Any member of the genus Hepadnavirus or family Hepadnaviridae of enveloped, partially double-stranded DNA viruses which are pathogens of a wide range of mammals and birds, infecting the liver and causing hepatitis (hepatitis B in humans) and (in some cases) hepatocellular carcinoma. Also (in form Hepadnavirus): the genus itself.
Hepadnaviruses persistently infect liver cells in the form of covalently closed circular DNA (cccDNA). Their replication involves a viral DNA polymerase with a reverse transcriptase function, which is a target for antiviral therapy.
1980s; earliest use found in The Journal of Virology. From hepa- + DNA (here treated as though an acronym rather than an initialism) + virus.