In a quarter of cases, the results influenced prescribing decisions, including starting, stopping or changing an antibiotic.
Dr Sam Ray, consultant in paediatric intensive care medicine at GOSH and co-author of the study said traditional testing required clinicians to make an educated guess about which infection they were looking for.
“The study has helped us to spot infections we would have missed, get children on the right treatment and stop antibiotics when we know they aren’t going to work.
“Removing unnecessary treatment is incredibly important for the fight against growing antimicrobial resistance.”
Metagenomic testing at GOSH also detected 50 organisms not identified by routine diagnostics, meaning it could play an early warning role against new infections.
Dr Julianne Brown, head of the GOSH Metagenomics Service and co-senior author of the study said the new testing was being gradually rolled out to around 30 intensive care units across the UK treating both adults and children.
“It could be a powerful tool for identifying new infections that pose a pandemic threat,” she added.
“In the future, if there was to be a new mystery pathogen that could be a cause of the next pandemic, we would detect that very quickly and put the right measures in place.”
The project at GOSH builds on trials at Guy’s and St Thomas’ NHS Trust which first used metagenomics to test for respiratory infections in adult patients.