title: Nationwide survey of rotavirus-associated encephalopathy and sudden unexpected death in Japan.
abstract: BACKGROUND
  Rotavirus can cause severe complications such as encephalopathy/encephalitis and sudden unexpected death. The incidence of rotavirus-associated encephalopathy/encephalitis or sudden unexpected death remains unknown. To clarify the clinical features of rotavirus-associated encephalitis/encephalopathy and sudden unexpected death, we conducted a nationwide survey in Japan.
  
  
  METHODS
  A two-part questionnaire was designed to determine the number of the cases and the clinical features of severe cases of rotavirus infection, including encephalitis/encephalopathy and sudden unexpected death, between 2009 and 2011.
  
  
  RESULTS
  Of the 1365 questionnaires sent to hospitals, 963 (70.5%) were returned and eligible for analysis. We determined 58 cases of rotavirus-associated encephalitis/encephalopathy and 7 cases of sudden unexpected death. These patients were diagnosed with rotavirus infection by immunochromatography. Although 36/58 (62.1%) encephalitis/encephalopathy patients had no sequelae, 15/58 (25.9%) patients had neurological sequelae, and 7/58 (12.1%) patients had fatal outcomes. Pleocytosis was observed in 9/40 (22.5%) patients and cerebrospinal fluid protein levels were elevated in only 4/40 (10%) patients. Elevated lactate dehydrogenase (LDH) (>500 IU/L) or acidemia (pH<7.15) were related to a poor prognosis.
  
  
  CONCLUSIONS
  We estimate that annual cases of rotavirus-associated encephalitis/encephalopathy and sudden unexpected death were 44.0 and 4.9 cases in Japan, respectively. Elevated LDH (>500 IU/L) or acidemia (pH<7.15) were related to a poor prognosis of the encephalitis/encephalopathy.
authors: Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Aichi, Japan.
authors: Yoshiki
authors: Y
authors: Kawamura
authors: Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Aichi, Japan.
authors: Masahiro
authors: M
authors: Ohashi
authors: Faculty of Clinical Engineering, Fujita Health University School of Health Sciences, Toyoake, Aichi, Japan.
authors: Masaru
authors: M
authors: Ihira
authors: Department of Hygiene, Fujita Health University School of Medicine, Toyoake, Aichi, Japan.
authors: Shuji
authors: S
authors: Hashimoto
authors: Department of Virology and Parasitology, Fujita Health University School of Medicine, Toyoake, Aichi, Japan.
authors: Koki
authors: K
authors: Taniguchi
authors: Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Aichi, Japan. Electronic address: tetsushi@fujita-hu.ac.jp.
authors: Tetsushi
authors: T
authors: Yoshikawa
mesh_terms: D002648:Child; D002675:Child, Preschool; D018792:Encephalitis, Viral / Q000453:epidemiology* / Q000401:mortality; D005260:Female; D006306:Health Surveys; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan; D008297:Male; D011379:Prognosis; D012400:Rotavirus Infections / Q000453:epidemiology* / Q000401:mortality; D011795:Surveys and Questionnaires
keywords: Encephalopathy; Neurological sequelae; Rotavirus; Sudden unexpected death