At least 49 people have died after catching a superbug at three hospitals in Leicester in the past eight months, an NHS trust has confirmed.
A spokesman for University Hospitals of Leicester NHS Trust said the coroner was investigating a further 29 cases.
The superbug Clostridium difficile (C-diff) is a common cause of diarrhoea although one in every 33 adults carries it without side-effects.
The trust has already set up a task force to fight the infection.
The trust said 28 patients had died after catching the superbug and in 21 other cases it was found that C Diff was present but another disease may have been the primary cause of death.
Dr David Jenkins, director of infection prevention and control for the trust, said: "Clostridium difficile (C-diff) is not a new bug, but the latest strain is extremely virulent.
"In common with other hospitals across the country, we are working very hard to combat it."
He said research had shown at least 1 in 5 cases occur in the community.
"We treat over one million people a year meaning that Leicester is one of the biggest hospital trusts in the country.
"So it is important that local people understand that although the number of cases of C-diff appears high the risk is actually very low.
"The fact that the chances are slim does not diminish the problem, we take it very seriously."
Zuffir Haq, chairman of Leicester Patients Forum, said: "They need to take more action - such as installing more sinks at the entrance to the hospital so patients and visitors are forced to use handwash - people should be confronted with sinks as soon as they walk in the door."
He said bed capacity was another problem as it made it very difficult to move patients around to allow cleaning to take place.
Mr Haq also called for hydrogen peroxide to be used as well as steam cleaning as a "double attack" on the bug.
The trust includes Leicester Royal Infirmary, Glenfield Hospital and Leicester General Hospital.
An investigation has also started at Maidstone Hospital in Kent after at least six people died from the diarrhoea bug there.
Maidstone and Tunbridge Wells NHS Trust and the strategic health authority have requested an investigation by the Healthcare Commission.
C-diff was linked to just under 1,000 deaths in the UK in 2003.