Hospitals 'missing sources of MRSA'

Instead, cleaning should be targeted on "hand touch" sites in wards, such as door handles, bed rails, lockers, and the switches, pumps and other equipment surrounding patients, said Dr Stephanie Dancer.

Evidence showed that these were the places most likely to harbour the antibiotic resistant MRSA superbug. Yet they were generally poorly cleaned, said Dr Dancer, from South General Hospital in Glasgow.

"The responsibility for cleaning many hand-touch sites usually rests with the ward nurses, who are often very busy and almost permanently understaffed in many hospitals," she wrote in the medical journal The Lancet Infectious Diseases.

Hospital hygiene was usually assessed visually, she said. Ward cleaners in the UK worked to a set of rules that prioritised the cleaning of floors and toilets, while scant regard was paid to the hidden dangers of invisible micro-organisms.

"Buffing the floors in outpatients departments might improve the appearance of the waiting areas, but patients do not generally acquire MRSA from floors," wrote Dr Dancer. "The greatest risk for patients is contaminated near patient hand-touch sites in clinical areas."

She called for extra attention to be given to sites which might look "clean" but were likely to harbour germs. One study found that even when up to 91% of a hospital's wards seemed visibly clean, they were only 30 to 45% microbially clean.

Cleaners should be included as an integral part of the infection control team, and given a bigger slice of a hospital's budget, said Dr Dancer.

Responding to the study, the Government's chief nursing officer, Professor Christine Beasley, said: "Infection control is a complex problem that needs a range of solutions and the fact is there is no single remedy.

"However, we know that, as part of a wider set of measures, proper cleaning is an important tool in tackling infections. That's why we have mandated that deep cleans should take place in all hospitals and that the new hospital regulator will have the powers to impose fines and close down entire wards in hospitals that do not meet strict hygiene requirements."