"Karshi" virus, a new flavivirus (Togaviridae) isolated from Ornithodoros papillipes (Birula, 1895) ticks in Uzbek S.S.R.

Three identical strains of an arbovirus were isolated from 475 Ornithodoros papillipes ticks collected in June, 1972, in burrows of the great gerbil (Rhombomys opimus Licht., 1882) in the environs of Beshkent, Karshinsk steppe, Uzbek S.S.R. The isolate was found to range among flaviviruses. Complement-fixation, agar diffusion precipitation and neutralization tests is tissue culture and mice indicated a one-way antigenic relationship between the isolate and West Nile virus. However, the pattern of differences between them made it possible to consider the isolated agent as a new virus, "Karshi" virus. The results of electron microscopic studies of this virus are presented.