New natural variants of hepatitis B virus among Amerindians from Argentina with mainly occult infections

DELFINO C; BERINI CA; EIRIN ME; MALAN R; PEDROZO W; KRUPP R; BLEJER J; ESPEJO R; FIERRO L; PUCA A; OUBIÑA J; MATHET V; BIGLIONE MM

JOURNAL OF CLINICAL VIROLOGY : THE OFFICIAL PUBLICATION OF THE PAN AMERICAN SOCIETY FOR CLINICAL VIROLOGY.

ELSEVIER SCIENCE BV

Año: 2012

1386-6532

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 acidsequence of both S and viral polymerase (P) genes among Amerindians of Argentina.Study design: A cross-sectional study including 561 individuals belonging to distinct ethnic groups, theMbyá-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 wasdetected in all communities. HBV DNA of S/P and preCore-Core genomic regions were amplified by nestedpolymerase chain reaction in 59 reactive samples for anti-HBc total Ig and/or HBsAg. Of them, thirteenexhibited detectable HBV DNA, eleven of which were identified as OBI. Genotype F was predominant inthe MG community with co-circulation of subgenotypes F4, F1b, A2 and D3, while subgenotype C2 prevailedwithin the SH community. All cases exhibited the polymorphism rtL217R within the RT domainassociated to resistance to adefovir. Mutations rtD206E and rtV207I associated with lamivudine resistancewere found in two MG and three SH respectively. Other new substitutions were described withinthe P sequence.Conclusions: This study shows for the first time the predominance of OBI, HBV subgenotypes and naturalvariants in Amerindians from Argentina.