A nationwide survey of human metapneumovirus-associated encephalitis/encephalopathy in Japan

Brain Dev. 2023 Apr;45(4):197-204. doi: 10.1016/j.braindev.2023.01.001. Epub 2023 Jan 24.

Abstract

Background: As there have been no comprehensive reports of human metapneumovirus-associated encephalopathy (hMPVE), this study examined the clinical features of hMPVE in children in Japan.

Method: A nationwide survey of children with hMPVE was conducted using a structured research form. An initial survey asked pediatricians about children with hMPVE treated between 2014 and 2018. A second survey obtained patient information from hospitals that responded to the initial survey and those identified as having treated cases from a literature search. We collected demographic data, symptoms of hMPV infection, neurological symptoms, laboratory data, treatment, and outcomes. Outcomes were determined using the Pediatric Cerebral Performance Category Score.

Result: Clinical information was available for 16 children. Their median age was 37 months. Six had preexisting neurological disorders. The interval between the onsets of infection and hMPVE was 4 days. Outcomes were good in 11 patients and poor in 5. There were no significant differences in demographic data, neurological symptoms, or laboratory data between the patients with good and poor outcomes. The encephalopathy subtypes were acute encephalopathy with biphasic seizures and late reduced diffusion in 3, clinically mild encephalitis/encephalopathy with a reversible splenial lesion in 3, hemorrhagic shock and encephalopathy syndrome in 2, and others in 8.

Conclusion: The outcomes of children with hMPVE were not very different from those of acute encephalopathy due to other viruses. We found no factors associated with poor outcomes.

Keywords: Children; Encephalopathy; Human metapneumovirus; Outcome.

MeSH terms

  • Brain Diseases* / complications
  • Brain Diseases* / epidemiology
  • Child
  • Child, Preschool
  • Encephalitis* / complications
  • Encephalitis* / epidemiology
  • Humans
  • Japan / epidemiology
  • Metapneumovirus*
  • Seizures / complications