Some 700 hospital patients in the Republic and Northern Ireland were found to be infected by a bacterium spread mainly by the hands of hospital staff during one fortnight last year.
The bacterium can cause fever and pneumonia in already-ill patients and could be fatal in some cases.
It also increases hospital costs by extending the length of time patients have to stay and it disrupts treatment and surgery where operations have to be cancelled because of an outbreak of infection.
The latest figures were included in a report launched yesterday by the Minister for Health and Children, Mr Micheal Martin, and by the Minister for Health, Social Services and Public Safety in Northern Ireland, Ms Bairbre de Brun. Both Ministers were in Dublin for a meeting of the North/South Ministerial Council on food safety promotion and health. They were accompanied by Dr Tom Moffatt, Minister of State at the Department of Health and Children, and by Mr Dermot Nesbitt, Minister at the Office of First Minister and Deputy First Minister.
The bacterium which was the subject of the study is Methicillin-resistant Staphylococcus aureus (MRSA). The report stresses that it is not a "superbug" but the antibiotics needed to treat it can be relatively toxic and expensive.
The study found it occurred in all acute hospitals, North and South, and that it was found in all hospital departments.
Of the 700 people found to be infected during the two weeks of the study, the majority were carriers only and about 9 per cent had infections in the bloodstream and in other locations beneath the skin.
In the Republic, the prevalence varied from 7.5 cases per 100,000 of the population in the Southern Health Board to 21.8 per 100,000 in the North Western Health Board. In Northern Ireland it varied from 5.5 per 100,000 in the Southern Health and Social Services Board to 13.6 per 100,000 in the Eastern Health and Social Services Board.
The report warns that it is difficult to draw conclusions from the variation, especially in such a short-term study.
Factors which encourage the spread of the MRSA bacterium include overcrowding in hospitals, transfers of patients between hospitals and failure by people to wash their hands.
Incorrect or excessive use of antibiotics enables bacteria to develop resistance and the report urges every hospital to have a written antibiotic policy against which it can monitor its performance.
Effective ward cleaning and isolation of infected patients also help to prevent the spread of MRSA in hospitals. The report notes that isolation rooms are less common in the South than in the North.
The report also says there is no reason why a patient who is a carrier of MRSA cannot be admitted to a nursing home.
Patients with major illnesses or who have had recent surgery or require internal devices are at an increased risk of MRSA infection.
The all-Ireland Food Safety Promotion Board will be formally launched in September, according to a communique issued after yesterday's meeting. The board will promote food safety through public campaigns, conferences and training and by advising professionals and the general public. It is currently based in Dublin but its permanent headquarters will be in Cork. pomorain@irish-times.ie