The o'nyong'nyong virus (ONNV) was first isolated by researchers at the Uganda Virus Research Institute in Entebbe, Uganda, during a large outbreak of a disease in 1959 that resembled dengue fever. ONNV is a togavirus (family Togaviridae), genus Alphavirus, is closely related to the chikungunya and Igbo Ora viruses, and is a member of the Semliki Forest antigenic complex...