Genomic and serologic characterization of enterovirus A71 brainstem encephalitis

Neurol Neuroimmunol Neuroinflamm. 2020 Mar 5;7(3):e703. doi: 10.1212/NXI.0000000000000703. Print 2020 May.

Abstract

Objective: In 2016, Catalonia experienced a pediatric brainstem encephalitis outbreak caused by enterovirus A71 (EV-A71). Conventional testing identified EV in the periphery but rarely in CSF. Metagenomic next-generation sequencing (mNGS) and CSF pan-viral serology (VirScan) were deployed to enhance viral detection and characterization.

Methods: RNA was extracted from the CSF (n = 20), plasma (n = 9), stool (n = 15), and nasopharyngeal samples (n = 16) from 10 children with brainstem encephalitis and 10 children with meningitis or encephalitis. Pathogens were identified using mNGS. Available CSF from cases (n = 12) and pediatric other neurologic disease controls (n = 54) were analyzed with VirScan with a subset (n = 9 and n = 50) validated by ELISA.

Results: mNGS detected EV in all samples positive by quantitative reverse transcription polymerase chain reaction (qRT-PCR) (n = 25). In qRT-PCR-negative samples (n = 35), mNGS found virus in 23% (n = 8, 3 CSF samples). Overall, mNGS enhanced EV detection from 42% (25/60) to 57% (33/60) (p-value = 0.013). VirScan and ELISA increased detection to 92% (11/12) compared with 46% (4/12) for CSF mNGS and qRT-PCR (p-value = 0.023). Phylogenetic analysis confirmed the EV-A71 strain clustered with a neurovirulent German EV-A71. A single amino acid substitution (S241P) in the EVA71 VP1 protein was exclusive to the CNS in one subject.

Conclusion: mNGS with VirScan significantly increased the CNS detection of EVs relative to qRT-PCR, and the latter generated an antigenic profile of the acute EV-A71 immune response. Genomic analysis confirmed the close relation of the outbreak EV-A71 and neuroinvasive German EV-A71. A S241P substitution in VP1 was found exclusively in the CSF.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Brain Stem*
  • Child, Preschool
  • Cohort Studies
  • Encephalitis, Viral / virology*
  • Enterovirus A, Human / genetics*
  • Enterovirus A, Human / isolation & purification*
  • Enterovirus Infections / virology*
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • High-Throughput Nucleotide Sequencing
  • Humans
  • Infant
  • Male
  • Meningitis, Viral / virology*
  • Phylogeny
  • RNA, Viral / blood
  • RNA, Viral / cerebrospinal fluid
  • RNA, Viral / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sequence Analysis, RNA

Substances

  • RNA, Viral