A bug which can cause a lethal infection affected almost 400 older patients in the district last year, new figures have revealed.

The Department of Health statistics show that in 2004 there were 386 cases of Clostridium difficile (C difficile) infection among over-65s in hospitals in Bradford and Airedale.

The bug causes severe diarrhoea and is potentially lethal. It gained national attention in June when it emerged that more than 300 patients at Stoke Mandeville Hospital in Buckinghamshire had been infected with a virulent strain. Twelve of them died.

Now for the first time the Department of Health has published the results of its mandatory surveillance of the infection.

Between January and December 2004 Bradford Teaching Hospitals NHS Foundation Trust, which manages Bradford Royal Infirmary and St Luke's Hospital reported 240 cases of C difficile in patients over the age of 65, a rate of 1.60 per 1,000 bed days for over-65s.

There was a total of 150,364 bed days for patients over 65 during this period. Airedale NHS Trust, which manages Airedale General Hospital near Steeton, reported 146 cases in patients over the age of 65.

This is a rate per 1,000 bed days of 1.52. There was a total of 96,039 bed days for this group of patients.

Leeds Teaching Hospitals NHS Trust had one of the largest number of cases in the country with 794 patients over 65 infected, a rate of 1.81 per 1,000 bed days.

Cases of the infection across the UK have risen from around 1,000 in the early 1990s to more than 20,000 by 2000.

A spokesman for Bradford Teaching Hospitals said the data showed Bradford had below-average figures compared with similar hospitals.

"The data includes patients who were admitted from the community with this infection and those who acquired the infection while in hospital," she said.

"C difficile causes diarrhoea often triggered by treatment with antibiotics for other infections. Treatment includes specific antibiotics - it is not antibiotic resistant.

"All patients who develop diarrhoea in hospital have a sample taken to test for the infection.

"Patients with diarrhoea are isolated to reduce the spread to other patients and are reported to the infection control team.

"A ward investigation is also carried out to see if there are any connected cases."

She said hygiene and the tackling of hospital-acquired infections were top priorities for staff.

The Trust had revised its antibiotic prescribing guidelines to decrease the prescription of antibiotics which may trigger the infection and was working hard to educate patients, visitors and staff about how to cut healthcare associated infections.

The county's Chief Nursing Officer Christine Beasley said: "C difficile diarrhoea occurs in patients who have received broad spectrum antibiotics, particularly the elderly and debilitated, but most patients make a full recovery."