The hospital said it reported all cases of the bug to help control it

Figures from the Office for National Statistics (ONS) report there were 22 deaths in 2002 at Derriford Hospital in Plymouth as a result of the superbug.

The hospital said that the bug was actually a contributory factor to the deaths of 10 people.

It said it reported all MRSA cases, despite it not being mandatory, even if they did not contribute to deaths.

We question the data particularly as there are national variations Peter Jenks, Consultant Microbiologist

The MRSA infection is dangerous in hospitals because it can get into the bloodstream through open wounds.

The spread of the bacteria has been previously blamed on poor hygiene practices by medical staff.

Consultant Microbiologist Peter Jenks said: "There is currently no system that allows valid national comparison of such data because it is not mandatory to record MRSA as a contributory factor on a death certificate.

"Consequently we believe there will be significant variation in reporting."

Plymouth Hospitals NHS Trust said it had a very open policy about reporting MRSA.

It said doctors were encouraged to record the bug, not just when it contributed to a patient's death, but even when it was not thought to be relevant.

Mr Jenks said: "We actively record MRSA both when it has contributed to a patient's death and when the patient is carrying it at the time of death but it is not a contributing factor.

Mortality rate

"For the last five years we have operated a very open policy regarding the monitoring and reporting of MRSA here.

"We believe that if we have a true understanding of the scale of MRSA rates within our hospital then we are better able to tackle and control them.

"We question the data particularly as there are national variations in the reporting on death certificates of this important hospital-acquired infection.

"Our MRSA bacteraemia rates are comparable to other specialist trusts and there is no evidence to suggest that our mortality rate is any higher than at other specialist trusts."

The figures from the ONS said the total number of deaths reported from 1,014 hospitals and nursing homes studied in England and Wales was 721.

The second-worst trust for MRSA deaths in 2002 was Birmingham Heartlands hospital with 17, followed by Queen Alexandra hospital in Portsmouth, which declared 15.