While attention has been focussed recently on MRSA, another stealthy superbug has been creeping up on the UK's hospitals.
So successfully has it taken a grip that clostridium difficile now contributes to the deaths of four times as many people as MRSA.
I was astounded to learn from Professor Brendan Wren, of the London School of Hygiene and Tropical Medicine, that the equivalent of one person every hour is dying in our hospitals with c.difficile.
Watch Sally Magnusson's report on Panorama: How Safe is Your Hospital? BBC One 10.20pm Sunday 27 April 2008
These are mostly people who came into hospital to be treated for one thing, only to be felled by a preventable hospital infection.
As hospitals struggle to contain this bug, we were given unprecedented access to a trust in which 90 people died of c.difficile, with over 1100 people infected.
Maidstone and Tunbridge Wells Trust, now under new management, provides a tragic object lesson for other hospitals.
Exclusive interviews with nurses, doctors, the former chairman and the Healthcare Commission investigator reveal the sloppy hygiene, understaffing and management failures which allowed the bug to spread there.
Some nurses are still haunted today by the way that staffing pressures meant they could not provide proper care for patients suffering multiple episodes of diarrhoea every day.
Bereaved families also gave a harrowing picture of how vulnerable elderly relatives met their deaths.
The trust is now taking positive steps to beat the superbug.
I was shown round the c.diff isolation ward, where careful hygiene and tight nursing procedures have helped reduce infection rates by between 30 and 40% in the last twelve months.
But the truly sobering fact about the Maidstone trust is that it wasn't alone in succumbing to c.difficile.
Nor was it even the worst trust in England for c.diff deaths.
How much are other trusts and health boards doing to protect their patients?
We carried out an exclusive Freedom of Information survey to find out.
Some hospitals are doing better than others in key areas known to have an impact on infection, such as bed occupancy, isolation of patients and hand hygiene.
But the central message from our programme is that every hospital in the land will have to be super-vigilant if we're to beat this super-bug.
It is shocking to learn from the leading expert Professor Richard James that there are ten times as many deaths from it here among people over 65 than in any other country in the world.
As belated attempts are made to combat it, the bug itself is mutating and strengthening.
One of only two antibiotics used to treat it is showing signs of resistance.
The deadly 027 strain has been found in some farm animals, prompting scientists to ask whether c.diff could be being transmitted through the food chain.
More research is needed. Our programme asks: given the scale of the problem and the cost of c.diff infections to the NHS, why is more money for vital research to understand this deadly infection not being made available?
Panorama: How Safe is Your Hospital? BBC One 10.20pm Sunday 27 April 2007.