The family Reoviridae consists of four genera (Orthovirus, Coltivirus, Orbivirus, and Rotavirus) of which only orbiviruses aretransmitted by arthropods. These viruses have double-stranded RNA genome by which they differ from other arboviruses. Colorado tick-borne virus is the only orbivirus, which causes infection in humans. The virus causes Colorado tick fever transmitted by the tick Dermacentor andersoni. The virus causes natural infection in rodents. The disease is restricted in its distribution to the western United States. The virus causes a self-limiting disease in humans.
Kasba, Vellore, and Palyam are the arboviruses that have beenisolated from mosquitoes in India. Their association with the disease in humans is yet to be ascertained.