MRSA rates at Oxfordshire's major hospital almost doubled last month, although experts claim the increase is random and patients have nothing to fear.

In March 2006, there were 17 cases of the bug within the Oxford Radcliffe Hospitals NHS Trust, compared with nine the previous month.

Methicillin-resistant Staphylococcus aureus is a bug that has evolved to fight off antibiotics, and preys on the sick and vulnerable in hospital, whose immune systems are too weak to battle against them.

Infection control specialist Dr Derrick Crook said although staff had looked at the sudden rise in numbers, it was well known that variations could be random on a month-to-month basis, and figures had to be looked at long term.

He said: "Even if you have a decreasing rate of infection, you could vary from as many as 25 on a bad month down to as few as two or three on another.

"Having said that, we're pretty motivated about dealing with this and other infection control issues.

"We are appointing a number of people in infection control and have initiated a number of new projects.

"The main activity is to intensively reduce infections around intra-vascular devices, which are things like drips and intravenous lines.

"We would hope to see a reduction in MRSA through that, because quite a few of these infections come from lines."

Of the 17 new cases in March, 12 were identified in general medicine and the kidney disease department, but experts found nothing to link them.

Dr Crook said kidney dialysis patients, whose blood was routinely "cleaned" through a machine, were susceptible to infection, while patients in general medicine were usually more vulnerable to infection than other people.

A lorry driver who developed MRSA in his leg following an accident at work cannot sue an Oxford hospital for damages, a High Court judge ruled yesterday.

But although John Anderson, of Sycamore Avenue, Beith, Ayrshire, doesn't have a case against the Oxford Radcliffe Hospital NHS Trust, he can still seek compensation from a second hospital in Milton Keynes where he was treated.