[Observational Study on the Diagnostic Efficacy of Metagenomic Next-Generation Sequencing for Bloodstream Infections Secondary to Hematologic Diseases in Children].

Objective: To explore the clinical application value of metagenomic next-generation sequencing (mNGS) in pathogen detection of bloodstream infection secondary to hematologic diseases in children.

Methods: 42 children with bloodstream infections secondary to hematologic diseases admitted to the Children's Hematology and Tumor Center of the Affiliated Hospital of Guangdong Medical University from November 2021 to May 2023 were included in the study, and their clinical data, results of peripheral blood mNGS and traditional blood culture, pathogen distribution characteristics, and diagnostic efficacy of mNGS were retrospectively analyzed.

Results: Among the 42 children included, there were 2 cases (4.8%) of aplastic anemia (AA), 27 cases (64.3%) of acute lymphoblastic leukemia (ALL), 7 cases (16.7%) of acute myeloid leukemia (AML), 1 case (2.4%) of chronic myeloid leukemia (CML), 2 cases (4.8%) of hemophagocytic lymphohistiocytosis (HLH), 2 cases (4.8%) of non-Hodgkin lymphoma (NHL), and 1 case (2.4%) of Wiskott-Aldrich syndrome (WAS). In mNGS testing, pathogens were detected in 31 peripheral blood samples, with a positive rate of 73.8% (31/42), significantly higher than the pathogen positive rate of 16.7% (7/42) detected by traditional blood culture, and the difference was statistically significant (P < 0.05). Among the pathogen-positive cases detected by mNGS, 23 cases (74.2%) were positive for bacteria, 12 cases (38.7%) were positive for viruses, and 9 cases (29.0%) were positive for fungi. 32.2% (10/31) of the pathogen-positive samples detected by mNGS were mixed pathogens, which could not be effectively detected by traditional blood culture.

Conclusion: Peripheral blood mNGS has advantages in the detection of pathogens of bloodstream infection secondary to hematologic diseases, with a higher detection rate of pathogen positivity than traditional blood cultures. It can detect viruses, rare pathogens and mixed pathogens, and has good clinical application value.