List of World Fauna Vertebrate Animals - Carriers of Plague Agent

Consequently to the long-term investigations conducted in natural and anthropourgic foci of plague, situated in Africa, Eurasia, North and South America, identified were not less than 340 species of mammals and birds infected with plague agent. The paper contains the list of plague agent carriers described, both in domestic and foreign publications

Rhamnose-Positive Strains of Plague Agent: Virulence and Epidemiological Significance

The aim of the review is to show the groundlessness of the unconditional assessment of rhamnose-positive strains of plague pathogen as avirulent for most species of carriers and humans and having no epidemiological significance. The main carriers of rhamnose-positive strains are several species of voles and the Mongolian pika. The vast majority of experts are of the opinion that rhamnose-positive (“vole`s” and “pika`s”) strains of Yersinia pestis are avirulent or weakly virulent for many species of warm-blooded animals and humans, and therefore have no epidemiological significance. However, in a series of experiments on infecting marmots, ground squirrels, and large gerbils with rhamnose-positive strains, some of the experimental animals fell ill acutely and died from the plague. In nature, rhamnose-positive strains have been isolated from carcasses of relatively resistant red marmots. When evaluating the epidemiological significance of rhamnose-positive strains, such an important criterion as the presence or absence of effective factors and pathways of pathogen transmission in foci of the vole and pika types is omitted. Voles and pikas are not eaten; therefore, the contact route of infecting humans in these foci is impossible. The second way of transmission of the pathogen to humans – vector-borne – is difficult due to the lack of migration of vole fleas from burrows to the surface and their low efficiency as vectors. Nevertheless, cases of human infection with rhamnose-positive strains of the plague agent in the Caucasus and Mongolia give grounds to assert that at least some rhamnose-positive strains have a sufficiently high virulence and are capable of causing infectious process in humans as well. Therefore, epidemiological surveillance in the foci of plague of the vole and pika types cannot be totally abandoned. It can be conducted according to an abbreviated scheme

Differentiation of the Pre-Caspian Sandy Plague Foci on the Basis of the Frequency of Epizootic Manifestations

Displayed are the results of epizootiological differentiation of the Pre-Caspian sandy plague focus in the territory supervised by Astrakhan and Elista plague control stations (Volga-Kumsk Interfleuve). This differentiation is significant for further development of epizootiological monitoring practice in the enzootic regions. Using circular extrapolation method, designed is the map of the persistent epizootic region within the last period of the focus activation since 1979 till 2010. Depicted is the dislocation of focus activity nucleuses and areas where short-term epizootic process is registered. Identified are their qualitative characteristics. Determined is the fact that density of plague-positive samples in the nucleuses is much higher, than in the areas with non-recurring manifestations. This cartographic differentiation model can be used for justified and substantiated planning of epidemiological control measures and further investigation of problems related to plague epizootiology

Anthropourgic Foci of Plague in Vietnam: Past and Present

The review contains the results of ecological-epizootiological and epidemiological investigations of plague in the territory of the Socialist Republic of Vietnam in 1989-2012. Studied has been the structure of epizootic triad - carrier-vector-pathogen. There is a low probability of plague foci occurrence in zones of tropical forests and savanna under the conditions of humid subequatorial climate. Main plague agent carrier on the Thai Nguyen Plateau is the synanthropic little rat, Rattus exulans . Specialized fleas species are absent on wild-living rats Rattus genus, as well as mice, and bandicoots, and the abundance of other species is small. It has been demonstrated that all the elements of the parasitic plague system are classified as introduced species. Thereupon it is inferred that plague foci in Vietnam are anthropourgic and are of anthropogenic origin solely. Plague cases in humans across the territory of the country were registered between 1898 and 2002. The most persistent ones functioned on the Thai Nguyen Plateau. Although epizootic activity of the foci in territory of the former endemic provinces has decreased, it is necessary to continue epizootiological monitoring further on in the modern period

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

Non-Specific Prophylaxis of Plague in the Gorno-Altai High-Mountain Natural Focus in 2016

Objective of the study is to substantiate performance, assess the conditions, and analyze the results of activities on non-specific plague prophylaxis in the epizootic territory. Materials and methods. Utilized were archival data and operational reports of Altai Plague Control Station, Irkutsk RAPI, RusRAPI “Microbe”, Center of Hygiene and Epidemiology in the Republic of Altai, and Rospotrebnadzor Administration in the Republic of Altai, as well as literature sources. Spatial analysis was carried out using GIS-technologies. Results and conclusions. Concerted and coordinated activities of the Rospotrebnadzor institutions, medical and veterinary institutions, local executive authorities have allowed for complex prophylactic and anti-epidemic measures on prevention of plague dissemination and transmission in the territory of the Republic of Altai in 2016. Demonstrated has been the necessity to expand the scope and scale of operations and scientific research in the focus, deploying advanced toolkit of methods and means

Effectiveness of Disinsection and Deratization in Gorno-Altai High-Mountain Natural Plague Focus

Epidemic complications in the territory of Gorno-Altai high-mountain natural plague focus, associated with increase in numbers of carriers and vectors of the dangerous diseases, entailed strengthening of preventive element in the system of epidemiological surveillance. Objective of the study was to assess the efficiency of disinsection and deratization during anti-epidemic campaign. Materials and methods. Investigations were performed in 2014-2017 in the territory of Kosh-Agach district of the Republic of Altai, based on the archival and operational records from Altai Plague Control Station, Rospotrebnadzor Administration in the Republic of Altai, and our own data. “Interactive Map on Management of Health Promotion Measures in Gorno-Altai high-mountain natural plague focus” was used as an assessment tool. Results and conclusions. The most hard-hitting sections of preventive complex as regards plague are still disinsection and deratization. Application of advanced methods and means of control over numbers of carriers and vectors of the infection testify to their high anti-epidemic effectiveness. Insecticide and rodenticide treatments of encampments situated in epizootic areas, disinsection and deratization in major population centers in the territory of the focus allowed for the reduction in risk of population infection. Technical efficiency of the field disinsection amounted to 96.7 %, community deratization and disinsection varied from 91.6 to 100 %. Emergency insecticide and rodent treatments in epizootic areas alongside other measures provided for epidemiological welfare on plague

Coordination of Measures of Plague Control Institutions, Aimed at Rehabilitation and Sanitation of Gorno-Altai High-Mountain Natural Plague Focus in 2016

Objective of the study is to sum-up the results of prophylactic (anti-epidemic) measures associated with elimination of epidemic focus in Kosh-Agach Region of the Republic of Altai in 2016. Materials and methods. Utilized were the data of reporting and source documentation from Altai Plague Control Station, Rospotrebnadzor Administration in the Republic of Altai, RusRAPI “Microbe”, and Irkutsk RAPI. Results and conclusions. It is pointed out that carried out in 2016 complex of organizational, anti-epidemic, and sanitary-prophylactic activities against plague is the importnant stage of rehabilitation of Gorno-Altai high-mountain natural plague focus, the final goal of which is maximally possible decrement of risks of primary human infection with plague, and in case of occurrence of such – performing of prompt response measures on localization and elimination of epidemic focus. It has been substantiated that for epidemic risk minimization in 2017 it is necessary to continue prophylactic vaccination, desinsection and deratization in the areas of predictive epizootic situation aggravation, which is contained in “Complex Action Plan of the Rospotrebnadzor Institutions for Sanitation and Rehabilitation of Gorno-Altai high-mountain natural plague focus in Kosh-Agach Region of the Altai Republic in 2017”. It is also necessary to provide for implementation of the Program on lowering risks of importation from cross-border Sailyugemsky natural focus and spread of plague in the territory of the Russian Federation, within the frames of RF Government Order No 1864-p, dated 05.09.2016

The Role of Disinsection and Deratization in the Framework of Non-Specific Prophylaxis of Diseases among the Population in Natural Plague Foci in the Territory of the CIS Countries

Natural foci of plague – a particularly dangerous transmissible zoonotic disease – are widely spread across the world, including in the territory of Russia and a number of neighboring countries in Central Asia. Between 2000 and 2019, 28339 cases of plague were registered in 21 states around the world; lethality rates reached 8 %. Active plague manifestations are associated with the increase in the abundance of carriers and vectors of the disease, which increases the risk of human infection. Prophylactic measures against plague are aimed at prevention and eradication of epidemic foci; they incorporate a whole complex (system) of activities. Disinsection and deratization remain the most radical of them. Control of the numbers of carriers and vectors of plague involves decrement up to the levels at which epizooties will not develop, they are suppressed and liquidated. Currently in the Russian Federation and CIS countries, the focus is on the field and community disinsection when planning and performing exterminatory interventions. The decrease in the numbers of fleas – carriers and vectors of plague microbe – results in disruption of epizootic process and, consequently, in provision of epidemiological welfare as regards this dangerous disease. Insecticide treatments in natural biotopes are carried out using powder-like or aerosolized products, the class of pyrethroids, organophosphorous compounds and phenylpyrazoles by means of advanced equipment: knapsack dusters, power operated air blowers, and foggers. Within the boundaries of residential areas wet disinsection is performed with the help of spraying devices. Field deratization is allowed upon epidemiological grounds only, in localized territories of epizooties, within the boundaries of the settlements of plague infected carriers. Zinc phosphide- or anticoagulant-based bait products are used as rodenticides. Therewith, the eradication of valuable animal species, rare species of small mammals and endemic species is prohibited. Community deratization is always accompanied by the community disinsection. When planning and carrying out insecticide and rodenticide treatments the priority is given to the safety of handling the chemical preparations, to the exclusion of the negative effect on target animal species