Alphavirus

**Semantic type:** Virus

**Definition:** A genus of enveloped, spherical, or pleomorphic viruses with T=4 icosahedral symmetry, in the family Togaviridae. The genome is composed of a linear, single-strand of positive sense RNA. Alphaviruses are spread by insect vector, able to infect vertebrates and invertebrates, and cause arthritis, encephalitis, rashes and fever in humans.

**Synonyms:** - ALPHAVIRUS - Arboviruses Group A