title: Geographic distribution and characteristics of genotype A hepatitis B virus infection in acute and chronic hepatitis B patients in Japan.
abstract: OBJECTIVE
  The prevalence of sexually transmitted acute infections of the genotype A hepatitis B virus (HBV) has been increasing in Japan. Genotype A HBV is associated with an increased risk of HBV progression to chronic infection after acute hepatitis B (AHB) in adults. A nationwide survey was conducted to evaluate the geographic distribution, clinical, and virologic characteristics of genotype A AHB and chronic hepatitis B (CHB) in Japan.
  
  
  METHODS
  Five hundred seventy AHB patients were recruited between 2005 and 2010, and 3682 CHB patients were recruited between 2010 and 2011. HBV genotypes were determined for 552 and 3619 AHB and CHB patients, respectively. Clinical characteristics were compared among different genotypes in AHB and CHB patients. Genomic characteristics of HBV genotype A were examined by molecular evolutionary analysis.
  
  
  RESULTS
  Hepatitis B virus genotype A was the predominant genotype for AHB between 2005 and 2010. Phylogenetic analysis showed that all strains in the AHB patients with genotype A were classified into subtype Ae. Among CHB patients, the occurrence of genotype A was 4.1%, and genotype A was spreading in young adults. In genotype A CHB patients, early stage liver diseases were predominant, although liver diseases progressed to cirrhosis or hepatocellular carcinoma in some patients.
  
  
  CONCLUSIONS
  The distribution of HBV genotypes is quite different between AHB and CHB in Japanese patients. Genotype A infection is spreading in young adults of Japanese CHB patients. Sequences derived from Japanese AHB patients were identical to or closely resembled the sequences derived from other Japanese AHB patients.
authors.affiliation: The Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, Ichikawa.|Department of Gastroenterology, Aichi Medical University School of Medicine, Nagakute.
authors.forename: Kiyoaki
authors.initials: K
authors.lastname: Ito
authors.affiliation: Department of Internal Medicine, Graduate School of Medicine, The University of Tokyo.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yotsuyanagi
authors.affiliation: The Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, Ichikawa.
authors.forename: Masaya
authors.initials: M
authors.lastname: Sugiyama
authors.affiliation: Clinical Research Center, NHO Nagasaki Medical Center, Nagasaki.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yatsuhashi
authors.affiliation: Department of Gastroenterology, Sapporo Kosei General Hospital, Sapporo.
authors.forename: Yoshiyasu
authors.initials: Y
authors.lastname: Karino
authors.affiliation: Division of Hepatology, Department of Internal Medicine, Iwate Medical University, Morioka.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Takikawa
authors.affiliation: Department of Gastroenterology, Yamagata University School, Yamagata.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Saito
authors.affiliation: Department of Hepatology, Toranomon Hospital.
authors.forename: Yasuji
authors.initials: Y
authors.lastname: Arase
authors.affiliation: Department of Medicine and Clinical Oncology, Graduate School of Medicine, Chiba University, Chiba.
authors.forename: Fumio
authors.initials: F
authors.lastname: Imazeki
authors.affiliation: Division of Gastroenterology and Hepatology, Musashino Red Cross Hospital, Tokyo.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kurosaki
authors.affiliation: Department of Medicine, Shinshu University School of Medicine, Matsumoto.
authors.forename: Takeji
authors.initials: T
authors.lastname: Umemura
authors.affiliation: Department of Gastroenterology and Hepatology, Juntendo University Shizuoka Hospital, Shizuoka.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ichida
authors.affiliation: Department of Gastroenterology, Ogaki Municipal Hospital, Ogaki.
authors.forename: Hidenori
authors.initials: H
authors.lastname: Toyoda
authors.affiliation: Department of Gastroenterology, Aichi Medical University School of Medicine, Nagakute.
authors.forename: Masashi
authors.initials: M
authors.lastname: Yoneda
authors.affiliation: Nagoya City University Graduate School of Medical Sciences, Nagoya.
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: National Hospital Organization Osaka National Hospital, Osaka.
authors.forename: Eiji
authors.initials: E
authors.lastname: Mita
authors.affiliation: Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Okayama.
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: Department of Gastroenterology, Ehime University Graduate School of Medicine, Toon.
authors.forename: Kojiro
authors.initials: K
authors.lastname: Michitaka
authors.affiliation: First Department of Internal Medicine, University Hospital, Faculty of Medicine, University of the Ryukyu, Okinawa, Japan.
authors.forename: Tatsuji
authors.initials: T
authors.lastname: Maeshiro
authors.affiliation: AIDS Clinical Center, National Center for Global Health and Medicine, Tokyo.
authors.forename: Junko
authors.initials: J
authors.lastname: Tanuma
authors.affiliation: The Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, Ichikawa.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Korenaga
authors.affiliation: The Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, Ichikawa.
authors.forename: Kazumoto
authors.initials: K
authors.lastname: Murata
authors.affiliation: The Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, Ichikawa.
authors.forename: Naohiko
authors.initials: N
authors.lastname: Masaki
authors.affiliation: Department of Internal Medicine, Graduate School of Medicine, The University of Tokyo.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Koike
authors.affiliation: The Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, Ichikawa.
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizokami
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D005260:Female; D005838:Genotype; D006509:Hepatitis B / Q000453:epidemiology* / Q000821:virology*; D006515:Hepatitis B virus / Q000235:genetics*; D019694:Hepatitis B, Chronic / Q000453:epidemiology* / Q000821:virology*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010802:Phylogeny
keywords: acute hepatitis B; chronic hepatitis B; distribution; genotype; human immunodeficiency virus