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.

Clinical features of capillary bronchitis related to bordetella pertussis.

Pertussis infection can mimick the clinical manifestations of lower airway infection, while the symptoms and signs in some cases are like Bronchiolitis. The paper carried out retrospective analysis of infant pertussis bordetella infected cases admitted by the Respiratory Dept. of Tianjin Children's Hospital for "capillary bronchitis" from Sept. 2015 to Feb. 2016. It analyzed its clinical features, radiological features, laboratory characteristics and outcome through comparing the capillary bronchitis cases induced by the non-bordetella pertussis. 26 cases of patients infected with bordetella pertussis were included in the group, 15 male patients and 11 female patients, aging from 40 days to 11 months. Comparing with non-pertussis infected cases, the capillary bronchitis induced by pertussis presents spasmodic cough, vomiting after cough, apnea suspension and lymphocythemia and obvious prolong of LOS. However the clinical symptom score is decreased and the duration of breathing is shorter. The follow-up visit detects that the recurrent number of respiratory symptoms of pertussis infected children is higher than that of non-pertussis infected children. The clinical symptoms of patients with capillary bronchitis infected by bordetella pertussis are not typical and are susceptible to be ignored. The duration of respiratory symptoms is longer and susceptible for recurrence.