Activity Of Natural Plague Foci Research Articles

Epidemiological Situation on Plague around the World. Forecast of Epizootic Activity of Natural Plague Foci in the Russian Federation for 2024

The aim of the review was to assess the epidemiological situation in natural plague foci in the Russian Federation, near and far abroad countries in 2023 and to forecast their epizootic activity for 2024. In 2023, cases of plague were registered in five countries worldwide: the Democratic Republic of the Congo (60 cases), the Republic of Madagascar (14), the United States of America (2), the People’s Republic of China (3), and Mongolia (5). A total of 84 cases of plague were recorded, of which 22 (26.2 %) were fatal. In the Russian Federation, in 2023, epidemic risks in epizootically active natural foci were significantly reduced due to the implementation of a set of preventive measures carried out by Rospotrebnadzor institutions, which was the guarantor of ensuring epidemiological well-being as regards plague. Plague epizootics were detected on the territory of two (Gorno-Altai high-mountain and Tuva mountain) out of 11 natural plague foci in the Russian Federation in 2023. Epizootics were reported on the territory of the Kosh-Agach district of the Altai Republic and the Mongun-Taiginsky kozhuun of the Tuva Republic. The total area of epizootics was 731.2 km2 (in 2022 – 248.3 km2). In total, 55 cultures of the antique biovar of the main subspecies Yersinia pestis pestis were isolated in 2023 (19 in 2022). The forecast for continuation of the tense epidemiological situation in the territory of the Altai and Tuva Republics in 2024 is substantiated. The trend of sustained growth in the epizootic potential of the East Caucasus high-mountain and Dagestan plain-piedmont plague foci is outlined. The prospects for introducing an automated electronic system for assessing the epidemic potential of natural plague foci into practice are explained.

Improvement of Epidemiological Surveillance of Natural Plague Foci of the Russian Federation and the Forecast of Their Epizootic Activity for 2023

The aim of the work was to assess the epidemic situation on plague in the world and epizootic activity of natural plague foci of the Russian Federation in 2022. Following the implementation of comprehensive preventive interventions plans, there was a decrease in the epizootic activity of the Gorno-Altai high-mountain and Tuva mountain natural foci, the cessation of plague epizootics in the Central Caucasian high-mountain focus. The total area of epizootics in the Russian Federation in 2022 reached 248.3 km2, which is 7 times less than in 2021. Infected animals were not found in the Tersko-Sunzhensky low-mountain, Dagestan plain-piedmont, Caspian North-Western steppe, Volga-Ural steppe, Trans-Baikal steppe, Volga-Ural sandy, Caspian sandy, East Caucasian high-mountain natural foci. Persistence of tense epizootiological situation in 2023 is predicted for the territory of the Altai Republic and the Republic of Tuva. The prospects of using the GIS portal of the Russian Anti-Plague Institute “Microbe” of the Rospotrebnadzor for an operational assessment of the actual epidemiological situation in natural plague foci are substantiated.

Enhancement of Epidemiological Surveillance in Natural Plague Foci of the Russian Federation and Forecast of Epizootic Activity for 2022

The aim of the research was to assess epizootic activity of natural plague foci in the Russian Federation in 2021 and provide a prognosis for 2022. Activation of epizootic process has been detected in Central-Caucasian high-mountain natural plague focus after a recess since 2007. Local epizootics persist to develop in Tuva Mountain and Gorno-Altai highmountain plague foci. Total area of epizooties in Russia in 2021 amounted to 1649.5 km2. 28 plague microbe strains were isolated. Animals infected with plague were not found in Tersko-Sunzhensky low-mountain, Dagestan plain-piedmont, Precaspian north-western steppe, Volga-Ural steppe, Trans-Baikal steppe, Volga-Ural sandy, Caspian sandy and EastCaucasian high-mountain natural plague foci. It is demonstrated that epidemiological welfare as regards plague in Russia in 2017–2021 was achieved through annual epizootic monitoring of plague-enzootic territories, timely epizooty detection and preventive activities aimed at reducing the risk of infection. Substantiated has been the forecast for tense epidemiological situation on the territory of Karachay-Cherkessia, Kabardino-Balkaria, Altai Republic and Tuva Republic in 2022. A new Epitracker application has been proven to be prospective for rapid assessment of actual epidemiological situation in natural plague foci.

Ecological-Epizootiological Differentiation of Natural Plague Foci

Plague foci differentiation is at the core of surveillance and forecasting of epizootic activity and hence achieving high effectiveness of prophylactic measures for prevention of human plague cases. Improvement of the plague foci differentiation taking into account recent data on their status and functioning is a relevant objective. The aim of the study was to differentiate natural plague foci according to the significance of ecology factors in the dynamics of epizootic activity. Materials and methods. Various models for forecasting epizootic activity of natural plague foci, based on the consistent statistical pattern recognition procedure were applied. 11 plague focal territories for which predictive models had ever been developed were surveyed. Results and discussion. The plague foci differ by impact of biotic and abiotic factors on epizootic activity. If epizootic activity depends on the biotic factors, forecasting can only be made on the basis of the data obtained directly during epizootiological surveillance. If epizootic activity depends on abiotic factors, such plague foci can be more depended on the global climate change. The put forward differentiation of focal areas allows for searching the common patterns of plague epizootic process in foci with different species of hosts and vectors, plague microbe variants and geographic setting, as well as for additional typification alongside the existing ones.

Epidemiological Situation on Plague in 2020. Forecast of Episootic Activity of Natural Plague Foci in the Russian Federation and Other CIS Countries for 2021

The aim of the work was to substantiate the forecast of the epidemiological and epizootiological situation in natural foci of plague in the Russian Federation, countries of the near and far abroad for the year of 2021. Characteristics of the distribution of Yersinia pestis strains of the main subspecies (subspecies pestis) of medieval and antique biovars, Caucasian (ssp. caucasica) and central Asian (ssp. central asiatica) subspecies by 45 natural foci of the CIS countries are presented in the paper. The persistence of a multidirectional trend in the dynamics of epizootic activity of natural foci of the CIS countries with the circulation of Y. pestis pestis strains of the medieval biovar of the 2.MED1 phylogenetic branch and the antique biovar of the 0.ANT5, 4.ANT phylogenetic branches in the current decade has been outlined. For the Russian Federation, the development of epizootics is predicted in the Gorno-Altai highland and Tuva mountain natural foci caused by the circulation of Y. pestis pestis strains of the antique biovar 4.ANT and Y. pestis of the Altai biovar of the Central Asian subspecies 0.PE4a in 2021. For the Republic of Kazakhstan, there is a high probability of preserving epizootic activity in the North Aral, Aral-Karakum, Balkhash, Mojynkum, Taukum desert and Ili intermountain natural foci with the circulation of Y. pestis pestis strains of the medieval biovar of the phylogenetic branch 2.MED1. For the Kyrgyz Republic, the forecast for the development of plague epizootics caused by Y. pestis pestis strains of the antique biovar 0.ANT5 phylogenetic branch in the Sarydzhaz and Upper Naryn high-mountain natural foci has been substantiated. A high epidemic risk of epizootic manifestations caused by highly virulent strains of Y. pestis pestis of antique biovars 0.ANT5, 4.ANT and medieval biovar 2.MED1 for the entire territory of the CIS countries is noted. The relevance of implementing forecasts of the epidemiological situation into practice, taking into account the molecular-genetic and epidemiological characteristics of Y. pestis strains circulating in areas of expected epizootic manifestations of plague, is highlighted.

Analysis of the Current Epidemiological Situation in Natural Plague Foci around the World. Enhancement of the Effectiveness of Epidemiological Surveillance in Natural Plague Foci of the Russian Federation and Forecast of their Epizootic Activity for 2019

The paper presents the analysis of epidemic activity of natural plague foci around the world, including in CIS and the Russian Federation, over the period of 2000–2018. It was established that in 2010–2018, epidemic manifestations took place in natural plague foci where the main carriers are synanthropic (black, multinippled rats) and commercial (marmots, souslik, ground squirrels) species of rodents. Retaining of low epizootic activity of lowland natural plague foci in the territory of the Russian Federation is observed. In 2018, plague epizooties were detected in the territory of the Gorno-Altai high-mountain and Tuva mountain natural foci, the total coverage area being 2641 km2. 13 strains of the main subspecies and 6 strains of Altaic subspecies of plague microbe were isolated. Demonstrated were the prospects of GIS-technology usage for the enhancement of epidemiological surveillance over plague in Russia. Epizootiological forecast for persisting challenging epidemiological situation in Kosh-Agach district of the Republic of Altai and Mongun-Taiginsky, Ovyursky and Tes-Khemsky Kozhuuns of the Republic of Tuva was substantiated. Recorded was high probability of retention of strained epizootic and epidemiological situation in the south and central parts of the desert zone in the Republic of Kazakhstan, high-mountain areas of the Republic of Kyrgyzstan. Also conservation of epidemic risks for the territories of the countries in Africa (Republic of Madagascar), South (Peru, Bolivia), and North (USA) America, China, and Mongolia was noted.

Бонитировочные показатели природных объектов в оценке активности природных очагов чумы Жамбыльской области Республики Казахстан.

Бонитировочные показатели природных объектов в оценке активности природных очагов чумы Жамбыльской области Республики Казахстан.

Epizootic Activity of Natural Plague Foci of the Russian Federation in 2008–2017 and Forecast for 2018

Epizootic Activity of Natural Plague Foci of the Russian Federation in 2008–2017 and Forecast for 2018

PROSPECTS OF STANDARDIZATION AND SYSTEMATIZATION OF THE POINTS FOR EPIZOOTIOLOGICAL SURVEILLANCE OF NATURAL PLAGUE FOCI

Currently existent procedure for free positioning and registration of sites for field sample collection results in chaotic concentration of visualized on electronic map icons of surveyed areas, which obstructs spatial analysis of the results on monitoring in a given period of time. Objective of the study is to develop the system of standardization, positioning, and numbering of the points for epizootiological surveillance as part of monitoring over natural plague foci. Materials and methods . Topographical maps, epizootiological mapping data and their analysis. Results and conclusions . Optimum size of the icons corresponding to sites of epizootiological surveillance (SES) is 10 seconds in latitude and 15 seconds in longitude. One sector comprises 900 standard SESs. Put forward system of optimization is able to significantly ease epizootiological and epidemiological mapping, enhance visualization of monitoring data, as well as expand the capacities and improve the quality of spatial and retrospective analysis of epizootic activity of natural plague foci.

Эпизоотическая активность природных очагов чумы Российской Федерации в 2015 г. и прогноз на 2016 г.

Objective of the study is to evaluate the state of parasitic systems and activity of natural plague foci of the Russian Federation in 2015 and to develop epizootiological forecast for 2016. In 2015, plague epizooties were detected in the territory of Gorno-Altaisk high-mountain, Tuva mountain, and Pre-Caspian sandy natural plague foci with a total area amounting to 1573.4 square kilometers. Isolated were 46 strains of plague microbe, including the isolates from rodents and leporines - 18, and from fleas - 28. Substantiated is epizootiological prognosis for sustaining challenging epidemiological situation in Gorno-Altaisk high-mountain and Tuva mountain natural foci in 2016. Demonstrated is the fact that consequently to effective prompt prophylactic measures (field deratization, disinsection) in 2015 decreased epizootic activity of Pre-Caspian sandy focus is observed. Specified is retention of low numbers of carriers and vectors of plague in natural foci of North and North-Western Caspian Sea Region, Pre-Caucasian, Caucasian, and Transbaikal Territories. Identified is upward trend for numbers of the little souslik in Pre-Caspian North-Western steppe, Volga-Ural steppe, Dagestan lowland-piedmont, and Pre-Caspian sandy natural plague foci.

Epizootic Activity of Natural Plague Foci in the Territory of the Russian Federation in 2014 and Prognosis for 2015

. Isolated were 128 plague agent strains: from rodents and lagomorphs - 24, 103 - from bloodsucking arthropods. One strain was obtained from a patient in the territory of Gorno-Altaisk high-mountain natural plague focus. Substantiated has been epizootiological prognosis claiming persistent challenging epidemiological situation in the foci. Outlined is the necessity to use epizootiological forecasting as the basis for scheduling and carrying out epidemiological monitoring and preventive measures in active natural plague foci. Due to the varying epidemiological significance of Y. pestis ssp. pestis , Y. pestis ssp. caucasica , and Y. pestis ssp. altaica strains the data on their spatial distribution should be deployed for differentiation of focal areas according to the degree of the potential epidemic hazard.

Epizootic Activity of Natural Plague Foci in the Russian Federation in 2013 and Prognosis for the Year of 2014

Analyzed are the data of the epizootiologic survey of plague enzootic territories in Russia in 2013. Evaluated are the numbers of major carriers and vectors as well as the epizootic activity of natural foci of different types. Analysis of preconditions for decrease of epizootic potential of plague natural foci of Caucasus, Altai and Tyva is carried out. Single findings of infected fleas are registered at the sites of steady focality in the territory of Pre-Caspian lowland. Forecast of epizootic situation for 2014 is presented. Marked is raising probability that Volga-Ural sandy and Central Caucasian high-mountain plague foci would get out of the inter-epizootic period state. Substantiated are the possibility of plague epizootics continuation and their intensity in Pre-Caspian sandy, Altai and Tyva mountain, and Eastern-Caucasus high-mountain plague natural foci.

Impact of the Present-Day Climate Changes on the Natural Plague Foci Condition, Situated in the Territory of the Russian Federation and Other CIS Countries

Climate changes determine dynamics of epizootic activity of natural plague foci in the XX and XXI centuries. Obvious shift to continentality in the Northern hemisphere can put an end to inter-epizootic period in lowland steppe and semi-desert natural foci of the Pre-Caucasian region, North and North-West Caspian Sea regions. Presently observed conjoined development of inter-epizootic periods in natural plague foci with different biocoenotic structure in the territory of Pre-Caspian Lowland gives the grounds for assuming the presence of a common cause preconditioning parasitic system depression in the region. One of the key elements of this phenomenon is a change of status of little souslik – formerly the main plague carrier in the region. Subsequent to the climate change the key role of plague carrier is more often played by non-hibernating rodent species nowadays. Thus a significant increase in epizootic potential of steppe natural plague foci in the territory of Kazakhstan and Central Asia is prognosticated. With the further temperature fall during wintertime, snow cover height increase and glacial area extension epizootic activity of the mountain and high mountain foci must drop off significantly. Alongside with this updated data on plague agent ecology, predetermining possibility of its existence in the soil biota, confirm the key role of climactic factors in the plague enzootic outbreak.

Epizootic Activity of Natural Plague Foci in the Russian Federation in 2012 and Prognosis for the Year of 2013

Integrated are the data on the number of major carriers and vectors as well as the epizootic activity of natural foci of plague of different types in the territory of Russia in 2012. Submitted is the short-term forecast of epizootic situation for 2013. Analyzed are the reasons of current low epizootic activity of plain natural foci of plague. The role of climatic factors in the development of long inter-epizootic periods in plague natural foci in the Pre-Caucasus, Pre-Caspian regions and Siberia is discussed. Assessed is the change of potential epidemiologic hazard of plague-enzootic territories under the current warming of climate. The long-term forecast of epizootic activity of natural plague foci for the period of up to 2020 is substantiated.

Epizootic Activity of Natural Plague Foci in the Territory of the Russian Federation in 2011, and Prognosis for 2012

Epizootic Activity of Natural Plague Foci in the Territory of the Russian Federation in 2011, and Prognosis for 2012

Development of views on natural focality of plague

The theory of natural focality of human diseases, basically formulated by Academician E.N. Pavlovsky in 1939, invigorated research on plague, the disease whose epidemics had taken millions of lives in the past. Numerous studies in Russia and abroad have provided a great amount of data on the pathogen, its carriers, and vectors, specific features of infection spread and dynamics of activity of natural plague foci. Over a long period, plague was considered to be an obligate transmissible zoonosis. However, recent laboratory experiments and direct observations in natural foci of this infection indicate that plague is probably a zoophilous sapronosis.

Prognosis of Epizootic Activity of Natural Plague Foci in the Russian Federation for the Year of 2010

Short-term prognosis of epizootic activity of 11 natural plague foci in Russia for 2010 is substantiated. The analysis of the main plague carries and vectors abundance in natural foci of different types was carried out. Determined were the modern tendencies of the dynamics of epizootic activity of natural plague foci with different biocenotic structure.