Natural Focal Infections Research Articles

Generation of Databases and Visualization of Current Epidemiological Information for Purposes of a Medical-Ecological Monitoring of a Region

The geo-ontology principles of identifying the functional connectivity of all components of the socio-biological system have been used as the basis for developing a unified and scientifically rigorous methodology of preprocessing epidemiological information and its preparation for further use. The specific features in epidemiological information are highlighted as well as the need for territorial linkage of the objects and situations under study in order to ensure the adequacy of management decisions. According to the principles of designing relational databases, an integrated epidemiological database has been generated, which includes the geographical coordinates of the objects and situations under study. Such a territorial linkage when implemented using GIS technologies provides a means of solving regional problems of estimating the probability of disease with due regard for the specific features of the location, which ensures competent and targeted work of the system of medical and environmental monitoring. The continually updated databases have been created and patented, which are compatible with ArcGIS and contain basic epidemiological data on the incidence of tick-borne encephalitis and tick-borne borreliosis, based on information received from hospitals in Irkutsk. For updating the integrated database with information on the occurrence of infections across landscapes, annual (since 2005) expeditions have been conducted in several key areas of Irkutsk oblast which are distinguished by landscape diversity, vector size, attendance and morbidity of the population. Ticks and their hosts are collected and analyzed for the presence of pathogens of natural focal infections. More than 25 thousand ticks were caught, whose infection with tick-borne encephalitis virus averaged 1.5%. Visualization of epidemiological information used the methods of end-to-end geographical mapping of the territory, the logic of which formulates the principles of geoinformation mapping and naturally includes a natural territorial component.

СУЧАСНІ МОЖЛИВОСТІ ГЕОІНФОРМАЦІЙНОГО КАРТОГРАФУВАННЯ ПРИРОДНИХ ФАКТОРІВ ВПЛИВУ НА ПОШИРЕННЯ ХВОРОБ НАСЕЛЕННЯ

The article is devoted to the consideration of existing possibilities of geoinformation mapping for the identification of natural factors of influence on the spread of diseases among the population. The author identified the features of maps of natural factors influencing the distribution of diseases of the population are determined as to the types thereof: estimate maps and forecast maps. The latter is due to natural-focal infections, which are relatively stable in time regarding the possibilities of infection with them. The necessity of perfection of the algorithm of cartographic modelling of natural factors of influence on the distribution of natural-focal infectious diseases among the population based on modern geoinformation technological solutions is substantiated. It is indicated on the features of three methodical schemes in the process of geoinformation creation of such maps regarding the use of specific cartographic materials. These are the using of small-scale maps; the using of large-scale maps on the basis of the original materials of the appropriate scale; the using of small- scale maps based on other small-scale maps and large-scale maps. On the basis of network technologies, in particular, modern technological solutions Web 2.0, the author determined the possibilities of geoinformation mapping of natural factors of influence on the distribution of diseases among the population. These are: improved database model (transition from relational model to object-relational variant); conducting of mathematical and cartographic modeling with all necessary techniques in the environment of a full-function geoinformation system; choosing the best options for presenting and distributing developed cartographic models among the more quantity of potential users; the presence of feedback with them. In the article, the author defined the specifications of Web 2.0, relevant for creating/using maps of the risk of infection of the population with natural focal diseases, with adapting to four groups technological solutions in relation to services (platform, software, data, infrastructure).

Experience of the Rospotrebnadzor Administration in the Republic of Tatarstan in the Prevention of Internal epidemiological Risks During the Preparation and Holding of the FIFA World Cup-2018

Objective of the study was to describe the organization of epidemiological surveillance over internal risks associated with the intensification of natural-focal diseases in the Republic of Tatarstan, analysis of the measures taken to prevent natural focal diseases during the preparation and holding of the FIFA World Cup-2018. Materials and methods . The data from surveys and forecasts as regards the numbers of small mouse-like rodents as carriers and arthropod vectors of natural-focal diseases, epizootic and epidemiological situation reports in the Republic of Tatarstan and information on infectious and parasitic disease morbidity rates in the Republic of Tatarstan, presented by the Center of Hygiene and Epidemiology in the Republic of Tatarstan over 2015-2018 were utilized for analysis. Results and conclusions . The natural conditions of the Republic of Tatarstan are favorable for the circulation of pathogens of natural-focal diseases, which carriers are mammals (primarily small rodents) and birds, and vectors - blood-sucking arthropods: Ixodidae ticks, mosquitoes. The results of circulation monitoring of natural focal infection pathogens in the ambient environment made it possible to conclude that during the FIFA World Cup-2018, the epidemic risk of occurrence of natural-focal diseases would remain high. Considering the existing and forecasted internal risks, priorities were identified in the organization of preventive measures aimed at minimizing epidemiological risks in relation to natural-focal infections during the preparation and holding of the FIFA World Cup 2018. The chosen preventive strategy made it possible to prevent the infection with natural-focal infectious diseases among the population and ensure a stable epidemiological situation during the FIFA World Cup-2018.

Genetic Profiling of the Causative Agents of Natural-Focal infections, Circulating in the Stavropol Territory

Objective of the study was genetic typing of the strains and nucleic acid isolates of causative agents of natural focal infections, both bacterial and viral etiology, accumulation of data on genetic features of regional strains cir­culating in the Stavropol Territory . Material and methods. To study the genetic spectrum of causative agents of natural- focal infections, analysis of the strains and nucleic acids isolates detected in the samples of field and clinical material was carried out. Indication of causative agents of natural focal infections in the samples was carried out by PCR. For genetic typing of the strains and DNA/RNA isolates of natural focal infections agents, MLVA and sequencing of genome regions with subsequent phylogenetic analysis were used. The analysis of territorial distribution of the causative agent genetic variants and mapping was performed in ArcGIS 10.1. Results and conclusions. MLVA-25 typing of 20 strains of Francisella. tularensis, MLVA-10 typing of 4 Coxiella burnetii isolates, species identification of 20 isolates of Rickettsia sp., sub-species genetic typing of 40 RNA isolates of CCHF virus and 8 RNA isolates of hantaviruses circulating in the Stavropol Territory in 2016-2017 were performed. The studied strains of F. tularensis belong to eight MLVA genotypes. They are mainly confined to specific areas. The isolates of C. burnetii have the same MLVA type. Rickettsia, belonging to 5 species: R. massiliae R. raoultii, R. sibirica, R. aeschlimannii, R. slovaca, RNA-isolates of hantavirus of the «Tula» genotype and variants of the CCHF virus of the Europe-1 and Europe-3 genotypes were identified. The obtained data can be used in the epidemiological investigation of possible cases of infectious diseases to determine the source and pathways of infection.

Urgent natural foci infections transmitted by ticks in Saint-Petersburg

Purpose: to conduct a comparative analysis and to identify the epidemiological and clinical features of tick-borne encephalitis (TBE) and Lyme borreliosis as a mono- and coinfections in St. Petersburg. Materials and methods. 718 cases of TBE, 4353 cases of Lyme borreliosis and 127 combined diseases registered by the St. Petersburg epidemiological bureau in 2006-2017 were studied. Identification of combined diseases was carried out by a special software that allows to identify co-morbid diseases from the array of monoinfections. To identify clinical and epidemiological features, 144 cases of TBE, 286 Lyme borreliosis, and 43 cases of co-infection were studied. Age and sex characteristics, places of human contagion, infection rates of ticks, clinical forms of mono- and associated diseases, morbidity dynamics changes and patients’ IgM seropositivity were studied. Results. The long-term dynamics of TBE and Lyme borreliosis incidence had did not have significant upward or downward trends, it was characterized by synchronous fluctuations. The priority of the incidence of men over women is revealed. 61–69% cases of TBE and Lyme borreliosis occurred in Leningrad region, 19–30% – in the adjacent territories of Russia, 5,7–6,7% of cases were imported from other countries. High tick infection rates of TBE virus and Borrelia was revealed. Borrelia аnd virus of TBE and were detected in 81,6–87,5% of the examined ticks removed from patients with a later established diagnosis. Seasonal distribution of Lyme borreliosis was shifted by a month to the right in comparison with TBE. The clinical forms of both diseases did not differ in their structure from the country data, however after 2012 subclinical forms were more common in women. The proportion of non-erythematous forms of Lyme borreliosis in 2011–2015 compared with the 2006–2010 observation period increased almost 1,5-fold mainly forms, including those with co-infection. The IgM seropositivity rate in the dynamics of the disease testifies to the incomplete rehabilitation of patients. Conclusion. The clinical and epidemiological characteristics of TBE, Lyme borreliosis and combined infection in the North-West region of Russia, with the example of St. Petersburg, have certain distinctive features. The reasons for the revealed features need further study.

EPIDEMIC AND EPIZOOTIC SITUATION OF NATURAL-FOCAL ZOONOTIC INFECTIONS IN VLADIMIR REGION

Aim. Assessment of the epidemiological and epizootic situation and the degree of danger of the territory of Vladimir region in terms of a complex of natural focal zoonotic infections. Materials and methods. In the work, a retrospective analysis of statistical data on the incidence of zooanthroponosis in the population, obtained from Reporting Form No. 2 «Information on Infectious and Parasitic Diseases» of Center for Hygiene and Epidemiology in the Vladimir Region for the period 1958 - 2016 was conducted. Studies of biological material for the presence of pathogens of natural focal infections were conducted in the laboratory of natural focal and especially dangerous infections of Center of Hygiene and Epidemiology in the Vladimir Region. Results. It is established that the following natural focal diseases are registered in the territory of the Vladimir region: rabies, heemorrhagic fever with renal syndrome (HFRS), tick-borne borreliosis (ТВВ), leptospirosis, pseudotuberculosis and tularemia. The largest share in the structure of morbidity falls on HFRS and ТВВ. Annual laboratory studies of biological material for the presence of pathogens of natural focal infections indicate the presence of epizootics among rodent mice, the dominant species among which is the red vole. The ratio of men to women with HFRS is about 3 to 1, the main risk factors for transmission are harvesting in summer cottages and visiting forest areas. As for the ТВВ, in the region there are persistent natural foci of this infection. It was established that there is no territorial dependence between the incidence and «riches» of the territory, and the main epidemiological significance is the iksodid mites I.ricinus and I.persulcatus. Conclusion. The cartographic mapping of the registered incidence allowed to show the territories with different degree of epidemic manifestation for individual natural-focal diseases and for a complex of morbidity in general. Positive laboratory results indicate epizootic activity and a constant risk of exacerbation of the epidemic situation of zooanthroponous infections, and the absence of human morbidity over a number of years is not evidence of the attenuation of the natural focus of infection and the basis for the curtailment of preventive measures.

MIGRATION WORKERS AND HIV IN SIBERIA

This research was carried out within the framework of joint research work between the Siberian Federal District Center for the Prevention and Control of AIDS of the Omsk Research Institute of Natural Focal Infections and the multifunctional medical center for migrants .NISO.. The work involves several stages from the beginning of 2016. A questionnaire method was used to collect primary data and laboratory results of testing for HIV and syphilis were used. During the period under study, there was a tendency to reduce the number of examined and identified foreign citizens in the Omsk region and the low prevalence of HIV infection in this category of citizens. However, the revealed cases of syphilis, irresponsible attitude to the passage of medical examinations, failure to use protective equipment during sexual intercourse, insufficient knowledge or lack of them for the prevention of dangerous infectious diseases, low level of education can contribute to worsening of the epidemic situation both in the region of stay and in the country of exodus.

THE DYNAMICS OF ORTHOHANTAVIRUS HANTAAN STRAINS REPLICATION ON THE MODEL OF MOUSE PERITONEAL MACROPHAGES

Orthohantaviruses (Orthohantavirus genus, Hantaviridae family) are the causative agents of a widespread natural focal infection in the Russian Federation, hemorrhagic fever with renal syndrome (HFRS). An important role in the persistence of orthohantavirus in reservoir hosts among other immunological responses, as well as in the spread of the virus in the infected organism, is played by infected macrophages, which, along with the vascular endothelium, are the main targets for orthohantaviruses.The aim of our study was to investigate the characteristics of replication of orthohantavirus Hantaan strains isolated from Apodemus mice and detect the influence of different values of multiplicity of infection (MOI) on replication dynamics of orthohantaviruses on cell culture.Materials and methods. We used 4 strains of Hantaan virus, isolated from A. agrarius (n = 2) and A. peninsulae (n = 2), captured in the different areas of Primorsky Krai of Russia. The modeling of infection was performed on the primary cell culture of mouse peritoneal macrophages with different MOI (from 10 to 0.1). The assessing of infection was conducted via indirect fluorescent antibody assay, and results were expressed as rate of antigen- positive cells per all cells in the field of vision. Results. Common dynamics of orthohantavirus infection on this in vitro model was characterized by periodically increased rates of infected cells after 2, 4, 6 и 8 hours post infection (p.i.). Replication of A. agrarius-borne strains was more intensive compare with viruses, isolated from A. peninsulae, in the time point 4 hour p.i. on the background the same MOI the statistically significant difference of rate of antigen-positive cell 24.9 ± 2.38 % vs 15.2 ± 1.87 % (t = 3.20; p = 0.001414) was observed. Additionally, the decrease of MOI was followed by determined decrease of replication effectivity.Conclusion. The results of our study showed the significant phenotyping heterogeneity of orthohantavirus Hantaan strains, isolated from Apodemus mice, resulting in different rates of replication in the culture of mouse peritoneal macrophages.

Results of Epizootiological Monitoring of Small Mammals Habitant in Crimea Over the Period of 2015–2017

Objective of this work is to analyze the spatial distribution of various species of small mammals, caught between 2015 and 2017, and to identify the dominant species in different landscape areas, as well as their role in functioning of natural foci of zoonotic infections (tularemia, leptospirosis, tick-borne encephalitis, Lyme disease, Crimean hemorrhagic fever, hantavirus infection) in the territory of Crimea. Materials and methods. Small mammals were caught during the period of 2015–2017 and investigated using polymerase chain reaction (PCR), enzyme immunoassay (ELISA) and direct hemagglutination reaction. Results and conclusions. The dominant species of small mammals, containing the causative agents of some or other natural-focal infection are ubiquitous species, i.e. disseminated across the territory of the whole peninsula. In the presence of concomitant favorable conditions, they may contribute to the expansion of the natural foci of these infections. Positive tests for Lyme disease detected not only in small mammals caught in mountain-forest areas, but in steppe zone too may testify to the fact that the border of the natural focus of this infection is expanded. To clarify the boundaries of the natural foci of infections circulating in the territory of Crimea, it is necessary to conduct comprehensive analysis of distribution of small mammals, blood-sucking ectoparasites, and also epidemic manifestations in different natural areas of Crimea.

Epizootologic Potential of Certain Natural Foci Infections in Northeastern Armenia

ObjectiveThe objective of this study was to analyze the epizootic potential of four areas of Tavush Marz.IntroductionTavush Marz, in northeastern Armenia, occupies 9,1% of its territory. In recent years in this area either no surveys were conducted or they were incomplete. Tavush Marz is a tourism center as well as a border Marz with strategic importance. The presence of tularemia was first confirmed in 1949 in Noyemberyan. Natural foci of tularemia are located in forest zones where Sylvemus uralensis and its flea vectors are the source of infection.MethodsTavush Marz, in northeastern Armenia, occupies 9,1% of its territory. In recent years in this area either no surveys were conducted or they were incomplete. Tavush Marz is a tourism center as well as a border Marz with strategic importance. The presence of tularemia was first confirmed in 1949 in Noyemberyan. Natural foci of tularemia are located in forest zones where Sylvemus uralensis and its flea vectors are the source of infection.ResultsThe first detection of the Aedes albopictus species of Culicoidea subfamily in Armenia was on the border between Noyemberyan and Georgia in 2016; this is a vector of especially dangerous infections and arboviruses. The presence of the mosquito was confirmed in 2017 and it makes up 13.5% of the mosquitoes collected in the northeast. It is capable of transmitting the chikungunya, Dengue, and West Nile viruses. Since the end of 2015, we have recorded a significant increase in carriers and vectors, mainly S. uralensis, Microtus socialis, and ectoparasites specific to them. In October 2016 six cases of infection with tularemia were recorded in the village of Tsakhkavan in Tavush region and in Bagratashen Village of Noyemberyan region in 2017.ConclusionsAnalysis of the density of rodents and vectors, as well as their typical ectoparasites leads us to conclude that there are favorable conditions for the spread of not only tularemia but also other natural foci infections and that a comprehensive and regular epizootological survey is required to control this situation.

Epizootic Monitoring of Erysipeloid Foci in the Republic of Armenia, 2007-2016

ObjectiveThe goal of this study was to characterize the epidmiological, geographic, and historical characteristics of erysipeloid outbreaks in the Republic of Armenia.IntroductionErysipeloid is a zoonotic bacterial infection transmitted to humans from animals. Symptoms include inflamed joints and skin; there is also a generalized type of the infection in which bacteria spread through the lymphatic and blood vessels, leading to the emergence of widespread skin lesions and the formation of secondary foci of infection in internal organs. Morbidity has no age or gender specifics; there is summer and autumn seasonality. The agent of the infection - Erysipelothrix rhusiopathiae can be found in many domestic and wild animals. Wild rodents and ectoparasites play an essential role in spreading the disease and serve as a source of infection contaminating the environment.MethodsTests are conducted on both national and Marz levels in Reference Laboratory Center of NCDC SNCO and Marz branch laboratories of Especially Dangerous, Zoonotic and Natural Foci Infections respectively. Tests for detection of E. rhusiopathiae and confirmation of epizootics are conducted on rodents and ectoparasites collected from their hair and nests from 373 sectors of Armenia. Tests include smear microscopy and a bioassay in which cultures from a suspension of rodent organs or an emulsion of ticks and fleas are injected into white mice to assess the presence of agent in the organs or parasites.ResultsTen years of monitoring indicates that erysipeloid epizootics have been recorded annually in Armenia with a total number of 119 cases. The most outbreaks were recorded in 2011 when 26 cases were recorded while in 2009 there were 20. The lowest number of cases recorded was five in 2008. Kotayk, Aragatsotn and Lori Marzes have the least number of cases with only 1-3 recorded epizootics, while Vayk, Gegharkunik and Shirak Marzes are considered active foci with 5-7 cases reported. Microbiological analyses indicates that 80% of cultures were isolated from field mice, 13.3% from gamasid ticks, 4.2% from fleas and 2.5% from ixodid ticks.ConclusionsThe presence of E. rhusiopathiae is stable in Armenia. It is found among rodents, where the epidemiological situation remains unfavorable. Constant regular tests/analyses are required to prevent human and animal infection. There is a need to enhance the area of test sites and apply most up-to-date methods of analysis i.e. ELISA, PCR so that the live bioassays in mice can be halted.

Experience of GIS Technology Application in the Surveillance of Tick-Borne Infections

ObjectiveThe main aim of this work is to estimate the projected risks based on the incidence rate of natural foci infections and to expand the list of criteria for the characterization of natural foci of tick-borne infections.IntroductionThe epidemiological situation of natural foci of tick-borne infections (TBI) in Ukraine, as well as globally, is characterized by significant activation of processes due to global climate change, growing human-induced factor and shortcomings in the organization and running of epidemiological surveillance [1]. For the Western region of Ukraine, among all tick-borne zoonoses the most important are tick-borne viral encephalitis (TBVE), Lyme disease (LD), human granulocytic anaplasmosis (HGA) and some others [2-4]. Taking into account the increased incidence rate for these infections, we have developed baseline criteria (indicators of natural contamination of the main carriers and levels of the serum layer among the population in relation to the TBI pathogens in the endemic areas) to identify areas with different risk of contamination through GIS-technologies [5].MethodsEpi Info 7.1.1.14 software was used to analyze patient questionnaires with tick-borne infections (TBI) for 2010-2015. Prevalence maps of vector-borne infections were created by means of GIS technology using the QGIS 2.0.1. software to assess the risks of infection. Maps demonstrating the distribution of TBVE, LD and HGA were also developed based on contamination risk assessment criteria.ResultsRetrospective epidemiological analysis of incidence rates for TBVE, LD and HGA was conducted based on laboratory tests that were performed in the laboratory of vector-borne viral infections of the State Institution Lviv Research Institute of Epidemiology and Hygiene of the Ministry of Health of Ukraine. A direct correlation between the infection of I. ricinus, B. burgdorferi and LB (P <0.05) and infections of I. ricinus ticks, anaplasma and incidence of HGA (P <0.05) was established. However, this connection has not been confirmed for indicators with TBE.Data was obtained during the assessment of possible risks of tick-borne infections. For TBVE, the indicator of predicted risks based on the basic criteria was 60.3%, taking into account the cases of the disease. This was based on indicators of natural infection of the main carriers and the level of the serum layer among the population on the TBI activators in the endemic areas. The data obtained can be explained by the low level of morbidity and the detection of TBVE cases. The predicted risk for LD according to these criteria is 88.9%, due to the high level of clinical and laboratory diagnosis.As for the HGA, the predicted risk indicator reaches 66.7% due to the fact that the study of human anaplasmosis in Ukraine is at the initial level (the incidence rate and incidence are not included in the official reporting system).Taking into account the results obtained, it is advisable to supplement the list of criteria for determining the degree of activity of natural foci of tick-borne infections and the identification of areas with high risk of morbidity. These calculations were made by grouping statistical data (indicators) [5]. The reliability of the difference between the same indicators for individual zones was 95% (Table 1).ConclusionsTick-borne zoonoses are a serious problem for the public health system of the Western region of Ukraine. Extending the list of criteria for the characterization of natural foci of tick-borne infections will improve epidemiological surveillance and focus on key measures in high and medium-risk areas for the rational use of funds.

Structured RNA Markers for Genotyping of Tick-Borne Encephalitis Virus

Tick-borne encephalitis is one of the most dangerous natural focal infections. The causative agent of the disease is tick-borne encephalitis virus (TBEV ) transmitted by ticks . There are three main subtypes of TBEV with different clinical manifestations of the disease, but existence of other subtypes is also possible. Effectiveness of the disease treatment can largely depend on the correct identification of TBEV genotype. Comprehensive information about the genotype is contained in the full coding sequence of TBEV genome. А limited number of genotyping markers can be extracted from it in the form of relatively short structured RNA fragments. In this paper, a rather general approach to the isolation of structured RNA markers for the genotyping of TBEV is formulated. Three types of structures are considered: periodicity, fractal-like constructs and compactly localized combinations of different types of repetitions. The choice of these structures for the purposes of genotyping and their possible role in the formation of the pathogenic potential of the virus is substantiated. The approach was tested on the full coding sequences of TBEV (161 strains). Examples of the most characteristic markers of each of the three types are given.

ВЕРОЯТНОСТЬ ЗАРАЖЕНИЯ НАСЕЛЕНИЯ ВОЗБУДИТЕЛЯМИ, АССОЦИИРОВАННЫМИ С РУКОКРЫЛЫМИ, В РОССИЙСКОЙ ФЕДЕРАЦИИ

There was analyzed the situation of natural focal infections, the pathogens of which are associated with bats and modern ideas about the possible epizootic and epidemic importance of bats, as well as the prospects of ongoing epizootiological monitoring under epidemiological supervision in the Russian Federation. There were stated the main tasks of the organization of observations of the representatives of Chiroptera order – the possible reservoir hosts and/or sources of dangerous for human pathogens.

HUMAN GRANULOCYTOTROPIC ANAPLASMOSIS

Natural focal tick-borne infections are widespread in the world and are characterized by a great etiologic diversity. Human granulocytotropic anaplasmosis (HGA), also transmitted by the bite of ticks became relevant in the last century of detection not only in animals but also in humans. The review provides an overview of the incidence of HGA in Russia and in the world, the prevalence of the habitat of mites, the diversity of reservoirs and sources of infection, mechanisms and pathways of transmission of the pathogen Anaplasma phagocytophilum and its biological features. The links and stages of the disease pathogenesis are considered in detail. Scientific data on the clinical course of the disease, the frequency and diversity of various symptoms of the disease, the issues of laboratory and differential diagnosis of anaplasmosis and its place in the nosological structure in patients with fever of unknown origin are discussed. At the same time, choosing a method of laboratory diagnostics it is necessary to take into account that molecular-genetic method (polymerase chain reaction PCR-diagnosis) allows to confirm the diagnosis quickly, while serological methods of research in a greater degree - to put a retrospective diagnosis. The article presents current data on the treatment of disease and methods of HGA prevention and also presents the results of the authors’ own observations based on the survey of 63 patients. The analysis of Moscow residents treatment about sucking mites is carried out and summarized the incidence of infections transmitted by ixode mites. For the diagnosis of HGA and other tick-borne fever used a technique called polymerase chain reaction. It has been revealed that in Moscow, lime borreliosis occupies a leading place among mites associated with infections 60%, and the share of granulocytic anaplasmosis of a person is only 5% of patients. However, the study of ticks for the presence of HGA pathogens and other natural focal tick infections is carried out in insufficient volume (less than 30%), which should be considered in clinical and laboratory differential diagnosis, as well as preventive measures.

МОНИТОРИНГ ПРИРОДНО-ОЧАГОВЫХ ИНФЕКЦИЙ НА ЮГЕ ЕВРОПЕЙСКОЙ ЧАСТИ РОССИИ В 2016 ГОДУ

The results of epizootological monitoring of the Southern European part of Russia (Southern and North- Caucasian Federal Districts), which has been tested for 18 nosological forms of natural focal infections are presented. There have been tested the laboratory studies of 45 615 samples of field material, the markers of pathogens of 15 nosological forms are identified. The circulation of Crimean-Congo hemorrhagic fever virus is identified in 10 subjects, the pathogen of tularemia – in eight regions, Lyme borreliosis – in seven, Q fever – in six; pathogens of hemorrhagic fever with renal syndrome, West Nile fever, leptospirosis and human granulocytic anaplasmosis – in five subjects. The markers of pathogens of human monocytic ehrlichiosis and tick-borne viral encephalitis were detected in four subjects, pseudotuberculosis and intestinal yersiniosis – in three and Arboviruses (Sindbis, Inkoо, Tahyna) – in one region.

Векторы трансмиссивных вирусных болезней животных

The article reviews the data of Russian and foreign literature sources concerning the spread of vector-born animal infectious diseases such as lumpy skin disease (LSD), Rift Valley fever (RVF), bluetongue. Epidemiology, spread of diseases as well as geographical distribution of their vectors are described, the most probable reasons for expanding the areas of vector-borne infections are considered. Insects and ticks serve not only as vectors, but also as reservoirs and amplifying agents of many pathogens of natural focal infections of human and animals. Of great epidemiological importance is the ability of some vectors to transmit vertically the pathogens from infected females to their offspring. An important role in the epidemiology of vector-borne infections belongs to the following bloodsucking insects - mosquitoes (family Culicidae), sandflies (family Phlebotomidae), midges (family Simuliidae), biting midges (family Heleidae), flies (family Muscidae). Spread of lumpy skin disease to the new territories in recent years is associated with blood-sucking ticks and flying biting insects of the order Diptera (Muscidae -Stomoxys calcitrans; Culicoides - C. Punctatus; Anopheles - An. stephensi; Culex, - Cx. quinquefasciatus). Rift Valley fever virus is transmitted through the bites of infected mosquitoes of the genera Aedes, Anopheles, Coquillettidia, Culex, Eretmopodites Eunelanomyia, Mansonia, Neomelaniconion, Ochlerotatus, Stegomyia. A wide range of mosquitoes’ feeders and the ability of some species to feed consistently on birds and mammals allowed these insects to become the most important vectors of many zoonoses. The major vectors of the bluetongue virus are representatives of blood-sucking biting midges of the genus Culicoides (Diptera: Ceratopogonidae), numbering about 1350 species distributed throughout the world (about 117 species in Europe). This article summarizes data on species composition Culicoides in the world and in the Russian Federation and their competence in the transmission of the bluetongue virus. The major vectors of the bluetongue virus in Africa include representatives of the species C. imicola, in North America - C. sonorensis,.in Australia - C. brevitarsis. In Europe the bluetongue virus is transmitted by biting midges from the complex obsoletus and pulicaris.

Epidemiological Features of Combined Natural-Focal Infections

On the basis of literature data and results of own research in the article describes the features of the epidemiology of combined natural focal infections, their distribution in the Russian Federation, pathogenesis and clinical features to suit different combinations of pathogen agents. The data on the mixed infection of ticks by different agents in various combinations, as well as polyetiology infected of reservoir hosts Showing different variants of combined natural focal infections in humans caused by the associations of microorganisms, including up to five assiociants, as well as features of the pathogenesis and clinical manifestations Based on original research developed a method of a quantitative estimation the activity of combined natural foci and complex of measures on surveillance and control of combined natural focal infections.

THE DIVERSITY OF THE PARASITIC SYSTEM IS THE BASE OF THE STABILITY OF THE FUNCTIONING OF NATURAL FOCUS OF THE INFECTION

This paper presents the authors’ opinion concerning such understudied issue of epizootology as the cause of the stability of the functioning of the natural focus of infection. The diversity of the biocenotic complex including main, secondary and casual carriers; numerous, small in number and rare vectors; strains with high virulence, low virulence and altered strains of the causative agent of infection, as well as population nonuniformity of biocenosis constituents contribute to the stability of the functioning of the natural focus in certain landscape-geographic conditions. The heterogeneity during the achievement of the abundance peak by various carrier and vector species also promotes to the stability. Universality of the principle of the proposition offered here for three- and two-component constituents of a natural focus of infection, as well as for infections caused by sapronotic pathogens, allows consider it as a biological law of the stable functioning of a natural focus of infection.

Chorological Structure of natural focal infections in the Asian part of the Russian Federation

Division of the Asian part of the Russian Federation into southern and northern zones was implemented on the basis of physical-climatic features. The retrospective analysis of the natural focal infectious diseases in humans was carried out. Spectrum of nosological forms and epidemic process intensity in each of the evolved zones were established. Epidemic manifestations were the most expressed in the Subjects belonging to the southern zone, with domination of the Ixodes tick-borne infections. In northern zone natural focal infections included 57,1 % of local cases, they were registered only in the population of Yamal-Nenets Autonomous Okrug (District), and barely nontransmissible infections: hemorrhagic fever with renal syndrome and rabies.