http://repub.eur.nl/res/aut/460/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/17178/ 1998-04-22T00:00:00Z The hepatitis B virus (HBV) is one of the smallest human viruses known and belongs to the family of Hepadnaviridae; it was the first human hepatitis virus that could be characterized. Before the discovery of the virus two types of transmission of infectious hepatitis were distinguished on the basis of epidemiological observations: the classical hepatitis (type A) was transmitted by the faecal-oral route, while type B was transmitted parentally.' In 1963, B8 Blumberg discovered a previously unknown antigen in the blood of an Australian aboriginal (Australia antigen) and within a few years this was found to be related to the parentally transmitted type B hepatitis.' In the early seventies the virus was seen by electron microscopy3 and the genome was found to be a small, circular DNA that was partially double-stranded (figure I). The nucleotide sequence of the virus contains only 3200 nucleotides (3.2 kb) and revealed 4 overlapping genes for the production of seven viral proteins.