The hepatitis B virus (HBV) genotype was determined in a total of 121 plasma samples collected in France and the US from patients chronically infected with HBV HBV genotype A was predominant in this collection, appearing in 66 samples (54%), while genotypes B, C, D, E and F occurred in 4 (3%), 14 (12%), 23 (19%), 1 (1%) and 0 (0%) of samples, respectively However, the genotype of a total of 13 (11%) samples (2 from France, 11 from the US) could not be determined with the methodology used Sequence analysis, and subsequent phylogenetic analysis of the complete genome and the individual open reading frames, showed that the virus isolate from these samples was 3248 bp long and, phylogenetically, did not cluster with any of the known genotypes This strain was provisionally called HBV genotype G Virus isolates that were obtained from geographically separated regions like France and the US were closely related to each other All virus strains analysed contained some characteristic differences when compared to genotype A: a translational stop codon at aa 2 and 28 of the preCore region; a 36 nt (12 aa) insert in the amino-terminal part of the Core antigen (HBcAg); a 2 aa deletion in the carboxy-terminal part of HBcAg; and a 1 aa deletion in the preS1 open reading frame The deduced amino acid sequence of HBsAg suggests that this newly discovered genotype G strain belongs to serological group adw2

A new genotype of hepatitis B virus: complete genome and phylogenetic relatedness

The complete genomes were sequenced for ten hepatitis B virus (HBV) strains. Two of them, from Spain and Sweden, were most similar to genotype D, although encoding d specificity. Five of them were from Central America and belonged to genotype F. Two strains from Nicaragua and one from Los Angeles, USA, showed divergences of 3·1–4·1% within the small S gene from genotype F strains and were recognized previously as a divergent clade within genotype F. The complete genomes of the two genotype D strains were found to differ from published genotype D strains by 2·8–4·6%. Their S genes encoded Lys122, Thr127 and Lys160, corresponding to the putative new subtype adw3 within this genotype, previously known to specify ayw2, ayw3 or, rarely, ayw4. The complete genomes of the three divergent strains diverged by 0·8–2·5% from each other, 7·2–10·2% from genotype F strains and 13·2–15·7% from other HBV strains. Since pairwise comparisons of 82 complete HBV genomes of intratypic and intertypic divergences ranged from 0·1 to 7·4% and 6·8 to 17·1%, respectively, the three sequenced strains should represent a new HBV genotype, for which the designation H is proposed. In the polymerase region, the three strains had 16 unique conserved amino acid residues not present in genotype F strains. So far, genotype H has been encountered in Nicaragua, Mexico and California. Phylogenetic analysis of the complete genomes and subgenomes of the three strains showed them clustering with genotype F but forming a separate branch supported by 100% bootstrap. Being most similar to genotype F, known to be an Amerindian genotype, genotype H has most likely split off from genotype F within the New World.

Genotype H: a new Amerindian genotype of hepatitis B virus revealed in Central America.

Hepatitis B virus genotypes.

Hepatitis B virus (HBV) infection has shown an intermediate or high endemicity level in low-income countries over the last five decades. In recent years, however, the incidence of acute hepatitis B and the prevalence of hepatitis B surface antigen chronic carriers have decreased in several countries because of the HBV universal vaccination programs started in the nineties. Some countries, however, are still unable to implement these programs, particularly in their hyperendemic rural areas. The diffusion of HBV infection is still wide in several low-income countries where the prevention, management and treatment of HBV infection are a heavy burden for the governments and healthcare authorities. Of note, the information on the HBV epidemiology is scanty in numerous eastern European and Latin-American countries. The studies on molecular epidemiology performed in some countries provide an important contribution for a more comprehensive knowledge of HBV epidemiology, and phylogenetic studies provide information on the impact of recent and older migratory flows.

Hepatitis B virus burden in developing countries.

Serological detection of hepatitis B virus genotypes by ELISA with monoclonal antibodies to type-specific epitopes in the preS2-region product.

The preS2/S genes of hepatitis B virus isolated from 29 acutely or chronically infected individuals in the Gauteng province of South Africa were sequenced. Phylogenetic analysis of these sequences in comparison with global isolates from the GenBank database showed that 24 sequences clustered with genotypic group A, three with genotypic group D and one each with genotypic groups B and C. Group A isolates had greater identity with groups D (variation of 6.6%) and E (6.8%) than with the Eastern groups B (7.4%) and C (8.1%) and were most different from group F (11.0%). Of the South African group A specimens, 59.1% clustered with two global sequences to form a discrete segment which we have called subgroup A. The amino acid differences that set these isolates apart from the rest of group A tended to cluster in the preS2 region (amino acids 7, 10, 32, 35, 47, 48, 53 and 54), with a few changes occurring in the major surface antigen (amino acid sites 207 and 209). Analysis of isolates showed that there was a 9-fold higher prevalence of the ay determinant in South Africa than previously reported.

A unique segment of the hepatitis b virus group a genotype identified in isolates from south africa

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A unique segment of the hepatitis b virus group a genotype identified in isolates from south africa