[The problem of the so-called "change" of the tick-borne encephalitis virus genotype in the middle urals for the last 60 years].

Although the history of the tick-borne encephalitis in Urals dates back to 75 years ago, the problem of the spread and evolution of the tick-borne encephalitis virus (TBEV) largely remains terra incognita. Any research in this area is of great basic and practical importance. A few years ago, a hypothesis about the change of the TBEV genotype in the Sverdlovsk region in the 50-60-year period was put forward. In other words, replacement of the Far-Eastern genotype by Siberian genotype was suggested. The goal of this work was to discuss this hypothesis and the fallacy of this view. Recent large-scale data show the long history of the formation of Siberian TBEV virus population in the Middle Urals, as well as a foreign nature of Far-Eastern genotype through their introduction in the past. The concept of the decisive role of anthropogenic factor in the spread of TBEV in the Urals is discussed as an alternative to the hypothesis of the genotype change.