A new test can identify intensive care patients at highest risk of potentially life-threatening secondary infections, including from antibiotic-resistant bacteria such as MRSA and C difficile, according to UK researchers.
They noted that infections in intensive care units (ICU) tend to be caused by organisms, such as multi-resistant gram-negative bacteria found in the gut, that are resistant to frontline antibiotics.
“These markers help us create a ‘risk profile’ for an individual”
Andrew Conway Morris
They highlighted that treating such infections meant relying on broad spectrum antibiotics, which run the risk of breeding further drug-resistance, or antibiotics that have toxic side-effects.
In a study, which involved 138 patients, the researchers identified markers on three immune cells that correlate with an increased risk of secondary infection.
Working across four sites in Edinburgh, Sunderland and London, the team was led by researchers at the universities of Cambridge and Edinburgh and biotech company BD Bioscience. Their findings have been published in the journal Intensive Care Medicine.
Dr Andrew Conway Morris, from the University of Cambridge, said: “These markers help us create a ‘risk profile’ for an individual. This tells us who is at greatest risk of developing a secondary infection.
“In the long term, this will help us target therapies at those most at risk, but it will be immediately useful in helping identify individuals to take part in clinical trials of new treatments,” he said.
“In the long term, this will help us target therapies at those most at risk”
Andrew Conway Morris
Trials for interventions to prevent secondary infections have previously met with mixed success, in part because it has been difficult to identify patients who are most susceptible, said the researchers.
Using this new test should help fine tune the selection of clinical trial participants and improve the trials’ chances of success, they said.
The markers identified are found on the surface of key immune cells – neutrophils, T-cells, and monocytes. The researchers tested the correlation of the presence of these markers with susceptibility to a number of bacterial and fungal infections.
An individual who tests positive for all three markers would be at two to three times greater risk of secondary infection, compared with someone who tested negative, they said.
They noted that the markers do not indicate which secondary infection an individual might get, but rather that they are more susceptible in general.
Senior study author Professor Tim Walsh, from the University of Edinburgh, said: “Our priority is to prevent patients developing secondary infections and, if they do, to ensure they get the best treatment.”