Viral Hemorrhagic Septicaemia Virus (VHSV) is an RNA virus of the Novirhabdovirus genus which causes Viral Hemorrhagic Septicemia (VHS), an acute infectious disease of Salmonid fish which is also known as Egtved disease. The viral partical is enveloped and bullet shaped with a size of about 180nm in length and 60nm in diameter. The virion contains a single stranded, negative-sense RNA genome of approximately 11,158 nucleotides in length which encodes six genes. Fives of these code for structural proteins while the other codes a nonstructural protein of unknown function. Transmission of this virus usually occurs via contact with infected bodily secretions and excretions although direct contact and vertical transmission are also possible. Infection causes severe haemorrhaging of internal organs and petechial haemorrhaging of the muscles and skin. Fish that survive the infection become lifelong carriers of the virus, assisting in transmission. Infection with this virus does not necessarily result in any clinical features but may cause bulging eyes, distended abdomens and bruised-looking reddish tints to the eyes, skin, gills and fins as a result of the haemorrhaging.