[Molecular characteristics of tick-borne encephalitis virus from the Southern Sikhote-Alin endemic region].

Molecular characteristics of 38 strains of tick-borne encephalitis (TBE) virus isolated in the Southern Sikhote-Alin focus were studied using 10 synthetic oligonucleotide probes complementary to the genomic RNA of the Sofyin strain. The isolated strains were divided into 4 groups, depending on the source of isolation: 1) strains isolated from Ixodes persulcatus (n = 8); 2) from the brain of patients dead from TBE (n = 10); 3) from the blood of patients with the febrile form of TBE (n = 7); and 4) from the blood of patients with an unapparent infection (n = 13). The total level of hybridization in the four groups was as follows: 61.8, 75.2, 55.8, and 35.2%. The "tick" strains with a great variety of the genofund are regarded as the stock group of the natural TBE virus population, 40% of which are strains close by their characteristics to avirulent strains of TBE virus.