title: Possible widespread presence of hepatitis A virus subgenotype IIIA in Japan: Recent trend of hepatitis A causing acute liver failure.
abstract: OBJECTIVE
  Recently, the number of acute hepatitis A cases has decreased in Japan. However, six patients with acute liver failure caused by hepatitis A virus (HAV) have been admitted to Chiba University Hospital, Japan, in the last 18 months, between 2010 and June 2011. The aim of this study is to characterize the recent HAV genotypes from an urban hospital in Japan and to compare the clinical differences.
  
  
  METHODS
  Hepatitis A virus RNA was detected by strand-specific reverse transcription. Then, HAV VP1/2A regions were amplified by nested polymerase chain reaction (PCR). Sequences were directly determined and phylogenetic trees were constructed for determining HAV subgenotypes.
  
  
  RESULTS
  Analysis of these HAV genomes revealed that 4 and 2 belonged to subgenotypes IA and IIIA, respectively.
  
  
  CONCLUSIONS
  Fujiwara et al. reported a frequency of HAV subgenotype IIIA of only 2.1% in Japan. We conclude that HAV subgenotype IIIA might be widespread in our country.
authors.affiliation: Department of Medicine and Clinical Oncology, Graduate School of Medicine, Chiba University, Chiba             Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Miyamura
authors.forename: Koji
authors.initials: K
authors.lastname: Ishii
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Kanda
authors.forename: Akinobu
authors.initials: A
authors.lastname: Tawada
authors.forename: Tadashi
authors.initials: T
authors.lastname: Sekimoto
authors.forename: Shuang
authors.initials: S
authors.lastname: Wu
authors.forename: Shingo
authors.initials: S
authors.lastname: Nakamoto
authors.forename: Makoto
authors.initials: M
authors.lastname: Arai
authors.forename: Keiichi
authors.initials: K
authors.lastname: Fujiwara
authors.forename: Fumio
authors.initials: F
authors.lastname: Imazeki
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kiyohara
authors.forename: Takaji
authors.initials: T
authors.lastname: Wakita
authors.forename: Osamu
authors.initials: O
authors.lastname: Yokosuka