Acariological situation in the south part of Tomsk region

There are some centers of natural diseases, trans-missed by ixodes ticks оп the territory of Tomsk region. The most dangerous of this are ixodes ticks encephalitus (ITE) and ixodes ticks borreliosus (ITB); but some other diseases have been registered (erlihiosus, West Nile fever). Between 16000 to 25000 suction attacks of ticks and up to 1000 morbid events are registered on the territory of Tomsk region annually. Ixodes pavlovskyi Pom 1946 dominated on town and suburbs territories, but as far as from town and the Tom river valley Ixodespersulcatus P.Sch 1930 became dominant species (up to 100%). Seasonal activity of ticks in Tomsk district characterized by a cleary shown one pike. Maximal density of ticks is registered in the first part ofJune, but in August most part of ticks disappears. On the town's territory the pike of activity is registered early - in the 2-3 decades of May. On the town's territory ticks disappear at the end of June and on the suburbs territories up to mid-July respectively (2-4 weeks earlier). The whole period of ticks activity on the south part of Tomsk region is 120-200 days in case of absence of human impact. Ticks virus infectiousness collected from the grass on the territory of Tomsk district was specified. The part of ticks infected by ITE was 1.9-7.7% during 2002-2011. The lowest part of infected ticks was nearby Kolarovo (0-6.3%) and Kurlek (0-0.5%) villages. There were no viruses in ticks collected nearby Semiluzhki and kuzovlevo villages, The high part of infected ticks were collected in the forests nearby Bogashevo (up to 11.1%), Haldeevo (up to 12.7%) andNekrasovo (up to 13.3%) villages. Virus of ITE was specified more often (by the IFA method) in ticks suckinghu-man blood. The virus of ITE was found in the ticks sucking human blood as often as: in Kolarovo 21.2-29.7% in Bogashevo - 15.7-33.3%, in Haldeevo - 16.0-22.2%. In the ticks sucked to a human in Tomsk and in suburbs the virus of ITE was found in Ixodes pavlovskyi (from 34.76%) and in Ixodes persulcatus (49.78%). Among ticks inhabited in the natural ecosystems of Tomsk the percent of ticks infected by ITB was up to 63,8 in Academgorodok and up to 36,4% nearby Irkutsky road. The virus of ITB was found in ticks in Kolarovo (62%), in Bogashevo - up to 36.6%, in Haldeevo - up to 40% , in Nekrasovo -15.4% and in Kuzovlevo -13.3%. The middle percent of ITB infected ticks in Tomsk region was between 21.3 and 49.8% during last ten years. There were maximal infectiousness among ticks collectedfrom the grass in spring period (3.1-7.1%); in the mid-July there were few infectious ticks only. The percent of infectiousness among over-wintering ticks were at the minimum in spring (19-25%), but increasing during summer up to 32-35%. The most effective measure against ticks was on the territories with clear borders and with good preliminary preparation for the action. For example, on the territories of summer child camps the effectiveness of actions was 95-100% and the number of sucking ticks were as less as ten during the season.

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