VHSV is a negative-sense single-stranded RNA virus of the order Mononegavirales, family Rhabdoviridae, and genus Novirhabdovirus. Viral hemorrhagic septicemia (VHS) is a deadly infectious fish disease caused by viral hemorrhagic septicemia virus (VHSV). It afflicts fish of over 50 species of freshwater and marine fish in several parts of the northern hemisphere.