It is an abbreviation for Koi Herpes Virus. It is characteristic of Koi fish and carp for human consumption. Although discovered earlier, in 1998 it experienced its expansion and expanded to many farms and ponds around the world. It is thought to have originated in some open fishponds in Eastern Europe. In those years, great fish deaths and huge losses were recorded in the world. The virus is dangerous because it can stay inside Koi fish for a long time without being noticed, and they can be carriers of this virus.