Clinical utility of metagenomic next-generation sequencing in infants with severe infections.

Objective: This study aimed to compare pathogen detection rates between metagenomic next-generation sequencing (mNGS) and conventional microbiological culture in critically ill infants younger than 1 year of age, and to investigate the associations between mNGS positivity and clinical laboratory parameters. Methods: We conducted a single-centre retrospective study including infants with severe infections admitted to the Children's Hospital of Soochow University between 1 January 2023 and 31 December 2025, who underwent both mNGS and conventional culture testing. Patients were classified into mNGS-positive and mNGS-negative groups, and clinical characteristics and laboratory findings were compared between groups. Candidate predictors of mNGS positivity were identified using least absolute shrinkage and selection operator (LASSO) regression, followed by multivariable logistic regression analysis. The predictive performance of key variables was evaluated using receiver operating characteristic (ROC) curve analysis. Results: A total of 105 infants and 153 biological specimens were included. The overall mNGS positivity rate, as well as positivity rates across all specimen types except cerebrospinal fluid, were significantly higher than those of conventional culture ( Conclusion: mNGS demonstrated superior pathogen detection compared with conventional culture in critically ill infants. MCH, cholinesterase, and PCT were independently associated with mNGS positivity, and a combined multi-marker model substantially improved the prediction of mNGS-positive cases.