[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. The most significant population-ecologic and ecologic-epizootological methods and criteria were used for comparative analysis of differences for 3 types of foci. RESULTS: Based on analysis of multi-year data seasonal differences for HFRS foci of various types were shown by 10 population-ecologic and ecologic-epizootologic criteria. CONCLUSION: The results obtained allow to state that modern means and methods of non-specific prophylaxis of HFRS and other zoonoses in foci of various types different significantly. This allows the most rational use of material and financial resources.

[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. Genetic, population-ecological and ecological-epizootological methods and criteria were used for comparative analysis of 3 types of loci: PCR diagnostics and sequencing of pathogenic for humans hantaviruses, species cadaster and features of season dynamics of species composition of hantavirus carriers, domination indexes, parameters of quantity and infection of carriers by hantaviruses; distribution of the latter by biotopes, degree and character of population contacts with natural-foci complexes, epizootic potential of foci. RESULTS: Based on multi-year data analysis features of 3 types of HFRS foci were shown in various, mostly forest, biotopes of Northern and a part of typical barrens. A stable domination of Pumala genotype hantavirus was noted; a weakly expressed circulation in parasite systems with Apodemus genus carriers, first of all Dobrava genotype Apodemus agrarius, was established as well. CONCLUSION: A certain specter of most universal criteria;that are closely interconnected, are necessary during typing of HFRS foci and a number of other zoonozes.

[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. 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.

[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]. / Dinamika mikrobiotsenoz nor malogo suslika.

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. On the contrary, microbiocoenoses of vertical nest burrows can be regarded as biocoenotic systems dynamic in space and time. Here in the period of rodent's vital activity occurs a constant construction of underground passages and periodical change of nests. In this case the fauna of new nests is formed largely at the expense of migration of nidicols along free or obstructed with loose earth underground horizontal passages. Microbiocoenoses in burrows of different types are not connected between each other by morphoprocess and their development is of independent character.