title: New natural variants of hepatitis B virus among Amerindians from Argentina with mainly occult infections.
abstract: BACKGROUND
  Hepatitis B virus infection is frequent among Amerindians. In Argentina HBV genotypes A, B, C, D, E, F and H were described in different populations, while some cases of occult hepatitis B infection (OBI) were reported in human immunodeficiency virus (HIV) coinfected patients.
  
  
  OBJECTIVE
  To determine the prevalence, genetic diversity of HBV and to analyze the deduced amino acid sequence of both S and viral polymerase (P) genes among Amerindians of Argentina.
  
  
  METHODS
  A cross-sectional study including 561 individuals belonging to distinct ethnic groups, the Mbyá-guaraní (MG), the Kolla (K), the Sagua-Huarpe (SH) and the Wichi (W) was performed.
  
  
  RESULTS
  The prevalence of HBsAg was 1.7% and 1.4% for the MG and SH, respectively, while anti-HBc was detected in all communities. HBV DNA of S/P and preCore-Core genomic regions were amplified by nested polymerase chain reaction in 59 reactive samples for anti-HBc total Ig and/or HBsAg. Of them, thirteen exhibited detectable HBV DNA, eleven of which were identified as OBI. Genotype F was predominant in the MG community with co-circulation of subgenotypes F4, F1b, A2 and D3, while subgenotype C2 prevailed within the SH community. All cases exhibited the polymorphism rtL217R within the RT domain associated to resistance to adefovir. Mutations rtD206E and rtV207I associated with lamivudine resistance were found in two MG and three SH respectively. Other new substitutions were described within the P sequence.
  
  
  CONCLUSIONS
  This study shows for the first time the predominance of OBI, HBV subgenotypes and natural variants in Amerindians from Argentina.
authors.affiliation: National Reference Center for AIDS, Department of Microbiology, Parasitology and Immunology, Faculty of Medicine, University of Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina. cdelfino@fmed.uba.ar
authors.forename: Cecilia M
authors.initials: CM
authors.lastname: Delfino
authors.forename: Carolina
authors.initials: C
authors.lastname: Berini
authors.forename: María E
authors.initials: ME
authors.lastname: Eirin
authors.forename: Richard
authors.initials: R
authors.lastname: Malan
authors.forename: Williams
authors.initials: W
authors.lastname: Pedrozo
authors.forename: Ramón
authors.initials: R
authors.lastname: Krupp
authors.forename: Jorgelina
authors.initials: J
authors.lastname: Blejer
authors.forename: Rogelio
authors.initials: R
authors.lastname: Espejo
authors.forename: Leopoldo
authors.initials: L
authors.lastname: Fierro
authors.forename: Alberto
authors.initials: A
authors.lastname: Puca
authors.forename: José R
authors.initials: JR
authors.lastname: Oubiña
authors.forename: Verónica L
authors.initials: VL
authors.lastname: Mathet
authors.forename: Mirna M
authors.initials: MM
authors.lastname: Biglione
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001118:Argentina; D016000:Cluster Analysis; D003430:Cross-Sectional Studies; D004279:DNA, Viral / Q000097:blood* / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006509:Hepatitis B / Q000821:virology*; D006515:Hepatitis B virus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007199:Indians, South American; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D014764:Viral Proteins / Q000235:genetics; D055815:Young Adult
chemical_list: D004279:DNA, Viral; D014764:Viral Proteins