Roughly 16-40% of sexual partners of individuals with hepatitis B will be infected through sexual contact.
The virus that causes hepatitis B is a member of the Hepadnavirus family and it is composed of an icosahedral nucleocapsid (core) enclosing a circular, double-stranded DNA genome. The virus is unique amongst the DNA viruses in that it uses a reverse transcriptase to generate the genomic DNA to deliver to its progeny. Additionally, the DNA genome is incomplete on one strand.
Hepatitis D infection requires a concomitant infection with hepatitis B.
Hepatitis B infection can lead to a chronic inflammation of the liver, leading to cirrhosis. This type of infection dramatically increases the incidence of liver cancer.
A recombinant vaccine to prevent hepatitis B is available.