RNA- sequencing- based detection of human viral pathogens in cerebrospinal fluid and serum samples from children with meningitis and encephalitis

Encephalitis and meningitis are notable global public health concerns, especially among infants or children. Metagenomic next- generation sequencing (mNGS) has greatly advanced our understanding of the viruses responsible for these diseases. However, the detection rate of the aetiology remains low. We conducted RNA sequencing and virome analysis on cerebrospinal fluid (CSF) and serum samples commonly used in the clinical diagnosis to detect viral pathogens. In total, 226 paired CSF and serum samples from 113 children with encephalitis and meningitis were enrolled. The results showed that the diversity of viruses was higher in CSF, with a total of 12 viral taxa detected, including one case each of herpesvirus, coronavirus and enterovirus, and six cases of adenovirus related to human diseases. In contrast, the Anelloviridae was the most abundant viral family detected in serum, and only a few samples contained human viral pathogens, including one case of enterovirus and two cases of adenovirus. The detection rate for human viral pathogens increases to 10.6 %(12/113) when both types of samples are used simultaneously, compared to CSF along 7.9 % (9/113) or serum alone 2.6 % (3/113). However, we did not detect these viruses simultaneously in paired samples from the same case. These results suggest that CSF samples still have irreplaceable advantages for using mNGS to detect viruses in patients with meningitis and encephalitis, and serum can supplement to improve the detection rate of viral encephalitis and meningitis. The findings of this study could help improve the etiological diagnosis, clinical management and prognosis of patients with meningitis and encephalitis in children.