HPeV3-associated acute encephalitis/encephalopathy among Japanese infants

Objective: The current study aimed to identify and compare the clinical characteristics of human parechovirus type 3 (HPeV3)associated acute encephalitis/encephalopathy (HPeV3E/E) between infants with abnormal brain magnetic resonance imaging (MRI) findings (typical, or MRI-positive HPeV3E/E) and those with MRI-negative findings (MRI-negative HPeV3E/E). Methods: This is a retrospective study on patients with HPeV3 infection, and a two-step questionnaire survey performed on 837 hospitals in Japan between 2014 and 2016. Results: We identified 240 infants with HPeV3 infection, of which 34 had been clinically-diagnosed HPeV3E/E (cHPeV3E/E). However, detailed clinical data were provided by 32 of the 34 patients. Among these 32, 23 had undergone MRI and were categorized into two groups, MRI-positive (n = 17) and-negative (n = 6). There were no significant intergroup differences in clinical lab results or symptoms, except for gastrointestinal symptoms that were only present in the MRI-negative patients. The MRI-positive group showed white matter involvement on brain MRI during the acute phase, and 8 patients presented with lesions on follow-up MRI. Furthermore, 4 (50%) of the 8 patients had neurological sequelae. Conclusion: Clinical characteristics of cHPeV3E/E patients with and without lesions on brain MRI showed no significant differences. Therefore, considering the difficulty in distinguishing febrile infants with cHPeV3E/E from those with a sepsis-like illness, during an HPeV3 infection epidemic, it is imperative to frequently perform brain MRI in febrile infants presenting with severe disease for the early diagnosis of HPeV3E/E presenting with brain lesions. (c) 2020 The Japanese Society of Child Neurology Published by Elsevier B.V. All rights reserved.

Automated summary

This study aimed to compare the clinical characteristics of human parechovirus type 3 (HPeV3) associated acute encephalitis/encephalopathy (HPeV3E/E) between infants with abnormal and normal brain MRI findings. The results showed no significant differences in lab results or symptoms between the two groups, except for gastrointestinal symptoms present only in the MRI-negative patients.