West Nile Fever across the World and in the Russian Federation in 2015. Forecast of the Epidemic Situation Development in 2016

Abstract

The intensity of epidemic West Nile fever (WNF) manifestations in the Russian Federation during the season, 2015 was low; morbidity rates coincided with those characteristic of inter-epidemic period. It total, 41 cases in 9 RF constituent entities were registered. WNF incidence rates among the population in the territory of Europe and North-American continent slightly exceeded morbidity rates, 2014, but then again did not reach epidemic levels. During the past two years seasonal development of WNF epidemic process in Russia has had a tendency to defer the incidence climax to early autumn. The presence of West Nile virus (WNV) markers was established in 11 entities of the Russian Federation in 2015, and existence of immunity to WNV in the population - in the 27 territories. According to the results of molecular-genetic surveillance, in the territory of the Russian Federation in 2015 circulation of WNV genotype 1a and 2 continued. The ongoing changes of climatic conditions towards warming predetermine high probability of further WNV circulation in the environment and emergence of infection cases in areas of the country far to the north. However probability of WNF epidemic manifestations intensification in 2016 remains insignificant.