Metagenomic next-generation sequencing for diagnosis of infectious encephalitis and meningitis: a retrospective study of 90 patients

Infections of the central nervous system (CNS) are potentially life-threatening and can cause serious morbidity. We evaluated the clinical value of metagenomic next-generation sequencing (mNGS) in the diagnosis of infectious encephalitis and meningitis and explored the factors affecting the results of mNGS.Patients with suspected cases of encephalitis or meningitis who presented in Northern Jiangsu People's Hospital from 1 March 2018 to 30 September 2022 were collected. Demographic, historical, and clinical information were obtained, and cerebrospinal fluid (CSF) samples were treated with mNGS. The pathogen was identified using National Center for Biotechnology Information (NCBI) GenBank sequence data.Ninety-six patients were screened and finally 90 subjects enrolled. Of the 90 enrolled cases, 67 (74.4%) were diagnosed with central nervous system infections, which included 48 cases (71.6%) of viral infection, 11 (12.2%) of bacterial infection, 5 (7.5%) of mycobacterium tuberculosis, 2 (3.0%) of fungal infection, and 1 (1.5%) of rickettsia infection. From these cases, mNGS identified 40 (44.4%) true-positive cases, 3 (3.3%) false-positive case, 22 (24.4%) true-negative cases, and 25 (27.8%) false-negative cases. The sensitivity and specificity of mNGS were 61.5% and 88%, respectively. mNGS of CSF could show a higher positive rate in patients with marked CSF abnormalities, including elevated protein concentrations and monocyte counts.mNGS of CSF is an effective method for detecting infectious encephalitis and meningitis, and the results should be analyzed combined with conventional microbiological testing results.