Medical doctors fear that there will be a widespread of Clostridium difficile in Australia when three elderly patients at a Melbourne private hospital were reported to be infected by the bug.

Clostridium difficile, is a potentially fatal and highly infectious stomach bug and has never been detected in Australia before.

The strain of Clostridium difficile has killed thousands of people in Europe and North America.

Three elderly patients at the Epworth Hospital in Richmond have been infected with the bug, which causes severe diarrhoea, but they have all recovered well.

The executive medical director at the Epworth, Dr Megan Robertson, says the strain could be more widespread and hospitals need to be vigilant.

This particular bug is not destroyed by alcohol so we have to clean with bleach and detergent, but that's well identified with the common strain, Dr Robertson said.

So those precautions and those spread measures are no different with the hypervirulent strain, it's just that we need to be more vigilant.

She says the strain may be going undetected in other hospitals.

Clostridium difficile infection is widespread in Australia; it's the hypervirulent strain that has not been detected previously, but it is not so widely tested for, she said.

So I expect that there is potentially a hypervirulent strain in Australia that hasn't previously been detected.