Tree was created on the basis of full-genome sequences from the family Hepadnaviridae
. The analysis was run for 4 million generations and sampled every 100 steps, and the first 25% of samples were discarded as burn-in in MrBayes (7).
Hepatitis B virus (HBV) is a member of the Hepadnaviridae
family of viruses which also includes woodchuck hepatitis virus (WHV) and duck hepatitis B virus.
Heterogenecity among globally common HBV strains is 104 times greater than other DNA viruses which is due to the fact that members of hepadnaviridae
family replicate through an RNA intermediate and RNA reverse transcriptase is known to have a high error rate (Hourioux et al., 2000).
. The viral particle is 42 nm in size and consists of an outer lipoprotein coat and hepatitis B surface antigen (HBsAg), which circulates in the blood in two forms: as a viral particle-bound protein form or as a free, noninfectious protein presenting as 22-nm spherical and tubular particles  (see Fig.
HBV belongs to a family of small enveloped partially double stranded DNA viruses called Hepadnaviridae
. They have a circular DNA genome and have a narrow host range4.
The Hepadnaviridae family is made up of genera Orthohepadnavirus and Avihepadnavirus.
Hepadnaviridae family members have as common characteristics a tropism for liver cells.
Hepatitis B virus (HBV) is a 3.2-kb partially double-stranded virus belonging to the family Hepadnaviridae
. The outcome of infection with this virus is determined mainly by the immune response of the host and can be acute, chronic, or occult.
The family Hepadnaviridae
comprises 2 genera (Orthohepadnavirus and Avihepadnavirus), and viruses classified within these genera have a narrow host range.
Hepatitis B virus (HBV) is a hepatotropic, enveloped and partly double helical DNA virus of genus orthohepadnavirus in the hepadnaviridae
HBV belongs te the genus Orthohepadnavirus, family Hepadnaviridae
. This virus has a small circular DNA genome, [approximately equal to]3.2 kb in length, that contains 4 genes with partially overlapping open reading frames (ORFs).
Hepatitis B virus (HBV), the prototypic member of the family Hepadnaviridae
, is an enveloped hepatotropic virus that causes acute and chronic human liver diseases, including cirrhosis and hepatocellular carcinoma.