Mongolian Part of the Transboundary Sailugem Natural Plague Focus in 2017. Communication 1. Epizootic condition

Objective – estimation of current epizootic condition of Mongolian part of transboundary Sailugem natural plague focus. Materials and methods. Epizootiological survey was performed for the area of 2335 km2, 277 mammals and 516 ectoparasites were investigated for plague. Results and conclusions. Eight Yersinia pestis subsp. pestis strains were isolated, including 7 strains – from grey marmots (6 – from the remains of meals of predatory birds, 1 from a corpse) and 1 – from long-tailed souslik (corpse). Y. pestis DNA was detected in 52 objects. Serological samples showed 40 positive results. Epizootic manifestations, confirmed by isolation of Y. pestis cultures, detection of plague microbe DNA, and positive serological results, were observed across the area of 1611 km2 covering 69 % of the inspected territory. Epizootic results indicated high infection rate of mass mammal species and first of all grey marmots. The data demonstrated that the extended plague epizooty caused by Y. pestis of the main subspecies occurred in the inspected territory in the carrier settlements. For the first time the circulation of Y. pestis subsp. pestis was registered in the Mongolian part of the transboundary Sailugem focus

Results of Epizootiological Survey along the Border Areas of Kharkhira-Turgensky Natural Plague Focus between Russia and Mongolia in 2019

Objective of the study was to assess the current epizootic settings along the border part of KharkhiraTurgensky natural plague focus betweenRussia andMongolia.Materials and methods. Epizootiological survey covered 2715.5 km2. 213 samples of field material were tested (90 specimens of mammals, 102 specimens of ectoparasites, 17 samples of leftover food of predatory birds and dry skeletal remnants of marmots, 4 regurgitates of birds of prey). Laboratory works were carried out in “Microbiological laboratory for express diagnostics” mounted on the platform of the minibus “GAZelle”. Tests of field material were performed using immune-chromatographic (IC) assay and polymerase chain reaction (PCR). PCR and IC positive samples were further investigated applying bacteriological method. Epizootiological surveyed deployed GIS instruments. All the results obtained were plotted on the electronic maps using QGIS 2.18.26 software.Results and discussion. Capsular antigen (F1) of Yersinia pestis was detected in three (1.4 %) studied samples (n=213), DNA of plague microbe – in eight samples (3.7 %). Bacteriological investigation of positive samples revealed one sample (leftover food of predatory birds – Mongolian marmot) from which plague agent culture was isolated. The culture belonged to Y. pestis of the main subspecies. Geographical positioning of the epizootiological survey sites was conducted, as well as positive findings of immunological and molecular-genetic assays. Results of epizootiological survey are indicative of active phase of plague agent circulation (main subspecies) in Kharkhira-Turgensky natural focus in Mongolia

Epizootic Situation in the Mongolian Part of the Transboundary Sailugem Natural Plague Focus in 2018

Objective of the study was monitoring of epizootic situation in the Mongolian part of the trans-boundary Sailugem natural plague focus through 2018 for optimization of preventive and anti-epidemic activities to decrease the level of risk of human plague cases among the population in the border areas of Mongolia and Russia.Materials and methods. Epizootic survey was conducted across the area of 2668 km2 ; 282 mammals, 261 ectoparasites, including 257 fleas, were tested for plague. All laboratory investigations of the field material were carried out in the mobile laboratory for monitoring and diagnostics, mounted on the platform of KAMAZ. Field samples were subjected to molecular-genetic (PCR) and serological tests. Fresh and mummified pickings of birds of prey, corpses, caught rodents and lagomorphs, fleas collected from corpses, were tested using immune-chromatographic method (ICM) to detect capsular antigen (F1) of plague microbe. PCR and ICM positive samples were investigated applying bacteriological method. In the course of epizootiological survey, GIS-tools were employed. All the results obtained were plotted on electronic maps using QGIS 2.12.3 software package.Results and discussion. The total of 47 Yersinia pestis ssp. pestis strains were isolated from grey marmots and their fleas. Y. pestis DNA was detected in 60 objects. Serological testing showed 60 positive results. Contamination of the caught souslik with plague agent reached 4.5 % (n=22), fresh corpses and picking of predatory birds – 63.4 % (n=41), mummified corpses and leftovers, skeletal remains – 10.0 % (n=140). It was established that in the border territory, adjacent to Russia, an intensive diffused plague epizooty, caused by the agent of the main subspecies, takes place. All epizootic manifestations were revealed at the altitudes of 2400–2800 m above sea level, in densely populated grey marmot settlements. The epizooty was registered in most of the southern macro-slope of Sailugem ridge, throughout 100 km and along the whole Karalakhtu ridge – throughout 30 km. The epizooty area, confirmed by plague agent isolation, amounted to 1207 km2 (45.2 % of the examined territory)