Hospital cases of MRSA bloodstream infections in England are continuing to fall, the latest quarterly figures from the surveillance body the Health Protection Agency (HPA) show.
But cases of the stomach bug Clostridium difficile have risen sharply over the previous quarter's figures.
Between January and March 2007, the latest period for which figures are available, there were 2% fewer (1444) cases of MRSA reported to the HPA.
This compares with 1542 cases in the previous quarter, and adds up to a 10% drop over the course of 12 months.
The largest falls have occurred at London, which previously had the highest number of cases, and in acute teaching trusts, says the HPA.
Preliminary data from a more detailed MRSA surveillance scheme at the HPA show that almost three quarters of cases occur in those aged 60 and above.
Dr Georgia Duckworth, who heads up the Agency's Healthcare Associated Infection & Antimicrobial Resistance Department said that the elderly were particularly at risk because many of had lengthy stays in hospitals I specialist units.
Although cases of C difficile have risen just 2% over the course of the year, they were 22% higher in the first quarter of this year compared with the last quarter of 2006, when 12797 cases were reported.
Some 15592 cases were reported to the Agency between January and March 2007.
The Agency says that patient throughput tends to be higher during the first quarter of the year, which might explain the sharp increase.
Dr Christine McCartney, who leads the Healthcare Associated Infections Programme at the Agency, described the fall in MRSA cases as "very encouraging."
But she cautioned: "There is still a lot of work to be done if we are to continue to achieve reductions in both MRSA and C difficile. Many of these infections are preventable if hygiene and antibiotic prescribing guidelines are strictly followed by trusts."
Figures on Glycopeptide Resistant Enterococcal infections (GRE), published at the same time, show that case numbers remain small.
Only 20 trusts reported more than 10 cases, and most were in acute teaching trusts.
Dr Gill Morgan, chief executive of the NHS Confederation, which represents over 90% of NHS organisations, said that the figures showed just how much progress had been made in tackling healthcare associated infections (HAIs).
Although any case was an extremely serious matter, she said "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."
But Liberal Democrat shadow health secretary Norman Lamb said that the figures indicated that the government's strategy to tackle these infections had "spectacularly failed."
He suggested that failure to comply with hygiene standards should be treated as akin to gross misconduct and attract disciplinary action.
Figures on individual trusts' performance for HAIs can be found at:
www.hpa.org.uk