Abundance of Ixodes persulcatus ticks in Komi Republic as a function of an air temperature
The sharp rising incidence of tick-borne encephalitis (TBE) in Komi Republic at the North-east of European Russia was recorded last decades. Tick-bite incidence also was grown. Rapid rise of TBE incidence growth and Ixodidae ticks depends on a number of factors, and the impact of climate change bein...
| Published in: | Russian Journal of Infection and Immunity |
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| Main Authors: | , , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Publishing house of Saint Petersburg Pasteur Institute
2020
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| Subjects: | |
| Online Access: | https://www.iimmun.ru/iimm/article/view/896 https://doi.org/10.15789/2220-7619-2019-5-6-811-816 |
| Summary: | The sharp rising incidence of tick-borne encephalitis (TBE) in Komi Republic at the North-east of European Russia was recorded last decades. Tick-bite incidence also was grown. Rapid rise of TBE incidence growth and Ixodidae ticks depends on a number of factors, and the impact of climate change being one of them. Ixodes persulcatus ticks is considered as a main vector of TBE in Komi. Our objective is to estimate the influence of air temperature change on the tickbite incidence and Ixodes persulcatus population in Komi. Komi Republic is located near the Polar circle where the northern frontier of Ixodes persulcatus ticks situated and we expected the growth of tick’s population. The number of Komi inhabitants seeking medical care after tick bites in 1992–2014 was considered. Gridded monthly air temperature data with grid size 0.5 degree were recalculated to temperature referred to Komi administrative units. The time series of annual number of tick victims from 1992 till 2014 and model air temperature from 1948 till 2016 for all Komi administrative units were compiled. We analyzed the data on tick-bite incidence in Komi administrative units in relation to changes in local annual average air temperature within the study area. The linear dependence of the tick-bite incidence on air temperature was established when of the tick-bite incidence is represented in logarithm form. The tick population depends not only on temperature but humidity, landcover and hosts. Described areas of Komi belong to humid climate, where precipitations exceed evaporation. Most of the Komi territory is covered by taiga with underwood, grass and bush. Hosts of the first and the major levels are represented by birds and rodents. The dependence of tick-bite incidence and temperature looks like “Malthus’s law”, but the development of population depends on temperature not on time. The exponential growth in the nearest future will ceased and the population will proceed to stable phase. Ticks population in Komi Republic is moving to the North and the air temperature determines the dynamics of population. Резкий рост заболеваемостью клещевым энцефалитом зафиксирован в Республике Коми на Северо-Востоке Европейской части России в последние десятилетия. Также выросло число нападений клещей. Основным носителем вируса клещевого энцефалита является клещ Ixodes persulcatus. Целью работы является определение влияния изменений температуры воздуха на число нападений клещей на человека и численность популяции Ixodes persulcatus в Коми. Республика Коми находится у Полярного круга, на северной границе ареала Ixodes persulcatus, который, по-видимому, будет расширяться и будет расти численность популяции клещей. В работе рассматривается число обратившихся за медицинской помощью жителей Коми, подвергшихся нападению клещей в 1992–2014 гг. Было проанализировано изменение среднегодовой температуры воздуха и числа пострадавших от нападения клещей. В результате исследований был сделан вывод о расширении ареала клещей на север и определяющей роли температуры воздуха в этом процессе. Зависимость числа пострадавших от температуры похожа на «закон Мальтуса», при этом развитие популяции зависит не от времени, а от температуры воздуха. |
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