THE CLIMATE CHANGE IN THE EXPANSION RANGE OF WEST NILE FEVER IN RUSSIA: SPATIAL-TEMPORAL TRENDS EVALUATION
This work aims to estimate the spatial-temporal trends of climatic conditions changes for the spread of West Nile fever (WNF) in the south of the European part of Russia. We used observations data with 58 weather stations (1997-2018) and data the ERA-Interim reanalysis (1981-2018). We assessed the suitability of climatic conditions for West Nile virus (WNV) transmission using the degree-day method. Based on the data obtained, we demonstrate the growth of the sums of effective temperatures (ET). The increase in the duration of the season of effective infectivity of mosquitoes was not tracked down. The changes in the sums ET coincide with the increase in the average air temperature for the epidemiological season. This creates favorable conditions for the development of the virus in the mosquito, as with an increase in ET the circulation of the virus is more efficient. The most favorable situation for the transmission of WNV is in the Caspian and Ciscaucasia region. In this territory, there is a further improvement in the conditions for the circulation of WNF due to an increase in the sums of ET. Compared to the Urals region, conditions suitable for the transmission of WNV are developing much faster in the central part of the European territory of Russia. It may lead to the further spread of WNV in this region.