The government strategy to battle MRSA at hospitals by screening patients has been called into question by a study which suggests it has little effect.
The government is phasing in MRSA screening by the end of next year
Geneva University compared rates for 22,000 surgical patients, some screened and some not, the Journal of the American Medical Association reported.
They found little difference between the numbers getting the superbug.
The government said screening, being phased in at English hospitals, is just one part of its anti-infection plans.
It has called for NHS hospitals to introduce screening for routine operations by next year and for emergency patients over the next three years.
It also set out a range of other measures including the deep-cleaning of hospitals and recruitment of extra infection control nurses.
In the Swiss study, those found to be carrying MRSA in the screening group were exposed to a range of measures, including isolation and decontamination.
But in the end there was no significant difference between the numbers getting MRSA infections during their hospital stay.
Some 93 patients developed MRSA in the screening group - 1.11 per 1,000 patient days - compared to 76 - 0.91 per 1,000 patient days - in the control group.
Lead researcher Stephan Harbarth said: "The trial did not show an added benefit for widespread rapid screening on admission compared with standard MRSA control alone.
"To increase effectiveness, MRSA screening could be targeted to surgical patients who undergo elective procedures with a high-risk of MRSA infection."
Professor Mark Enright, a leading MRSA expert from London's Imperial College, said England had higher infection rates than Switzerland, which could make screening a little more effective.
But he added: "In my view the government would be better targeting the screening. The contamination of the hospital environment is more of a cause of infections than patients coming into hospital with it."
A Department of Health spokesman said: "MRSA screening is one part of a range of measures needed to ensure good hygiene and to drive down infection rates.
"Our strategy demonstrates the comprehensive approach required across the NHS."