Infectious hematopoietic necrosis virus (IHNV), is a negative-sense single-stranded, bullet-shaped RNA virus that is a member of the Rhabdoviridae family, and from the genus Novirhabdovirus. It causes the disease known as infectious hematopoietic necrosis in salmonid fish like trout and salmon. The disease may be referred to by a number of other names such as Chinook Salmon Disease, Coleman Disease, Columbia River Sockeye Disease, Cultus Lake Virus Disease, Oregon Sockeye Disease, Sacramento River Chinook Disease and Sockeye Salmon Viral Disease. IHNV is commonly found in the Pacific Coast of Canada and the USA, and has also been found in Europe and Japan. The first reported epidemics of IHNV occurred in the United States at the Washington and the Oregon fish hatcheries during the 1950s. IHNV is transmitted following shedding of the virus in the feces, urine, sexual fluids, and external mucus and by direct contact or close contact with surrounding water. The virus gains entry into fish at the base of the fins.
The disease is listed as a non-exotic disease of the EU and is therefore watched closely by the European Community Reference Laboratory for Fish Diseases. In order to keep track of the distribution of different IHNV genotypes a database called Fishpathogens.eu has been created to store data on different fish pathogens (including IHNV) and their sequences.