Application Of Metagenomic Next Generation Sequencing In Infectious Diseases

Objective:In infectious diseases,accurate and rapid etiological diagnosis can guide clinical medication in time,which is very important for the treatment and prognosis of patients.This paper aims to compare the positive rate of the results of second generation sequencing with the results of traditional etiology test and the final clinical diagnosis,and analyze the application value and shortcomings of the second generation sequencing in the etiological diagnosis of infectious diseases.Methods:This study is a retrospective case analysis study.From May 2018 to April 2020,72 patients in the First Affiliated Hospital of Guangxi Medical University were enrolled in this study.Blood,bone marrow fluid,cerebrospinal fluid and other samples were collected.Each patient’s samples were divided into two copies for traditional etiological joint detection and second-generation sequencing.The positive rate of the results obtained by two different detection methods and the coincidence degree with the final clinical diagnosis were compared and analyzed.Results: A total of 72 patients were included in this study.Among them,18 cases got positive results by traditional etiological detection methods,including smear microscopy,pathogen culture and virus nucleic acid detection,and 47 cases got positive results through second-generation sequencing.Compared with the two methods,the second-generation sequencing had a higher positive detection rate,25.00% vs 65.28%(P = 0.000).In terms of virus,1 case was detected by traditional detection method and 20 cases were detected by second-generation sequencing,the positive rate was 1.39% vs 27.78%(P =0.000).In terms of bacteria,5 cases were detected by traditional detection method and 27 cases were detected by second-generation sequencing,the positive rate was 6.94% vs 37.50%(P = 0.000).In terms of fungi,13 cases were detected by traditional pathogen detection method and 11 cases were detected by second-generation sequencing.The positive rate was 18.06% vs 15.28%(P =0.655).Parasite and Rickettsia were only detected in the second generation sequencing,including 3 cases of parasites and 1 case of Rickettsia.Among 18 cases,15 cases were consistent with the final clinical diagnosis,47 cases were positive by second-generation sequencing,and 17 cases were consistent with the final clinical diagnosis,the coincidence rate was 83.33% vs 36.17%(P = 0.01).Conclusion: In the etiological detection of infectious diseases,the positive rate of second-generation sequencing is higher than that of traditional methods.The positive rate of the second generation sequencing was higher in the detection of viruses and bacteria,but there was no significant difference in the detection of fungi.At present,there is no culture method for parasites and Rickettsia,and the clinical diagnosis of pathogens is lack.The second generation sequencing has certain advantages and application value in the diagnosis of parasites and Rickettsia infection.Compared with the final clinical diagnosis,the coincidence of the results of the two methods was higher than that of the second generation sequencing.