Application Of Metagenomic Next-generation Sequencing Of Cerebrospinal Fluid In Central Nervous System Infection

Objectives:To explore the application of Metagenome Next-Generation sequencing(mNGS)in cerebrospinal fluid in central nervous system infection(ICNS)diseases.ICNS disease is an acute or chronic inflammatory or non-inflammatory disease caused by pathogenic microorganisms invading the substance,capsule and blood vessels of the central nervous system(CNS).ICNS disease represented by encephalitis can be acute and severe,which can lead to disability and death,so timely and correct diagnosis is very important for the treatment and prognosis of patients.mNGS can detect pathogens in a short time,and the positive rate is higher than traditional pathogen detection methods,so it can guide early diagnosis and improve the course and prognosis of patients.Methods:I collected the clinical data of 62 patients who were hospitalized in the Department of Neurology of the first Bethune Hospital of Jilin University from January 2021 to December 2021 and were finally diagnosed as ICNS disease and tested by mNGS in cerebrospinal fluid: sex,age,past history,clinical symptoms,positive signs,serological examination(blood routine,hypersensitive C-reactive protein,procalcitonin),cerebrospinal fluid test(pressure,protein,white blood cell),Traditional pathogen detection results such as cerebrospinal fluid smear,staining,microscopic examination and culture,cerebrospinal fluid serological immune reaction test,polymerase chain reaction detection,cerebrospinal fluid pathogen nucleic acid,cerebrospinal fluid mNGS results(including pathogen species,sequence number,background microorganism and its sequence number),final clinical diagnosis,admission to neurological intensive care unit,disease prognosis.A single center retrospective study was conducted on 62 cases included in the study.The statistical method of Mc Nemar test was used to compare the difference of the positive rate of pathogens in cerebrospinal fluid between traditional pathogen detection method and mNGS test.Results:The age of the patients ranged from 17 to 82 years old,with an average age of 45.5years.There were 36 male patients and 26 female patients.Among the 62 patients,28 cases were diagnosed with viral infection,17 cases with general bacterial infection,15 cases with Mycobacterium tuberculosis infection and 2 cases with fungal infection.mNGS detection method detected 32 cases of pathogens,with a positive rate of 51.6%.The positive results included 17 cases of general bacteria,7 cases of viruses,5 cases of Mycobacterium tuberculosis and 3 cases of fungi.11 cases of pathogens were detected by traditional detection methods,with a positive rate of 17.7%.Fever,headache and disturbance of consciousness are the most common first symptoms,and other clinical manifestations include dizziness,nausea and vomiting,abnormal mental behavior,seizures,limb weakness,speech dysfunction,cranial nerve paralysis;the most common positive signs are Neck rigidity,positive Kirschner sign,and others include eye movement disorder,aphasia,positive pathological signs,paralysis,skin herpes and so on.Routine serological examination showed that routine blood leukocyte count,hypersensitive C-reactive protein and procalcitonin were increased,and cerebrospinal fluid pressure,white blood cell count and protein were all increased.42 patients were in critical condition and were admitted to neurological intensive care unit.After active treatment,60 patients improved and 2 patients died.Conclusion:The positive rate of pathogens detected by mNGS detection method in cerebrospinal fluid is higher than that of traditional detection methods,and has significant statistical significance,which can assist in early diagnosis of ICNS,so as to improve the prognosis of patients and reduce mortality.In viral ICNS,the positive rate of mNGS is higher than that of traditional methods,and the two methods are consistent,but the consistency is poor.However,in general bacteria,Mycobacterium tuberculosis and fungal ICNS,it can not be considered that the positive rate of mNGS is higher than that of traditional methods.And the two detection methods are not consistent.In the final clinical diagnosis,there are still nearly 2 hand 5 patients who can not identify the pathogens,most of which are consistent with viral infection.