RESUMEN
Three identical strains of a new virus Kama (Flaviviridae, Flavivirus, Tyuleny antigenic group) were isolated from Ixodes lividus Roch, obligate parasites of Riparia riparia L. The ticks were collected in June, 1990 in Tatarstan on the islands in the basin of the Kama river. The strains were examined under electron microscope and by serological tests (neutralization, complement fixation, hemagglutination inhibition, and indirect immunofluorescence). The virus is antigenically related but not identical to Tyuleny virus. Hence, the Tyuleny antigenic group at present includes viruses Tyuleny, Meaban, Gadgest Gally, Saumares Reef, and Kama. All these viruses are associated with an ecosystem including ixodide ticks, obligate parasites of colonial birds.