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1.
Artigo em Inglês | MEDLINE | ID: mdl-38396153

RESUMO

AIMS: Haemorrhagic fever with renal syndrome (HFRS) is a significant zoonotic disease transmitted by rodents. The distribution of HFRS in the European part of Russia has been studied quite well; however, much less is known about the endemic area in the Russian Far East. The mutual influence of the epidemic situation in the border regions and the possibility of cross-border transmission of infection remain poorly understood. This study aims to identify the spatiotemporal hot spots of the incidence and the impact of environmental drivers on the HFRS distribution in the Russian Far East. METHODS AND RESULTS: A two-scale study design was performed. Kulldorf's spatial scan statistic was used to conduct spatiotemporal analysis at a regional scale from 2000 to 2020. In addition, an ecological niche model based on maximum entropy was applied to analyse the contribution of various factors and identify spatial favourability at the local scale. One spatiotemporal cluster that existed from 2002 to 2011 and located in the border area and one pure temporal cluster from 2004 to 2007 were revealed. The best suitability for orthohantavirus persistence was found along rivers, including those at the Chinese-Russian border, and was mainly explained by land cover, NDVI (as an indicator of vegetation density and greenness) and elevation. CONCLUSIONS: Despite the stable incidence in recent years in, targeted prevention strategies are still needed due to the high potential for HRFS distribution in the southeast of the Russian Far East.

2.
Prev Vet Med ; 221: 106051, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37918209

RESUMO

Peste des petits ruminants (PPR) is a highly contagious and fatal disease of mostly domestic goats and sheep. First reported in Uganda in 2007, the extent of peste des petits ruminants virus (PPRV) exposure, geographical distribution and risk factors of its transmission and spread are not clearly understood. In this study, we used cluster random sampling methodology to select study villages from three districts representing three different production systems along Uganda's "cattle corridor". Between October and December 2022, 2520 goat and sheep serum samples were collected from 252 households with no history of PPR vaccination in the past one year. The household heads were interviewed to assess possible risk factors of PPRV transmission using a structured questionnaire. The serum samples were screened with a commercial competitive enzyme-linked immunosorbent assay (cELISA) for PPRV antibodies. The determined overall true seroprevalence of PPRV was 27.3% [95% CI: 25.4-29.1]. The seroprevalence of PPRV antibodies in different production systems was 44.1% [95% CI: 40.6-47.7], 31.7% [95% CI: 28.4-35.0] and 6.1% [95% CI: 4.4-7.9] for pastoral, agropastoral and mixed crop-livestock production systems respectively. A mixed-effects multivariable logistic regression model revealed strong statistical evidence of association between female animals and PPRV antibody seropositivity compared to males [OR= 2.45, 95% CI: 1.7-3.5, p < 0.001]. The likelihood of being PPRV antibody seropositive significantly increased with increasing small ruminant age. Animals older than 3 years were more than three times as likely to be PPRV seropositive compared to animals aged under 1 year [OR= 3.41, 95% CI: 2.39-4.85, p < 0.001]. There was no statistical evidence of association between small ruminant species and PPRV antibody seropositivity (p = 0.423). Village flocks that interacted with neighboring flocks daily during grazing (IRR = 1.59, 95% CI: 1.19-2.13) and watering around swamps (IRR = 1.59, 95% CI: 1.19-2.13) were highly correlated with increased number of PPRV seropositive animals as compared to flocks that were more restricted in grazing and watered around other water sources other than swamps. Flocks from pastoral and agropastoral production systems were more than 10 times more likely to have seropositive animals than mixed crop-livestock flocks. Targeting PPR control interventions (vaccination and livestock movement control) to pastoral and agro-pastoral small ruminant production systems that are very prone to PPR incursions is recommended to prevent PPRV spread to low-risk smallholder mixed crop-livestock production systems.


Assuntos
Doenças dos Bovinos , Doenças das Cabras , Peste dos Pequenos Ruminantes , Vírus da Peste dos Pequenos Ruminantes , Doenças dos Ovinos , Masculino , Feminino , Animais , Ovinos , Bovinos , Peste dos Pequenos Ruminantes/epidemiologia , Estudos Soroepidemiológicos , Uganda/epidemiologia , Doenças das Cabras/epidemiologia , Doenças dos Ovinos/epidemiologia , Ensaio de Imunoadsorção Enzimática/veterinária , Fatores de Risco , Cabras , Anticorpos Antivirais , Gado
3.
Microorganisms ; 11(10)2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37894184

RESUMO

Rabies is a fatal disease of mammals that poses a high zoonotic risk to humans as well. The distribution of rabies is mainly driven by host animal migration and human-mediated dispersion. To contribute to the global understanding of the rabies virus (RABV) molecular epidemiology, 94 RABV field isolates collected from animals in 13 European Russian regions were phylogenetically characterized using the nearly full-size N gene nucleotide sequences. According to phylogenetic inferences, all isolates belonged to one of the two established phylogenetic groups, either group C (n = 54) or group D (n = 40), which are part of the clade Cosmopolitan of RABVs. Some representatives of group C collected from regions located far apart from each other had a remarkably high level of nucleotide identity. The possibility of the contribution of local bat species to the distribution of RABVs was discussed. Interestingly, over the years, the fraction of group D isolates has been constantly decreasing compared with that of group C isolates. The phylogenetic insights generated herein might have an important contribution to the control and surveillance of animal rabies epidemiology in the region.

4.
Animals (Basel) ; 13(19)2023 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-37835687

RESUMO

African swine fever (ASF) is an infectious disease that affects both domestic pigs (DPs) and wild boar (WB). The WB population plays an important role in the spread of ASF as the WB acts as a natural reservoir of the virus and transmits it to other susceptible wild and domestic pigs. Our study was aimed at revealing the areas with a high concentration of the WB population, and their potential relationships with the grouping of ASF cases in WB during the course of the ASF spread in the Russian Federation (2007-2022). We collected the annual data on WB numbers by municipalities within the regions of the most intensive ASF spread. We then conducted spatiotemporal analysis to identify clustering areas of ASF cases and compare them with the territories with a high density of WB population. We found that some of the territories with elevated ASF incidence in WB demonstrated spatial and temporal coincidence with the areas with a high WB population density. We also visualized the zones ("emerging hot spots") with a statistically significant rise in the WB population density in recent years, which may be treated as areas of paramount importance for the application of surveillance measures and WB population control.

5.
Front Vet Sci ; 10: 1252265, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37732145

RESUMO

Rabies is a fatal zoonotic disease that remains endemic in Kazakhstan despite the implementation of annual vaccination campaigns. Using data collected over a 10-year time period, the objective of this study was to provide updated information on the epidemiological situation of the disease in the country, and quantitative data on the species-specific spatial distribution of rabies and on the epidemiological features associated with that clustering. Five significant (p < 0.05) clusters of disease were detected. Clusters in southern Kazakhstan were associated with companion animals, which are likely explained by the maintenance of a domestic cycle of the disease in the most densely populated region of the country. Livestock cases were most frequent in clusters in the eastern (where wildlife cases were also frequent) and western regions of Kazakhstan, with higher probability of occurrence in spring and summer, compared to the rest of the year. The results here are consistent with differential patterns for disease transmission in Kazakhstan and will contribute to the design and implementation of zoning approaches to support the progressive control of rabies in the country.

6.
Spat Spatiotemporal Epidemiol ; 45: 100580, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37301595

RESUMO

Our study investigated the spatial distribution of tuberculosis and the influence of social determinants in Russia between 2006 and 2018 using the regional incidence of multi-drug resistance tuberculosis, HIV-TB coinfection, and mortality data. The "space-time cube" method identified the uneven geographical distribution of the tuberculosis burden. There is a clear distinction between a healthier European Russia, where a statistically significant stable trend towards a decrease in incidence and mortality was found, and the eastern part of the country, where there is no such trend. Generalized linear logistic regression analysis found that the challenging situation was associated with HIV-TB coinfection incidence, with a high incidence rate being detected even in more prosperous regions of European Russia. HIV-TB coinfection incidence was determined by a set of socioeconomic variables, out of which the influence of income and urbanization were the most pronounced. The influence of crime could indicate the spread of tuberculosis in socially disadvantaged regions.


Assuntos
Coinfecção , Infecções por HIV , Tuberculose , Humanos , Coinfecção/complicações , Coinfecção/epidemiologia , Determinantes Sociais da Saúde , Tuberculose/epidemiologia , Tuberculose/complicações , Infecções por HIV/epidemiologia , Federação Russa/epidemiologia , Incidência
7.
Viruses ; 15(3)2023 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-36992307

RESUMO

Foot-and-mouth disease (FMD) has long been recognized as a highly contagious, transboundary disease of livestock incurring substantial losses and burdens to animal production and trade across Africa, the Middle East, and Asia. Due to the recent emergence of the O/ME-SA/Ind-2001 lineage globally contributing to the expansion of FMD, molecular epidemiological investigations help in tracing the evolution of foot-and-mouth disease virus (FMDV) across endemic and newly affected regions. In this work, our phylogenetic analysis reveals that the recent FMDV incursions in Russia, Mongolia, and Kazakhstan in 2021-2022 were due to the virus belonging to the O/ME-SA/Ind-2001e sublineage, belonging to the cluster from Cambodian FMDV isolates. The studied isolates varied by 1.0-4.0% at the VP1 nucleotide level. Vaccine matching tests indicated that the vaccination policy in the subregion should be tailored according to the peculiarities of the ongoing epidemiologic situation. The current vaccination should change from such vaccine strains as O1 Manisa (ME-SA), O no 2102/Zabaikalsky/2010 (O/ME-SA/Mya-98) (r1 = 0.05-0.28) to strains that most closely antigenically match the dominant lineage O No. 2212/Primorsky/2014 (O O/ME-SA//Mya-98) and O No. 2311/Zabaikalsky/2016 (O ME-SA/Ind-2001) (r1 = 0.66-1.0).


Assuntos
Vírus da Febre Aftosa , Febre Aftosa , Animais , Filogenia , Cazaquistão/epidemiologia , Mongólia/epidemiologia , Epidemiologia Molecular , Federação Russa/epidemiologia , Sorogrupo
8.
Transbound Emerg Dis ; 69(6): 3664-3672, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36219553

RESUMO

Novel lumpy skin disease virus (LSDV) strains of recombinant origin are on the rise in South East Asia following the first emergence in 2017, and published evidence demonstrates that such genetic lineages currently dominate the circulation. Mongolia reported first LSD outbreaks in 2021 in a north-eastern region sharing borders with Russia and China. For each of 59 reported LSDV outbreaks, the number of susceptible animals ranged from 8 to 8600 with a median of 572, while the number of infected animals ranged from one to 355 with a median of 14. Phylogenetic inferences revealed a close relationship of LSDV Mongolia/2021 with recombinant vaccine-like LSDV strains from Russia, China, Taiwan, Thailand and Vietnam. These findings support the published data that the circulating strain of LSDV belongs to the dominant recombinant lineage recently established in the region.


Assuntos
Doenças dos Bovinos , Doença Nodular Cutânea , Vírus da Doença Nodular Cutânea , Bovinos , Animais , Vírus da Doença Nodular Cutânea/genética , Doença Nodular Cutânea/epidemiologia , Filogenia , Mongólia/epidemiologia , Surtos de Doenças/veterinária , Doenças dos Bovinos/epidemiologia
9.
Pathogens ; 11(8)2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-36015040

RESUMO

African swine fever virus (ASFV), classified as genotype II, was introduced into Georgia in 2007, and from there, it spread quickly and extensively across the Caucasus to Russia, Europe and Asia. The molecular epidemiology and evolution of these isolates are predominantly investigated by means of phylogenetic analysis based on complete genome sequences. Since this is a costly and time-consuming endeavor, short genomic regions containing informative polymorphisms are pursued and utilized instead. In this study, sequences of the central variable region (CVR) located within the B602L gene were determined for 55 ASFV isolates submitted from 526 active African swine fever (ASF) outbreaks occurring in 23 different regions across the Russian Federation (RF) between 2013 and 2017. The new sequences were compared to previously published data available from Genbank, representing isolates from Europe and Asia. The sequences clustered into six distinct groups. Isolates from Estonia clustered into groups 3 and 4, whilst sequences from the RF were divided into the remaining four groups. Two of these groups (5 and 6) exclusively contained isolates from the RF, while group 2 included isolates from Russia as well as Chechnya, Georgia, Armenia, Azerbaijan and Ukraine. In contrast, group 1 was the largest, containing sequences from the RF, Europe and Asia, and was represented by the sequence from the first isolate in Georgia in 2007. Based on these results, it is recommended that the CVR sequences contain significant informative polymorphisms to be used as a marker for investigating the epidemiology and spread of genotype II ASFVs circulating in the RF, Europe and Asia.

10.
Transbound Emerg Dis ; 69(5): e2551-e2562, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35583857

RESUMO

Lumpy skin disease (LSD) is an economically important transboundary disease affecting cattle, causing large economic losses such as decreased production and trade restrictions. LSD has been a historically neglected disease since it previously caused disease limited to the African continent. Currently, the epidemiology of LSD virus is based on how the disease is transmitted in tropical and sub-tropical climates. The understanding of its epidemiology in hemiboreal climates is not well understood and needs urgent attention to expand the current knowledge. In this study, the epidemiological findings on LSD in Russia over a 6-year period are summarized and discussed. A total of 471 outbreaks were identified spanning over a 9000 km range. The outbreaks of LSD occur primarily in small holder farms (backyard) compared to commercial farms between mid-May through mid-November including weather conditions with snow and freezing temperatures that preclude vector activity. Mortality and morbidity varied across the 6 years ranging from 1.19% to 61.8% and 0% to 50%, respectively, with a tendency to decline from 2015 to 2020. The geographic pattern of spread was assessed by means of directionality, indicating a northward movement from 2015 to 2016, with a consequent East turn in 2017 through Siberia to the Far East by 2020. All cases occurred along the border with Kazakhstan. Mathematical modelling showed that the disease tended to form statistically verified annual spatiotemporal clusters in 2016-2018, whereas in 2019 and 2020 such segregation was not evident. The trend of spread was mainly either from south to north or from south to a north-east direction.


Assuntos
Doenças dos Bovinos , Doença Nodular Cutânea , Vírus da Doença Nodular Cutânea , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Surtos de Doenças/veterinária , Doença Nodular Cutânea/epidemiologia , Federação Russa/epidemiologia
11.
Transbound Emerg Dis ; 69(5): e1642-e1658, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35231154

RESUMO

Peste des Petits Ruminants (PPR) is a transboundary, highly contagious, and fatal disease of small ruminants. PPR causes global annual economic losses of between USD 1.5 and 2.0 billion across more than 70 affected countries. Despite the commercial availability of effective PPR vaccines, lack of financial and technical commitment to PPR control coupled with a dearth of refined PPR risk profiling data in different endemic countries has perpetuated PPR virus transmission. In Uganda, over the past 5 years, PPR has extended from northeastern Uganda (Karamoja) with sporadic incursions in other districts /regions. To identify disease cluster hotspot trends that would facilitate the design and implementation of PPR risk-based control methods (including vaccination), we employed the space-time cube approach to identify trends in the clustering of outbreaks in neighbouring space-time cells using confirmed PPR outbreak report data (2007-2020). We also used negative binomial and logistic regression models and identified high small ruminant density, extended road length, low annual precipitation and high soil water index as the most important drivers of PPR in Uganda. The study identified (with 90-99% confidence) five PPR disease hotspot trend categories across subregions of Uganda. Diminishing hotspots were identified in the Karamoja region whereas consecutive, sporadic, new and emerging hotspots were identified in central and southwestern districts of Uganda. Inter-district and cross-border small ruminant movement facilitated by longer road stretches and animal comingling precipitate PPR outbreaks as well as PPR virus spread from its initial Karamoja focus to the central and southwestern Uganda. There is therefore urgent need to prioritize considerable vaccination coverage to obtain the required herd immunity among small ruminants in the new hotspot areas to block transmission to further emerging hotspots. Findings of this study provide a basis for more robust timing and prioritization of control measures including vaccination.


Assuntos
Doenças das Cabras , Peste dos Pequenos Ruminantes , Vírus da Peste dos Pequenos Ruminantes , Animais , Análise por Conglomerados , Doenças das Cabras/epidemiologia , Doenças das Cabras/prevenção & controle , Cabras , Peste dos Pequenos Ruminantes/epidemiologia , Peste dos Pequenos Ruminantes/prevenção & controle , Ruminantes , Solo , Uganda/epidemiologia , Água
12.
PLoS Negl Trop Dis ; 16(1): e0010145, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35100289

RESUMO

Southern Russia remains affected by West Nile virus (WNV). In the current study, we identified the spatial determinants of WNV distribution in an area with endemic virus transmission, with special reference to the urban settings, by mapping probable points of human infection acquisition and points of virus detection in mosquitoes, ticks, birds, and mammals during 1999-2016. The suitability of thermal conditions for extrinsic virus replication was assessed based on the approach of degree-day summation and their changes were estimated by linear trend analysis. A generalized linear model was used to analyze the year-to-year variation of human cases versus thermal conditions. Environmental suitability was determined by ecological niche modelling using MaxEnt software. Human population density was used as an offset to correct for possible bias. Spatial analysis of virus detection in the environment showed significant contributions from surface temperature, altitude, and distance from water bodies. When indicators of location and mobility of the human population were included, the relative impact of factors changed, with roads becoming most important. When the points of probable human case infection were added, the percentage of leading factors changed only slightly. The urban environment significantly increased the epidemic potential of the territory and created quite favorable conditions for virus circulation. The private building sector with low-storey houses and garden plots located in the suburbs provided a connection between urban and rural transmission cycles.


Assuntos
Aves/virologia , Culicidae/virologia , Carrapatos/virologia , Febre do Nilo Ocidental/epidemiologia , Febre do Nilo Ocidental/transmissão , Aedes/classificação , Aedes/virologia , Animais , Anopheles/classificação , Anopheles/virologia , Argasidae/virologia , Culex/classificação , Culex/virologia , Meio Ambiente , Geografia , Humanos , Ixodidae/virologia , Densidade Demográfica , Federação Russa/epidemiologia , Análise Espacial , Temperatura , Vírus do Nilo Ocidental/isolamento & purificação
13.
Front Vet Sci ; 9: 1019808, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36686186

RESUMO

Introduction: Since the first report of outbreaks of African swine fever (ASF) in Georgia in 2007, the disease has expanded into Europe, Russia, and Asia, spreading rapidly via contact with infected animals including domestic pigs and wild boars. The vast expansion of this Genotype II African swine fever virus (ASFV) across wide-ranging territories and hosts inevitably led to the acquisition of novel mutations. These mutations could be used to track the molecular epidemiology of ASFV, provided that they are unique to strains restricted within a certain area. Whilst whole-genome sequencing remains the gold standard for examining evolutionary changes, sequencing of a single locus with significant variation and resolution power could be used as a rapid and cost-effective alternative to characterize multiple isolates from a single or related outbreak. Material and methods: ASFVs obtained during active ASF outbreaks in the Russian region of Kaliningrad between 2017 and 2019 were examined. Since all of the viruses belonged to Genotype II and no clear differentiation based on central variable region (CVR) sequencing was observed, the whole-genome sequences of nine ASFV isolates from this region were determined. To obtain insights into the molecular evolution of these isolates, their sequences were compared to isolates from Europe, Asia, and Africa. Results: Phylogenetic analysis based on the whole-genome sequences clustered the new isolates as a sister lineage to isolates from Poland and Germany. This suggests a possible shared origin followed by the addition of novel mutations restricted to isolates from this region. This status as a sister lineage was mirrored when analyzing polymorphisms in MGF-505-5R and MGF-110-7L, whilst a polymorphism unique to sequences from Kaliningrad was identified at locus K145R. This newly identified mutation was able to distinguish the isolates obtained from Kaliningrad with sequences of Genotype II ASFVs available on GenBank. Discussion: The findings of this study suggest that ASFVs circulating in Kaliningrad have recently obtained this mutation providing an additional marker to the mutations previously described.

14.
Transbound Emerg Dis ; 69(4): 2296-2305, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34264015

RESUMO

Peste des petits ruminants (PPR) is a viral transboundary disease seen in small ruminants, that causes significant damage to agriculture. This disease has not been previously registered in the Republic of Kazakhstan (RK). This paper presents an assessment of the susceptibility of the RK's territory to the spread of the disease in the event of its importation from infected countries. The negative binomial regression model that was trained on the PPR outbreaks in China, was used to rank municipal districts in the RK in terms of PPR spread risk. The outbreak count per administrative district was used as a risk indicator, while a number of socio-economic, landscape, and climatic factors were considered as explanatory variables. Summary road length, altitude, the density of small ruminants, the maximum green vegetation fraction, cattle density, and the Engel coefficient were the most significant factors. The model demonstrated a good performance in training data (R2  = 0.69), and was transferred to the RK, suggesting a significantly lower susceptibility of this country to the spread of PPR. Hot spot analysis identified three clusters of districts at the highest risk, located in the western, eastern, and southern parts of Kazakhstan. As part of the study, a countrywide survey was conducted to collect data on the distribution of livestock populations, which resulted in the compilation of a complete geo-database of small ruminant holdings in the RK. The research results may be used to formulate a national strategy for preventing the importation and spread of PPR in Kazakhstan through targeted monitoring in high-risk areas.


Assuntos
Surtos de Doenças , Peste dos Pequenos Ruminantes , Ruminantes , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/prevenção & controle , Doenças dos Bovinos/transmissão , Surtos de Doenças/prevenção & controle , Surtos de Doenças/veterinária , Cazaquistão/epidemiologia , Peste dos Pequenos Ruminantes/epidemiologia , Peste dos Pequenos Ruminantes/prevenção & controle , Peste dos Pequenos Ruminantes/transmissão , Vírus da Peste dos Pequenos Ruminantes , Densidade Demográfica , Medição de Risco , Ruminantes/virologia
15.
Front Vet Sci ; 8: 723375, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34504890

RESUMO

African swine fever (ASF) is an incurable viral disease of domestic and wild pigs. A large-scale spread of ASF began in Eurasia in 2007 and has affected territories from Belgium to the Far East, occurring as both local- and regional-level epidemics. In 2020, a massive ASF epidemic emerged in the southeastern region of European Russia in the Samara Oblast and included 41 outbreaks of ASF in domestic pigs and 40 cases in wild boar. The Samara Oblast is characterized by a relatively low density of wild boar (0.04-0.05 head/km2) and domestic pigs (1.1-1.3 head/km2), with a high prevalence of small-scale productions (household farms). This study aims to understand the driving forces of the disease and perform a risk assessment for this region using complex epidemiological analyses. The socioeconomic and environmental factors of the ASF outbreak were explored using Generalized Linear Logistic Regression, where ASF infection status of the Samara Oblast districts was treated as a response variable. Presence of the virus in a district was found to be most significantly (p < 0.05) associated with the importation of live pigs from ASF-affected regions of Russia (OR = 371.52; 95% CI: 1.58-87290.57), less significantly (p < 0.1) associated with the density of smallholder farms (OR = 2.94; 0.82-10.59), volume of pork products' importation from ASF-affected regions of Russia (OR = 1.01; 1.00-1.02), summary pig population (OR = 1.01; 0.99-1.02), and insignificantly (p > 0.1) associated with presence of a common border with an ASF-affected region (OR = 89.2; 0.07-11208.64). No associations were found with the densities of pig and wild boar populations. The colocation analysis revealed no significant concentration of outbreaks in domestic pigs near cases in wild boar or vice versa. These results suggest that outbreaks notified in low biosecurity household farms were mainly associated with the transportation and trade of pigs and pork products from ASF-affected regions of Russia. The findings underline the importance of taking into account animal transportation data while conducting future studies to develop a risk map for the region and the rest of European Russia.

16.
Front Vet Sci ; 8: 723081, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34422950

RESUMO

African swine fever (ASF) is an emerging viral contagious disease affecting domestic pigs (DP) and wild boar (WB). ASF causes significant economic damage to the pig industry worldwide due to nearly 100% mortality and the absence of medical treatments. Since 2019, an intensive spread of ASF has been observed in the Russian Far East region. This spread raises concerns for epidemiologists and ecologists given the potential threat to the WB population, which is an essential member of the region's wild ungulates and provides a notable share of food resources for predatory species. This study aims to determine the genotype of ASF virus circulating in the region, reveal the spatio-temporal patterns of the ASF outbreaks' emergence, and assess the potential reduction of the regional fauna because of expected depopulation of WB. The first historical case of ASF in the study region was caused by an African swine fever virus (ASFV) isolated from DPs and belonging to Genotype 2, CVR1; IGR-2 (TRS +). Sequencing results showed no significant differences among ASFV strains currently circulating in the Russian Federation, Europe, and China. The spatiotemporal analysis with the space-time permutations model demonstrated the presence of six statistically significant clusters of ASF outbreaks with three clusters in DPs and one cluster in WBs. DP outbreaks prevail in the north-west regions of the study area, while northern regions demonstrate a mixture of DP and WB outbreaks. Colocation analysis did not reveal a statistically significant pattern of grouping of one category of outbreaks around the others. The possible damage to the region's fauna was assessed by modeling the total body mass of wild ungulates before and after the wild boars' depopulation, considering a threshold density of WB population of 0.025 head/km2, according to the currently in force National Plan on the ASF Eradication in Russia. The results suggest the total mass of ungulates of the entire study region will likely decrease by 8.4% (95% CI: 4.1-13.0%), while it may decrease by 33.6% (19.3-46.1%) in the Primorsky Krai, thereby posing an undeniable threat to the predatory species of the region.

17.
Front Vet Sci ; 8: 668420, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34250061

RESUMO

The Yamal Peninsula in the Russian Federation experienced a massive outbreak of anthrax in reindeer (Rangifer tarandus) in July-August 2016, with 2,650 (6.46% of the total susceptible population) animals infected, of which 2,350 died (case fatality rate of 88.67%). In our study, we analyzed climatic and epidemiological factors that could have triggered the outbreak. The cancelation of reindeer vaccination against anthrax in 2007 resulted in an increase in population susceptibility. In response to the outbreak, total vaccination of all susceptible animals was resumed. To assess the vaccination effectiveness, we tested 913 samples of blood serum taken from vaccinated reindeer using an antigenic erythrocyte diagnostic kit to detect specific anti-anthrax antibodies via an indirect hemagglutination assay (IHA) 9 months after vaccination. We found that 814 samples had sufficiently high levels of anti-anthrax antibodies to indicate a protection level of 89% (95% confidence interval: 87-91%) of the whole reindeer population. Abnormally high ambient temperature in the summer of 2016 contributed to the thawing of permafrost and viable Bacillus anthracis spores could have become exposed to the surface; the monthly average air temperatures in June, July, and August 2016 were 20-100% higher than those of the previous 30-year period, while the maximum air temperatures were 16-75% higher. Using the projected climate data for 2081-2100 according to the "worst case" RCP8.5 scenario, we demonstrated that the yearly air temperature may average above 0°C across the entire Yamal Peninsula, while the yearly number of days with a mean temperature above 0°C may rise by 49 ± 6 days, which would provide conditions for reactivation of soil anthrax reservoirs. Our results showed that the outbreak of anthrax occurred under conditions of a significant increase in air temperature in the study area, underlined the importance of vaccination for controlling the epidemic process, and demonstrated the effectiveness of monitoring studies using the IHA diagnostic kit for detecting erythrocyte anthrax antigens.

18.
Front Vet Sci ; 8: 647838, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34277750

RESUMO

Classical swine fever (CSF) is considered one of the most important diseases of swine because of the far-reaching economic impact the disease causes to affected countries and regions. The state of Mato Grosso (MT) is part of Brazil's CSF-free zone. CSF status is uncertain in some of MT's neighboring States and countries, which has resulted in the perception that MT is at high risk for the disease. However, the risk for CSF introduction into MT has not been previously assessed. Here, we estimated that the risk for CSF introduction into the MT is highly heterogeneous. The risk associated with shipment of commercial pigs was concentrated in specific municipalities with intense commercial pig production, whereas the risk associated with movement of wild boars was clustered in certain municipalities located close to the state's borders, mostly in northern and southwestern MT. Considering the two pathways of possible introduction assessed here, these results demonstrate the importance of using alternative strategies for surveillance that target different routes and account for different likelihoods of introduction. These results will help to design, implement, and monitor surveillance activities for sustaining the CSF-free status of MT at times when Brazil plans to expand the recognition of disease-free status for other regions in the country.

19.
Front Vet Sci ; 8: 658675, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33912609

RESUMO

Leptospirosis is a re-emerging zoonotic infectious disease caused by pathogenic bacteria of the genus Leptospira. Regional differences in the disease manifestation and the role of ecological factors, specifically in regions with a subarctic and arctic climate, remain poorly understood. We here explored environmental and socio-economic features associated with leptospirosis cases in livestock animals in the Russian Arctic during 2000-2019. Spatial analysis suggested that the locations of the majority of 808 cases were in "boreal" or "polar" climate regions, with "cropland," "forest," "shrubland," or "settlements" land-cover type, with a predominance of "Polar Moist Cropland on Plain" ecosystem. The cases demonstrated seasonality, with peaks in March, June, and August, corresponding to the livestock pasturing practices. We applied the Forest-based Classification and Regression algorithm to explore the relationships between the cumulative leptospirosis incidence per unit area by municipal districts (G-rate) and a number of socio-economic, landscape, and climatic factors. The model demonstrated satisfactory performance in explaining the observed disease distribution (R 2 = 0.82, p < 0.01), with human population density, livestock units density, the proportion of crop area, and budgetary investments into agriculture per unit area being the most influential socio-economic variables. Climatic factors demonstrated a significantly weaker influence, with nearly similar contributions of mean yearly precipitation and air temperature and number of days with above-zero temperatures. Using a projected climate by 2100 according to the RCP8.5 scenario, we predict a climate-related rise of expected disease incidence across most of the study area, with an up to 4.4-fold increase in the G-rate. These results demonstrated the predominant influence of the population and agricultural production factors on the observed increase in leptospirosis cases in livestock animals in the Russian Arctic. These findings may contribute to improvement in the regional system of anti-leptospirosis measures and may be used for further studies of livestock leptospirosis epidemiology at a finer scale.

20.
Front Vet Sci ; 8: 605910, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33644144

RESUMO

African swine fever (ASF) is a disease of swine that is endemic to some African countries and that has rapidly spread since 2007 through many regions of Asia and Europe, becoming endemic in some areas of those continents. Since there is neither vaccine nor treatment for ASF, prevention is an important action to avoid the economic losses that this disease can impose on a country. Although the Republic of Kazakhstan has remained free from the disease, some of its neighbors have become ASF-infected, raising concerns about the potential introduction of the disease into the country. Here, we have identified clusters of districts in Kazakhstan at highest risk for ASF introduction. Questionnaires were administered, and districts were visited to collect and document, for the first time, at the district level, the distribution of swine operations and population in Kazakhstan. A snowball sampling approach was used to identify ASF experts worldwide, and a conjoint analysis model was used to elicit their opinion in relation to the extent at which relevant epidemiological factors influence the risk for ASF introduction into disease-free regions. The resulting model was validated using data from the Russian Federation and Mongolia. Finally, the validated model was used to rank and categorize Kazakhstani districts in terms of the risk for serving as the point of entry for ASF into the country, and clusters of districts at highest risk of introduction were identified using the normal model of the spatial scan statistic. Results here will help to allocate resources for surveillance and prevention activities aimed at early detecting a hypothetical ASF introduction into Kazakhstan, ultimately helping to protect the sanitary status of the country.

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