An alphavirus of the Togaviridae family. It has a positive-stranded RNA genome and an icosahedral capsid enveloped by a host-cell derived lipid bilayer and has been extensively used as a model system for studying the synthesis and incorporation of the transmembrane spike glycoproteins. It is spread by mosquitos and was first isolated from mosquitos in the Semliki forest of Uganda. It causes a lethal encephalitis in rodents but only one human infection, of an immunocompromised individual, has been reported.
Subjects: Medicine and Health.