RESUMEN
AIM: Establish the main reasons of low epizootic activity of natural foci of plague in Russian Federation in 2000-2009. MATERIALS AND METHODS: Multiyear data on the number of isolated Yersinia pestis strains, area of detected epizootic sites, amounts of the field material studied for plague were used to evaluate annual activity of natural foci. RESULTS: In the current decade mountain and high-mountain natural foci of plague were characterized by constant high epizootic activity. In plains and low-mountain natural foci a low periodic epizootic activity was noticed, a development of intra-epizootic periods. A conditioning role of helioclimatic factors on the status of parasitic systems and epizootic activity of natural foci of plague was noticed. CONCLUSION: The warming of climate in 1990-2007 was the main reason for low epizootic activity of plains natural foci of plague in Russia. In the contemporary conditions of a recurrent cooling (from 2008) and an increase of humidity in the Northern, North-Western pre-Caspian and pre-Caucasus territories, a new significant activation of them is predicted there with a peak in 2017-2019.
