The mutant 0157 strain of the E. coli bacterium can cause gut cramps, bloody diarrhoea and life-threatening kidney damage.

Twenty-two people, half of them children, needed hospital treatment after being infected with the bug in West Cumbria last week following the contamination of milk supplies.

An outbreak of E. coli killed 21 people in central Scotland in 1996 and 1997.

The number of cases of E. coli poisoning has tripled in the UK over the last decade.

New Scientist magazine reports that a biotech company in Canada has developed the first drug to treat the condition.

In trials the drug has reduced by half the risk of patients going on to develop haemolytic uremic syndrome (HUS), the stage of the disease in which the kidney is damaged.

The company says that the drug could have been made available on "compassionate grounds" to help treat the victims of the outbreak in Cockermouth, Cumbria, had it been notified earlier.

Howard Trachtman, of the Schneider Children's Hospital, New York, who is in charge of trials of the drug in the US and Canada, said: "It's a wonderful drug for this terrible, terrible condition."

"The beneficiaries would be patients like those kids."

The drug, which was developed by Synsorb Biotech of Calgary, consists of an inert sphere of silicon dioxide from which multiple copies of a trisaccharide sugar molecule protrude.

These mimic the receptors on gut cells to which the bacterium's deadly "shiga" toxin binds.

When patients swallow the drug, it reaches the gut undigested and mops up the toxin.

Intensive trials are under way at hospitals throughout the US and Canada.

The results of earlier trials in Japan and Argentina have been encouraging, although Japanese recipients received antibiotics as well.

Only 1% of patients receiving the combination developed HUS compared with a usual rate of 15% for antibiotics alone.

Cautious welcome

Professor Hugh Pennington said more research was needed

E. coli expert Professor Hugh Pennington, of Aberdeen Royal Infirmary, said: "This drug will be worthwhile trying because even if it only works in some cases it will be a significant advance.

"At the moment there is nothing to stop the complications which can develop, and which can in some cases kill people or seriously damage their kidneys."

However, Professor Pennington warned much research was needed before the drug could be widely used.

He said nobody knew at present how quickly the drug had to be administered to be effective, or which people would benefit from taking it.