Occult hepatitis B and new natural variants of the virus among Amerindians from Argentina”.

DELFINO CB, EIRIN M, BERINI C, MALAN R, PEDROZO W, KRUPP R, BLEJER J, SALAMONE H, ESPEJO R, FIERRO L, PUCCA A, CASTILLO A, GENTILE E, OUBIÑA JR, MATHET VL, BIGLIONE M.

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

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2011

1386-6532

Background: HBV infection is frequent among Amerindians. Objective: To determine theprevalence, 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 crosssectional study was conducted from 2007 to 2008 including 561 Amerindians belonging todistinct ethnic groups, the Mbyá-guaraní (MG), the Kolla (K), the Sagua-Huarpe (SH) andthe 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 andpreCore-Core (pC/C) genomic regions was amplified by nPCR in 59 reactive samples foranti-HBc and/or HBsAg (46 belonging to MG, 6 K, 4 W and 3 SH). Thirteen samples werepositive for nPCR presenting 11 of them an occult hepatitis B infection. Genotype F waspredominant in the MG community with co-circulation of subgenotypes F4, F1b, A2 andD3. Subgenotype C2 was detected among the SH community. All cases exhibited thepolymorphism rtL217R within the RT domain associated to resistance to adefovir. TwoMG presented the substitution rtD206E and 3 SH rtV207I, both associated to resistance tolamivudine. Moreover, in the P sequence of F and C genotypes, other new substitutionswere described. Conclusions: This study shows for the first time the presence of occulthepatitis infection with different HBV subgenotypes and natural variants potentiallyresistant to antivirals, circulating in aborigines of Argentina.