also known as: IHN, Infectious Hematopoietic Necrosis Virus
Infectious hematopoietic necrosis virus (IHN) is a ssRNA virus that belongs to the Rhabdoviridae family. It is known also as Sacramento River Chinook disease, sockeye salmon viral disease, Coleman disease, Chinook salmon disease, Columbia River sockeye disease, Cultus Lake virus disease and Oregon sockeye disease It affects both salmon and trout. During the 1950’s the first reported outbreaks of IHN occurred at hatcheries in Oregon and Washington State. The virus infects fish by entering at the base of the fins. It is transmitted via direct contact or via a contaminated water source, through mucus, feces, urine, and sperm (and is therefore transmitted both horizontally and vertically from fish-to-fish). Annelid worms and crustaceans may be vectors of the virus, making it harder to contain. Signs of infection include swollen abdomen, exophthalmia, anemia, abnormal behavior, pale gills and hemorrhaging near the fins, mouth, and in the muscles near the vent. The virus can be detected using molecular diagnostic methods, of tissues such as the kidney. It is not transmissible to humans.