[IMPACT OF CASPIAN SEA LEVEL FLUCTUATIONS ON THE EPIZOOTIC ACTIVITY OF THE CASPIAN SANDY NATURAL PLAGUE FOCUS].

There is evidence that in 1923-2014 the sharp aggravations of the epizootic situation of plague in the area of its Caspian sandy natural focus after long interepizootic periods are in time with the ups of the Caspian Sea in the extrema of 11-year solar cycles. There were cases of multiple manifestations of plague in the same areas in the epizootic cycles of 1946-1954, 1979-1996, 2001, and 2013-2014. The paper considers the possible role of amebae of the genus Acanthamoeba and nematodes, the representatives of the orders Rhabditida and Tylenchida in the microfocal pattern of plague manifestations.

[CRITERIA OF DIFFERENCE EVALUATION FOR VARIOUS TYPES OF HEMORRHAGIC FEVER WITH RENAL SYNDROME FOCI. HFRS FOCI IN VARIOUS BIOTOPES OF TYPICAL BARRENS].

Aim: Examine features of natural, natural-anthropourgic and anthropourgic foci of hemorrhagic fever with renal syndrome (HFRS) in various, mostly forest, biotopes of typical barrens due to differences of non-specific HFRS prophylaxis in foci of various types.

Materials And Methods: Epizootological and epidemiologic data from 1998 to 2012 were analyzed, gathered in HFRS foci of all types in Saratov area of Saratov Region (typical barrens). 14,606 trap-nights were worked off and 2669 small mammals were procured.

[Criteria of difference evaluation for-various types of hemorrhagic fever with renal syndrome foci. HFRS foci in various biotopes of northern barrens].

Aim: Determine qualitative and quantitative criteria of evaluation of features for natural, natural-anthropourgic and anthropourgic foci of hantaviruses (using hemorrhagic fever with renal syndrome--HFRS foci as an example), that have formed in various areas of Saratov Region.

Materials And Methods: Epizootological and epidemiologic data from 1998 to 2012 were analyzed. During this period in all the types of foci of Atkarsk area (Northern barrens) 13,004 trap-nights were worked off, 2577 small mammals were procured.

[Reasons of low epizootic activity of natural foci of plague in Russia at the beginning of the 21st century].

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.

[Role of burrow microbiocenosis in plague enzootia].

The paper analyzes relationships of the plague bacilli to the representatives of different types of living organisms inhabiting the burrows. The authors give their own data on the qualitative and quantitative composition of indicoles of the burrow of little sousliks (Spermophillus pygmaeus). They assess the role of mutagenic agents in burrow microbiocenoses.

[The ecology and prevalence of arboviruses on the territory of the Saratov Region].

The territorial spread of Tahyna, Batai, Sindbis, West Nile fever and Crimean-Congo hemorrhagic fever viruses throughout the Saratov region in 1998 - 2000 was analyzed. The characteristics of the epizootic activity of the natural foci of these arboviruses in different landscape zones (temperate forest-steppes, steppes and semi-deserts) were calculated. The species composition of small mammals, the natural reservoirs of the causative agents of arbovirus infections, was determined.

[The dynamics of the microbiocenosis in the burrows of the little suslik].

Microbiocoenoses being formed in burrows of little souslik have been investigated. Microbiocoenoses of sloping burrows have most simple organization. Comparative analysis of the fauna and functional structure, conducted during the spring-summer period, has not shown the existence of any directed process in the development of microbiocoenoses of sloping burrows.