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The review features the situation on Crimean-Congo hemorrhagic fever (CCHF) in the world and the analysis of the epidemiological and epizootiological situation in the Russian Federation in 2023. The number of CCHF cases (26) in Russia was 2.3 times less than in 2022, and 71.6 % lower than the long-term average (in 2013–2022 – an average of 88.8 cases per year, mortality (8 %) is 2.4 times higher than the long-term average (3.3 %). The epidemically significant indicator of the abundance of the main vector of the CCHF virus, ticks Hyalomma marginatum, was 5 times higher than the threshold value (abundance index for cattle – 15.5) at long-term observation points in April. For the first time, one case of CCHF disease was registered in a new epidemically active territory – in the Botlikh and Novolaksky districts of the Republic of Dagestan. For the first time in the Zaporozhye Region, RNA of the CCHF virus was detected in ticks H. marginatum and Rhipicephalus rossicus. Markers of CCHF virus were found in 0.67–18.27 % of samples, CCHF virus variants of the genetic line Europe 1 were circulating on the territory of Russia in 2023. According to the forecast of the epidemic situation for 2024, CCHF morbidity is likely to increase in the south of the European part of Russia. The recommendations for undertaking preventive measures have been provided.

The review presents an analysis of the epidemiological and epizootiological situation on Crimean-Congo hemorrhagic fever (CCHF) in the Russian Federation in 2022. The incidence rate of CCHF registered in 2022 (59 cases) was 1.2 times higher as compared to 2021, however, below the long-term average annual values. The mortality rate was 10.2 %, which exceeds the indicators of long-term observations (in 2012–2021 – 3.2 %). Following epizootiological survey of stationary observation points, it was found that the number of Hyalomma marginatum imago in 2022, in general, corresponded to the average long-term indicators. CCHF virus isolates circulating in Russia in 2017–2022 belonged to the genetic lines “Europe-1” (V), “Europe-2” (VI), and “Europe-3” (VII). The ratio of CCHF virus genovariants in the population on the territory of the Russian Federation in 2017–2022 didn’t change. Based on the analysis of naturalclimatic factors, the forecast for the incidence of CCHF in the Russian Federation for 2023 has been made.

The review presents an analysis of the epidemiological and epizootiological situation on Crimean-Congo hemorrhagic fever (CCHF) in the Russian Federation in 2021. 49 cases of CCHF were detected in 2021, which is 1.53 times higher than in 2020. The mortality rate was 6.1 %. Sporadic cases of CCHF were registered in the Stavropol Territory, Rostov, Volgograd Regions, the Republics of Dagestan and Kalmykia. The incidence rates of CCHF were below the long-term average annual values in the majority of the constituent entities. Epizootiological survey of stationary observation points has revealed that the number of Hyalomma marginatum imago corresponded to the average long-term indicators in 2021, the peak of H. marginatum activity was noted in the II–III decades of May. The proportion of Ixodidae tick pools positive for Crimean-Congo hemorrhagic fever (CCHF) virus markers exceeded the long-term average indexes in a number of regions. On the territory of the natural focus of CCHF, the circulation of the CCHF virus of the genetic lineages “Europe-1” and “Europe-3” was detected in 2021. Based on the analysis of the epidemiological data of the previous year and natural and climatic factors affecting the abundance and vital activity of H. marginatum ticks, risk-based quantitative forecast for the incidence of CCHF in the Stavropol Territory for 2022 has been compiled.

The purpose of the research is the assessment of the Francisella tularensis occurrence in nature in ticks of the genus Dermacentor; understanding the physiological age in terms of tick infection with tularemia pathogen.Materials and methods. For the period from 2015 to 2019, we examined 8449 specimens of Dermacentor marginatus (916 pools), 8674 specimens of D. reticulatus (705 pools), and 109 specimens of D. niveus (40 pools) for tularemia infection. To assess the dependence of tularemia pathogen found in ticks of different physiological ages, we examined 2440 specimens of D. marginatus (360 pools), and 3349 specimens of D. reticulatus (412 pools) for the period from 2016 to 2019. Studies of ixodid ticks infected with tularemia pathogen were performed by the Natural Focal Infection Laboratory of the Stavropol Anti-Plague Institute. Pools of ixodid ticks were examined for the pathogen DNA of tularemia using reagent kits for identifying Francisella tularensis DNA by polymerase chain reaction with fluorescence hybridization of results recorded in real time.Results and discussion. The infection rate of the tularemia pathogen in ticks in the Central Pre-Caucasian region ranged from 0.044–1.127% in D. marginatus and 0.035–1.455% in D. reticulatus in different years. The greatest number of F. tularensis was isolated from the III physiological age ticks. For D. reticulatus ticks, no statistically significant dependence of the detected tularemia pathogen on physiological age was found.

The review presents an analysis of the epidemiological and epizootiological situation on Crimean hemorrhagic fever in the Russian Federation in 2020. During the stated period, 32 CHF cases were registered, which is the minimum indicator since the activation of the natural focus of CHF in 1999. The mortality rate was 3.1 %. The incidence was recorded in the Rostov, Astrakhan Regions, Stavropol Territory, the Republics of Dagestan and Kalmykia. A significant decrease in the incidence of CHF was noted in all entities of the Southern Federal District and the North-Caucasian Federal District. An imported from the Republic of Crimea case of CHF was detected in Moscow. The seasonality of morbidity, occupational, and age composition of CHF patients, modes of transmission, features of the clinical course of the disease in 2020 corresponded to the data of long-term observations. Epizootiological monitoring of the territory of the CHF natural focus showed that the abundance of Hyalomma marginatum adults and the percentage of Ixodidae tick pools positive for the presence of CCHF virus markers corresponded to the average long-term indicators at stationary observation points in 2020 , which indicates the persisting epizootiological disadvantage of the territory of the natural CHF focus in the Russian Federation. The persisting high numbers and infection rate of H. marginatum ticks can contribute to the development of an unfavorable epidemiological situation in the south of the country with a possible increase in the incidence of CHF in the Russian Federation in 2021.

The review presents an analysis of epidemic and epizootic situation of Crimean-Congo hemorrhagic fever in the Russian Federation in 2010–2019, summarizes the results of epizootiological monitoring of the CCHF natural focus territory in the south of European part of Russia. An unfavorable epidemiological situation regarding CCHF is maintained in the Russian Federation. In 2010–2019, 999 CCHF cases were registered in nine regions of Southern and North-Caucasian Federal Districts. In 2019, an increase in the CCHF incidence level in the entities of the SFD and NCFD was observed as compared to 2017–2018. The expansion of the territory with registered epidemic manifestations of CCHF continues. In 2010–2019, the number of imago and pre-imaginal phases of Hyalomma marginatum – the main vector of the CCHF virus in Russia, remained consistently high. High numbers of H. marginatum ticks and their CCHFV infection rates can contribute to the development of an unfavorable epidemiological situation in the south of the Russian Federation with a possible increase in the CCHF incidence in 2020.

The aim is to analyze the current epidemiological and epizootiological situation on ixodic tick-bome borreliosis in the South of the European part of Russia. Materials and methods. The research materials were the epidemiological and epizootiological data for 2014-2018 provided by the Rospotrebnadzor Departments, the Hygiene and Epidemiology Centers of the North Caucasian and Southern Federal Districts, and regional anti-plague institutions: Stavropol, Volgograd and Rostov-on-Don research anti-plague institutes, Astrakhan, Dagestan, Kabardino-Balkar, Black Sea, North Caucasus, Elista plague control stations, as well as the plague control station of the Republic of Crimea. The data of scientific publications on epizooitological monitoring, the species composition of vectors and agents of tick-borne borreliosis involved in the epizootic and epidemic process in the region were studied. In the study descriptive, analytical epidemiological methods, retrospective epidemiological and cartographic analyzes were used. Results and discussion. It has been noted that in 1999, the incidence of tick-borne borreliosis in the South of the European part of Russia, has occurred in 11 of the 15 administrative regions. The incidence of tick-borne borreliosis in the Republic of Kalmykia, has not been recorded since 2007, in the Chechen Republic - since 2014. To clarify the sources of tick-borne borreliosis infection in the territory of the Krasnodar and Stavropol Territories, the Volgograd and Rostov Regions, the Republic of Dagestan and the Karachay-Cherkess Republic, and also, to determine the boundaries of natural and natural-anthropurgic foci of ixodic tick-borne borreliosis constant epizootiological monitoring is required. In addition, it is necessary to create a unified algorithm for monitoring natural foci, to analyze data using modern geographic information and statistical tools.

Objective – analysis of epizootiological manifestations of natural focal infections in the territory of the south of the European part of the Russian Federation in 2017.Materials and methods. Statistical documentation data from the Rospotrebnadzor Administrations, Centers of Hygiene and Epidemiology in the constituent entities of the Russian Federation, and Plague Control Research Institutes and Stations were used. The information was processed using Microsoft Excel 2010 software.Results and discussion. Epizootiological survey for 19 nosological forms of natural focal infections in the territory of the south of the European part of the Russian Federation was conducted. The total of 70155 samples of field material was tested; markers of 14 pathogens of natural focal infections were identified. The circulation of Crimean-Congo hemorrhagic fever virus was revealed in 11 constituent entities, tularemia and Lyme borreliosis pathogens – in 8 entities, West Nile virus – in 7. Markers of leptospirosis, Q fever, human granulocytic anaplasmosis and human monocytic ehrlichiosis pathogens were detected in 6 constituent entities, markers of the agent of hemorrhagic fever with renal syndrome – in 5 entities; markers of intestinal yersiniosis pathogen – in 3 constituent entities of the Russian Federation, pathogens of tick spotted fevers group, tick-borne viral encephalitis and pseudotuberculosis – in 2. The circulation of the virus Sindbis was identified in the Rostov Region.

The review presents the analysis of epidemic and epizootic situation on Crimean hemorrhagic fever (CHF)in the Russian Federation in 2009–2018. Over the past decade, 980 CHF cases have been registered in Russia (2,8 %lethal). In 2009–2018, there was a significant expansion of the epidemiologically active area of the natural CHF focus.Epizootiological monitoring of the territory of natural CHF focus showed that in 2009–2018 the number of imago andpreimaginal phases of Hyalomma marginatum – the main vector of the CCHF virus in Russia, remained consistently high.The average long-term rate of Ixodidae ticks infestation by the CCHF virus in 2013–2017 was 3,3 %. In 2009–2018 in the south of the European part of Russia CCHF virus variants belonging to the genetic lines Europe-1 (V), Europe-3 (VII) and Africa-3 (III) were detected. There were no significant changes in the ratio of circulating genetic variants of the virus in the regions of the Russian Federation, which confirms the relative stability of the CCHF virus population. In 2018, CHF morbidity rate in the Russian Federation retained downward trend, however, in some regions of South Federal District the number of CHF cases increased. One of the reasons for CHF morbidity rate decrement in the Russian Federation in 2018 was the well-timed acaricidal treatments of cattle and natural biotopes in most of CHF endemic regions.

This paper presents the analysis of Crimean hemorrhagic fever (CHF) morbidity rates in Russia in 2017; summarized are the results of epidemiological survey of the territory of the natural CHF focus in the south of the European part of Russia, discussed are the results of genetic typing of CCHF virus isolates. In 2017, the Russian Federation reported 78 cases of CHF. Decrease in the incidence of CHF occurred in the Volgograd Region, Stavropol Territory, Astrakhan Region, Republic of Kalmykia, and Rostov Region. For the first time since 1967, CHF case has been identified in Crimea Republic. It is expected that the level of epizootic activity of CHF natural focus in Russia in 2018 will be at least equal to 2017. In case of favorable for Ixodidae ticks weather and climate conditions of the winter 2017–2018, as well as untimely acaricidal treatments, the number of Ixodidae ticks may increase, which along with the high scale of CCHF virus infection in ticks, will contribute to the increase in CHF incidence.

Aim. Chracteristic of number and distribution of mosquitoes Ae. aegypti and Ae. albopictus in the Republic of Abkhazia and a risk assessment of virus Zika spread. Materials and methods. The accounting of mosquitoes number was made by the method «on the observer» in 20 minutes at the 70 nature landscapes points in april-oktober 2016. Results. The Black sea coast of the Republic of Abkhazia has favorable ecological conditions for the mosquitoes ingrowth of Ae. aegypti and Ae. albopictus. At 2016 the mosquitoes Ae. albopictus having vector competence to spread a Zika virus, has been revealed in the open stations in the territory from Ochamchirsky district to border with the Russian Federation. Their number is correlated with the air temperature in the region. The control of efficiency of the insecticidal works showed that in the open stations Ae. albopictus were not found within 3 - 7 days after the disinsection actions. However, their number of recovered as a result of settling from nearby natural biotopes. Conclusion. The risk of local Zika virus transmission has estimated as a low. Considering the gravity of the disease caused by the Zika virus carrying out a wider complex of the control methods of the mosquitoes number in areas of their dwelling, especially on the epidemiologically significant objects is necessary. The most effective of the population protection action is riddance of the reproduction mosquitoes places and sanitation of territory.

Aim.The analysis of causes of deterioration epidemiological situation on Crimean-Congo haemorrhagic fever (CCHF) in the Russian Federation in 2016. Materials and methods. Data of statistical documentation of Departments of Rospotrebnadzor, Centers of Hygiene and Epidemiology in subjects of the Russian Federation, Plague Control Research Institutions and Anti-Plague stations from 8 subjects of the Southern and 7 subjects of the North-Caucasian Federal Districts were used. The findings have been treated using by Excel program. Results. In 2016, epidemiological manifestations of CCHF are identified on the territory of 6 subjects of the south of Russia. An increase in the incidence of CC H F occurred in the Stavropol Territory, the Republic of Kalmykia, Astrakhan and Volgograd Regions. The main cause of the deterioration epidemiological situation on CCHF was increasing of the number and the period of activity of ticks marginatum, in the epidemic season as a result of favorable climatic conditions; incorrect dates of the realization and inadequacy of the acaricide treatments livestock and natural biotopes. Conclusion. For the improvement epidemiological situation on CCHF timely realization of the acaricide treatments in the early spring (March-April) livestock and natural biotopes using effective insecticides and with its further entomological control it is necessary.

Abstract. This paper presents analysis of epidemiological situation on Crimean hemorrhagic fever (CHF) in Russia in 2016. Summarized are the results of epizootiological survey of the territory of the natural CHF focus in the south of the European part of Russia, discussed are the results of genetic typing of CCHFV RNA isolates. In 2016, the Russian Federation reported 162 cases of CHF. Increase in the incidence of CHF occurred in the Astrakhan, Volgograd Regions, Republic of Kalmykia, and Stavropol Territory. For the first time CHF case was identified in Kabardino-Balkar Republic. In 2016 in stationary points for the long-term observation of the natural CHF focus, high abundance rates of larvae and nymphs of H. marginatum remain. In case of successful Ixodidae ticks wintering and late onset of the hot and dry season in the summer, 2017, there is probability that high numbers of H. marginatum will be retained and the period of the imago activity is prolonged, which may in its turn contribute to the increase in CHF morbidity rates.

Aim. Analyze epizootologic manifestations of natural-focal infections (NFI) in the south of Russia in 2015. Materials and methods. Reports provided by administrations of Federal Service of Surveillance for Protection of Consumers Rights and Human Welfare, Centers of Hygiene and Epidemiology, Research Institutes for Plague Control and Station for Plague Control were used. Data processing was carried out using Excel program. Results. A total of 37 738 samples of field material were studied, most of those - for tularemia (8268), Crimea hemorrhagic fever (6894) and West Nile fever (4875). Causative agents of 15 nosologic forms of NFI were detected during epizootologic examination of the territory of south of Russia, predominating amount of positive samples was obtained during study of material for tick-borne borreliosis (612), Crimea hemorrhagic fever (279) and tularemia (237). Conclusion. Analysis of epizootologic situation on natural-focal infections in the south of Russia gives evidence on the increase of activity of natural foci of bacterial (tularemia, tick-borne borreliosis), rickettsia (tick-borne spotted fevers) and viral infections (Crimea hemorrhagic fever, West Nile fever, tick-borne viral encephalitis), and thus problems of prophylaxis of natural-focal infectious diseases and constant monitoring of natural foci in subjects of Southern, North-Caucasian and Crimea federal districts are of particular importance.

Objective of the study is to analyze epidemiological and epizootiological manifestations of natural-focal infections in the territory of the North-Caucasian Federal District (NCFD) in 2015. Materials and methods. Utilized were the reports of the Rospotrebnadzor Administrations, “Centers of Hygiene and Epidemiology” in the NCFD entities, Stavropol Research Anti-Plague Institute, Dagestan and Kabardino-Balkaria Plague Control Stations. Data processing was conducted using Excel Microsoft ware. Results and conclusions. Identified have been 8 nosological forms of natural-focal infections, including infections of bacterial etiology – 6 (75 %), and viral etiology – 2 (25 %). The majority of patients (164) are identified in the Stavropol Region: 67 (intestinal yersiniosis), 43 (Crimean–Congo hemorrhagic fever), 40 (Lyme borreliosis), 9 (leptospirosis), 2 (pseudotuberculosis), 1 (rabies), 1 (human granulocytic anaplasmosis) and 1 (human monocytic ehrlichiosis). The patients with 2 nosological forms of natural focal infections are identified in the Republic of Dagestan: 2 – Crimean–Congo hemorrhagic fever and one patient – tularemia. Also 2 nosological forms of natural focal infections are revealed in the Republic of Karachay-Cherkessia: one case of leptospirosis and one case of Crimean–Congo hemorrhagic fever (imported from the Stavropol region). 8502 field samples have been tested for the presence of markers of 12 nosological forms of natural-focal infections. Positive results for 10 of them have been obtained. The most comprehensive epizootiological monitoring has been carried out in the Stavropol Territory (10 nosological forms), whereat circulation of 8 pathogenic agents is registered.

Aim. Analysis of results of epidemiologic monitoring of especially dangerous, natural-foci and other infectious diseases, as well as epizootologic activity of natural foci of infection on the territory of city-resort Sochi. Materials and methods. Laboratory studies of 820 samples by PCR, immune- and bacteriologic methods were carried out, among those 344 - clinical material, 12 - water from open bodies and 321 - field material. Molecular-genetic identification of 143 strains of Vibrio cholerae, isolated from open water bodies of city-resort Sochi, was carried out. Results. Circulation of causative agents of Q fever, tularemia and hemorrhagic fever with renal syndrome of Dobrava-Adler genotypes was established, as well as rickettsia of tick spotted fever group. Predomination of rotaviruses (70.9%) was detected during study of samples of clinical material in etiologic structure of sporadically emerging acute intestine infections. Relatively high temperature values of river water during summer months (from 18 to 30°C), exit of sulfide mineral waters into the riverbed, that create alkaline medium, seasonal reduction of river debit and speed of water current facilitated sustenance of contamination of water of Agura river by V. cholerae. Conclusion. Activity of natural foci of the infectious disease and contamination of Agura river by V. cholerae 01 (atoxigenic) gives evidence on the necessity of constant control of epidemiologic situation by dangerous and natural-foci infectious diseases on the territory of city-resort Sochi, as well as study regional features of their causative agents, including using genetic methods.

Epidemic outspread of Zika fever has given WHO authority to declare emergency situation in the sphere of international healthcare. Major risks for the Russian Federation are associated with the import of the disease by persons, infected in epidemiologically hazardous territory, or import of Zika virus vectors by transport means of international traffic. In this context, developed and normatively regimented is the complex of measures aimed at prevention of Zika virus disease, comprising activities to control import of the infection from enzootic territories, monitoring over the vectors of virus, Ae. aegypti and Ae. albopictus , and procedure for disinfection operations. Developed and introduced into practice is a home-made preparation for laboratory diagnostics and detection of Zika virus RNA using PCR. The article covers the issue of possible dissemination of the vectors in southern regions of Russia in view of climate warming. It is concluded that nowadays probability of local Zika virus transmission in “human-mosquito” cycle is extremely low and no complications of epidemiological situation on arboviral Ae. aegypti- and Ae. albopictus- borne infections are predicted.

Aim. Analysis of epidemic manifestations of natural-foci infections (NFI), clarification of spectrum of their causative agents, determination of epizootic activity of natural foci in the Crimea Federal District (KFD). Materials and methods. Epizootologic examination of 10 administrative districts of KDF was carried out. 291 pools (2705 specimens) of ixodes ticks and 283 samples of organs of small mammals were studied by PCR method for the presence of DNA/RNA of causative agents of a number of NFI. Results. Morbidity by NFI in KFD was registered by 6 nosologies: Lyme borreliosis, Marseilles fever, leptospirosis, tularemia, intestine yersiniosis and tick-borne viral encephalitis, wherein, transmissive infections made up 91.6%. Circulation of causative agents of Crimea hemorrhagic fever, Q fever, group of tick-borne spotted fever, Lyme borreliosis, human granulocytic anaplasmosis, human monocytic ehrlichiosis, hemorrhagic fever with renal syndrome, West Nile fever, tularemia and leptospirosis was established. Conclusion. Due to activity of natural foci of NFI further monitoring of epidemiologic and epizootologic manifestations of these infections in the Crimea, including using genetic methods of analysis, is necessary for ensuring sanitary-epidemiologic welfare of KFD population.

This paper presents analysis of epidemiological situation on Crimean-Congo hemorrhagic fever (CCHF) in Russia in 2015; summarized are the results of epidemiological survey of the territory of the natural CCHF focus in the south of the European part of Russia. In 2015, the Russian Federation reported 139 cases of CCHF. The most significant increase in the incidence of CCHF occurred in the Stavropol Territory and Rostov Region. Identified was CCHF case in Voronezh city imported from the Crimean Federal District. Marked is the involvement of new administrative areas in the epidemic core of the natural focus. The aggravation of the epidemiological situation in the South of Russia was mainly due to the favorable for dissemination of ticks, H. marginatum, climatic conditions in winter 2014-2015. In 2016, in the case of successful Ixodids wintering, as well as ineffectively exercised acaricide treatments, the numbers of H. marginatum may increase compared to 2015, which may become the cause of augmented incidence among the population.

The territory of the Crimean Peninsula is an endemic one as regards various natural-focal infections. The paper contains the data on epizootiological survey of 8 administrative regions of the Crimean Federal District (CFD). Carried out has been small mammals and Ixodidae ticks census. Identified is their species composition. Performed have been the field samples collection and laboratory studies for the presence of bacterial and viral infection agents. Established is the fact that H. marginatum is a dominating species among the ticks, collected during the spring season, while the house mouse prevails among the small mammals. As for the autumn collection of samples, the dominating species are H. punctata and common vole, respectively. Laboratory investigation results indicate the circulation of the agents of Ku fever, tick-borne spotty fever, Ixodidae tick-borne borreliosis, human granulocytic anaplasmosis, monocytic ehrlichiosis, hemorrhagic fever with renal syndrome and leptospirosis.

Crimean hemorrhagic fever (CHF) is one of the priority infections in the south of the European part of the Russian Federation. Persistently high morbidity rates are retained within the past five year term, with case fatality amounting to 4.3 % on the average. In 2014 registered were 91 CHF cases. Therewith, displayed is the analysis of epidemiological situation on CHF in the territory of Russia in 2014, consolidated are the results of epizootiological surveillance of the CHF natural focus area, represented are the findings of genetic typing of CCHF virus which circulated in Russia in 2014. Using the data on epizootiological monitoring, made has been the forecast of CHF epidemiological situation development for 2015.

Crimean hemorrhagic fever remains one of the priority infections in the South of Russia. Within the past five years morbidity rates are retained consistently high in a number of regions; mortality rates are on average 4.4 %. In 2013 registered were 79 cases of CHF in the Southern and North-Caucasian Federal Districts. Therewith performed has been analysis of epidemiological situation on CHF in the Russian Federation for 2013, summarized have been the results of epizootiological surveillance of the natural CHF focus area in the South of European Russia, discussed are the results of genetic CCHF virus typing, identified in 2011-2013 in the South of Russia. Based on epizootiological surveillance data made has been the forecast of epidemiological situation development as regards CHF for 2014.

Represented is epidemiological evaluation of the morbidity rate as regards Crimean-Congo hemorrhagic fever (CCHF) in Russia in 2012. Summarized are the results of epizootiological surveillance over the territory of CHF natural focus in the South of European part of Russia. Forecast of CCHF epidemiological situation development for 2013 is made based on the epizootiological monitoring data.

The analysis carried out demonstrates that China is inhabited not with Callopsylla caspia fragilis, but with 1 or 2 new (ssp. n.) subspecies of Cal. caspia. Cal. yui was proved to be the subspecies (stat. nov.) of Cal. caspia. In Tadjikistan, Afghanistan and Pakistan representatives of new (1 or 2) subspecies of Cal. caspia reside. Peculiarities of the females of different subspecies of Cal. caspia are presented.