Metagenomic next-generation sequencing for detecting lower respiratory tract infections in sputum and bronchoalveolar lavage fluid samples from children

Lower respiratory tract infections are common in children. Bronchoalveolar lavage fluid has long been established as the best biological sample for detecting infections; however, it is not easily collected Sputum may be used an alternative yet its diagnostic accuracy remains controversial. Therefore, this study sought to evaluate of sputum lower using metagenomic next-generation sequencing. Paired and bronchoalveolar samples were obtained from 68 patients; pathogens detected 67 64 by sequencing, respectively. The combined pathogen-detection rates 80.90% 66.2%, For sputum, positive predictive values (PPVs) negative (NPVs) bacteria 0.72 0.73, respectively, with poor Kappa agreement (0.30; 95% confidence interval: 0.218–0.578, P < 0.001). However, viral detection had good sensitivity (0.87), fair specificity (0.57), moderate (0.46; 0.231–0.693, PPVs NPVs 0.82 0.67, consistency between was bacterial detection. Thus, clinicians should cautious when interpreting results suspected cases infections, particularly regards sputum. Viral appears more reliable; must still use comprehensive clinical judgment.