International Union for Circumpolar Health Ministry of Public Health and Social Development of RF Russian Academy of Medical Sciences Siberian Branch of Russian Academy of Medical Sciences Siberian Branch of Russian Academy of Sciences Medical Polar Fund “Science” The Northern Forum

Abstracts

Seminar Infection Diseases in Arctic

OBJECTIVES: Yakutia is an endemic region for Hepatitis B and D. The Hepatitis B virus (HBV) has been divided into 8 genotypes (A-H) on the basis of the nucleotide sequence similarity of the whole genome. The Hepatitis D virus (HDV) has been classified into 7 genotypes (I-VII). The aim of the present study was to evaluate the distribution of HBV/HDV genotypes in Yakutia.

STUDY DESIGN: Ten plasma specimens from patients with HBV infection were studied along with sixty six from patients with HBV/HDV (Yakutsk City Hospital, 2004-2005). HBV DNA was amplified from twenty seven specimens and sixty six for HDV RNA.

METHODS: HBV genotyping was performed by RFLP analysis of 470 bp S-gene PCR product, using endonucleases Bst4CI and Sse9I. HDV isolates were characterized by partial nucleotide sequencing of the Delta antigen region (410 bp). Maximum likelihood and neighbour-joining (NJ, K80 model) phylogenetic analyses were performed with Phylip 3.65 and/or MEGA 3 programs. Bootstrap analysis (1000 replicates) was carried out for NJ algorithm to assess the robustness of nodes.

RESULTS: A restriction pattern consistent with HBV genotype D was found in 19 specimens (70.4%), and the remainder were consistent with genotype A (7; 25.9%) or C (1; 3.7%). Phylogenetic analysis of 66 HDV sequences revealed 33 (50%) formed a distinct cluster belonging to genotype II. The rest were found to be genotype I. Within the genotype I sequences some tended to group together in two separate clusters, while the others were dispersed between sequences from different geographical regions.

CONCLUSIONS: The dominant HBV genotypes in Yakutia mirror other Russian territories, but the prevalence of genotype A is significantly higher. HDV is represented by two genotypes (I and II) in equal proportions. Genotype II sequences form distinct cluster, whereas genotype I sequences have much higher heterogeneity. This data support the hypothesis of multiple introductions of genotype I HDV strains in Yakutia.

Note. Abstracts are published in author's edition

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Last update: 06-Jul-2012 (11:52:05)