Hepatitis E virus (HEV) is a small, non-enveloped, single-stranded, positive-sense RNA virus. The genome size is approximately 7.2 Kb. In 2004, Hepatitis E virus (HEV) was designated as the sole member of the genus Hepevirus in the family hepeviridae. Recently, consensus proposals were made to divide the family of Hepeviridae into the genera, Orthohepevirus and Piscihepevirus, of which the genus Orthohepevirus contains all mammalian and avian HEVs. The HEV genome has three open reading frames (ORFs): ORF1 encoding the non-structural polyprotein (nsp), ORF2 encoding the viral capsid protein and ORF3 encoding a small regulatory phosphoprotein. Hepatocytes are assumed to be the primary target cells in which the virus replicates in the cytoplasm. Due to the lack of an efficient cell culture system, the mechanism by which HEV enters the cells and how the virions are released from the cells is not fully understood yet. In humans HEV infections often run an asymptomatic course but after an incubation period of 4 to 5 weeks HEV disease can present like an acute icteric viral hepatitis. Frequently observed symptoms include anorexia, nausea, jaundice, fever and abdominal pain. Mortality rates are generally under 0.5% but may reach up to 25% in pregnant women for at least genotype 1. HEV is a main cause of epidemic hepatitis in developing countries and single cases of hepatitis in higher income countries. According to the World Health Organisation http://www.who.int/mediacentre/factsheets/fs280/en/) worldwide there are 20 million hepatitis E infections, over three million acute cases of hepatitis E and 57,000 hepatitis E-related deaths every year.