Hepatitis B virus and hepatitis delta virus subtypes circulating in Algeria and seroprevalence of HDV infection.

BACKGROUND: Little is known about molecular characteristics of HBV strains circulating in Algeria and there are few data regarding HDV infection.

OBJECTIVES: The aim of this study is to describe the genetic diversity of HBV and HDV strains existing in Algeria and to determine the seroprevalence of HDV infection.

STUDY DESIGN: Plasma samples from 134 patients were analyzed by enzyme immunoassay method for HBV and HDV serological markers. Genotyping of HBV and HDV strains were performed using direct sequencing followed by phylogenetic analyses of the PreS1 and R0 region of the HBV and HDV genome respectively.

RESULTS: The PreS1 gene was successfully amplified in 119 patients (82 males and 37 females). Phylogenetic analysis of HBV strains revealed the presence of genotypes D (86.5%) and A2 (11.76%). The subgenotypes D are distributed as follows: HBV/D7 (43.5%), HBV/D3 (24.75%), HBV/D1 (16.8%) and HBV/D2 (14.85%). A recombinant between genotypes A, E and D was found. The seroprevalence of HDV infection among HBV carriers was less than 5.35%. Only one isolate of HDV genotype 1 was identified.

CONCLUSIONS: Our data indicate the predominance of HBV subgenotype D7 and a low prevalence of HDV infection.