Hebadnaviridae

enveloped liver specific DNA viruses;

• Hepatitis B Virus (18 species- different genotypes)

• Woodchuck hepatisis virus WHV

• Bat hepatisis virus BtHV

• Duck hepatisis B virus DHBV

all:

• Genome: 3 kb partially ds DNA, 4 ORF (C, E, P, X);

• Ancient Virus: Detected in 4,500 year old human remains;

• 1963/66: Discovery of „antigen“ („Australo-Antigen“; known today as HBsAG)

• Blomberg is credited for discovery of HBV and the development of a diagnostic test and vaccine.

• 1979: cloning, Vaccine development:

• in the virus particle

4 promoters (C, PS1, PS2, X)

1 polyA site

5 translation start site

Control of HBV-transcription:

• Genome replication via reverse transcription of a terminally redundant pgRNA;

In natural infections with hepatitis B virus (HBV), there is an excess of empty noninfectious subviral particles (SVP) that do not contain the viral capsid

Virions: up to 10^10/ml serum

Subviral particles: up to 10^14/ml serumh

Fatigue, Flu-like symptoms, Dark urine, Pale stool, Abdominal pain, Loss of appetite, Unexplained weight loss, Jaundice (gelbsucht)

• Appr. 10 % of infections are chronic (adults), appr. 50 % inapparent;

• Transmission: parenteral (sex, i.v. drugs, birth);

• •High prevalence in Africa, far-east Asia; (subsahara)

• hepatitics C: USA; brasil, Russia, Sahara, australia

• Active vaccination: recombinant vaccine (HBsAg containing the small surface proteins S and lipid from yeast);

• Therapy: RT inhibitors, interferon; do not clear infection (cccDNA persists);

HDV is a dangerous satellite of HBV; HBV and HDV genomes replicate by different mechanisms. HDV particles bear HBV-surface antigens and use the same receptor for cell entry as HBV.