John von Radowitz

Overcrowding and understaffing are key factors in the failure of many hospitals to control the superbug MRSA, say doctors.

Researchers identified a "vicious cycle" with inadequate patient facilities and nursing levels encouraging the spread of MRSA, which in turn placed more pressure on staff and resources.

They pointed an accusing finger at efficiency drives and cost-cutting in hospitals.

"The drive towards greater efficiency by reducing the number of hospital beds and increasing patient throughput has led to highly stressed healthcare systems with unwelcome side effects," the authors led by Dr Archie Clements, from the University of Queensland, Australia, wrote in the journal The Lancet Infectious Diseases.

Patients infected with methicillin-resistant Staphylococcus aureus (MRSA) spent longer in hospital, so that fewer beds were available for new admissions, said the researchers.

In some cases, multi-bed rooms had to be used for isolation, making both occupied and unoccupied beds unavailable - a phenomenon known as "bed blocking".

Lack of staff and high workload meant more nurses and doctors failed to comply with hand-washing rules and also undermined other infection control strategies.

"Understaffing is both an ongoing and long-term future problem with severe consequences for hospital patients," they wrote.

In Australia, the number of public hospital beds per head of population fell by 40% between 1982 and 2000, the review of evidence carried out by the researcher found. Yet the number of patients passing through Australian hospitals over the same period had risen 20%.

In the UK, higher patient admission rates together with reduced numbers of hospital beds had led to 71% of NHS trusts exceeding the government's bed-occupancy target of 82%, said the researchers.

Staff-to-patient ratios were also associated with infection rates. One of the studies reviewed showed that more than one-quarter of healthcare-acquired infections in intensive care units could be avoided, with a ratio at or below 2.2 patients per health worker.