title: Distribution of HBV genotypes among HBV carriers in Benin:phylogenetic analysis and virological characteristics of HBV genotype E.
abstract: OBJECTIVE
  To determine the distribution of Hepatitis B virus (HBV) genotypes in Benin, and to clarify the virological characteristics of the dominant genotype.
  
  
  METHODS
  Among 500 blood donors in Benin, 21 HBsAg-positive donors were enrolled in the study. HBV genotypes were determined by enzyme immunoassay and restriction fragment length polymorphism. Complete genome sequences were determined by PCR and direct sequencing.
  
  
  RESULTS
  HBV genotype E (HBV/E) was detected in 20/21 (95.2%), and HBV/A in 1/21 (4.8%). From the age-specific prevalence of HBeAg to anti-HBe seroconversion (SC) in 19 HBV/E subjects, SC was estimated to occur frequently in late teens in HBV/E. The comparison of four complete HBV/E genomes from HBeAg-positive subjects in this study and five HBV/E sequences recruited from the database revealed that HBV/E was distributed throughout West Africa with very low genetic diversity (nucleotide homology 96.7-99.2%). Based on the sequences in the basic core promoter (BCP) to precore region of the nine HBV/E isolates compared to those of the other genotypes, a nucleotide substitution in the BCP, G1757A, was observed in HBV/E.
  
  
  CONCLUSIONS
  HBV/E is predominant in the Republic of Benin,and SC is estimated to occur in late teens in HBV/E. The specific nucleotide substitution G1757A in BCP,which might influence the virological characteristics, is observed in HBV/E.
authors.affiliation: Department of Clinical Molecular Informative Medicine, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho, Nagoya 467-8601, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Fujiwara
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Etsuro
authors.initials: E
authors.lastname: Orito
authors.forename: Tomoyoshi
authors.initials: T
authors.lastname: Ohno
authors.forename: Takanobu
authors.initials: T
authors.lastname: Kato
authors.forename: Kanji
authors.initials: K
authors.lastname: Sugihara
authors.forename: Izumi
authors.initials: I
authors.lastname: Hasegawa
authors.forename: Mayumi
authors.initials: M
authors.lastname: Sakurai
authors.forename: Kiyoaki
authors.initials: K
authors.lastname: Ito
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ozasa
authors.forename: Yuko
authors.initials: Y
authors.lastname: Sakamoto
authors.forename: Isao
authors.initials: I
authors.lastname: Arita
authors.forename: Ahmed
authors.initials: A
authors.lastname: El-Gohary
authors.forename: Agossou
authors.initials: A
authors.lastname: Benoit
authors.forename: Sophie I
authors.initials: SI
authors.lastname: Ogoundele-Akplogan
authors.forename: Namiko
authors.initials: N
authors.lastname: Yoshihara
authors.forename: Ryuzo
authors.initials: R
authors.lastname: Ueda
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizokami
mesh_terms: D000293:Adolescent; D000328:Adult; D001541:Benin / Q000453:epidemiology; D002353:Carrier State / Q000453:epidemiology / Q000821:virology; D005260:Female; D005838:Genotype; D006509:Hepatitis B / Q000453:epidemiology* / Q000821:virology*; D006512:Hepatitis B Core Antigens / Q000235:genetics; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D008297:Male; D010802:Phylogeny
chemical_list: D006512:Hepatitis B Core Antigens