Same-day test helps doctors detect hidden infections in critically ill children

A groundbreaking same-day test has revolutionized the detection of hidden and drug-resistant infections in critically ill children, particularly at London's Great Ormond Street Hospital (GOSH). This metagenomic testing, which sequences all genetic material present in a respiratory sample, surpasses conventional diagnostic methods that require prior knowledge of the infection being sought.

Metagenomics can identify bacteria, viruses, and fungi from a single sample, potentially altering the course of treatment for many critically ill patients.

The test's impact became evident in the case of 10-year-old Willow Crowther, who suffered from a severe pneumonia infection that led to a seizure and multiple cardiac arrests. Initially, her family was told she had a 50% chance of survival. However, metagenomics uncovered that Willow was dealing with a drug-resistant bacterial infection, necessitating a different antibiotic than the one she had been prescribed.

Thanks to this timely detection, Willow received the correct treatment and eventually recovered, although she required several months in the hospital.

During a study in 2024-25, metagenomic testing was employed on 122 critically ill children in GOSH's pediatric intensive care unit (ICU), with the results published in the Lancet Microbe. The study revealed that the test identified around nine in ten bacteria and viruses, as well as all fungi, in the samples. In a quarter of cases, the results influenced prescribing decisions, including the initiation, cessation, or modification of antibiotics.

Dr. Sam Ray, consultant in pediatric intensive care medicine at GOSH and co-author of the study, explained that traditional diagnostic methods forced clinicians to make educated guesses about the infection, whereas metagenomics helped spot infections that would have otherwise gone unnoticed. This early detection and appropriate treatment have been crucial in the fight against growing antimicrobial resistance.

Additionally, metagenomics identified 50 organisms not detected by routine diagnostics, which could serve as an early warning system against emerging infections.

Dr. Julianne Brown, head of the GOSH Metagenomics Service and co-senior author, stated that the new testing is being gradually introduced to approximately 30 intensive care units across the UK, treating both adults and children. Dr. Brown believes this testing could serve as a powerful tool for identifying new infections that could potentially pose a pandemic threat.

As the project at GOSH continues to build on previous trials at Guy's and St Thomas' NHS Trust, which first utilized metagenomics to test for respiratory infections in adult patients, the future of healthcare looks promising with this innovative diagnostic method.