Influence of altitude on tick-borne encephalitis infection risk in the natural foci of the Altai Republic, Southern Siberia

2015 ◽  
Vol 6 (3) ◽  
pp. 322-329 ◽  
Author(s):  
L.D. Shchuchinova ◽  
I.V. Kozlova ◽  
V.I. Zlobin

Tick-borne encephalitis virus (TBEV) exists in natural foci, which are areas where TBEV is circulating among its vectors (ticks of different species and genera) and reservoir hosts (usually rodents and small mammals). Based on phylogenetic studies, four TBEV subtypes (Far-Eastern, Siberian, European, Baikalian) and two putative subtypes (Himalayan and “178-79” group) are known. Within each subtype, some genetic lineages are described. The European subtype (TBEV-EU) (formerly known also as the “Western subtype”) of TBEV is prevalent in Europe, but it was also isolated in Western and Eastern Siberia in Russia and South Korea. The Far-Eastern subtype (TBEV-FE) was preferably found in the territory of the far-eastern part of Eurasia, but some strains were isolated in other regions of Eurasia. The Siberian (TBEV-SIB) subtype is the most common and has been found in almost all TBEV habitat areas. The Baikalian subtype is prevalent around Lake Baikal and was isolated several times from ticks and rodents. In addition to the four TBEV subtypes, one single isolate of TBEV (178-79) and two genetic sequences (Himalayan) supposed to be new TBEV subtypes were described in Eastern Siberia and China. The data on TBEV seroprevalence in humans and animals can serve as an indication for the presence or absence of TBEV in studied area.


Parasitology ◽  
2008 ◽  
Vol 135 (13) ◽  
pp. 1531-1544 ◽  
Author(s):  
A. PUGLIESE ◽  
R. ROSÀ

SUMMARYDeer are important blood hosts for feeding Ixodes ricinus ticks but they do not support transmission of many tick-borne pathogens, so acting as dead-end transmission hosts. Mathematical models show their role as tick amplifiers, but also suggest that they dilute pathogen transmission, thus reducing infection prevalence. Empirical evidence for this is conflicting: experimental plots with deer removal (i.e. deer exclosures) show that the effect depends on the size of the exclosure. Here we present simulations of dynamic models that take into account different tick stages, and several host species (e.g. rodents) that may move to and from deer exclosures; models were calibrated with respect to Ixodes ricinus ticks and tick-borne encephalitis (TBE) in Trentino (northern Italy). Results show that in small exclosures, the density of rodent-feeding ticks may be higher inside than outside, whereas in large exclosures, a reduction of such tick density may be reached. Similarly, TBE prevalence in rodents decreases in large exclosures and may be slightly higher in small exclosures than outside them. The density of infected questing nymphs inside small exclosures can be much higher, in our numerical example almost twice as large as that outside, leading to potential TBE infection risk hotspots.


2012 ◽  
Vol 24 ◽  
pp. 350-387
Author(s):  
Olle Sundström

In his exhaustive study of ‘shamanism’ among the Altaic peoples in Southern Siberia, the renowned Soviet ethnographer Leonid P. Potapov contends that ‘under the present conditions there are no remnants or survivals of Shamanism as such left in Altai’. What remains are legends and reminiscences, but these can no longer be told by people with personal experiences of Altaic ‘shamans’ and their rituals. According to Potapov, modern socialist culture has changed the minds of the Altaic peoples to the degree that they are now a materialistically thinking people, and ‘shamanism’ has completely disappeared. In addition, he contends that there are no prospects of its return after the deathblow dealt by Soviet anti-religious repression in the 1930s ‘shamanic’ rituals were forbidden and ritual paraphernalia such as drums and costumes were expropriated by the authorities. Considering that Potapov in his study follows Altaic ‘shamanism’ through 1500 years, depicting it as a ‘religion’ and ‘theology’ which stayed more or less intact over the centuries, his statement seems more like a pious hope based on the Soviet vision of a society liberated from superstition, religion, and spiritual exploitation. Potapov himself delineates Altaic ‘shamanism’s’ development from a ‘state religion’to a ‘folk religion’. From this perspective it might seem remarkable that ‘shamanism’ should not have survived 70 years of atheist repression, missionary work and the Soviet transformation of society. Already by the time Potapov’s book was published, during the very last months of the existence of the Soviet Union, there had, in fact, appeared a number of persons claiming to be ‘shamans’, with an ancestry dating from the time of ‘shamans’ of the first half of the twentieth century. These individuals were also part of organisations and movements promoting the revival of ‘shamanism’ in the autonomous Altai Republic. In other parts of the former Soviet Union similar processes took place. Today, in post-Soviet Altai, as well as in many other parts of Siberia, shamanism exists in the same sense that there is Buddhism, Christianity and Islam in the region.


2018 ◽  
Vol 8 (3) ◽  
pp. 335-340
Author(s):  
A. O. Turanov ◽  
A. Y. Nikitin ◽  
E. I. Andaev

Studying of immune interlayer value to tick-borne encephalitis virus in human population of the Transbaikalia Territory resulted from natural immunization of the healthy population in 31 Municipal areas in 2011–2016 is presented. Human selections were formed proportionally to the population size in the concrete human settlement among persons of the various age and professional groups living at this territory not less than 10 years and unvaccinated against tick-borne encephalitis virus. Total 4367 blood sera were investigated. Laboratory testing for antibodies of G class to tick-borne encephalitis virus in blood sera of the human population was performed by immune-enzyme analysis using a set of reagents “VektoVKE-IgG” of Joint-Stock Company “Vektor-Best” (Novosibirsk city). The monitoring data indicated the presence of natural immunity to tick-borne encephalitis virus in the human population. Mean annual level of immune interlayer in Municipal areas varied from 3.1 to 52.7% (in Transbaikalian Territory — 13.1±0.51%). High level (from 20 to 52.7%) was characteristic for mountain-taiga-forest-steppe zone (Krasnochikoisky — 23.8±3.36%; Uletovsky — 52.4±4.48%; Gazimuro-Zavodsky — 29.4±4.94% districts) and mountain-tundra-taiga zone (Tungokochensky district — 20.0±3.58%). In steppe zone the level of immune interlayer was lower and observed in districts with elements of south-taiga larch and pine forests. It was established that levels of the immune interlayer in human population living in mountain-taiga-foreststeppe and mountain-tundra-taiga zones authentically higher than in steppe area — t = 3.8; Р < 0.001 and t = 2.27; Р < 0.05, respectively. Distinctions in the value of the immune interlayer between mountain-tundra-taiga and mountain-taigaforest-steppe zones were non-authentic: t = 0.1; P > 0.05. Active circulation of tick-borne encephalitis virus was accompanied by authentic (Р < 0.01) increase of the interlayer in persons with the virus antibodies in 2014–2016 (15.8±0.69%) in comparison with 2011–2013 (9.7±0.78%). Also it was noted in all landscape zones: in steppe zone the increase was to 42.8% (P > 0.05); in mountain-taiga-forest-steppe — to 61.3% (P > 0.05); in mountain-tundra-taiga — to 150.0% (Р < 0.01). It was not possible to reveal correlation between the recourse for medical aid and the value of immune interlayer in the population formed as a result of latent immunization. Results of the population immunity studying essentially expand our knowledge about the condition of the natural foci and dynamics of development of the epidemic processes in it, and can be used at planning of the preventive actions.


2017 ◽  
Vol 62 (1) ◽  
pp. 30-35 ◽  
Author(s):  
N. M. Pukhovskaya ◽  
O. V. Morozova ◽  
N. B. Belozerova ◽  
S. V. Bakhmetyeva ◽  
N. P. Vysochina ◽  
...  

The tick-borne encephalitis virus (TBEV) strain Lazo MP36 was isolated from the pool of mosquitoes Aedes vexans collected in Lazo region of Khabarovsk territory in August 2014. Phylogenetic analysis of the strain Lazo MP36 complete genome (GenBank accession number KT001073) revealed its correspondence to the TBEV Far Eastern subtype and differences from the following strains: 1) from ticks Ixodes persulcatus P. Schulze, 1930 [vaccine strain 205 (JX498939) and strains Khekhtzir 1230 (KF880805), Chichagovka (KP844724), Birobidzhan 1354 (KF880805) isolated in 2012-2013]; 2) from mosquitoes [strain Malyshevo (KJ744034) isolated in 1978 from Aedes vexans nipponii in Khabarovsk territory; strain Sakhalin 6-11 isolated from the pool of mosquitoes in 2011 (KF826916)]; 3) from human brain [vaccine strain Sofjin (JN229223), Glubinnoe/2004(DQ862460). Kavalerovo (DQ862460), Svetlogorie (DQ862460)]. The fusion peptide necessary for flavivirus entry to cells of the three TBEV strains isolated from mosquitoes (Lazo MP36, Malyshevo and Sakhalin 6-11) has the canonical structure 98-DRGWGNHCGLFGKGSI-113 for the tick-borne flaviviruses. Amino acid transition H104G typical for the mosquito-borne flaviviruses was not found. Structures of 5’- and 3’-untranslated (UTR) regions of the TBEV strains from mosquitoes were 85-98% homologous to the TBEV strains of all subtypes without recombination with mosquito-borne flaviviruses found in the Far East of Russia. Secondary structures of 5’- and 3'-UTR as well as cyclization sequences (CS) of types a and B are highly homologous for all TBEV isolates independently of the biological hosts and vectors. similarity of the genomes of the TBEV isolates from mosquitoes, ticks and patients as well as pathogenicity of the isolates for new-borne laboratory mice and tissue cultures might suggest a possible role of mosquitoes in the TBEV circulation in natural foci as an accidental or additional virus carrier.


Almost the entire territory of Belarus is believed to be endemic for tick-borne encephalitis virus (TBEV), with the Central European subtype, also known as TBEV-EU (Figure 1). In all, 96 counties (i.e., 71.5% of all administrative districts) are considered to be risk areas for tick-borne encephalitis (TBE). The most intensive natural foci have been found in the western part of the country (Brest and Grodno Area), and infections in these areas account for an average of 40% each of the total number of reported cases


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Silvius Frimmel ◽  
Anja Krienke ◽  
Diana Riebold ◽  
Micha Loebermann ◽  
Martina Littmann ◽  
...  

The incidence of tick-borne encephalitis has risen in Europe since 1990 and the tick-borne encephalitis virus (TBEV) has been documented to be spreading into regions where it was not previously endemic. In Mecklenburg-West Pomerania, a federal state in Northern Germany, TBEV was not detectable in over 16,000 collected ticks between 1992 and 2004. Until 2004, the last human case of TBE in the region was reported in 1985. Following the occurrence of three autochthonous human cases of TBE after 2004, however, we collected ticks from the areas in which the infections were contracted. To increase the chance of detecting TBEV-RNA, some of the ticks were fed on mice. Using nested RT-PCR, we were able to confirm the presence of TBEV in ticks for the first time after 15 years. A phylogenetic analysis revealed a close relationship between the sequences we obtained and a TBEV sequence from Mecklenburg-East Pomerania published in 1992 and pointed to the reemergence of a natural focus of TBEV after years of low activity. Our results imply that natural foci of TBEV may either persist at low levels of activity for years or reemerge through the agency of migrating birds.


2020 ◽  
Vol 181 (3) ◽  
pp. 25-31
Author(s):  
E. V. Zhmud ◽  
N. S. Zinner ◽  
O. V. Dorogina

Background. Trypsin-inhibiting activity (TIA) is one of the factors of plant immunity. This factor provides the presence of general non-specific systemic resistance. Representatives of the genus Hedysarum L. are promising medicinal and high-protein fodder plants with high TIA in the leaves. High TIA values in the aboveground part of plants lead to a decrease in protein assimilation by animals. Therefore, identifying the differentiation in the features of TIA seasonal dynamics will make it possible to use the potential of these species most effectively under the conditions of Southern Siberia.Materials and methods. TIA in the leaves of mature generative plants of Hedysarum theinum Krasnob. and H. flavescens Regel & Schmalh. was analyzed. H. theinum is a rare species for Siberia; H. flavescens is a settled one in the forest-steppe zone of Western Siberia. The studies were conducted with H. theinum in 2010 under natural conditions (Altai Republic) and in cultivation (forest zone of Western Siberia). In 2017, H. theinum and H. flavescens were studied under cultivation in the forest-steppe zone of Western Siberia. The research method was based on the spectrophotometric measurement of the optical density in protein substrate (BAPA) decomposition products under the effect of trypsin (at 405 nm). Bovine trypsin manufactured by ISNBiomedical (USA) was used. BAPA (Na -benzoyl-DL-argininep-nitroanilide) served as a substrate.Conclusions. The TIA values in the flowering phase of seasonal plant development reached their maximum only under favorable conditions: in Altai Republic for the leaves of H. theinum, and in the foreststeppe zone of Western Siberia for H. flavescens. TIA values in H. theinum did not increase during flowering in the forest zone of Western Siberia and significantly decreased in the forest steppe. In view of these findings, these two species may be recommended for practical utilization in this phase of seasonal development. 


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