Hepadnavirus

Hepadnavirus is a family of viruses that primarily infect the liver. The name 'Hepadnavirus' is derived from the Greek word 'hepar' (or 'hepat-'), meaning 'liver', and 'DNA', indicating that these viruses carry their genetic material in the form of DNA.

Classification

Hepadnaviruses are classified under the family Hepadnaviridae. This family is further divided into two genera: Orthohepadnavirus and Avihepadnavirus. The Orthohepadnavirus genus includes the Hepatitis B virus, which infects humans and other mammals. The Avihepadnavirus genus includes the Duck hepatitis B virus and similar viruses that infect birds.

Structure and Genome

Hepadnaviruses are small, enveloped viruses with an icosahedral nucleocapsid. The genome of hepadnaviruses is made up of partially double-stranded circular DNA. The full length of the DNA strand is about 3.2 kilobases.

Replication

Hepadnaviruses replicate through an RNA intermediate by a process called reverse transcription. The replication process is initiated in the nucleus of the infected cell, where the viral DNA is repaired and transcribed into pregenomic RNA.

Pathogenesis

Hepadnaviruses are known to cause chronic liver diseases such as hepatitis, cirrhosis, and hepatocellular carcinoma. The Hepatitis B virus is a notable member of this family due to its significant impact on human health worldwide.

Prevention and Treatment

Prevention of hepadnavirus infection is primarily through vaccination. The Hepatitis B vaccine is effective in preventing infection. Treatment of chronic Hepatitis B infection can be achieved through antiviral medications.

See Also

• Hepatitis B virus
• Hepatitis B vaccine
• Hepatocellular carcinoma
• Cirrhosis