Hepatitis B and circadian rhythm of the liver

Table 1 Prevalence of hepatitis B surface antigen

	Low prevalence area (< 2%)	Area of medium prevalence (2%-7%)	Area of high prevalence (> 8%)
Geographical areas	United states, Canada, and Western European countries	Parts of Russia, border Eurasian, and Asian-African areas	Asia, sub-Saharan Africa, South, and Central America
% of the world population	12%	43%	45%

Table 2 Classification of hepatitis B virus

Genus	Orthohepadnavirus
Family	Hepadnaviridae
Species	HBV
Genotypes	A-J
Virion	42 nm, spherical
Envelope	Yes (HBs)
Genome	Circular ds/ssDNA
Genome size	3.2 kb
Sensitivity	Acid-sensitive
Virus antigens	HBsAg, HBcAg, HBeAg, polymerase

HBV: Hepatitis B virus; HBs: Hepatitis B surface protein; ds/ssDNA: Double-stranded/single-stranded DNA; HBsAg: Hepatitis B surface antigen; HBcAg: Hepatitis B nuclear core antigen; HBeAg: Hepatitis B envelope E antigen.

Table 3 Prevalence of hepatitis B virus genotypes and subgenotypes

Genotype	Subgenotype	Prevalence
A	A1 -A6	Africa, India, Northern Europe, USA
B	B1-B8	Asia, USA
C	C1-C14	Asia, USA
D	D1-D9	India, Middle East, Southern Europe, USA
E	F1-F4	West and South Africa
F		Central and South America
G		Europe, USA
H		Central and South America, California (USA)
I	I1-12	Vietnam
J		Japan

USA: United States.