The number of cases of the superbug MRSA is falling in England, but the potentially more dangerous Clostridium difficile is thriving, figures show.
Some trusts say targets get in the way of keeping clean
A review by the Health Protection Agency showed hospital MRSA cases had fallen by 10% in the first three months of 2007 compared with a year ago.
But rates for C. difficile, which mainly strikes the elderly, rose by 2%.
Some NHS trusts complained that targets - both clinical and financial - were hindering the fight against infection.
In a separate survey carried out by the Healthcare Commission - an NHS watchdog - some 45% of the 155 trusts said time targets for treating patients in A&E were getting in the way of infection control measures.
Pressure to move patients to any available bed rather than the most appropriate bed or an isolation ward was one reason cited for the difficulties.
A further 36% of trusts said they were having problems combining investment in cleaning with financial targets, while 88% said their limited IT infrastructure "was restricting their ability to draw important lessons from incidents of infection".
The survey was carried out in May 2006, and the watchdog noted that a number of practices - particularly regarding individual staff objectives for bringing down infection - had changed.
But Healthcare Commission chief executive Anna Walker added: "We cannot afford to lose momentum. Trusts should be asking themselves what more they can do to protect patients and the public from healthcare associated infection."
The National Audit Office has estimated that these infections cost the NHS as much as £1bn each year.
Hitting the vulnerable
Between April 2006 and March 2007, there were 6,378 cases of MRSA infections reported, compared with 7,096 for the previous year, the Health Protection Agency (HPA) said.
C. difficile attacks the gut
The biggest falls were in London which previously had the highest number of cases.
Meanwhile, there were 15,592 reported cases of C. difficile in patients aged 65 and over in England in the first quarter of 2007. This represents a 2% rise when compared with the same period last year, but is 22% higher than the previous quarter.
The HPA says this rise can be explained by the fact that higher numbers of vulnerable people are admitted to hospital at this time of year.
C. difficile usually affects the elderly, and can prove fatal if antibiotic treatment fails to kill all the spores in the gut, and they take hold again before the patient's own gut bacteria have had chance to mount a resistance.
It is also very difficult to eradicate from the ward environment, which means it is easy for other patients to become infected.
The NHS Confederation said it was nonetheless clear that progress was being made in tackling infections.
"It should also be emphasised that these figures represent a very small proportion of the 10 million inpatients that the NHS treats in hospitals every year," said its chief executive Gill Morgan.
Liberal Democrat health spokesman Norman Lamb said the government had "spectacularly failed" to halt C. difficile.
Shadow health secretary Andrew Lansley called the figures "the tip of the iceberg, because they do not include the number of infections in people aged under 65".
But Health Minister Ann Keen praised the hard work of NHS staff in reducing the number of MRSA infections.
"We now need to redouble our efforts to tackle C. difficile and continue this progress."