A pioneering same-day test has been used to detect hidden and drug-resistant infections among children in intensive care at Great Ormond Street Hospital (GOSH). The technology, known as metagenomic testing, analyzes all genetic material in a sample to identify bacteria, viruses, and fungi that standard diagnostic methods often miss.
During a study conducted between 2024 and 2025, respiratory samples from 122 critically ill young patients were sent for this advanced testing. The results showed that the test identified around nine in 10 bacteria and viruses, as well as all fungi present in the samples. In a quarter of the cases, the findings directly influenced prescribing decisions, leading doctors to start, stop, or change antibiotic treatments.
Changing Treatment Plans for Young Patients
The case of 10-year-old Willow Crowther from Kent illustrates the potential impact of this diagnostic approach. In March, Willow became dangerously ill with pneumonia, which triggered a seizure and multiple cardiac arrests. She was admitted to the pediatric intensive care unit at GOSH, where her mother, Stacey Moore, was told she had only a 50% chance of survival.
“The consultant said… we should bring our family up to say goodbye to her. This is how critical and in how much danger she was of passing away,” Moore said.
Doctors at the hospital used metagenomics to sequence all genetic material in Willow’s samples. This method differs from conventional techniques where clinicians must decide in advance what specific pathogen they are looking for. The test identified a drug-resistant bacterial infection, allowing the medical team to prescribe a different antibiotic that was effective against the specific strain.
“The fact that they had a test there available to her was paramount. It saved her life,” said Stacey Moore. Her father, Russ, added, “It is a miracle she is here and we are extremely grateful for that.” Willow required several months in the hospital to recover fully.
Combating Antimicrobial Resistance
Dr. Sam Ray, a consultant in paediatric intensive care medicine at GOSH and co-author of the study, noted that traditional testing often requires clinicians to make an educated guess about the infection. The new testing capability allows medical staff to spot infections that would otherwise go undetected and to remove unnecessary treatments.
“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,” Dr. Ray said. “Removing unnecessary treatment is incredibly important for the fight against growing antimicrobial resistance.”
The study also detected 50 organisms that routine diagnostics failed to identify. This early warning capability could help hospitals manage outbreaks and prevent the spread of new infections within intensive care units.
Dr. Julianne Brown, head of the GOSH Metagenomics Service and co-senior author of the study, stated that the new testing is being gradually rolled out to approximately 30 intensive care units across the UK. These units treat both adults and children. Dr. Brown highlighted the potential for this technology to identify new infections that pose a pandemic threat.
“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,” she said.
The project at GOSH builds on earlier trials conducted by Guy’s and St Thomas NHS Trust, which first used metagenomics to test for respiratory infections in adult patients. The shift from Victorian-era culture methods and limited PCR tests to comprehensive genetic sequencing marks a significant advancement in pediatric critical care diagnostics.
Source: BBC
