Patients in intensive care are more likely to develop the hospital superbug MRSA if there is a shortage of trained nurses, research suggests.

A study of one eight-bed intensive care unit over a five-month period found staff shortages, as well as poor hygiene, increased infection risk.

MRSA - methicillin resistant Staphylococcus aureus - is linked to around 1,000 deaths a year.

The findings were presented to a meeting of the Intensive Care Society.

Over the course of the study, 174 patients were admitted to the intensive care unit at the un-named hospital.

Of these, 7% acquired MRSA during seven of the weeks studied.

In six of these seven weeks, the ICU was particularly busy, due to a shortage of trained nurses in the daytime.

In addition, during five of those weeks, ICU ward standards of cleanliness were defined as below average.

'No time'

Dr Stephanie Dancer, a Consultant Microbiologist from Scotland, who conducted the study, said: "These results were something of a surprise to me.

"I have studied the acquisition of MRSA for several years now, and have previously focused on levels of hygiene.

"These results show that MRSA acquisition is caused by the culmination of a number of different factors. In this study, understaffing was a significant factor, exacerbated by poor ward hygiene and further studies are required to explore this in more detail."

She added: "It is assumed that when nurses are particularly busy due to understaffing, they do not have time to wash their hands."

Dr Anna Batchelor, President of the Intensive Care Society said: "Under-staffing is a particular problem in many ICUs.

"This study highlights how a lack of trained staff puts patient lives in danger.

"The challenge for intensive care is now to ensure more nurses are brought into the specialty and that the new government commits to adequate funding for trained staff."