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

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

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

. 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

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

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

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

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

Противоэпидемическая эффективность санитарно -просветительской работы с контингентами риска заражения чумой в Горно-Алтайском высокогорном природном очаге чумы

Objective is to reduce the risk of infection of people with plague in the territory of a natural focus on the basis of the targeted public health educational work with risk groups.Materials and methods. In 2017, 30 visits were made by epidemiological groups to livestock farms in the epizootic zone to inform the population about the existing risks of plague infection and to conduct interviews to assess the level of alertness regarding the risk of the disease. Work was carried out with risk contingents with coverage of 1652 people (81% of the total number of people living in livestock camps).Results. It was found that 64% of the respondents knew about the danger of plague infection in the region. 91% are aware of the role of marmots in infecting people with plague. 96.3% of respondents are aware of the ban on hunting groundhogs, while 39% continue to prey upon the grey (Altai) groundhog. The identified gaps in the population’s alertness regarding the risk of plague infection were eliminated through active sanitary and educational work with the population.Conclusion. Direct work with the population, anti-epidemic groups, significantly affected the provision of epidemiological welfare as regards plague, which is confirmed by the absence of human plague cases in the natural focus in 2017-2019. Цель – снижение риска заражения людей чумой на территории природного очага на основе кампании целенаправленной санитарно-просветительской работы с контингентами риска.Материалы и методы. В 2017 г. было осуществлено 30 выездов эпидемиологических групп на стоянки животноводов в зоне эпизоотии для информирования населения о существующих рисках заражения чумой и анкетирования с целью оценки уровня настороженности в отношении риска заболевания. Проведена работа с контингентами риска с охватом в 1652 человека (81% от общего количества людей, проживающих на животноводческих стоянках).Результаты. В ходе работы установлено, что знали об опасности заражения чумой в регионе 64% опрошенных. Осведомлены о роли сурков в заражении человека чумой – 91%. О запрете охоты на сурков известно 96,3% опрошенных, при этом 39% продолжают промысел серого (алтайского) сурка. Выявленные пробелы в настороженности населения в отношении риска заражения чумой удалось устранить за счет активной санитарно-просветительской работы с населением.Заключение. Прямая работа противоэпидемических групп с населением существенным образом сказалась на обеспечении санитарно-эпидемиологического благополучия по чуме, что подтверждается отсутствием заболеваний людей чумой в природном очаге в 2017–2019 гг.

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

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

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