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The aim of the work – analysis of peculiarities of the plague epizooty found in the southern steppe part of the Ukok Plateau in 2020.Materials and methods. Epizootiological survey was conducted over the area of 1573 km2 in July and August, 2020. 141 mammals, 157 ectoparasites (including 152 fleas), 17 bone remains samples, and 50 regurgitates of predatory birds have been tested for plague.Results and discussion. The background species of mammals – natural hosts of Yersinia pestis in the southern steppe part of the Ukok plateau are gray marmot, long-tailed souslik, and Daurian pika. Abundance of the gray marmot was high and amounted to 1.7±0.18 inhabited burrows per 1 ha (n=30) with 90 % occupancy. Three strains of Yersinia pestis ssp. pestis have been isolated: from Oropsylla alaskensis fleas collected from long-tailed souslik, gray marmot carcass, and regurgitates of predatory birds. Yersinia pestis DNA have been detected in 14 objects. Eight positive results of serological tests have been obtained. The epizooty area that was confirmed by Yersinia pestis isolation totaled 252 km2 . As a result of the survey the circulation of Yersinia pestis ssp. pestis have been for the first time established on the Ukok Plateau. The target species – the gray marmot, as well as the long-tailed souslik, are actively involved into the epizooty.

The review presents the materials on the use of mobile laboratories, developed in the Russian Federation, in the framework of four main areas: monitoring of territories to identify the circulation of pathogens of natural-focal infectious diseases; monitoring of territories during the exacerbation of the epizootic situation; participation in the elimination of outbreaks of infectious diseases; monitoring of territories to control and predict the epidemiological and epizootiologic situation in preparation for mass events. The tactical and technical characteristics and the procedure for organizing the operation of the mobile laboratory for monitoring and diagnostics mounted on the platform of the KamAZ chassis are considered. A distinctive feature of the laboratory from the existing Russian and foreign counterparts is the availability of the necessary conditions for conducting research using bacteriological analysis, rapid and accelerated diagnostic methods, and performing a full cycle of works – from the preparatory stage to the destruction of infected material. Hightech equipment allows the realization of two research schemes: the first – bacteriological analysis alongside the PCR, which ensures high reliability of the results; the second – conducting the PCR at the first stage, and when identifying genetic markers of the pathogen – performing bacteriological analysis of positive samples in order to isolate the culture of the pathogen and identify it subsequently. The second scheme will reduce the volume of bacteriological studies; make changes in the tactics of epizootiological survey. Tests of the mobile laboratory have demonstrated the effectiveness of its use in the epizootiological examination of natural plague foci, including cross-border ones. Owing to the use of a mobile laboratory in the Gorno-Altaisk high-mountain natural focus of plague, a new epizootic site was identified, located in a remote area, used by the population as a summer pasture for grazing domestic animals. The use of mobile laboratories will strengthen the laboratory base of institutions that monitor particularly dangerous, natural-focal and other dangerous infectious diseases; will help to bring the advanced diagnostic technologies directly to the natural focus, reduce the risk of epidemic complications due to plague and other particularly dangerous infections in cross-border natural foci.

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.

Objective of the study was a complex pheno- and genotypic investigation of Yersinia pestis I-3595 and Y. pestis I-3596 strains, isolated from marmots that were the source of human infection in 2015. Materials and methods. A comprehensive microbiological, molecular-genetic and mass-spectrometric studying of Y. pestis ssp. pestis strains, isolated from two grey marmots that became a cause of the plague case in Gorno-Altai high-mountain focus in 2015, was performed using up-to-date methods. Results and conclusions. It was established that the studied Y. pestis strains belonged to the main subspecies. Results of plasmid screening, multilocus VNTR-and mass-spectrometric analyses showed that those strains were closely related to Y. pestis variant detected in the focus in 2012 and in 2014, and circulating in Northwest Mongolia and Tuva natural focus.

Objective of the study is to analyze the situation on anthrax in the Altai Territory and the Republic of Altai in 1985–2015. Materials and methods. Utilized were statistical and report forms provided by the Rospotrebnadzor, veterinary, and Phytosanitary Surveillance Service institutions in the Republic of Altai and Altai Territory, as well as by Altai Plague Control Station. Laboratory investigations of Bacillus anthracis cultures, field and clinical samples was conducted in accordance with Methodological Recommendations 4.2.2413- 08. Results and conclusions. Between 1985–2015, in the Altai Territory, an expressed unfavorable situation on anthrax was observed, defined by the large number of stationary potentially hazardous areas (SPHA) (1262 sites) and their high density (7.68); registration of six novel SPHA in five separate districts; and excess of long-term average annual morbidity rates among live-stock animals (0.111 per 100 thousand animals) and the population (0.022±0.001 о /оооо). The Republic of Altai is classified as a territory with relatively favorable epizootiological-epidemiological situation on anthrax. Current situation on anthrax in this region is characterized by domination of old non-manifesting SPHA; infections among cattle stock on farms and private subsidiary holdings; and registration of sporadic cases among non-vaccinated rural population. The major cause of human infection was participation in compulsory slaughtering, cutting, and skinning of cattle, as well as in cooking of the infected meat (88.2 %). It manifested itself in cutaneous anthrax (94.1 %). Indicated has been an ineffective organization of sanitary-veterinary measures in private holdings and on the farms.

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.

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.

Objective of the study is to characterize the case of human plague in the territory of Gorno-Altaisk high-mountain natural focus in 2015 and to analyze the initiated measures, associated with localization and elimination of epidemic focus. Materials and methods. Utilized are the data contained in reporting and source (primary) documentation of the FGHI “Altai Plague Control Station”, records of the Rospotrebnadzor Administration in the Republic of Altai, and information collected by the FGHI “Irkutsk Research Anti-Plague Institute”. Results and conclusions. Human infection occurred as a result of gray marmot dressing, which was caught in the Elangash River-Valley, against the background of unfavorable epizootic situation, caused by proliferation of the plague agent of main subspecie in the territory of the focus. Clinical material investigations, performed by means of bacteriological and molecular-genetic methods, showed negative findings. Applying serological method within the system of indirect hemagglutination test (IHAT)/antigen neutralization test (ANT), in blood sera, obtained at the time of hospitalization, low-titred specific antibodies to plague microbe (recognized as post-vaccinal ones) were detected. In blood serum sample, obtained 7 days later, identified were high-titer antibodies, which allowed for confirmation of clinical diagnosis - “bubonic plague”. Due to efficient cooperation between Rospotrebnadzor institutions and medical facilities, as well as municipal authorities it was possible to avoid further development of anthropogenic transmission of plague; to localize and eliminate epidemic outbreak of this dangerous infectious disease in Kosh-Agach Region of the Republic of Altai in the shortest possible time.

Laboratory diagnostics of plague was carried out in compliance with valid operational guidelines and regulations. But its peculiarity consisted in the performance of diagnostic investigations secondary to antimicrobial therapy with application of preparations characterized by the expressed activity towards gram-negative microorganisms, including the agent of plague (ceftriaxone, ciprolet, and amikacin). The studies revealed that under antibiotic treatment during the early phase of infection the most effective method for the laboratory plague diagnostics was PCR. Based on the results of the assay it was possible to establish not only provisional, but also the final diagnosis in a patient. Obtained was genetic characteristics of the strains isolated from the patient and the marmot, withdrawn at the patient’s place, using techniques of molecular-genetic analysis, in particular PCR, multilocus VNTR, and multilocus and genome-wide sequencing. Thereupon the strains were attributed to antique biovar of the main subspecies of plague agent. In addition, close relation to Y. pestis of the main subspecies isolated in the same focus in 2012 and to the strains from Mongolian Altai and Tuvinian mountain focus was determined based on phylogenetic analysis of the isolates.

For the first time ever since the discovery of the Gorno-Altaisk high-mountain natural focus in 1961, registered has been a case of human plague infection. It occurred in the consequence of the grey marmot cutting that was caught in the territory of one of the persistent epizootic regions of the natural plague focus. The outbreak was localized and eliminated following complex anti-epidemic measures, including medical treatment of the patient; identification, isolation and management of the contact persons, both to the patient and marmot; withdrawal and disposal of marmots’ carcasses, obtained during unauthorized commercial hunting; specific and non-specific prophylaxis of the disease. Also for the first time ever received have been the evidences of concurrent circulation of the strains, subspecies Y. pestis ssp pestis and Y. pestis ssp. altaica in the regions of cohabitation of Pallas’ pika (Ochotona pallasi), Siberian souslik (Citellus undulatus), and grey marmot. Specified is the necessity to reconsider the tactics of epizootiological plague monitoring in enzootic territories where circulation of various Y. pestis subspecies is registered.

Performed is a complex microbiological, molecular-genetic and mass-spectrometric identification of Yersinia pestis main ssp. strain, which was isolated for the first time in the history of surveillance over the Altai mountain natural plague focus in June, 2012. Determined is its high universal virulence. Plasmid screening, multi-locus VNTR- and mass-spectrometric analyses have revealed the strain to be more closely related to the plague agent variant, circulating in the territory of the natural focus Khuukh-Serkh-Munkh-Khairkhan, Bayan-Ul’giisk aimak, Mongolia.