At least 8,000 patients tested positive for a range of potentially fatal superbugs in Irish hospitals last year, new figures show.
The figures, obtained by The Irish Times under the Freedom of Information Act, show that some 6,000 patients in more than 30 hospitals were infected by MRSA.
There are two types of MRSA infection, infection on the skin when a patient is referred to as being "colonised" by the bug but is in fact not ill from it, and bloodstream infections which result from the bug entering a patient's blood, usually through a wound.
Health authorities had previously indicated the total number of MRSA bloodstream infections for 2004 was about 500 but details of how many infections were found in each hospital were not published.
The figures obtained by The Irish Times reveal that the highest numbers of MRSA bloodstream infections were in large hospitals such as Dublin's Mater, which had 77 patients with MRSA bloodstream infections and St James's Hospital, which had 65 cases.
High numbers of MRSA bloodstream infections were also found at Galway's University College Hospital and Merlin Park Regional Hospital. The Health Service Executive (HSE) Western Area stressed it could not be assumed hospitals with higher numbers of cases have the biggest problem.
"It may simply be that they try harder to detect and document the scale of the problem and that they have more very sick people admitted," it said.
The Irish Times requested details of MRSA, Clostridium difficile, VRE and winter vomiting bug infections from Dublin's five major hospitals and all the former health board hospitals outside Dublin now run by the HSE.
Beaumont Hospital was the only hospital to refuse the request. It claimed releasing the information "would provide a seriously misleading picture which could reasonably be expected to severely prejudice the effectiveness of our own testing and have a significant adverse impact on the performance of the hospital in relation to management of staff." The Midland Regional hospitals in Tullamore and Mullingar and Kerry General Hospital in Tralee are still processing the FOI request.
The data shows the potentially fatal bug, Clostridium difficile, is prevalent in many hospitals. This bug was found in patients in 15 hospitals in 2004. There is no requirement on hospitals to collect data on it or to screen for it so its prevalence may be more widespread.
Some 900 patients in the hospitals which provided data were found to have Clostridium difficile in 2004. The hospital where most cases were identified was Letterkenny General Hospital where 223 patients were infected.
Dr Robert Cunney, consultant microbiologist with the Health Protection Surveillance Centre (HPSC), formerly the National Disease Surveillance Centre, said there were "certainly a lot" of cases of bloodstream infections with MRSA.
"Compared with other European countries, our rate would seem to be quite high. They are probably amongst the highest in Europe.
"It is likely it was a factor in some patient deaths but you can't say how many," Dr Cunney said. "Each one of those bloodstream infections represents a patient who had a serious and life-threatening infection."
The figures obtained by The Irish Times also show 135 patients were found to have VRE last year, a bug which resulted in the closure of the national bone marrow transplant unit at Dublin's St James's Hospital for several months in 2001.
Hospitals also reported having had more than 550 patients with the winter vomiting bug in 2004.
A national audit of hospital hygiene ordered by Minister for Health Mary Harney is currently under way.