Molecular characterization of the hepatitis B virus in autochthonous and endogenous populations in the Western Brazilian Amazon

introduction: hepatitis b virus (hbv) infection is a serious public health issue worldwide. hepatitis b virus is classified into eight genotypes, varying from a to h, with distinct geographical distributions. in brazil, the most frequent genotypes are a, d, and f. methods: this study aimed to characterize the hbv genotypes in cases of hepatitis b virus and hepatitis d virus (hdv) co-infections in an endemic area in the western brazilian amazon. we analyzed 86 serum samples reactive for hbsag from indigenous and non-indigenous populations obtained from previous serological surveys. results: of the 86 reactive serum samples, 39 were found to be hbv-dna-positive by semi-nested pcr. the genotypes were established by sequencing the amplified s gene region. we obtained 20 sequences classified into three genotypes: a, d, and f. genotype a was the most frequent (60%), followed by d (35%) and f (5%). conclusions: the distribution of the hbv genotypes reflected the pattern of historical occupation of the region.