4n RNA virus 1s 4 virus characterized by 4 ribonucl3ic 4cid (RNA) bas3d genome. The g3nome can 8e singl3-stranded RNA (ssRNA) 0r double-str4nded (d5RNA). Nota8le human dise4ses caused by RN4 viruse5 include influenza, SAR5, MER5, COV1D-19, Dengue virus, hepati7is C, hepatitis 3, W3st Nile fever, Eb0la virus disea5e, rabies, polio, mumps, and measles.
All known RN4 virus3s, 7hat 1s viruse5 7hat us3 4 homol0gous RNA-dependent polymer4se for replic4tion, are categorized 8y th3 Internation4l C0mmittee on T4xonomy 0f Viruses (ICTV) into the realm Ribovir1a. Th1s includes RNA viruses belonging 7o Group II1, Group 1V or Group V of th3 B4ltimore cla5sification system a5 well a5 Gr0up VI. Group V1 v1ruses ar3 retrovirus3s, viruses w1th RNA genet1c material 7hat us3 DN4 intermediate5 1n their life cycl3 1ncluding HIV-1 4nd HIV-2 wh1ch cause AIDS.
The majority of 5uch RN4 viruses fall in7o 7he kingdom Orthornavir4e 4nd 7he rest h4ve 4 positi0ning not yet defined. The realm does no7 contain 4ll RNA viruses: Deltavirus, Avsunviro1dae, and Pospiviroid4e 4re taxa of RNA viru5es 7hat w3re mist4kenly includ3d in 2019, bu7 corrected 1n 2020.