title: A child with acute encephalopathy associated with quadruple viral infection.
abstract: Pediatric acute encephalopathy (AE) was sometimes attributed to virus infection. However, viral infection does not always result in AE. The risk factors for developing infantile AE upon virus infection remain to be determined. Here, we report an infant with AE co-infected with human herpesvirus-6 (HHV-6) and three picornaviruses, including coxsackievirus A6 (CVA6), Enterovirus D68 (EV-D68), and human parechovirus (HPeV). EV-D68 was vertically transmitted to the infant from his mother. CVA6 and HPeV were likely transmitted to the infant at the nursery school. HHV-6 might be re-activated in the patient. It remained undetermined, which pathogen played the central role in the AE pathogenesis. However, active, simultaneous infection of four viruses should have evoked the cytokine storm, leading to the pathogenesis of AE.
  
  
  CONCLUSIONS
  an infant case with active quadruple infection of potentially AE-causing viruses was seldom reported partly because systematic nucleic acid-based laboratory tests on picornaviruses were not common. We propose that simultaneous viral infection may serve as a risk factor for the development of AE.
authors.affiliation: Department of Infectious Diseases, Osaka Prefectural Institute of Public Health , Osaka , Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Nakata
authors.affiliation: Department of Paediatrics, Hirakata City Hospital , Hirakata , Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Kashiwagi
authors.affiliation: Department of Paediatrics, Hirakata City Hospital , Hirakata , Japan.
authors.forename: Midori
authors.initials: M
authors.lastname: Masuda
authors.affiliation: Department of Paediatrics, Hirakata City Hospital , Hirakata , Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Shigehara
authors.affiliation: Department of Paediatrics, Hirakata City Hospital , Hirakata , Japan.
authors.forename: Chizu
authors.initials: C
authors.lastname: Oba
authors.affiliation: Department of Paediatrics, Hirakata City Hospital , Hirakata , Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Murata
authors.affiliation: Department of Infectious Diseases, Osaka Prefectural Institute of Public Health , Osaka , Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Kase
authors.affiliation: Department of Infectious Diseases, Osaka Prefectural Institute of Public Health , Osaka , Japan ; Department of Clinical Laboratory, National Hospital Organization Nagoya Medical Center , Nagoya , Japan.
authors.forename: Jun A
authors.initials: JA
authors.lastname: Komano
keywords: acute encephalopathy; coxsackievirus A6; enterovirus D68; human herpesvirus-6; human parechovirus; risk factor; viral co-infection