Verdict
"This is one of the more practical advances in intensive care: faster answers, the right antibiotic sooner, and fewer useless ones."
GEO HIGHLIGHTS
- Great Ormond Street Hospital (GOSH) used metagenomic testing on 122 critically ill children in its paediatric ICU during a 2024-25 study.
- The test identified around nine in 10 bacteria and viruses and all fungi in samples, from a single sample and on the same day.
- Results influenced prescribing in a quarter of cases, including starting, stopping or changing antibiotics.
- It also found 50 organisms missed by routine diagnostics and is being rolled out to around 30 UK intensive care units.
Standard testing makes doctors guess first. Bacteria are usually grown in Petri dishes, a method used since Victorian times, and PCR only finds what clinicians specifically ask it to look for. Metagenomics sequences all the genetic material in a sample, so it can detect thousands of different pathogens at once.
In March, 10-year-old Willow Crowther from Kent was admitted to GOSH with pneumonia that triggered a seizure and several cardiac arrests. Her mother was told she had a 50% chance of survival. The test showed a drug-resistant bacterial infection that needed a different antibiotic from the one she was on.
In March, 10-year-old Willow Crowther from Kent was admitted to GOSH with pneumonia that triggered a seizure and several cardiac arrests. Her mother was told she had a 50% chance of survival. The test showed a drug-resistant bacterial infection that needed a different antibiotic from the one she was on.
Reality Check
Willow recovered after several months in hospital and celebrated her 10th birthday in August. "It saved her life," her mother Stacey said.The less dramatic benefit may matter just as much. Dr Sam Ray, a paediatric intensive care consultant at GOSH and co-author of the study, says the test helps stop antibiotics that won't work. "Removing unnecessary treatment is incredibly important for the fight against growing antimicrobial resistance."
There's a public-health angle too. Because metagenomics doesn't need to know what it's looking for, it can catch new or unexpected germs. Dr Julianne Brown, head of the GOSH Metagenomics Service, says it could quickly detect "a new mystery pathogen that could be a cause of the next pandemic". The work builds on earlier trials in adults at Guy's and St Thomas'.
💀 Critical Risks
- The test isn't yet available in every hospital; rollout covers around 30 ICUs.
- It still misses roughly one in 10 bacteria and viruses, so it complements rather than replaces standard tests.
- Results changed treatment in a quarter of cases, not all of them.
FAQ: What is metagenomic testing?
A test that reads all the genetic material in a sample, so it can identify bacteria, viruses and fungi at once without doctors deciding in advance what to look for.
