The Impact of mNGS Technology in the Etiological Diagnosis of Severe Pneumonia in Children During the Epidemic of COVID-19

Purpose: Metagenomic next-generation sequencing (mNGS) is an emerging technique for pathogen detection. However, most literature on the clinical application of pediatrics generally comprises case reports or small-scale cohort studies. Patients and Methods: A total of 101 children with community-acquired severe pneumonia admitted to Tianjin Children’s Hospital from November 2021 to February 2022 were included. Pathogens in bronchoalveolar lavage fluid (BALF) specimens were detected using mNGS. The performances of mNGS and conventional tests on pulmonary infection diagnosis and pathogen identification were compared. Results: According to our data, mNGS had a broader spectrum for pathogen detection. The mNGS results of BALF showed that the number of children with severe pneumonia hospitalized for mycoplasma pneumoniae infection was more than that for other bacterial infections during the COVID-19 epidemic. In addition, 43 cases (42.6%) had been identified with mixed infection, including 36 cases (35.6%) of Mycoplasma pneumoniae mixed with other pathogenic bacteria. Analytically, the mNGS exhibited significantly enhanced detection in the BALF as compared with the conventional laboratory pathogenic detection approaches ( P < 0.05). The Pearson correlation analysis revealed positive correlation between the time of fever during hospitalization and the number of mycoplasma sequences ( P < 0.05). Conclusion: Compared with traditional methods, mNGS has a higher etiological detection rate and can comprehensively detect various pathogens of severe pneumonia. Therefore, mNGS of bronchoalveolar lavage fluid should be performed in children with severe pneumonia, which is of great significance for guiding treatment. Keywords: mNGS, severe pneumonia, pathogen, BALF, children