The Government was accused of "neglecting" deadly hospital bugs today as figures showed some infections may be rising.
Cases of MRSA have increased in more than one in 10 NHS trusts while Clostridium difficile has gone up in almost one in five - despite an overall reduction in the two illnesses since a £120 million crackdown was launched.
Other bloodstream infections - such as MSSA, which left actress Leslie Ash fighting for her life - may also be going up, the National Audit Office (NAO) said.
Edward Leigh, Conservative MP and chairman of the Committee of Public Accounts, said the increases were "threatening all those who use our healthcare system."
He said: "There has been a lamentable lack of progress in measuring these other infections and therefore they have been neglected."
While the Department of Health met its overall target to reduce MRSA bloodstream infections by 57 per cent and C diff was reduced by 41 per cent, Amyas Morse, head of the National Audit Office, said "compliance with good practice is still not universal".
It emerged there was no national data on some of the most common infections, such as urinary tract infections and pneumonia.
Mr Morse said there was a "lack of robust comparable data" on infection risks.
He added: "The Department of Health's hands-on approach to what seemed, in 2004, to be an intractable problem, has been successful in reducing MRSA bloodstream and C diff infections.
"This is a significant achievement and a good example of what concerted effort can achieve.
"Inevitably, with a focused and centrally-driven initiative of this kind, the improvements are not uniform across the NHS and we still don't know in any meaningful way what impact there has been on other healthcare-associated infections."
Key problems, he said, which needed to be addressed were "a lack of robust comparable data on other infection risks; increases in antibiotic resistance and poor data on hospital prescribing."
The Government had introduced a target to reduce MRSA across all NHS trusts by 50 per cent by 2008 and C diff by 30 per cent by 2010-11.
But evidence showed, while a quarter of trusts have reduced MRSA by more than 80 per cent, in 12 per cent of trusts there has been an increase in MRSA infections.
It also emerged that 29 per cent of trusts have reduced C diff by more than 50 per cent, but in 19 per cent of hospital trusts the numbers of C diff infections have increased.
About 9,000 people died in 2007 where MRSA or C Diff was a contributory factor.
The NAO insisted the £120 million spent on central initiatives tackling healthcare-associated infections was worthwhile however.
"These central initiatives, together with action at trust level, have led to savings on treatment of between £141 million and £263 million, as well as reducing discomfort, disability and, for some, death that might have been caused by these avoidable infections," a NAO statement said.
Nigel Ellis, head of National Assessment and Inspection at the Care Quality Commission, said: "The NAO is right to acknowledge improvements in the control of MRSA and C diff, which have had such a strong grip on hospitals in this country. This follows a big effort from people right across the NHS - and we are of course pleased that the report recognises the role that independent regulation has played.
"While the NHS as a whole is doing better, there are still individual trusts that have a great deal of room for improvement. So no one should be complacent. Everyone involved has to continue to drive down the rates of healthcare-associated infections - and that includes all infections, not just MRSA and C. difficile.
"We will keep up the pressure and encourage the NHS to stay focussed on improvements. That will include taking swift enforcement action if we find unacceptable performance."
Health minister Ann Keen welcomed the report.
She added: "We remain totally committed to eliminating all preventable healthcare associated infections. That is why the Health Secretary yesterday announced plans to develop a new minimum standard for MRSA which will help drive all NHS organisations towards reaching the standard of the top performers.
"As a nurse myself, I am especially pleased to see that the National Audit Office has recognised the contribution that nurses - and the reintroduction of matrons onto our wards - have had in delivering the reductions in MRSA and C diff infections."
Dr Peter Carter, chief executive of the Royal College of Nursing, said: "This report rightly recognises the hard work and dedication of those healthcare staff who are helping to tackle MRSA and C difficile.
"However, despite an overall fall in infection rates, a minority of trusts have seen infection rates rise, giving a clear warning that more needs to be done.
"If the Government is serious about reducing healthcare associated infections, it must invest in the appropriate training, support and equipment.
"Healthcare staff also need to recognise that fighting infection is about much more than just hand-washing.
"It's about keeping every part of the patient environment, and every piece of equipment, clean all of the time because infections like MRSA and C diff still pose a very serious threat.
"Good leadership is needed to foster a culture where excellent infection control is second nature to all health workers."