Inconsistency Analysis Between Metagenomic Next-generation Sequencing Results Of Cerebrospinal Fluid And Clinical Diagnosis In Suspected Central Nervous System Infection

Objective:The objective was to analyze the reasons for the inconsistency between CSF sequencing results and clinical diagnosis,and to establish a preliminary m NGS evaluation model.Background:Central nervous system infections,including meningitis,encephalitis,abscess,and myelitis are caused by various infectious agents.Infectious diseases of the CNS are associated with high morbidity and mortality.Metagenomic next-generation sequencing（m NGS）has the potential to identify a wide range of pathogens in a single test,which can increase the detection rate of pathogens of central nervous system infection,but the interpretation of m NGS reports still needs to be standardized.Methods:A retrospective analysis was conducted on 41 inpatients with suspected central nervous system（CNS）infections,and clinical data were recorded.The final diagnosis is determined by the expert group through the patient’s clinical manifestation,laboratory examination,response to treatment,etc.The results of m NGS were compared with the final diagnosis,and the reasons for the inconsistency were analyzed.Results:41 patients suspected of CNS infection were assigned into infected group（ID,31/41,75.61%）,non-infected group（NID,10/41,24.39%）after assessment by the panel of experts according to the composite diagnostic criteria.Mycobacterium tuberculosis（15/31,48.39%）and viruses（9/31,29.03%）are the most common types of pathogens,and the two most easily missed by m NGS detection.The positive coincidence rate of m NGS in the ID was 38.72%（12/31）.The most common cause of inconsistency is the omission of pathogen detection by m NGS（false negative,14 cases）,followed by the microorganisms detected by m NGS,which were regarded as contaminants after evaluation and unrelated to infection（false positive,8 cases）.In addition,the status of colonization cannot be ignored.And the negative coincidence rate of m NGS in the NID was 60%（6/10）.Conclusion:A simple m NGS result interpretation process is established.The integral method is very important to evaluate m NGS results.