title: Distribution of hepatitis B virus genotypes among patients with chronic infection in Japan shifting toward an increase of genotype A.
abstract: Acute hepatitis B virus (HBV) infection has been increasing through promiscuous sexual contacts, and HBV genotype A (HBV/A) is frequent in patients with acute hepatitis B (AHB) in Japan. To compare the geographic distribution of HBV genotypes in patients with chronic hepatitis B (CHB) in Japan between 2005 and 2006 and between 2000 and 2001, with special attention to changes in the proportion of HBV/A, a cohort study was performed to survey changes in genotypes of CHB patients at 16 hospitals throughout Japan. Furthermore, we investigated the clinical characteristics of each genotype and examined the genomic characteristics of HBV/A isolates by molecular evolutionary analyses. Of the 1,271 patients, 3.5%, 14.1%, and 82.3% were infected with HBV/A, -B, and -C, respectively. In comparison with our previous survey during 2000 and 2001, HBV/A was twice as frequent (3.5% versus 1.7%; P = 0.02). The mean age was lower in the patients with HBV/A than in those with HBV/B or -C. Based on phylogenetic analyses of 11 full-length genomes and 29 pre-S2/S region sequences from patients, HBV/A isolates were imported from Europe and the United States, as well as the Philippines and India. They clustered with HBV/A from AHB patients and have spread throughout Japan. HBV/A has been increasing in CHB patients in Japan as a consequence of AHB spreading in the younger generation through promiscuous sexual contacts, aided by a tendency of HBV/A to induce chronic hepatitis. The spread of HBV/A infection in Japan should be prevented by universal vaccination programs.
authors.affiliation: Department of Clinical Molecular Informative Medicine, Nagoya City University Graduate School of Medical Sciences, Kawasumi, Mizuho, Nagoya, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Matsuura
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Shuhei
authors.initials: S
authors.lastname: Hige
authors.forename: Gotaro
authors.initials: G
authors.lastname: Yamada
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Murawaki
authors.forename: Masafumi
authors.initials: M
authors.lastname: Komatsu
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Kuramitsu
authors.forename: Sumio
authors.initials: S
authors.lastname: Kawata
authors.forename: Eiji
authors.initials: E
authors.lastname: Tanaka
authors.forename: Namiki
authors.initials: N
authors.lastname: Izumi
authors.forename: Chiaki
authors.initials: C
authors.lastname: Okuse
authors.forename: Shinichi
authors.initials: S
authors.lastname: Kakumu
authors.forename: Takeshi
authors.initials: T
authors.lastname: Okanoue
authors.forename: Keisuke
authors.initials: K
authors.lastname: Hino
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Hiasa
authors.forename: Michio
authors.initials: M
authors.lastname: Sata
authors.forename: Tatsuji
authors.initials: T
authors.lastname: Maeshiro
authors.forename: Fuminaka
authors.initials: F
authors.lastname: Sugauchi
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Nojiri
authors.forename: Takashi
authors.initials: T
authors.lastname: Joh
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Miyakawa
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizokami
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016000:Cluster Analysis; D004279:DNA, Viral / Q000235:genetics*; D005260:Female; D005838:Genotype; D006515:Hepatitis B virus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D019694:Hepatitis B, Chronic / Q000821:virology*; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D055815:Young Adult
chemical_list: D004279:DNA, Viral