AT LEAST two patients have contracted the MRSA superbug at Macclesfield Hospital since April following intravenous injections by staff.

Refresher training has since been carried out amid fears the technique used in inserting cannula tubes into the patients may have caused the bacteraemia (bloodstream) infection.

John Wilbraham, chief executive of the East Cheshire NHS trust, which runs the hospital, said: "MRSA is often linked to cleanliness but this is about technique. Infection can occur when cannulae are not inserted properly.

"What has been identified is an issue with some of the ward staff’s methods of doing a cannula."

The two injections were carried out by nurses or junior doctors, he added.

Both patients have since recovered and are not thought to be in hospital anymore.

They are among five cases of MRSA within the trust in three months, with one patient still in hospital – although one patient was already suffering from the superbug before entering the premises. Mr Wilbraham said he did not believe the other two hospital cases were cleanliness-related either.

Derek Butler, chairman of the charity, MRSA Action UK, said: "It is a concern. We are hearing of these cases on a regular basis but a lot of them could be easily avoided. Cannulae shouldn’t be inserted unless absolutely necessary. Unfortunately, in most hospitals they are a routine procedure whether needed or not."

One problem was that too few staff were trained to do it, he said, so cannulae were often left in for days at a time to avoid finding a nurse who could re-insert it.

Alift Harewood, currently Macclesfield’s deputy mayor and also a trained nurse, urged for someone to be answerable if there had been any human error.

"If you are entering a vein, you must be expert and training must be done frequently – it is not like injecting into a muscle," she said. "It is something not all nurses are trained to do – I am not myself. Being injected intravenously means an infection travels within the blood very quickly."

Mr Wilbraham added: "What we are learning from is individual cases. Four is a very small number and stands up to comparison.

"The Clostridium Difficile rate is (also) dropping and I think that is down to our cleanliness agenda."

The government-set target for the whole year – a Department of Health priority – is ten and hospital bosses insist they can still achieve that figure. Three of the cases occurred in June.

Intravenous line infections are one of several ways MRSA – which about a third of us carry on our skin – can enter the bloodstream.

Others include an ulcer, abscess or infected wound according to Department of Health public guidance.

A trust spokesman said: "There is no implication of blame or negligence in these cases. Bacteraemia is a well recognised risk when inserting lines into the blood system."

Of the two patients specifically, he added: "The cannulae were identified as a high risk factor rather than the definitive cause of the bacteraemia. Such cannulae are inserted for a variety of reasons, but particularly to ensure rapid access for drugs and fluids to very sick patients."

The trust failed to hit its target of ten last year when there were 14 cases of MRSA between April 2007 and April 2008.