title: Difference of HBV genotype distribution between acute hepatitis and chronic hepatitis in Japan.
abstract: BACKGROUND
  Recently genotype A which is rare in the patients in chronic hepatitis B (CHB) was frequently noted in patients with acute hepatitis B (AHB). To investigate their clinical and virological features, we studied the AHB patients in the past 5 years.
  
  
  METHODS
  98 patients with AHB and 80 patients with CHB admitted to our hospital between 1998 and 2003 were studied.
  
  
  RESULTS
  Genotype A was not found in CHB but was frequently noted in AHB (p < 0.001). Comparison of the clinical features of acute hepatitis between the two major genotypes, A and C, homosexual and heterosexual with multiple partners were frequently seen among genotype A patients (p < 0.001). On the other hand, infection from steady partner showed a tendency to be more frequent in genotype C (p = 0.065). In genotype A, the levels of HBVDNA on admission was higher (p = 0.007) and AHB has significantly more frequently progress to chronic infection than in genotype C (p = 0.028). Phylogenetic analysis of genotype A revealed that almost all strains from homosexual men belonged not to the African type A1 but to the Western type A2.
  
  
  CONCLUSIONS
  Genotype A has increased recently among AHB in Japan. This fact may correlate to promiscuous intercourse in high risk group. Prophylactic efforts should be considered to prevent the prevailing of genotype A.
authors.affiliation: Department of Gastroenterology, Nagoya University School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi 466-8550, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Takeda
authors.forename: Y
authors.initials: Y
authors.lastname: Katano
authors.forename: K
authors.initials: K
authors.lastname: Hayashi
authors.forename: T
authors.initials: T
authors.lastname: Honda
authors.forename: S
authors.initials: S
authors.lastname: Yokozaki
authors.forename: I
authors.initials: I
authors.lastname: Nakano
authors.forename: M
authors.initials: M
authors.lastname: Yano
authors.forename: K
authors.initials: K
authors.lastname: Yoshioka
authors.forename: H
authors.initials: H
authors.lastname: Toyoda
authors.forename: T
authors.initials: T
authors.lastname: Kumada
authors.forename: H
authors.initials: H
authors.lastname: Goto
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D005838:Genotype; D006509:Hepatitis B / Q000453:epidemiology / Q000635:transmission* / Q000821:virology*; D006515:Hepatitis B virus / Q000235:genetics* / Q000302:isolation & purification*; D019694:Hepatitis B, Chronic / Q000453:epidemiology / Q000635:transmission* / Q000821:virology*; D018451:Homosexuality, Male; D006801:Humans; D018445:Infectious Disease Transmission, Vertical; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010802:Phylogeny