146 research outputs found

    Anthropourgic Foci of Plague in Vietnam: Past and Present

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    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

    Femtosecond pulse generation with a diode-pumped Yb3+:YVO4 laser

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    A diode-pumped Yb:YVO4 laser has been passively mode locked for the first time, to our knowledge. 120 fs pulses with an average output power of 300 mW and a peak power as high as 14.5 kW are obtained by use of a semiconductor saturable-absorber mirror for passive mode locking. The optical spectrum has a 10 nm bandwidth (full width at half-maximum) and is centered at 1021 nm

    Role of Mosquitoes, <I>Culex</I> <I>pipiens</I> Complex, in West Nile Fever Virus Persistence in Urbanized Biocoenoses of Saratov

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    . In wiggler samples as well as in imago ones detected are WNF virus markers, which indicate the possibility of transovarial and trans-phase transmission of virus into mosquito populations, habitant in urbanized biocoenoses. It is substantiated that Culex pipiens female mosquitoes, which reproduce autogenically, provide for the persistence of the virus within the inter-epidemic period. Therewith there is a possibility of sustained, epidemically-active WNF micro-foci to be formed in the residential area landscapes, and this issue should be given proper consideration when performing assessment of the risks associated with urban population exposure to the infection

    Conditions for Virus Circulation and Premises for Natural West Nile Fever Foci Formation in the Territory of the Saratov Region

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    Local climate change (rise of mean temperatures and amount of precipitation, prolongation of frost-free season) triggers further distribution, and increase in numbers of animals – carriers and vectors of West Nile fever virus in the territory of the Saratov region. Based on the results of ecological-epizootiological monitoring (2006–2012) traced out have been the species composition, abundance dynamics, and character of distribution of birds habitant in aquatic and anthropogenic complexes, mosquitoes and Ixodidae ticks. Investigated are possible causes of West Nile fever nosoarea expansion, related to ecology of migrating birds wintering in Africa. Persistent circulation of the virus in intra-zonal inundated biocoenosis facilitates formation of secondary natural foci of West Nile fever and factors into epidemic complications as regards this particularly dangerous vector-borne infection. On the basis of analytical data concerning hydrographic network density, fauna structure, population numbers of birds and mosquitoes – potential carriers and vectors of WNF, epizootiological and epidemiological surveillance, designed has been expectation-driven forecasting map chart which illustrates possibility of sustainable WNF foci formation in various territories of the Saratov region

    Modern Conception of the Control over the Abundance of Carriers and Vectors of Plague in the Territory of the Russian Federation

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    Disinfestation and deratization remain the main ways of non-specific disease prophylaxis in natural plague foci. Modern strategies, tactics, methods and means of control over carriers and vectors of plague and associated infectious diseases are selected with due consideration to epidemiological potential of territories, epizootic activity of a foci, peculiarities of population ecology of animals that are of a medical significance, preservation of biodiversity in natural ecosystems, and the requirements for human and natural environments protection from pollutants

    Studies of West Nile Virus Circulation in the Territory of the Saratov Region in 2010

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    Presented are the results of ecological and epizootiological surveillance of the territory of the Saratov region, which was carried out in autumn of 2010. The surveillance was aimed at detection of West Nile (WN) virus circulation and premises for WN Fever natural focus formation. It is demonstrated that in 2010 WN virus circulation took place in damp biotopes of the Saratov region territory, and that common species of small mammals were involved in it. Presented are the results of analysis of the WN virus role in the infectious pathology in the territory of the Saratov region

    Provision of Epidemiological Welfare on Plague under Aggravation of Epizootic Situation in the Pre-Caspian Sandy Natural Plague Focus in 2014

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    Reviewed are the lessons learned from cooperation between Rospotrebnadzor institutions in the provision of epidemiological welfare on plague under aggravation of epizootic situation in the territory of the Pre-Caspian sandy natural plague focus in 2014. Plague control measures combined epizootiological and epidemiological monitoring, specific and non-specific prophylaxis, training activities for medical and veterinary officers, instructional advice for medical facilities on matters of infection prevention, and sensitization campaign. Furthermore, vaccinated against plague were 4460 people, field disinsection over 50.5 km2 area was performed, as well as field deratization - 89.4 km2, township disinsection - 257.3 thous. m2, and township deratization - 329.1 thous. m2. Financial expenses on prophylactic (anti-epidemic) activities amounted to 23265.8 thousand rubles. Outlined was viability of preventive planning and prophylactic measures in the territories with forecasted aggravation of epizootic situation in natural plague foci of the Russian Federation

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

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    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

    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

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    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
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