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

CECILIA MARIA DELFINO; CAROLINA BERINI; MARIA EMILIA EIRIN; RICHARD MALAN; WILLIAM PEDROZO,; RAMÓN KRUPP; JORGELINA BLEJER; HORACIO SALAMONE; ROGELIO ESPEJO; LEOPOLDO FIERRO; ALBERTO PUCA; JOSÉ R.OUBIÑA; VERÓNICA L. MATHET; MIRNA BIGLIONE

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

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2012 vol. 54 p. 174 - 179

1386-6532

Background: HBV infection is frequent among Amerindians. Objective: To determine the prevalence, genetic diversity of HBV and to analyze the amino acidic sequence of HBsAg (S) and viral polymerase (P) among Amerindians of Argentina. Study design: A cross-sectional study was conducted from 2007 to 2008 including 561 Amerindians belonging to distinct ethnic groups, the Mbyá-guaraní (MG), the Kolla (K), the Sagua-Huarpe (SH) and the Wichi (W). Results: The prevalence of HBsAg was 1.7% and 1.4% for the MG and SH, respectively; while anti-HBc was found in all the communities. HBV DNA of S and preCore-Core (pC/C) genomic regions was amplified by nPCR in 59 reactive samples for anti-HBc and/or HBsAg (46 belonging to MG, 6 K, 4 W and 3 SH). Thirteen samples were positive for nPCR presenting 11 of them an occult hepatitis B infection. Genotype F was predominant in the MG community with co-circulation of subgenotypes F4, F1b, A2 and D3. Subgenotype C2 was detected among the SH community. All cases exhibited the polymorphism rtL217R within the RT domain associated to resistance to adefovir. Two MG presented the substitution rtD206E and 3 SH rtV207I, both associated to resistance to lamivudine. Moreover, in the P sequence of F and C genotypes, other new substitutions were described. Conclusions: This study shows for the first time the presence of occult hepatitis infection with different HBV subgenotypes and natural variants potentially resistant to antivirals, circulating in aborigines of Argentina.