Etiological analysis of the immunosuppressed children with severe pneumonia by metagenomics next generation sequencing / 中国小儿急救医学

ABSTRACT

Objective:To explore the application of metagenomics next generation sequencing(mNGS)in the immunosuppressed children with severe pneumonia and to understand the distribution of pathogens in order to provide reference for early prevention and treatment.Methods:We performed a retrospective analysis of the immunosuppressed children with severe pneumonia who had mNGS reports admitted to PICU according with the enrollment condition from July 2019 to July 2020.The records included general clinical data, traditional detection method report and mNGS results.We evaluated the consistency of the mNGS with the clinical microbiology reports and clinical judgment.Results:Twenty-three patients were enrolled, 15 were male and 8 were female, aging from 28 days to 10 years old, with an average age of(3.67±3.20)years old.Seven cases were cured, 2 were improved, and 14 died.A total of 23 samples were obtained, including 21 blood specimens and 2 bronchoal-veolar lavage fluid specimens.Among the 23 cases, 5 were single infected and 15 were mixed infected.Fungi were detected in 15 cases(65.22%), including 12 cases of Pneumocystis jirovecii, 2 cases of Aspergillus fumigatus and 2 cases of Candida albicans.Virus were detected in 14 cases(60.87%), including cytomegalovirus(CMV) in 10 cases(8 cases with pneumocystis infection), Herpes virus in 3 cases and fine ring virus in 2 cases(1 case with herpes virus infection). Bacteria were detected in 10 cases, including 3 cases of Acinetobacter, 1 case of Klebsiella pneumoniae, 1 case of Stenotrophomonas maltophilia, 1 case of Pinocytogenes, 4 cases of Staphylococcus and 1 case of Bacillus licheniformis.There were Mycoplasma in 3 cases with mixed infection.The positive rate and coincidence rate of mNGS were significantly higher than that of the traditional test group( P<0.05). A total of 19 cases were treated with hormone or immunosuppressive agents, and 17 cases were treated for 1 to 6 months when severe pneumonia occurred. Conclusion:Most immunosuppressed children with severe pneumonia are mixed infection.The common pathogens are Pneumocystis jirovecii and CMV.The use of mNGS can significantly improve the pathogen detection rate, effectively guiding the treatment.