# The role of bronchoalveolar lavage fluid metagenomic next-generation sequencing in detecting pathogens and optimising antibiotic therapy in paediatric severe community-acquired pneumonia

## TL;DR

This study shows that metagenomic sequencing of lung fluid improves pathogen detection and helps optimize antibiotic use in children with severe pneumonia.

## Contribution

The study demonstrates that early use of mNGS in pediatric SCAP improves clinical outcomes compared to conventional methods.

## Key findings

- mNGS had a 98.51% detection rate, significantly higher than conventional methods (47.52%).
- Early mNGS was linked to fewer complications and shorter hospital stays in pediatric SCAP patients.
- Antibiotic adjustments based on mNGS included escalation in 24.75% of cases and de-escalation in 10.89%.

## Abstract

Severe community-acquired pneumonia (SCAP) remains a major cause of mortality in the paediatric population, with current diagnostic and treatment approaches often proving insufficient and contributing to the growing challenge of antibiotic resistance. This study explored the potential of metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid as a tool to enhance the precision of antibiotic management in children with SCAP.

A retrospective cohort study of 202 paediatric patients with community-acquired pneumonia (aged 1 month–18 years) admitted to the First Affiliated Hospital of Xinxiang Medical University (November 2020–March 2023) was conducted. Patients were grouped by severity (intensive care unit [ICU]/non-ICU) and mNGS timing (early: ≤72 hours post-admission; late: >72 hours). The diagnostic efficacy of mNGS versus conventional microbiological techniques (CMT) was evaluated using sensitivity, specificity, positive/negative predictive values and area under the receiver operating characteristic curve (AUC) analysis. Antibiotic adjustments and clinical outcomes were analysed via survival statistics.

Metagenomic next-generation sequencing showed a higher positive detection rate (98.51%) than CMT (47.52%) (AUC = 0.82, 95%CI: 0.76–0.88). Of the 202 patients, 127 (62.87%) were male, with a median age of 1.88 years (interquartile range: 0.29–7 years). Early mNGS was associated with fewer extrapulmonary complications (69.63% vs 55.22% in the late group, p < 0.05), and shorter hospitalisation (median 13 vs 15 days, p <0.01). Antibiotic escalation occurred in 50 (24.75%) cases, de-escalation in 22 (10.89%) and same-level adjustment in 25 (12.38%).

Metagenomic next-generation sequencing outperforms CMT in pathogen detection. Early mNGS is associated with improved clinical outcomes, suggesting its potential utility in paediatric SCAP management.