Most deaths from C. difficile occur in the over 65s
Cases of the hospital bug, Clostridium difficile, are continuing to fall in England, latest figures suggest.
Between July and September, there was a 19% drop in cases in the over 65s compared with the previous quarter - from 8,696 to 7,061 cases.
The Health Protection Agency said the figures showed the hard work of NHS staff was "paying off" but hospital infections remained a challenge.
NHS trusts have a target to cut C. difficile infections by 30% by 2010/11.
C. difficile is a bacterium found in the gut, and in healthy adults and children it rarely causes problems.
But people over the age of 65 years are more susceptible to contracting infection, particularly if they are on antibiotics which disrupt the "normal" bacteria in the gut.
Symptoms range from mild diarrhoea to severe inflammation of the bowel, which can occasionally be fatal.
The latest quarterly figures show that rates of the infection have fallen by 35% compared with the same period in 2007.
It follows an 18% drop between April and June.
Professor Mike Catchpole, director of the Health Protection Agency's Centre for Infections, said: "NHS staff are working hard to fight healthcare associated infections, such as C. difficile, and their hard work is paying off.
"But winning against these infections will only happen if this hard work continues.
"Healthcare-associated infections are a global problem and remain a challenge for all of us."
He said some infections were hard to avoid as the use of antibiotics in patients who are very sick can leave them susceptible to C. difficile which would normally be kept at bay in healthy people.
"However, this shouldn't lead to complacency around tackling the infections that are preventable."
Ministers have set a target of a 30% reduction in C. difficile rates over the next three years.
Health Secretary Alan Johnson said the NHS was on track - but said that to meet the target a reduction of at least 30% against the average quarter in 2007/08 would have to be sustained for four consecutive quarters.
"This is very good news, and shows that the relentless focus on tackling infections has been working effectively.
"It isn't just about extra investment and tighter regulation - it's also about ensuring that everyone follows the hand-washing routine, the bare below the elbows dress code, the proper hygiene measures and responsible prescribing of antibiotics."
Maggie Kemmner, head of safety at the Healthcare Commission, added: "Constant vigilance is required to guard against rises in rates in the future."
Liberal Democrat health spokesman Norman Lamb said the figures would come as an "enormous relief" to patients.