Study On The Application Value Of Next-generation Sequencing In Pulmonary Infectious Diseases

Objective:To explore the application value of next generation sequencing(NGS)in the distribution of microorganisms,etiological diagnosis and clinical diagnosis and treatment strategies in patients with pulmonary infection complicated with basic diseases,immunosuppression and severe pneumonia.Methods:A retrospective analysis was performed from August 2018 to December2019 of Hunan Provincial People’s Hospital’s Department of Respiratory and Critical Care Medicine for clinical diagnosis of lung infection.Clinical data of116 patients who had completed bronchoscopy and NGS examination were collected.63 patients with basic diseases,13 patients with immunosuppressive status,and 28 patients with severe pneumonia were excluded from the specimens.The results of NGS of alveolar lavage fluid were analyzed based on clinical data.Results:Among the three kinds of pulmonary infection patients with different characteristics,there is no significant difference in the distribution of bacteria,Streptococcus and veronococcus are the main bacteria;Candida plays an important role in the distribution of fungi in patients with three different characteristics of pulmonary infection,but Pneumocystis is the most common pathogen in patients with immunosuppression;The detection rate of Epstein Barr virus was the highest in the patients with three different characteristics of pulmonary infection,but adenovirus is the most common cause of disease in the patients with severe pneumonia.Compared with traditional laboratory culture,NGS showed an advantage in the positive rates of three pathogens with different characteristics of pulmonary infection: Patients with underlying diseases(66.67% vs 19.05%,P < 0.001)),patients with immunosuppression(69.23% vs 15.38%,P = 0.015),and patients with severe pneumonia(78.57%vs 32.14%),P = 0.001),but there was no significant difference in the positive rate of NGS among the patients with three different characteristics of pulmonary infection(66.67% vs 69.23% vs 78.57%)P = 0.517).In addition,this study found that the results of NGS have important guiding significance for clinical treatment strategies in patients with pulmonary infection complicated by basic diseases and severe pneumonia(38.10% and 53.57%),In contrast,only 23.08% of patients with pulmonary infection complicated by immunosuppression,and the difference between the three was a statistically significant difference(38.10% vs 53.57% vs 23.08%,P = 0.001).Conclusion:1.There is no significant difference in the distribution of bacteria amongthe three different characteristics of pulmonary infection patients,Streptococcus and veronicus are the main bacteria;Candida is the most important fungus among the three different characteristics of pulmonary infection,but Pneumocystis is the most common pathogen in patients with immunosuppression;The detection rate of Epstein Barr virus was the highest in the patients with three different characteristics of pulmonary infection,but adenovirus is the most common cause of disease in the patients with severe pneumonia.2.NGS is better than traditional laboratory culture in the diagnosis of three different characteristics of pulmonary infection,especially in patients with basic diseases and severe pneumonia.3.Compared with the combination of immunosuppression,the results of NGS have more guiding significance for the treatment strategies of patients with pulmonary infection complicated with basic diseases and patients with pulmonary infection developed into severe pneumonia.