Genotypes and phylogenetic characterization of hepatitis B and delta viruses in Egypt

Hepatitis B virus (HBV) and hepatitis D virus (HDV) sequences among HBV carriers from Egypt have not been evaluated sufficiently. The genotypes of HBV isolated from 105 serum samples from Egyptian carriers were determined. Four complete genomes and 11 entire preS1/S2/S genes were sequenced and evaluated. All serum samples were classified into HBV genotype D using serologic and genetic methods. The length of four complete nucleotide sequences was 3,182 bp. In all 15 samples, the common 33 nucleotides (11 amino acids) deletions in the preS1 region specific for HBV genotype D were observed. In the phylogenetic analysis based on the complete nucleotide sequences, all samples were clustered with the HBV isolates reported from previously Western and Mediterranean countries with nucleotide homology ranging from 96.0-98.0%. Of 75 HBsAg positive samples, anti-HDV was found in 15 (20%), and HDV RNA was detected in 9 of 15 (60%). The proportion of the patients with liver disease was higher in HBV carriers of anti-HDV positive with HDV RNA than in HBV carriers of anti-HDV positive without HDV RNA (P < 0.05). In the phylogenetic analysis based on the sequences in nucleotide position 853-1267 of HDV, nine samples were classified into HDV genotype I with the nucleotide homology ranging from 88.3-92.1% (mean; 90.5%) and clustered with HDV strains reported previously from Ethiopia, Somalia, Egypt, and Lebanon. These results indicate that HBV genotype D and HDV genotype I are most prevalent in Egypt, and HDV co-infection in HBV carriers is related to severity of liver disease.