title: Identification of hepatitis B virus subgenotype A3 in rural Gabon.
abstract: An hepatitis B virus (HBV) molecular survey was conducted in five remote villages in the equatorial forest in Gabon, Central Africa. Two hundred seventy out of 311 inhabitants (86.8%) were HBV-infected or had evidence of past HBV infection. Chronic hepatitis corresponding to hepatitis B surface antigen (HBsAg) positivity was suspected in 27 (8.6%) of the HBV-infected subjects. High HBV viral loads were detected mainly in children aged 4-7 years. The pre-S/S domains were sequenced in 13 cases and 12 strains belonged to HBV-A genotype. In one case we found evidence for recombination between genotypes A and E. Phylogenetic analysis revealed that Gabonese HBV strains were distinct from HBV-A subgenotypes (A1 and A2). These new HBV strains from Gabon clustered with previously reported HBV-A3 subgenotype strains from Cameroon and Democratic Republic of Congo. The analysis of the pre-S2 domain allowed us to determine two amino acid substitutions (N/152/S and N/174/T) specific to the Central African HBV-A3 subgenotype strains and one amino acid substitution (P/155/Q) unique to these new Gabonese HBV-A3 subgenotype isolates. Two full genome sequences of two new Gabonese HBV isolates are also presented and confirm the distinctive HBV-Gab-A3 cluster.
authors.affiliation: Laboratoire de Rétrovirologie, Centre International de Recherches Médicales, CIRMF, Franceville, Gabon. mmakuwa@yahoo.com
authors.forename: Maria
authors.initials: M
authors.lastname: Makuwa
authors.forename: Sandrine
authors.initials: S
authors.lastname: Souquière
authors.forename: Paul
authors.initials: P
authors.lastname: Telfer
authors.forename: Cristian
authors.initials: C
authors.lastname: Apetrei
authors.forename: Muriel
authors.initials: M
authors.lastname: Vray
authors.forename: Issa
authors.initials: I
authors.lastname: Bedjabaga
authors.forename: Augustin
authors.initials: A
authors.lastname: Mouinga-Ondeme
authors.forename: Richard
authors.initials: R
authors.lastname: Onanga
authors.forename: Preston A
authors.initials: PA
authors.lastname: Marx
authors.forename: Mirdad
authors.initials: M
authors.lastname: Kazanji
authors.forename: Pierre
authors.initials: P
authors.lastname: Roques
authors.forename: François
authors.initials: F
authors.lastname: Simon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D002648:Child; D002675:Child, Preschool; D005260:Female; D005681:Gabon / Q000453:epidemiology; D005814:Genes, Viral; D006509:Hepatitis B / Q000453:epidemiology* / Q000821:virology; D006514:Hepatitis B Surface Antigens / Q000235:genetics; D006515:Hepatitis B virus / Q000145:classification* / Q000235:genetics; D006801:Humans; D007223:Infant; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D011498:Protein Precursors / Q000235:genetics; D012424:Rural Population; D016415:Sequence Alignment; D013045:Species Specificity; D019562:Viral Load
chemical_list: D006514:Hepatitis B Surface Antigens; D011498:Protein Precursors; C050807:presurface protein 2, hepatitis B surface antigen