Since its initial detection in Africa, the West Nile virus has disseminated widely across all continents, becoming endemic in numerous countries, including the Russian Federation. A substantial ...expansion of the West Nile virus range was observed in the European part of the Russian territory in 1999. In light of this epidemiological trend, research endeavours focusing on monitoring West Nile virus circulation activity in endemic regions of the country have gained paramount significance. A substantial dataset has been accrued from 2007 onwards regarding genomic variability and dissemination dynamics across the country throughout the entire monitoring period for the West Nile fever pathogen. The objective of this study was to characterise West Nile virus isolates that have been circulating in the Russian Federation and identify their molecular and genetic characteristics. A phylogenetic analysis of 55 complete genome sequences revealed that the West Nile virus population within the Russian Federation is genetically heterogeneous and is represented by four major clades. One of these clades is currently exhibiting extensive spread into new regions of the country.
The first report about Ebinur Lake orthotobunyavirus (EBIV) detected in mosquito pools in the northern provinces of China was published in 2014. The south of the European part of the Russian ...Federation is a known area of some arboviral infection foci such as West Nile Fever due to favorable climatic and geographic conditions and being a part of the bird’s migratory pathways. But very little is known about the spread of other bird-associated viruses. We describe here the first case of EBIV detection in the Volgograd region, Russia. The genomic RNA of EBIV was detected in bird brain tissues, mosquitoes (including overwintering ones) and ticks pools using metagenomic sequencing technique. Belonging of the detected RNA to EBIV (Orthobunyavirus, Peribunyaviridae) was confirmed by phylogenetic analysis. The simultaneous existence of EBIV and other arboviruses such as West Nile virus (WNV) and Sindbis virus (SINV) in environmental samples was revealed. The obtained results indicate the need for further studies of the EBIV circulation in the Volgograd region and possible epidemiological risks.
Objective: to evaluate the role of blood-sucking mosquitoes of various species living in the northern and central regions of the Crimean Peninsula in the transmission of West Nile virus (WNV). ...Materials and methods: the collection of bloodsucking mosquitoes was carried out in 7 administrative units of the Republic of Crimea with automatic traps and a vertical handheld vacuum cleaner from July 1 to August 5, 2022. The species composition of mosquitoes was determined visually using an MSP-1 stereomicroscope (option 22) using standard keys. Detection of WNV RNA in the samples was performed by RT-PCR. Mosquito infection levels and dominance index were calculated. Results: a common eudominant species for urban and rural biotopes of the surveyed areas was determined Ae. caspius, whose dominance index was 72.4% and 31.3%. Mosquitoes of the species Cx. modestus were the most numerous in rural biotopes (dominance index — 48.4%). The invasive species Ae. albopictus in the central part of the Crimean peninsula, which indicates the expansion of its habitat. Of 18.6 thousand mosquitoes of 12 species, merged in 693 samples, WNV RNA was detected in 14 samples (2.02%), 3 isolates of the pathogen were isolated. A high level of WNV infection of mosquitoes in urban biotopes was established, which amounted to 4.12%. WNV circulation was first confirmed in the northern part of Crimea (Krasnoperekopsky district). Conclusion: the epidemiological significance of mosquitoes of various species on the territory of the Crimean Peninsula has been determined. The data on the spread of WNV in the Republic of Crimea were supplemented, taking into account which the estimated zoning of the territory was carried out according to the degree of risk of infection with WNV. Recommendations are given to strengthen epidemiological surveillance and preventive measures.
Objective
: to assess the quality and effectiveness of West Nile fever (WNF) causative agent’s monitoring in the Volgograd region and to develop a set of measures to its optimization.
Materials and ...methods
: data on the detection of WNV cases, results of serological and zooentomological monitoring in 2009–2021. A comprehensive methodological approach was applied, including statistical and epidemiological methods.
Results
: based on the assessment of WNF causative agent’s monitoring key aspects in the Volgograd region, it was shown that one of the priority problems is the insufficient and untimely detection of cases among the population. Among the urgent problems of serological monitoring are the lack of a clearly established frequency of serological examination in the population of the region’s administrative territories and the termination of one of the indicator population groups examination, regulated by the current regulatory and methodological documents. An assessment of the parameters of monitoring studies of the external environment indicates an insufficient territorial coverage and a decrease in the volume of studies, primarily in relation to the main carriers of the West Nile virus, which determines the overall low detection rate of West Nile virus markers.
Conclusion
: recommendations are proposed for optimizing monitoring, which will enhance the efficiency of WNF epidemiological surveillance and develop a scientifically based forecast of the development of the epidemiological situation.
The epidemiological situation on West Nile fever (WNF) in Russia in 2021 was characterized by an increase in the incidence relative to 2020 (more than 6-fold increase). The peculiarities of the WNF ...epidemic process have been determined: the territorial distribution of cases (75 % – in the constituent entities of the Central Federal District), the expansion of the causative agent’s areal with the involvement of new territories (official registration of cases in Moscow and the Tula Region for the first time ever), the early end of the epidemic season. An increase in the proportion of neuroinvasive forms, an increase in the share of male patients and the age group of 30–39 years, a decrease in the proportion of the population in contact with the pathogen in natural places of mass recreation were observed in the incidence structure. According to the results of the monitoring studies carried out by the Reference Center, intensive circulation of the pathogen was established on the territory of the Central Federal District, Southern Federal District, and the North Caucasian Federal District. The low reported incidence was due to insufficient detection of WNF patients. The results of moleculargenetic study showed that in the European part of Russia, WNV lineage 2 circulated in both epizootic and epidemic cycles, lineage 2 in the south of Western Siberia (Omsk Region) and lineage 4 in the Volgograd Region – in the epizootic cycle only. Phylogenetic analysis revealed that strains isolated from the Astrakhan, Volgograd, Rostov, Voronezh Regions and the Republic of Dagestan in 2021 belong to the genovariant of WNV lineage 2 not registered in Russia previously. The topology of the phylogenetic tree indicates the possible African origin of the isolates, probably imported into Russia by migratory birds across the coast of the Caspian Sea. In the Volgograd Region, WNV of both the entrenched clade of lineage 2 (since 2007) and new genovariant circulated. The specialists of the Reference Center developed a forecast of WNF epidemiological situation development in the Volgograd Region in 2022 on the basis of the neural network modeling technique, according to which an increase in the incidence is expected, comparable to that in 2010 and 2012. Based on the climate projections, an increase in the incidence is possible in all Federal Districts of the European part of Russia, the southern territories of the Urals, Western Siberia, and the Far East.
In Europe, as in Russia and Canada, outlined was a tendency to the increase in the morbidity rates, while in the US – the incidence was somewhat lower as compared to previous years. On the whole, ...West Nile fever incidence rates in the Russian Federation by regions during the epidemic season, 2016 were below the average long-term index. Above the average regional annual incidence rates were registered in the Saratov region only and accounted for 64 % of all reported cases in Russia. Analysis of the monitoring results indicated the circulation of WNF virus markers in carriers of the pathogen in 10 constituent entities of the Russian Federation, and the presence of IgG antibodies in healthy population cohorts in 30 RF entities. According to molecular-genetic typing of WNF virus samples from a deceased patient in the Astrakhan Region and mosquito Culex samples from the Volgograd Region, WNF virus genotype I was established. Forecasting of epidemiological situation development for the year 2017 does not rule out the possibility of local increase in WNF incidence in certain regions of Russia.
West-Nile fever epidemic season lasted since May to September inclusively in 2014 in Russia. It was marked by the low morbidity intensity, which manifested itself in the old-established foci only. In ...total reported were 27 cases of West-Nile fever infection in 8 constituent entities of the Russian Federation. Decrease in epidemic process intensity was observed in other parts of the world too: the USA, Canada, European and Mediterranean countries. Sustained circulation of WNF virus of the second genotype in the territory of the Russian Federation (the Volgograd Region) was verified using sequencing of the fragments of the viral RNA genome locuses 5’UTR-protC, ProtE, NS3 obtained from clinical material and ambient environment objects.
Isolation of the virus from biological material from a two-month-old calf with pathology of the respiratory system from a herd with a morbidity rate of 48% was performed. After detection the presence ...of IRT antigens in the lungs of the dead animal, the pathogen was isolated on a continuous culture of calf kidney cells, where a characteristic cytopathic effect was observed. The genetic material of the bovine herpesvirus type 1 (Bovine herpesvirus-1, BHV-1) was identified by polymerase chain reaction in the test sample. The virus isolate was adapted to continuous cell cultures of calf kidneys, sheep kidney, cow embryo lung and calf trachea, and the most suitable biological system was determined, where adsorption and reproductive properties of the virus were more pronounced. It was found that the highest titer of infectious activity of BHV-1 isolate (6.1 lg TCD50/cm3) was obtained on continuous culture of lung embryonic cells of a cow embryo after its reproduction during three consecutive passages (observation period)
Diagnosis of paroxysmal conditions in neurology is one of the most difficult problems. Particular difficulties are caused by differential diagnosis of epileptic and non-epileptic paroxysmal states. ...There are no absolutely pathognomonic signs of epileptic and non-epileptic seizures. False positive diagnosis of epilepsy occurs in 2-71% of cases. Diagnosis of paroxysmal conditions requires an integrated approach to the problem and includes not only a clinical examination, but also a thorough history taking, neurophysiological, neuroimaging, laboratory research methods, involves the involvement of other specialists. The article presents a clinical case of 27-year-old young man who was initially misdiagnosed. Using the methods of functional and laboratory diagnostics, the patient was diagnosed correctly. Instead of idiopathic epilepsy, he was diagnosed with cytotoxic lesions of the corpus callosum (CLOCCs-syndrome associated with an infectious process) with motor paroxysms of non-epileptic genesis. Thus, using the example of this clinical case, it has been shown that the differential diagnosis of epileptic and non-epileptic paroxysmal states presents significant difficulties for a practicing neurologist.
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