also affected younger patients.

Main Problem Is Antibiotic Use

Andrew Berrington, consultant microbiologist at Sunderland City hospital and a member of the National C. difficile Standards Group set up by the health department, said: "Although cleaning and hygiene are important the main problem is antibiotic use. People are given antibiotics when they don't need them and when they need them they are given the wrong ones."

Cephalosporins, powerful antibiotics used to treat surgical, urinary tract and respiratory infections, were more likely to cause infections with C. difficile, he said.

Treatment of infection with C. difficile is with another antibiotic such as metronidazole or vancomycin. Professor Peter Boriello of the Health Protection Agency said the dramatic rise in infections with C. difficile was partly due to better reporting by laboratories. "But [in] my view there is an underlying rise. We have a more elderly population who are in hospital for longer, have more complicated surgery and are more susceptible."

He added: "There are reports from Canada and the US that this strain at Stoke Mandeville has caused particular problems. It is a more virulent strain but there have been highly virulent strains in the past."

The introduction of alcohol hand gels on NHS wards for cleansing between patients was meant to be convenient and compensate for a lack of sinks. But it was not adequate to deal with C. difficile, which creates spores difficult to destroy.