Copper change

Stainless steel hospital surfaces might look spotlessly clean, but the reported 300,000 patients who pick up infections such as MRSA in the UK each year tell a different story.

According to the

, 5,000 of those are likely to die as a result, and it costs the

an estimated £1bn a year.

With this in mind, a Birmingham hospital has launched an 18-month clinical trial to establish whether the installation of copper surfaces will kill MRSA and other hospital-acquired infections.

The trial follows years of laboratory tests at

which established that the natural antimicrobial properties of copper and its alloys dramatically reduce the presence of MRSA compared with stainless steel — the most commonly used surface-metal in health institutions.

Those findings will be put to the test in Selly Oak Hospital, and if the trial is successful, copper surfaces could be installed in hospitals across the UK.

One of the general wards at Selly Oak had all of its bathroom taps, toilet flush-handles, grabs, door handles and push-plates replaced by copper. Even the pens used by staff are copper alloy. All of this is necessary to determine the trial's success because 80 per cent of MRSA transmission is through surface contacts.

Tests at Southampton showed that the bacteria remained fully active for days on stainless steel. On brass (an alloy of copper and zinc) they died in less than five hours, and on pure copper the superbugs were eliminated in 30 minutes.

Southampton's principal researcher Bill Keevil explained the anti-microbial properties of copper effectively suffocates the germs.

'What we know is that all aerobic bacteria respire,' he said. 'Copper is interfering with the bacteria's electron transport chain of respiration. The bacteria have a series of receptors in their cell membrane and they pass electrons along a chain. And if you pass electrons along a chain energy is created. So if you block the electrons passing along that chain, the cell can't make energy, it can't respire and then dies.'

In bacteria other than MRSA, copper compromises the actual cell membrane. 'Think of a cell like a balloon,' explained Keevil. 'If you put a hole in the balloon, air comes out, and the same is true of bacteria. If you put holes in the bacterial cell membrane, then they start to leak out all their contents and again they die.'

Keevil said copper uses a different method to kill MRSA. 'We have shown that copper destroys its DNA,' he said. 'We're not exactly sure of the mechanism, but copper can generate free radicals, so one possibility is it is just generating free radicals to attack the DNA.'

According to Keevil one of the reasons stainless steels replaced copper in hospitals was because in most environments they don't corrode, unlike copper that tarnishes. 'Ironically, I would argue the point that copper is a self-indicating material,' he said. 'You know when it's clean and you know when it isn't. So if it starts to tarnish, you know someone hasn't done their cleaning job.'

He said many people think stainless steel is hygienic when inherently it's not. It is easy to clean as long as it doesn't have scratches or pits where bacteria can hide.

'The beautiful thing about coppers is that it almost doesn't matter if you scratch them or if you have pits in them, because you still have copper as the anti-microbial agent doing its job,' he said.

Keevil said he sees copper surfaces as being just one extra 'barrier' against infections in hospitals. 'We're not saying that copper is the be-all and end-all, but it is certainly very important,' he said.