title: [Long-term dynamics of the epizootic process in natural foci of ixodid tick borreliosis in mountain taiga forests of the Middle Ural].
abstract: During eleven spring-summer seasons (1992-2002), the dynamics of the epizootic process in natural foci of ixodid tick-borne borrelioses (ITBB) were studied in taiga forests of the Middle Ural (Perm Province, Russia). In these foci, Borrelia garinii and B. afzelii circulate, and their main vector is the Ixodes persulcatus tick. Main parameters of the epizootic process were calculated for each season. In four seasons (1993, 1996, 1999 and 2002), the parameters characterizing the abundance of unfed nymphs and adult ticks, as well as the prevalence of Borrelia in them, density of infected ticks, and approximate total number of Borrelia in them proved to increase essentially and simultaneously. These seasons were preceded by the years of population peaks in forest small mammals (1992, 1995, 1998 and 2001), especially in the Clethrionomys glareolus vole, the dominant species in the local fauna of these mammals and the main reservoir host of Borrelia. Apparently, the possibility of horizontal transmission of the ITBB agents sharply increased in such years, and this resulted in the intensification of their dissemination.
authors.forename: Iu V
authors.initials: IuV
authors.lastname: Kovalevskiĭ
authors.forename: E I
authors.initials: EI
authors.lastname: Korenberg
authors.forename: N B
authors.initials: NB
authors.lastname: Gorelova
mesh_terms: D000818:Animals; D001096:Arachnid Vectors / Q000382:microbiology*; D003411:Arvicolinae / Q000382:microbiology / Q000469:parasitology*; D001899:Borrelia Infections / Q000635:transmission / Q000662:veterinary*; D015748:Borrelia burgdorferi Group / Q000302:isolation & purification*; D004197:Disease Reservoirs / Q000706:statistics & numerical data / Q000662:veterinary; D018562:Disease Transmission, Infectious; D017753:Ecosystem; D018884:Ixodes / Q000382:microbiology* / Q000502:physiology; D012376:Rodent Diseases / Q000453:epidemiology / Q000635:transmission*; D012377:Rodentia; D012426:Russia; D012621:Seasons; D013045:Species Specificity; D014197:Trees