The Orthomyxoviruses (ὀρθός, orthós, Greek for "straight"; μύξα, mýxa, Greek for "mucus") are a family of RNA viruses that includes seven genera: Influenza virus A, Influenza virus B, Influenza virus C, Influenza virus D, Isavirus, Thogotovirus, and Quaranjavirus. The first four genera contain viruses that cause influenza in vertebrates, including birds (see also avian influenza), humans, and other mammals. Isaviruses infect salmon; the thogotoviruses are arboviruses, infecting vertebrates and invertebrates, such as ticks and mosquitoes.