646 results on '"Baylis, Matthew"'
Search Results
202. Effect of temperature on survival and rate of virogenesis of African horse sickness virus in Culicoides variipennis sonorensis (Diptera: Ceratopogonidae) and its significance in relation to the epidemiology of the disease
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Wellby, Martin P., primary, Baylis, Matthew, additional, Rawlings, Peter, additional, and Mellor, Philip S., additional
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- 1996
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203. Effect of host packed cell volume on the bloodmeal size of male tsetse flies, Glossina pallidipes
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BAYLIS, MATTHEW, primary and MBWABI, ALBERT L., additional
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- 1995
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204. Modelling the spatial distribution of Culicoides biting midges at the local scale.
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Kluiters, Georgette, Sugden, David, Guis, Helene, McIntyre, K. Marie, Labuschagne, Karien, Vilar, Maria J., Baylis, Matthew, and Morgan, Eric
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CULICOIDES ,CERATOPOGONIDAE ,BLUETONGUE virus ,INSECT traps ,ANALYSIS of variance ,INSECTS as carriers of disease ,SHEEP ,SCIENTIFIC satellites - Abstract
Culicoides midges (Diptera: Ceratopogonidae) are ubiquitous on farms in the United Kingdom ( UK), but little research has explored their abundance, an important determinant of disease risk. Models to explain and predict variation in their abundance are needed for effective targeting of control methods against bluetongue virus ( BTV) and other Culicoides-borne diseases. Although models have been attempted at the national scale (e.g. Scotland), no investigations have taken place at a finer spatial scale., Midge abundances were estimated using light traps on 35 farms in Bala, north Wales. Culicoides catches were combined with remotely sensed ecological correlates, and on-farm host and environmental data, within a GLM model. Drivers of local-scale variation were determined at the 1-km resolution., Local-scale variation in abundance exhibited an almost 500-fold difference (74-33 720) between farms in maximum Obsoletus Group catches. The Obsoletus Group model explained 81% of this variance and was dominated by normalized difference vegetation index ( NDVI). This is consistent with previous studies suggesting strong impacts of forest cover and vegetation activity on distribution, as well as shaded breeding site requirements., The variance explained was consistently high for the Pulicaris Group, C. pulicaris and C. punctatus (80%, 73% and 74%), the other probable BTV vector species in the United Kingdom. The abundance of all vector species increased with the number of sheep on farms, but this relationship was missing from any of the non-vector models. This is particularly interesting given that none of the species concerned are known to utilize sheep-associated larval development sites. Performance of the non-vector models was also high (65-87% variance explained), but species differed in their associations with satellite variables., Synthesis and application. At a large spatial scale, there is significant variation in Culicoides Obsoletus Group abundance, which undermines attempts to record their nationwide distribution in larger-scale models. Satellite data can be used to explain a high proportion of this variation and, if shown to be generalizable, they may produce effective predictive models of disease vector abundance. We recommend undertaking a prior survey for farms with high Culicoides catches within the sampling area and checking stability in catch size between seasons and years. [ABSTRACT FROM AUTHOR]
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- 2013
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205. Two-Host, Two-Vector Basic Reproduction Ratio (R0) for Bluetongue.
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Turner, Joanne, Bowers, Roger G., and Baylis, Matthew
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MATHEMATICAL formulas ,RUMINANTS ,ECONOMIC impact ,BLUETONGUE ,CROSS infection ,DEATH - Abstract
Mathematical formulations for the basic reproduction ratio (R
0 ) exist for several vector-borne diseases. Generally, these are based on models of one-host, one-vector systems or two-host, one-vector systems. For many vector borne diseases, however, two or more vector species often co-occur and, therefore, there is a need for more complex formulations. Here we derive a two-host, two-vector formulation for the R0 of bluetongue, a vector-borne infection of ruminants that can have serious economic consequences; since 1998 for example, it has led to the deaths of well over 1 million sheep in Europe alone. We illustrate our results by considering the situation in South Africa, where there are two major hosts (sheep, cattle) and two vector species with differing ecologies and competencies as vectors, for which good data exist. We investigate the effects on R0 of differences in vector abundance, vector competence and vector host preference between vector species. Our results indicate that R0 can be underestimated if we assume that there is only one vector transmitting the infection (when there are in fact two or more) and/or vector host preferences are overlooked (unless the preferred host is less beneficial or more abundant). The two-host, one-vector formula provides a good approximation when the level of cross-infection between vector species is very small. As this approaches the level of intraspecies infection, a combination of the two-host, one-vector R0 for each vector species becomes a better estimate. Otherwise, particularly when the level of cross-infection is high, the two-host, two-vector formula is required for accurate estimation of R0 . Our results are equally relevant to Europe, where at least two vector species, which co-occur in parts of the south, have been implicated in the recent epizootic of bluetongue. [ABSTRACT FROM AUTHOR]- Published
- 2013
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206. Feeding success of vectors on infected hosts: Reply
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Baylis, Matthew, primary
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- 1993
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207. The nutritional state of male tsetse flies, Glossina pallidipes, at the time of feeding
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BAYLIS, MATTHEW, primary and NAMBIRO, CHARLES O., additional
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- 1993
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208. Why Did Bluetongue Spread the Way It Did? Environmental Factors Influencing the Velocity of Bluetongue Virus Serotype 8 Epizootic Wave in France.
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Pioz, Maryline, Guis, Hélène, Crespin, Laurent, Gay, Emilie, Calavas, Didier, Durand, Benoît, Abrial, David, Ducrot, Christian, and Baylis, Matthew
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COMMUNICABLE diseases ,EPIDEMICS ,DISEASE management ,BLUETONGUE virus ,VACCINATION ,RAINFALL - Abstract
Understanding where and how fast an infectious disease will spread during an epidemic is critical for its control. However, the task is a challenging one as numerous factors may interact and drive the spread of a disease, specifically when vector- borne diseases are involved. We advocate the use of simultaneous autoregressive models to identify environmental features that significantly impact the velocity of disease spread. We illustrate this approach by exploring several environmental factors influencing the velocity of bluetongue (BT) spread in France during the 2007-2008 epizootic wave to determine which ones were the most important drivers. We used velocities of BT spread estimated in 4,495 municipalities and tested sixteen covariates defining five thematic groups of related variables: elevation, meteorological-related variables, landscape- related variables, host availability, and vaccination. We found that ecological factors associated with vector abundance and activity (elevation and meteorological-related variables), as well as with host availability, were important drivers of the spread of the disease. Specifically, the disease spread more slowly in areas with high elevation and when heavy rainfall associated with extreme temperature events occurred one or two months prior to the first clinical case. Moreover, the density of dairy cattle was correlated negatively with the velocity of BT spread. These findings add substantially to our understanding of BT spread in a temperate climate. Finally, the approach presented in this paper can be used with other infectious diseases, and provides a powerful tool to identify environmental features driving the velocity of disease spread. [ABSTRACT FROM AUTHOR]
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- 2012
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209. The development of linear regression models using environmental variables to explain the spatial distribution of Fasciola hepatica infection in dairy herds in England and Wales
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McCann, Catherine M., Baylis, Matthew, and Williams, Diana J.L.
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REGRESSION analysis , *FASCIOLA hepatica , *DAIRY cattle , *LIVESTOCK diseases , *CATTLE infections , *FASCIOLIASIS - Abstract
Abstract: Fasciolosis caused by Fasciola hepatica is a major cause of economic loss to the agricultural community worldwide as a result of morbidity and mortality in livestock. Spatial models developed with the aid of Geographic Information Systems (GIS) can be used to develop risk maps for fasciolosis for use in the formulation of disease control programmes. Here we investigate the spatial epidemiology of F. hepatica in dairy herds in England and Wales and develop linear regression models to explain observed patterns of exposure at a small spatial unit, the postcode area. Exposure data used for the analysis were taken from an earlier study of F. hepatica infection, performed in the winter of 2006/7. Climatic, environmental, soil, livestock and pasture variables were considered as potential predictors. The performance of models that used climate variables for 5years average data, contemporary data and a combination of both for England and Wales, and for England only, was compared. All models explained over 70% of the variation in the prevalence of exposure. The best performing models were those built using 5year average and contemporary weather data. However, the fit of these models was only slightly better than the fit of models using weather data from one time period only. Rainfall was a consistent predictor in all models. Other model covariates included temperature, the negative predictors of soil pH and slope and the positive predictors of poor quality land, as determined by the Agricultural Land Classification, and very fine sand content of soil. Choroplethic risk maps showed a good match between the observed F. hepatica exposure values and exposure values fitted by the models. The development of these detailed spatial models is the first step towards the development of a spatially specific, temporal forecasting system for liver fluke in the United Kingdom. [Copyright &y& Elsevier]
- Published
- 2010
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210. Emergence or improved detection of Japanese encephalitis virus in the Himalayan highlands?
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Baylis, Matthew, Barker, Christopher M., Caminade, Cyril, Joshi, Bhoj R., Pant, Ganesh R., Rayamajhi, Ajit, Reisen, William K., and Impoinvil, Daniel E.
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JAPANESE encephalitis viruses ,PUBLIC health ,ANTHROPOGENIC effects on nature ,PHYLOGEOGRAPHY ,SEROPREVALENCE ,UPLANDS - Abstract
The emergence of Japanese encephalitis virus (JEV) in the Himalayan highlands is of significant veterinary and public health concern and may be related to climate warming and anthropogenic landscape change, or simply improved surveillance. To investigate this phenomenon, a One Health approach focusing on the phylogeography of JEV, the distribution and abundance of the mosquito vectors, and seroprevalence in humans and animal reservoirs would be useful to understand the epidemiology of Japanese encephalitis in highland areas. [ABSTRACT FROM AUTHOR]
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- 2016
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211. Avian malaria affecting penguins in zoological gardens, aquariums and wildlife parks in the UK.
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Hernandez‐Colina, Arturo, Gonzalez‐Olvera, Merit, Eckley, Lindsay, Lopez, Javier, and Baylis, Matthew
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Background: Avian malaria has caused mortalities in captive penguins worldwide and it is a conservation threat for some wild penguins. The experience of staff working on penguins is highly valuable for the improvement of captivity conditions. Methods: An online questionnaire was designed to collect avian malaria information in penguins in the UK. Volunteers with diverse experience reviewed it for scientific value and clarity, and it was supported by the British and Irish Association of Zoos and Aquariums. Results: Forty‐two institutions were contacted by email, obtaining 27 complete and five partial responses. Eighteen institutions reported avian malaria in 38 suspected and 37 confirmed outbreaks in the past 20 years, mainly occurring in the summer and recent years. Proportional risk was higher in the south east region of England. Humboldt and African penguins were more commonly affected, and prevalence was mostly low or medium, but lethality was high. Different treatment protocols were reported with inconsistent outcomes. Conclusions: Penguins' susceptibility, their translocation across institutions, and the wide distribution of avian malaria make this disease a constant threat. Preventive and control measures are recommended, including testing for early diagnosis and treatment, avoiding prolonged stressful events in penguins, and monitoring and controlling mosquito vectors. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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212. Opinion: Climate change and the recent emergence of bluetongue in Europe.
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Purse, Bethan V., Mellor, Philip S., Rogers, David J., Samuel, Alan R., Mertens, Peter P. C., and Baylis, Matthew
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BLUETONGUE ,BLUETONGUE virus ,ANIMAL diseases ,RUMINANTS ,CULICOIDES ,INFECTIOUS disease transmission - Abstract
Bluetongue, a devastating disease of ruminants, has historically made only brief, sporadic incursions into the fringes of Europe. However, since 1998, six strains of bluetongue virus have spread across 12 countries and 800 km further north in Europe than has previously been reported. We suggest that this spread has been driven by recent changes in European climate that have allowed increased virus persistence during winter, the northward expansion of Culicoides imicola, the main bluetongue virus vector, and, beyond this vector's range, transmission by indigenous European Culicoides species — thereby expanding the risk of transmission over larger geographical regions. Understanding this sequence of events may help us predict the emergence of other vector-borne pathogens. [ABSTRACT FROM AUTHOR]
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- 2005
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213. Scientists' call to action: Microbes, planetary health, and the Sustainable Development Goals.
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Crowther, Thomas W., Rappuoli, Rino, Corinaldesi, Cinzia, Danovaro, Roberto, Donohue, Timothy J., Huisman, Jef, Stein, Lisa Y., Timmis, James Kenneth, Timmis, Kenneth, Anderson, Matthew Z., Bakken, Lars R., Baylis, Matthew, Behrenfeld, Michael J., Boyd, Philip W., Brettell, Ian, Cavicchioli, Ricardo, Delavaux, Camille S., Foreman, Christine M., Jansson, Janet K., and Koskella, Britt
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SUSTAINABILITY , *SUSTAINABLE development , *MICROBIAL biotechnology , *BIOSPHERE , *FOOD production - Abstract
Microorganisms, including bacteria, archaea, viruses, fungi, and protists, are essential to life on Earth and the functioning of the biosphere. Here, we discuss the key roles of microorganisms in achieving the United Nations Sustainable Development Goals (SDGs), highlighting recent and emerging advances in microbial research and technology that can facilitate our transition toward a sustainable future. Given the central role of microorganisms in the biochemical processing of elements, synthesizing new materials, supporting human health, and facilitating life in managed and natural landscapes, microbial research and technologies are directly or indirectly relevant for achieving each of the SDGs. More importantly, the ubiquitous and global role of microbes means that they present new opportunities for synergistically accelerating progress toward multiple sustainability goals. By effectively managing microbial health, we can achieve solutions that address multiple sustainability targets ranging from climate and human health to food and energy production. Emerging international policy frameworks should reflect the vital importance of microorganisms in achieving a sustainable future. Microbes are essential to life on Earth and will be core, with the advent of exciting new technologies, to our ability to achieve the United Nations Sustainable Development Goals for a sustainable future. [ABSTRACT FROM AUTHOR]
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- 2024
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214. Correction to: Cardinium symbiosis as a potential confounder of mtDNA based phylogeographic inference in Culicoides imicola (Diptera: Ceratopogonidae), a vector of veterinary viruses.
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Pilgrim, Jack, Siozios, Stefanos, Baylis, Matthew, Venter, Gert, Garros, Claire, and Hurst, Gregory D. D.
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CERATOPOGONIDAE ,DIPTERA ,MITOCHONDRIAL DNA ,SYMBIOSIS ,CULICOIDES - Abstract
An amendment to this paper has been published and can be accessed via the original article. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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215. Sero-surveillance and risk factors for avian influenza and Newcastle disease virus in backyard poultry in Oman
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Al Shekaili, Thunai, Clough, Helen, Ganapathy, Kannan, and Baylis, Matthew
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Food Animals ,Oman ,animal diseases ,Animal Science and Zoology ,Avian influenza ,Survey ,Poultry ,Newcastle disease - Abstract
Avian Influenza (AI) and Newcastle disease (ND) are the most important reportable poultry diseases worldwide. Low pathogenic AI (H9N2) and ND viruses are known to have been circulating in the Middle East, including in Oman, for many decades. However, detailed information on the occurrence of these pathogens is almost completely lacking in Oman. As backyard poultry are not vaccinated against either virus in Oman, this sector is likely to be the most affected poultry production sector for both diseases. Here, in the first survey of AI and ND viruses in backyard poultry in Oman, we report high flock-level seroprevalences of both viruses. Serum and oropharyngeal swabs were taken from 2350 birds in 243 backyard flocks from all regions and governorates of Oman. Information was recorded on location, type of bird and housing type for each sampled farm. Individual bird serum samples were tested using commercial indirect antibody detection ELISA kits. Pooled oropharyngeal samples from each flock were inoculated onto FTA cards and tested by RT-PCR. Samples came from chickens (90.5%), turkeys (2.1%), ducks (6.2%), guinea fowl (0.8%) and geese (0.4%). The bird-level seroprevalence of antibody to AI and ND viruses was 37.5% and 42.1% respectively, and at the flock level it was 84% and 90% respectively. There were statistically significant differences between some different regions of Oman in the seroprevalence of both viruses. Flock-level NDV seropositivity in chickens was significantly associated with AIV seropositivity, and marginally negatively associated with flock size. AIV seropositivity in chickens was marginally negatively associated with altitude. All oropharyngeal samples were negative for both viruses by RT-PCR, consistent with a short duration of infection. This study demonstrates that eight or nine out of ten backyard poultry flocks in Oman are exposed to AI and ND viruses, and may present a risk for infection for the commercial poultry sector in Oman, or wild birds which could carry infection further afield.
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216. Bayesian optimisation of restriction zones for bluetongue control.
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Spooner, Thomas, Jones, Anne E., Fearnley, John, Savani, Rahul, Turner, Joanne, and Baylis, Matthew
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BAYESIAN analysis ,ANIMAL mechanics ,BLUETONGUE ,LIVESTOCK diseases ,CLIMATE change - Abstract
We investigate the restriction of animal movements as a method to control the spread of bluetongue, an infectious disease of livestock that is becoming increasingly prevalent due to the onset of climate change. We derive control policies for the UK that minimise the number of infected farms during an outbreak using Bayesian optimisation and a simulation-based model of BT. Two cases are presented: first, where the region of introduction is randomly selected from England and Wales to find a generalised strategy. This "national" model is shown to be just as effective at subduing the spread of bluetongue as the current strategy of the UK government. Our proposed controls are simpler to implement, affect fewer farms in the process and, in so doing, minimise the potential economic implications. Second, we consider policies that are tailored to the specific region in which the first infection was detected. Seven different regions in the UK were explored and improvements in efficiency from the use of specialised policies presented. As a consequence of the increasing temperatures associated with climate change, efficient control measures for vector-borne diseases such as this are expected to become increasingly important. Our work demonstrates the potential value of using Bayesian optimisation in developing cost-effective disease management strategies. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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217. FORTEAN TRAVELLER.
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BAYLIS, MATTHEW
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TRAVEL - Abstract
The article presents a discussion of the author's travel experience at the Pacific island of Tanna in Vanuatu, adapted from the book "Man Belong Mrs Queen: Adventures With The Philip Worshippers by," Matthew Baylis.
- Published
- 2013
218. Cardinium symbiosis as a potential confounder of mtDNA based phylogeographic inference in Culicoides imicola (Diptera: Ceratopogonidae), a vector of veterinary viruses.
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Pilgrim, Jack, Siozios, Stefanos, Baylis, Matthew, Venter, Gert, Garros, Claire, and Hurst, Gregory D. D.
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CULICOIDES , *CERATOPOGONIDAE , *MITOCHONDRIAL DNA , *DIPTERA , *CYTOCHROME oxidase , *SOUTH Africans , *LINKAGE disequilibrium - Abstract
Background: Culicoides imicola (Diptera: Ceratopogonidae) is an important Afrotropical and Palearctic vector of disease, transmitting viruses of animal health and economic significance including African horse sickness and bluetongue viruses. Maternally inherited symbiotic bacteria (endosymbionts) of arthropods can alter the frequency of COI (cytochrome c oxidase subunit I) mitochondrial haplotypes (mitotypes) in a population, masking the true patterns of host movement and gene flow. Thus, this study aimed to assess the mtDNA structure of C. imicola in relation to infection with Candidatus Cardinum hertigii (Bacteroides), a common endosymbiont of Culicoides spp. Methods: Using haplotype network analysis, COI Sanger sequences from Cardinium-infected and -uninfected C. imicola individuals were first compared in a population from South Africa. The network was then extended to include mitotypes from a geographic range where Cardinium infection has previously been investigated. Results: The mitotype network of the South African population demonstrated the presence of two broad mitotype groups. All Cardinium-infected specimens fell into one group (Fisher's exact test, P = 0.00071) demonstrating a linkage disequilibrium between endosymbiont and mitochondria. Furthermore, by extending this haplotype network to include other C. imicola populations from the Mediterranean basin, we revealed mitotype variation between the Eastern and Western Mediterranean basins (EMB and WMB) mirrored Cardinium-infection heterogeneity. Conclusions: These observations suggest that the linkage disequilibrium of Cardinium and mitochondria reflects endosymbiont gene flow within the Mediterranean basin but may not assist in elucidating host gene flow. Subsequently, we urge caution on the single usage of the COI marker to determine population structure and movement in C. imicola and instead suggest the complementary utilisation of additional molecular markers. [ABSTRACT FROM AUTHOR]
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- 2021
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219. Evaluation of the vector competence of a native UK mosquito Ochlerotatus detritus (Aedes detritus) for dengue, chikungunya and West Nile viruses
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Blagrove, Marcus SC, Sherlock, Ken, Chapman, Gail E, Impoinvil, Daniel E, McCall, Philip J, Medlock, Jolyon M, Lycett, Gareth, Solomon, Tom, and Baylis, Matthew
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Infectious Diseases ,viruses ,parasitic diseases ,fungi ,virus diseases ,Parasitology - Full Text
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220. The challenges posed by equine arboviruses
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Chapman, Gail Elaine, Baylis, Matthew, Archer, Debra, Daly, Janet M., Chapman, Gail Elaine, Baylis, Matthew, Archer, Debra, and Daly, Janet M.
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Equine populations worldwide are at increasing risk of infection by viruses transmitted by biting arthropods including mosquitoes, biting midges (Culicoides), sandflies and ticks. These include the flaviviruses (Japanese encephalitis, West Nile and Murray Valley encephalitis), alphaviruses (eastern, western and Venezuelan encephalitis) and the orbiviruses (African horse sickness and equine encephalosis). This review provides an overview of the challenges faced in the surveillance, prevention and control of the major equine arboviruses, particularly in the context of these viruses emerging in new regions of the world.
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221. The challenges posed by equine arboviruses
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Chapman, Gail Elaine, Baylis, Matthew, Archer, Debra, Daly, Janet M., Chapman, Gail Elaine, Baylis, Matthew, Archer, Debra, and Daly, Janet M.
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Equine populations worldwide are at increasing risk of infection by viruses transmitted by biting arthropods including mosquitoes, biting midges (Culicoides), sandflies and ticks. These include the flaviviruses (Japanese encephalitis, West Nile and Murray Valley encephalitis), alphaviruses (eastern, western and Venezuelan encephalitis) and the orbiviruses (African horse sickness and equine encephalosis). This review provides an overview of the challenges faced in the surveillance, prevention and control of the major equine arboviruses, particularly in the context of these viruses emerging in new regions of the world.
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222. The challenges posed by equine arboviruses
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Chapman, Gail Elaine, Baylis, Matthew, Archer, Debra, Daly, Janet M., Chapman, Gail Elaine, Baylis, Matthew, Archer, Debra, and Daly, Janet M.
- Abstract
Equine populations worldwide are at increasing risk of infection by viruses transmitted by biting arthropods including mosquitoes, biting midges (Culicoides), sandflies and ticks. These include the flaviviruses (Japanese encephalitis, West Nile and Murray Valley encephalitis), alphaviruses (eastern, western and Venezuelan encephalitis) and the orbiviruses (African horse sickness and equine encephalosis). This review provides an overview of the challenges faced in the surveillance, prevention and control of the major equine arboviruses, particularly in the context of these viruses emerging in new regions of the world.
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223. The challenges posed by equine arboviruses
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Chapman, Gail Elaine, Baylis, Matthew, Archer, Debra, Daly, Janet M., Chapman, Gail Elaine, Baylis, Matthew, Archer, Debra, and Daly, Janet M.
- Abstract
Equine populations worldwide are at increasing risk of infection by viruses transmitted by biting arthropods including mosquitoes, biting midges (Culicoides), sandflies and ticks. These include the flaviviruses (Japanese encephalitis, West Nile and Murray Valley encephalitis), alphaviruses (eastern, western and Venezuelan encephalitis) and the orbiviruses (African horse sickness and equine encephalosis). This review provides an overview of the challenges faced in the surveillance, prevention and control of the major equine arboviruses, particularly in the context of these viruses emerging in new regions of the world.
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224. Field-based assessments of the seasonality of Culexpipiens sensu lato in England: an important enzootic vector of Usutu and West Nile viruses.
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Seechurn, Nicola, Herdman, M. Trent, Hernandez-Colina, Arturo, Vaux, Alexander G. C., Johnston, Colin, Berrell, Morgan, Lopez, Javier, Eckley, Lindsay, Gonzalez-Olvera, Merit, Gillespie, Lisa, Kelly, Paul Pearce, Baylis, Matthew, and Medlock, Jolyon M.
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WEST Nile virus , *CONSCIOUSNESS raising , *AQUATIC habitats , *DISEASE management - Abstract
Background: Usutu virus (USUV), which is closely related to West Nile virus (WNV), sharing a similar ecology and transmission cycle, was first reported in the UK in the southeast of England in 2020. Both USUV and WNV are emerging zoonotic viruses hosted by wild birds. The 2020 finding of USUV in England raised awareness of this virus and highlighted the importance of understanding the seasonality of Culexpipiens sensu lato (Cx. pipiens s.l.), the main enzootic vector of these viruses. Zoos are prime locations for trapping mosquitoes because of their infrastructure, security, and range of vertebrate hosts and aquatic habitats. Methods: Three independent zoo-based case studies at four locations that cover the seasonality of Cx.pipiens s.l. in England were undertaken: (i) London Zoo (Zoological Society London [ZSL]) and surrounding areas, London; (ii) Chester Zoo (Cheshire); (ii) Twycross Zoo (Leicestershire); and (iv) Flamingo Land (zoo; North Yorkshire). Various adult mosquito traps were used to catch adult Cx.pipiens s.l. across seasons. Results: High yields of Cx.pipiens s.l./Culex torrentium were observed in Biogents-Mosquitaire and Center for Disease Control and Prevention Gravid traps in all studies where these traps were used. Mosquito counts varied between sites and between years. Observations of adult Cx.pipiens s.l./Cx. torrentium abundance and modelling studies demonstrated peak adult abundance between late July and early August, with active adult female Cx.pipiens s.l./Cx. torrentium populations between May and September. Conclusions: The information collated in this study illustrates the value of multiple mosquito monitoring approaches in zoos to describe the seasonality of this UK vector across multiple sites in England and provides a framework that can be used for ongoing and future surveillance programmes and disease risk management strategies. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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225. Sheep breed and shearing influences attraction and blood-feeding behaviour of Culicoides (Diptera: Ceratopogonidae) on a UK farm.
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Hope, Andrew, Gubbins, Simon, Sanders, Christopher, Barber, James, Stubbins, Francesca, Baylis, Matthew, and Carpenter, Simon
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SHEEP breeding ,SHEEP-shearing ,CULICOIDES ,ARBOVIRUS diseases ,BLUETONGUE virus ,SCHMALLENBERG virus ,FARMS ,INFECTIOUS disease transmission - Abstract
Background: Culicoides biting midges (Diptera: Ceratopogonidae) are responsible for the biological transmission of arboviruses of international importance between ruminant livestock. These arboviruses include bluetongue virus (BTV) and Schmallenberg virus (SBV), which have emerged in unprecedented outbreaks in northern Europe. The impact of breed and shearing of sheep on Culicoides: host contact rates has not been investigated in detail and has the potential to influence arbovirus transmission and control measures employed to limit spread. Methods: Attraction of Culicoides to Hartline and Hartline/Suffolk cross-breed sheep was compared using 224 drop trap collections over 22 nights and 181 catches from sheared or unsheared Hartline/Suffolk ewes were made over 17 nights to compare Culicoides activity and rates of blood engorgement. Results: A total of 31,314 Culicoides was collected in the two trials and females of the subgenus Avaritia represented over 96.9% of individuals collected. Attraction to breed was dependent upon species of Culicoides and physiological status, with a significantly greater number of individuals collected on the cross-breed sheep. Shearing of sheep did not significantly increase or decrease the number of Culicoides attracted but increased the rate of successful engorgement. Conclusions: Both breed and shearing were shown to influence Culicoides biting rate on sheep. These data are useful in a direct context in understanding the likely impact of control measures against arboviruses including BTV and SBV and additionally in providing data from field-based studies to enable modelling exercises of arbovirus transmission and spread. [ABSTRACT FROM AUTHOR]
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- 2018
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226. The Tissue Tropisms and Transstadial Transmission of a Rickettsia Endosymbiont in the Highland Midge, Culicoides impunctatus (Diptera: Ceratopogonidae).
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Pilgrim, Jack, Siozios, Stefanos, Baylis, Matthew, and Hurst, Gregory D. D.
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CERATOPOGONIDAE , *RICKETTSIA , *CULICOIDES , *DIPTERA , *VIRAL tropism , *MICROBIOLOGY , *ARBOVIRUS diseases - Published
- 2020
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227. Integration of shared-pathogen networks and machine learning reveals the key aspects of zoonoses and predicts mammalian reservoirs.
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Wardeh, Maya, Sharkey, Kieran J., and Baylis, Matthew
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MACHINE learning , *RESERVOIRS , *ZOONOSES , *SIMPLE machines , *ECONOMIC equilibrium - Abstract
Diseases that spread to humans from animals, zoonoses, pose major threats to human health. Identifying animal reservoirs of zoonoses and predicting future outbreaks are increasingly important to human health and well-being and economic stability, particularly where research and resources are limited. Here, we integrate complex networks and machine learning approaches to develop a new approach to identifying reservoirs. An exhaustive dataset of mammal–pathogen interactions was transformed into networks where hosts are linked via their shared pathogens. We present a methodology for identifying important and influential hosts in these networks. Ensemble models linking network characteristics with phylogeny and life-history traits are then employed to predict those key hosts and quantify the roles they undertake in pathogen transmission. Our models reveal drivers explaining host importance and demonstrate how these drivers vary by pathogen taxa. Host importance is further integrated into ensemble models to predict reservoirs of zoonoses of various pathogen taxa and quantify the extent of pathogen sharing between humans and mammals. We establish predictors of reservoirs of zoonoses, showcasing host influence to be a key factor in determining these reservoirs. Finally, we provide new insight into the determinants of zoonosis-sharing, and contrast these determinants across major pathogen taxa. [ABSTRACT FROM AUTHOR]
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- 2020
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228. A non-invasive feather-based methodology for the detection of blood parasites (Haemosporida).
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González-Olvera, Merit, Hernandez-Colina, Arturo, Chantrey, Julian, Allen, Simon, Lopez, Javier, and Baylis, Matthew
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BLOOD parasites , *FEATHERS , *HAEMOSPORIDA , *RARE birds , *DIAGNOSTIC use of polymerase chain reaction ,BIRD infections - Abstract
Blood parasite (haemosporidian) infections are conventionally detected using blood samples; this implies capturing and handling birds to obtain them, which induces stress and causes pain. Feathers have blood vessels, and some blood could be preserved in the feather's shaft after moulting. We used feather DNA for detecting haemosporidians by PCR testing in diverse scenarios. First, haemosporidian DNA was detected in feathers from carcasses of infected birds, proving the feasibility of the approach. Storage temperature affected DNA recovery, with maximum retrieval and haemosporidian detection at the lowest temperature (− 20 °C). All feather types from infected birds kept at optimal conditions yielded haemosporidian DNA. Parasite detection by PCR was correlated with DNA yield, which was significantly higher in heavier birds, flight feathers, and more feathers per pool. Lastly, haemosporidians were detected employing feathers moulted from wild and captive birds to estimate infection prevalence. We show for the first time that using blood from feather shafts for haemosporidian detection can be an advantageous and less invasive alternative to blood sampling if feathers are optimally preserved. This method could contribute to uncovering haemosporidian infections in endangered and elusive birds, and it might facilitate routine screening in captive birds, thereby improving infection detection, prevention, and control. [ABSTRACT FROM AUTHOR]
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- 2023
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229. Validation of fluorescent dust marking of Culicoides biting midges and the design of a self-marking technique
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Kluiters, Georgette, Hunter, Kristina, and Baylis, Matthew
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MRR ,Behavior, Animal ,Research ,Culicoides ,Dust ,Dispersal ,Kaplan-Meier Estimate ,Ceratopogonidae ,Q1 ,complex mixtures ,Insect Vectors ,QH301 ,Infectious Diseases ,Fluorescent ,Animals ,Parasitology ,Marking ,Self-marking ,Mark-release-recapture ,Fluorescent Dyes - Abstract
Background Investigation of insect flight patterns frequently involves the use of dispersal studies. A common method for studying insect dispersal is mark-release-recapture (MRR) techniques using wild-caught insects in their natural environment; however, this requires a suitable marker. At present, no studies have been performed to identify markers that are suitable for use in midges within the Obsoletus Group, and visible by eye or down a light microscope. Methods A series of 11 experiments were undertaken to determine the effectiveness of three colours of Brilliant General Purpose (BGP) fluorescent dusts in marking Culicoides midges. Three areas were focused on: 1) dust properties, 2) the effect on Culicoides, and 3) dust application in the field. Results All three dusts were insoluble in water, 10% washing-up liquid and 70% ethanol. They were visible down a microscope, with and without the use of a black light, and two were highly visible without the need for a microscope. The dusts remained adherent to the marked Culicoides for the duration of the experiments, did not transfer between marked and unmarked individuals or the environment, and remained adherent when the Culicoides were stored in an ethanol or water-based solution. The dusts had no effect on the mortality rate of the insects over the 48 hrs of the experiment. There were no significant differences between the recorded behaviours undertaken by undusted control Culicoides and the BGP fluorescent dusted Culicoides. Field-based marking of Culicoides can be achieved using a ‘self-marking’ technique, whereby the trapping vessel is pre-dusted with fluorescent dust prior to trapping the individuals to be marked. Conclusions This is the first study to identify BGP fluorescent dusts as markers for use with Obsoletus Group Culicoides. BGP fluorescent dusts provide a quick and effective method of marking and identifying Culicoides for both field and laboratory studies. The self-marking technique minimises the time needed to handle specimens prior to release.
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230. Erratum for Graham-Brown et al., “Dairy Heifers Naturally Exposed to Fasciola hepaticaDevelop a Type 2 Immune Response and Concomitant Suppression of Leukocyte Proliferation”
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Graham-Brown, John, Hartley, Catherine, Clough, Helen, Kadioglu, Aras, Baylis, Matthew, and Williams, Diana J. L.
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- 2018
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231. Dairy Heifers Naturally Exposed to Fasciola hepaticaDevelop a Type 2 Immune Response and Concomitant Suppression of Leukocyte Proliferation
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Graham-Brown, John, Hartley, Catherine, Clough, Helen, Kadioglu, Aras, Baylis, Matthew, and Williams, Diana J. L.
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ABSTRACTFasciola hepaticais a parasitic trematode of global importance in livestock. Control strategies reliant on anthelmintics are unsustainable due to the emergence of drug resistance. Vaccines are under development, but efficacies are variable. Evidence from experimental infection suggests that vaccine efficacy may be affected by parasite-induced immunomodulation. Little is known about the immune response to F. hepaticafollowing natural exposure. Hence, we analyzed the immune responses over time in calves naturally exposed to F. hepaticainfection. Cohorts of replacement dairy heifer calves (n= 42) with no prior exposure to F. hepatica, on three commercial dairy farms, were sampled over the course of a grazing season. Exposure was determined through an F. hepatica-specific serum antibody enzyme-linked immunosorbent assay (ELISA) and fluke egg counts. Concurrent changes in peripheral blood leukocyte subpopulations, lymphocyte proliferation, and cytokine responses were measured. Relationships between fluke infection and immune responses were analyzed by using multivariable linear mixed-effect models. All calves from one farm showed evidence of exposure, while cohorts from the remaining two farms remained negative over the grazing season. A type 2 immune response was associated with exposure, with increased interleukin-4 (IL-4) production, IL-5 transcription, and eosinophilia. Suppression of parasite-specific peripheral blood mononuclear cell (PBMC) proliferation was evident, while decreased mitogen-stimulated gamma interferon (IFN-γ) production suggested immunomodulation, which was not restricted to parasite-specific responses. Our findings show that the global immune response is modulated toward a nonproliferative type 2 state following natural challenge with F. hepatica. This has implications in terms of the timing of the administration of vaccination programs and for host susceptibility to coinfecting pathogens.
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- 2017
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232. Seroprevalence of Fasciola hepatica in dairy herds.
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Coles, Gerald, Stafford, Kathryn, Williams, Diana, McCann, Cathy, and Baylis, Matthew
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LETTERS to the editor ,FASCIOLA hepatica - Abstract
A letter to the editor is presented about the seroprevalence of Fasciola hepatica found in milk samples taken from dairy herds in which secreted antigens have been assayed.
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- 2010
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233. Prioritization of livestock diseases by pastoralists in Oloitoktok Sub County, Kajiado County, Kenya.
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Mburu, Caroline M., Bukachi, Salome, Majiwa, Hamilton, Ongore, Dismas, Baylis, Matthew, Mochabo, Kennedy, Fevre, Eric, and Howland, Olivia
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LUMPY skin disease , *FOOT & mouth disease , *FEMALE livestock , *MALE livestock , *LIVESTOCK - Abstract
Introduction: Livestock diseases are a big challenge for the livelihood of pastoralists in sub-Saharan Africa because they reduce livestock productivity and increase mortality. Based on the literature available there is limited understanding on how pastoralists prioritize these diseases in the context of their culture, ecosystems and livelihoods. A study was conducted to provide insights on lay prioritization of animal diseases by pastoralists in Kenya. Methodology: A qualitative study was undertaken between March and July 2021. Thirty in-depth interviews and six focus group discussions (FGDs) were conducted with community members to explore community attitudes on livestock diseases prioritization. Male and female livestock keepers were purposively selected and interviewed and they were all long-term residents of the area. Fourteen key informant interviews (KIIs) were conducted with professionals from different key sectors to provide detailed stakeholder perspectives on livestock diseases. The interviews were analyzed thematically using the QSR Nvivo software to identify the emerging themes related to the study objectives. Results: The pastoralists prioritized livestock diseases based on effect on their economic wellbeing, cultural values and utilization of ecosystem services. There were gender variabilities in how diseases were prioritized among the pastoralists. Men cited high priority diseases as foot and mouth disease and contagious bovine pleuropneumonia due to their regular occurrence and effect on livelihood. Notably, women regarded coenuruses as very important because it affected sheep and goats with a high mortality rate and lumpy skin disease because it rendered the meat from the carcasses inedible. Malignant catarrhal fever and trypanosomiasis were noted as some of the common diseases in the livestock-wildlife interface but not cited as priority diseases. Challenges related to disease control in pastoralist contexts exist including limited access to livestock treatment services, inadequate information on disease impact and complex environmental factors. Conclusion: This study sheds light on the body of knowledge in Kenya regarding livestock diseases and their prioritization by livestock keepers. This could aid in the development of a common disease control framework and prioritization at the local level which would take into consideration the dynamic socio-cultural, ecological, livelihood and economic contexts of the communities. [ABSTRACT FROM AUTHOR]
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- 2023
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234. Development and validation of a protocol to identify and recruit participants into a large scale study on liver fluke in cattle.
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McCann, Catherine M., Clough, Helen E., Baylis, Matthew, and Williams, Diana J. L.
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Background: Liver fluke infection caused by the parasite Fasciola hepatica is a major cause of production losses to the cattle industry in the UK. To investigate farm-level risk factors for fluke infection, a randomised method to recruit an appropriate number of herds from a defined geographical area into the study was required. The approach and hurdles that were encountered in designing and implementing this study are described. The county of Shropshire, England, was selected for the study because of the variation between farms in exposure to fluke infection observed in an earlier study. Results: From a sampling list of 569 holdings in Shropshire randomly drawn from the RADAR cattle population dataset, 396 (69.6%) holdings were successfully contacted by telephone and asked if they would be interested in taking part in the study. Of 296 farmers who agreed to receive information packs by post, 195 (65.9%) agreed to take part in the study. Over the period October 2014 – April 2015 visits were made to 100 dairy and 95 non-dairy herds. During the farm visits 40 faecal samples +/− bulk-tank milk samples were collected and a questionnaire administered. Composite faecal samp leswereanalysedforthepresenceof F. hepatica eggs by sedimentation andbulktankmilksamplesweretestedwithanantibodyELISAfor F. hepatica . Forty-five (49%) of non-dairy herds were positive for liver fluke infection as determined by the finding of one or more fluke eggs, while 36 (36%) dairy herds had fluke positive faecal samples and 41 (41%) dairy herds were positive for F. hepatica antibody. Eighty-seven (45.8%) farmers said that they monitored their cattle for liver fluke infection and 118 (62.1%) reported that they used flukicide drugs in their cattle. Conclusions: Using a protocol of contacting farmers directly by telephone and subsequently sending information by post, 79% of the target sample size was successfully recruited into the study. A dataset of farm-specific information on possible risk factors for liver fluke infection and corresp onding liver-fluke infection status was generated for the development of statistical models to identify risk factors for liver fluke infection at the farm-level. [ABSTRACT FROM AUTHOR]
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- 2018
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235. Spatiotemporal activity of the Ixodes ricinus tick in England
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McGinley, Liz, Morse, Andy, Medlock, Jolyon, Baylis, Matthew, and Torr, Steve
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616.9 - Abstract
The Ixodes ricinus tick is an opportunistic, generalist species, capable of feeding on multiple hosts. It is the vector of several pathogens of human and veterinary concern. In the UK, this tick is the primary vector of Borrelia burgdorferi sensu lato, the causative bacterial agent of Lyme borreliosis. In recent years, the number of laboratory confirmed cases of Lyme borreliosis has increased in the UK, potentially due to an increased awareness of the disease or possibly of a change in the distribution or epidemiology of the pathogen. The aim of this research was to investigate the spatiotemporal activity of this tick and identify key weather and microclimate related variables which influence seasonal increases in its host seeking behaviour. This was achieved by deploying a comprehensive field monitoring strategy where multiple sites were monitored for I. ricinus activity over a number of years. The seasonality of I. ricinus activity was analysed alongside localised weather data to determine if specific weather related cues were associated with increases and declines in host seeking behaviour. Additionally, I. ricinus specimens collected from different locations during the study were analysed for the presence of Borrelia burgdorferi sensu lato. Peak I. ricinus nymphal questing activity in spring was found to be associated with seven consecutive days of mean temperature of ≥ 7 °C, while an increase in potential evapotranspiration towards 25 mm/week was associated with a decline in host seeking activity following spring peak. Investigations of Borrelia burgdorferi sensu lato infection in I. ricinus specimens, confirmed the widespread geographical distribution of this bacterial complex, and the presence of several genospecies of human pathogenic potential.
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- 2019
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236. Climate change and the recent emergence of bluetongue in Europe.
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Purse, Bethan V., Mellor, Phillip S., Rogers, David J., Samuel, Alan R., Mertens, Peter P.C., and Baylis, Matthew
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CLIMATE change - Abstract
A correction to the article "Climate Change and the Recent Emergence of Bluetongue in Europe." that the was published in the previews issue of Nature Reviews Microbiology.
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- 2006
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237. The epidemiology and surveillance of Culicoides-borne diseases of ruminants in the UK
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Stokes, J. E., Baylis, Matthew, Duncan, Jennifer, and Hiscox, Julian
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636.2 - Abstract
Between 2006 and 2011 two Culicoides-borne diseases of ruminants emerged in Europe: bluetongue virus serotype-8 (BTV-8) and Schmallenberg virus (SBV). This thesis sought to answer questions arising from this developing disease landscape, to better inform policymakers, stakeholder groups and disease modellers. SBV spread rapidly through Europe, reaching the UK in January 2012. However, in 2014 no cases were reported. It was unknown if this was a lack of circulation, or a lack of reporting. A freedom from disease study was designed. 1444 sheep, born between October 2014 and April 2015, were sampled from 131 farms from Cornwall to Kent. Samples were tested by ELISA for antibodies against SBV, 5 positive samples were confirmed negative by VNT. Circulation of SBV in 2015 in the south of England was concluded to have been unlikely. Like SBV, BTV-8 had circulated throughout Europe, only to be controlled by movement restrictions and vaccination. Subsequently, Europe was declared BTV-8 free in 2010 and vaccination production halted. In 2015 BTV-8 re-emerged in Europe. An online questionnaire determined that respondents from smaller farms, those that had previously vaccinated against BTV-8 and those who were deemed to be ‘risk adverse’ were all more likely to want to vaccinate, and more willing to pay more to vaccinate. Voluntary vaccination only achieved an 80% uptake if vaccination was free and after BTV-8 cases were reported in the UK despite 90% of farmer respondents stating they believed it important to keep BTV-8 out of the UK. Not all farmers vaccinated all of their flock/herd previously. This survey highlights the complex issues surrounding voluntary vaccination at the farm perceived risk versus cost level. The mechanisms for how either virus successfully overwintered are still poorly understood. A cross-sectional study demonstrated that Culicoides vectors are active during peak lambing periods inside lambing sheds. A longitudinal study the following lambing season demonstrated that Culicoides were more abundant indoors than outdoors, and demonstrated activity of gravid and parous Culicoides over the winter. This demonstrates a possible mechanism for overwintering of BTV-8 and SBV in the south of England. SBV re-emerged in 2016. A questionnaire was designed to determine the impact of SBV on the 2016/2017 lambing period. The impact was found to be highly comparable to a previous study of the 2012/2013 outbreak. Additionally SBV confirmed and suspected farms were more likely to have mated earlier in the season. If SBV continues to re-emerge cyclically then the impact of disease will continue to be significant unless intervention is taken. These studies have added to our understanding of, and farmer response to, the SBV and BTV-8 outbreaks, and added to policymakers, stakeholders groups and disease modellers knowledge.
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- 2018
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238. Blue Tongue.
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MELLOR, Philip, BAYLIS, Matthew, and MERTENS, Peter
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- 2009
239. Assessing the risk of bluetongue to UK livestock: uncertainty and sensitivity analyses of a temperature-dependent model for the basic reproduction number
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Gubbins, Simon, Carpenter, Simon, Baylis, Matthew, Wood, James L.N, and Mellor, Philip S
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- 2008
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240. Immune responses and interactions following simultaneous application of live Newcastle disease, infectious bronchitis and avian metapneumovirus vaccines in specific-pathogen-free chicks.
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Awad, Faez, Forrester, Anne, Baylis, Matthew, Lemiere, Stephane, Jones, Richard, and Ganapathy, Kannan
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IMMUNE response , *NEWCASTLE disease , *AVIAN infectious bronchitis virus , *HUMAN metapneumovirus infection , *VIRAL vaccines , *PATHOGENIC microorganisms , *CHICKS , *PHYSIOLOGY - Abstract
Interactions between live Newcastle disease virus (NDV), avian metapneumovirus (aMPV) and infectious bronchitis virus (IBV) vaccines following simultaneous vaccination of day old specific pathogen free (SPF) chicks were evaluated. The chicks were divided into eight groups: seven vaccinated against NDV, aMPV and IBV (single, dual or triple) and one unvaccinated as control. Haemagglutination inhibition (HI) NDV antibody titres were similar across all groups but were above protective titres. aMPV vaccine when given with other live vaccines suppressed levels of aMPV enzyme-linked immunosorbent assay (ELISA) antibodies. Cellular and local immunity induced by administration of NDV, aMPV or IBV vaccines (individually or together) showed significant increase in CD4+, CD8+ and IgA bearing B-cells in the trachea compared to the unvaccinated group. Differences between the vaccinated groups were insignificant. Simultaneous vaccination with live NDV, aMPV and IBV did not affect the protection conferred against aMPV or IBV. [ABSTRACT FROM AUTHOR]
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- 2015
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241. Modelling the continental-scale spread of Schmallenberg virus in Europe: Approaches and challenges.
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Gubbins, Simon, Richardson, Jane, Baylis, Matthew, Wilson, Anthony J., and Abrahantes, José Cortiñas
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BUNYAVIRUSES , *CULICOIDES , *VIRUS disease transmission , *PANDEMICS , *INFLUENZA transmission , *INSECT bites & stings - Abstract
Summary Following its emergence in northern Europe in 2011 Schmallenberg virus (SBV), a vector-borne disease transmitted by the bites of Culicoides midges, has spread across much of the continent. Here we develop simple models to describe the spread of SBV at a continental scale and, more specifically, within and between NUTS2 regions in Europe. The model for the transmission of SBV between regions suggests that vector dispersal is the principle mechanism for transmission, even at the continental scale. The within-region model indicates that there is substantial heterogeneity amongst regions in the force of infection for cattle and sheep farms. Moreover, there is considerable under-ascertainment of SBV-affected holdings, though the level of under-ascertainment varies between regions. We contrast the relatively simple approach adopted in this study with the more complex continental-scale micro-simulation models which have been developed for pandemic influenza and discuss the strengths, weaknesses and data requirements of both approaches. [ABSTRACT FROM AUTHOR]
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- 2014
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242. Inferences about the transmission of Schmallenberg virus within and between farms.
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Gubbins, Simon, Turner, Joanne, Baylis, Matthew, van der Stede, Yves, van Schaik, Gerdien, Abrahantes, José Cortiñas, and Wilson, Anthony J.
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VIRUS disease transmission , *BUNYAVIRUSES , *SEROPREVALENCE , *SHEEP ranches , *BAYESIAN analysis - Abstract
In the summer of 2011 Schmallenberg virus (SBV), a Culicoides -borne orthobunyavirus, emerged in Germany and The Netherlands and subsequently spread across much of Europe. To draw inferences about the transmission of SBV we have developed two models to describe its spread within and between farms. The within-farm model was fitted to seroprevalence data for cattle and sheep farms in Belgium and The Netherlands, with parameters estimated using approximate Bayesian computation. Despite the short duration of viraemia in cattle and sheep (mean of 3–4 days) the within-farm seroprevalence can reach high levels (mean within-herd seroprevalence >80%), largely because the probability of transmission from host to vector is high (14%) and SBV is able to replicate quickly (0.03 per day-degree) and at relatively low temperatures (threshold for replication: 12.3 °C). Parameter estimates from the within-farm model were then used in a separate between-farm model to simulate the regional spread of SBV. This showed that the rapid spread of SBV at a regional level is primarily a consequence of the high probability of transmission from host to vector and the temperature requirements for virus replication. Our results, obtained for a region of the UK in a typical year with regard to animal movements, indicate that there is no need to invoke additional transmission mechanisms to explain the observed patterns of rapid spread of SBV in Europe. Moreover, the imposition of movement restrictions, even a total movement ban, has little effect on the spread of SBV at this scale. [ABSTRACT FROM AUTHOR]
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- 2014
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243. Assessing the impact of non-pharmaceutical interventions (NPI) on the dynamics of COVID-19: A mathematical modelling study of the case of Ethiopia.
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Ejigu, Bedilu Alamirie, Asfaw, Manalebish Debalike, Cavalerie, Lisa, Abebaw, Tilahun, Nanyingi, Mark, and Baylis, Matthew
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COVID-19 pandemic , *CONTINUOUS time models , *CITY dwellers , *SOCIAL distancing , *HAND washing - Abstract
The World Health Organization (WHO) declared COVID-19 a pandemic on March 11, 2020 and by November 14, 2020 there were 53.3M confirmed cases and 1.3M reported deaths in the world. In the same period, Ethiopia reported 102K cases and 1.5K deaths. Effective public health preparedness and response to COVID-19 requires timely projections of the time and size of the peak of the outbreak. Currently, Ethiopia under the COVAX facility has begun vaccinating high risk populations but due to vaccine supply shortages and the absence of an effective treatment, the implementation of NPIs (non-pharmaceutical interventions), like hand washing, wearing face coverings or social distancing, still remain the most effective methods of controlling the pandemic as recommended by WHO. This study proposes a modified Susceptible Exposed Infected and Recovered (SEIR) model to predict the number of COVID-19 cases at different stages of the disease under the implementation of NPIs at different adherence levels in both urban and rural settings of Ethiopia. To estimate the number of cases and their peak time, 30 different scenarios were simulated. The results indicated that the peak time of the pandemic is different in urban and rural populations of Ethiopia. In the urban population, under moderate implementation of three NPIs the pandemic will be expected to reach its peak in December, 2020 with 147,972 cases, of which 18,100 are symptomatic and 957 will require admission to an Intensive Care Unit (ICU). Among the implemented NPIs, increasing the coverage of wearing masks by 10% could reduce the number of new cases on average by one-fifth in urban-populations. Varying the coverage of wearing masks in rural populations minimally reduces the number of cases. In conclusion, the models indicate that the projected number of hospital cases during the peak time is higher than the Ethiopian health system capacity. To contain symptomatic and ICU cases within the health system capacity, the government should pay attention to the strict implementation of the existing NPIs or impose additional public health measures. [ABSTRACT FROM AUTHOR]
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- 2021
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244. Blood-feeding ecology of mosquitoes in two zoological gardens in the United Kingdom.
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Hernandez-Colina, Arturo, Gonzalez-Olvera, Merit, Lomax, Emily, Townsend, Freya, Maddox, Amber, Hesson, Jenny C., Sherlock, Kenneth, Ward, Dawn, Eckley, Lindsay, Vercoe, Mark, Lopez, Javier, and Baylis, Matthew
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ZOOS , *ENDEMIC animals , *MOSQUITOES , *EXOTIC animals , *AVIAN malaria , *CULEX pipiens , *AEDES aegypti , *MALARIA - Abstract
Background: Zoological gardens contain unique configurations of exotic and endemic animals and plants that create a diverse range of developing sites and potential sources of blood meals for local mosquitoes. This may imply unusual interspecific pathogen transmission risks involving zoo vertebrates, like avian malaria to captive penguins. Understanding mosquito ecology and host feeding patterns is necessary to improve mosquito control and disease prevention measures in these environments. Methods: Mosquito sampling took place in Chester Zoo for 3 years (2017, 2018, and 2019) and for 1 year in Flamingo Land (2017) using different trapping methods. Blood-fed mosquitoes were identified and their blood meal was amplified by PCR, sequenced, and blasted for host species identification. Results: In total, 640 blood-fed mosquitoes were collected [Culex pipiens (n = 497), Culiseta annulata (n = 81), Anopheles maculipennis s.l. (n = 7), An. claviger (n = 1), and unidentifiable (n = 55)]. Successful identification of the host species was achieved from 159 blood-fed mosquitoes. Mosquitoes fed on birds (n = 74), non-human mammals (n = 20), and humans (n = 71). There were mixed blood meals from two hosts (n = 6). The proportions of blood-fed mosquitoes varied across sampling seasons and sites within the zoos. The use of resting traps and aspiration of vegetation were more efficient techniques for capturing blood-fed mosquitoes than traps for host-seeking or gravid mosquitoes. By relating the locations of zoo vertebrates to where fed mosquitoes were trapped, the minimum travelling distances were calculated (13.7 to 366.7 m). Temperature, precipitation, relative humidity, proximity to zoo vertebrate exhibits, and vegetation level were found to be significantly associated with the proportion of captured blood-fed mosquitoes by generalized linear modelling. Conclusions: Mosquito feeding behaviour in zoos is mainly influenced by time, location (sampling area), temperature, and host availability, which highlights the value of mosquito monitoring in complex settings to plan control strategies and potentially reduce inherent disease transmission risks for humans and threatened zoo vertebrates. [ABSTRACT FROM AUTHOR]
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- 2021
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245. One hundred years of zoonoses research in the Horn of Africa: A scoping review.
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Cavalerie, Lisa, Wardeh, Maya, Lebrasseur, Ophélie, Nanyingi, Mark, McIntyre, K. Marie, Kaba, Mirgissa, Asrat, Daniel, Christley, Robert, Pinchbeck, Gina, Baylis, Matthew, and Mor, Siobhan M.
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ZOONOSES , *AVIAN influenza , *Q fever , *POOR communities , *ONLINE databases - Abstract
Background: One Health is particularly relevant to the Horn of Africa where many people's livelihoods are highly dependent on livestock and their shared environment. In this context, zoonoses may have a dramatic impact on both human and animal health, but also on country economies. This scoping review aimed to characterise and evaluate the nature of zoonotic disease research in the Horn region. Specifically, it addressed the following questions: (i) what specific zoonotic diseases have been prioritised for research, (ii) what data have been reported (human, animal or environment), (iii) what methods have been applied, and (iv) who has been the doing the research? Methodology/principal findings: We used keyword combinations to search online databases for peer-reviewed papers and theses. Screening and data extraction (disease, country, domain and method) was performed using DistillerSR. A total of 2055 studies focusing on seven countries and over 60 zoonoses were included. Brucellosis attracted the highest attention in terms of research while anthrax, Q fever and leptospirosis have been comparatively under-studied. Research efforts did not always align with zoonoses priorities identified at national levels. Despite zoonoses being a clear target for One Health research, a very limited proportion of studies report data on the three domains of human, animal and environment. Descriptive and observational epidemiological studies were dominant and only a low proportion of publications were multidisciplinary. Finally, we found that a minority of international collaborations were between Global South countries with a high proportion of authors having affiliations from outside the Horn of Africa. Conclusions/significance: There is a growing interest in zoonoses research in the Horn of Africa. Recommendations arising from this scoping review include: (i) ensuring zoonoses research aligns with national and global research agendas; (ii) encouraging researchers to adopt a holistic, transdisciplinary One Health approach following high quality reporting standards (COHERE, PRISMA, etc.); and (iii) empowering local researchers supported by regional and international partnerships to engage in zoonoses research. Author summary: Zoonoses are diseases that are transmissible between animals and humans. Some emerging or re-emerging zoonoses, like avian influenza, regularly make the headlines in international media. Others, like rabies or echinococcosis, which mainly affect poor communities, attract much less attention, and are considered neglected by the World Health Organisation (WHO). In the Horn of Africa, many people live in close proximity to livestock and depend on them for food and income. Their constant interaction with animals increases the risk of contracting zoonoses. In our work, we have searched for existing research publications on zoonoses in the Horn of Africa to guide future research on most neglected areas. Based on 2055 publications, we have described which zoonoses have been studied where and using which method. Notably, we found that very limited research followed One Health approaches. That implies that separate focus was given to animals or humans and a single method or discipline was used, while the One Health approach advocates for multidisciplinary and multisectoral collaboration to address complex issues like zoonoses. Finally, we identified that a majority of authors were affiliated with countries from the Global North which hinders relevance, equity and sustainability of Global North-Global South research collaborations. [ABSTRACT FROM AUTHOR]
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- 2021
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246. Determining and modelling the Bluetongue vector landscape
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Kluiters, Georgette, Baylis, Matthew, and Read, Jonathan
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614.4 ,SF Animal culture - Abstract
Bluetongue (BT) is a seasonal vector-borne, viral, disease that causes significant economic and welfare problems in ruminants. It is transmitted by species of Culicoides midges (Diptera: Ceratopogonidae), and as such, the distribution of the disease is restricted to regions where the vectors are present. Once restricted to tropical and subtropical regions of the world, serotypes of BT have been causing outbreaks in southern Europe, following its introduction in 1998, and in 2006, BT serotype-8 emerged in northern Europe, causing devastating economic, welfare and production consequences. The northwards expansion of BT has been attributed to a shift in the geographic limit of the Culicoides imicola Meigen vector, and the involvement of the newly implicated Palaearctic vectors, the Obsoletus and Pulicaris Groups. Little is known about the ecological characteristics of the newly implicated vectors, or indeed those believed to be non-vectors, including their distribution and abundance, making disease risk assessment and management difficult. Within this thesis, a series of field experiments were initiated on a group of farms to gain insight into the distribution and abundance of Culicoides species. The results highlighted that a very high level of variation is seen when trapping Culicoides at the local-scale, yet it is possible to build a strong model explaining this variation using a mixture of host and environmental variables, with satellite-derived ecological correlates. This high level of variation in midge catches present between farms undermines attempts to record their nationwide distribution in larger scale models. The results uniquely model Obsoletus Group abundance, and highlight a difference in host involvement between vector and non-vector models. Further field studies which showed a lack of significant variation both between years and at the within-farm level highlight the robustness of this model in predicting the distribution of the BT vectors species, such that it could prove useful for exploring targeted surveillance and control methods. Culicoides distributions do not remain static, therefore an understanding of their flight behaviour is critical to determining the distance over which an insect may transmit a disease agent and the size of the area over which control should be applied. Laboratory studies were undertaken to validate the use of commercial fluorescent dusts as a quick and effective method of marking Culicoides for both field and laboratory studies, and a ‘self-marking’ technique was conceived. Dispersal studies, using the dusts, determined the distances that Obsoletus Group females and males, as well as C. pulicaris females, are able to disperse over a set period of time. This knowledge of flight speed and distance is of utmost value as a critical component in the modelling of BT disease and other Culicoides-borne diseases. The Obsoletus Group contains four members (C. obsoletus, C. scoticus, C. chiopterus and C. dewulfi¬) which are difficult to differentiate down a microscope. Using morphometric analyses, female C. obsoletus and C. scoticus individuals could be separated under a stereomicroscope based on abdominal measurements. Studies such as those contained in this thesis, therefore, are of utmost value in providing information on critical components in the modelling of BT disease and other Culicoides-borne diseases.
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- 2014
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247. Quantifying uncertainty in climate-driven disease risk predictions
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MacLeod, David, Morse, Andrew, and Baylis, Matthew
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550 ,G Geography (General) - Abstract
This thesis considers the uncertainty in forecasts of climate-driven disease risk, focusing on seasonal and decadal timescales. An analysis of the skill of decadal climate predictions is carried out, looking at the first multi-model decadal hindcast set produced as part of the ENSEMBLES project. Some skill in the prediction of global average temperature trends over the forthcoming decade is shown, with no skill evident for precipitation. Focusing on smaller areas shows limited skill in predicting temperature trends and no skill for precipitation trends, suggesting that decadal climate models cannot currently make useful predictions of disease risk. Seasonal climate forecasting skill is then considered. Seasonal hindcasts produced by two research projects, DEMETER and ENSEMBLES, are compared with the most recent version of the European Centre for Medium-Range Weather Forecast’s seasonal forecast model, System 4. The models are validated over Africa and the Indian subcontinent, and it is shown that in general System 4 forecasts are an improvement over the DEMETER and ENSEMBLES multimodel ensembles, particularly for West Africa. A more in depth study of System 4 is subsequently carried out, comparing the variation in skill between forecast start dates. Forecast value is demonstrated at multiple lead times, with most skill found for West African regions and Botswana and limited skill for India; indicating when and where forecasts can potentially be issued to users. Forecasting malaria is then studied by using Liverpool Malaria Model (LMM) driven by System 4. Skill is demonstrated over Botswana, particularly for forecasts issued in November, validating against laboratory confirmed cases of malaria. This is an improvement on previous work where the LMM was driven with the DEMETER seasonal hindcasts. Where malaria data is not available, System 4-driven LMM hindcasts are compared to LMM driven by ERA-Interim in a tier-2 validation context. Skill is demonstrated at the epidemic fringe of the Sahel and in north west Malawi, whilst the Gulf of Guinea shows no skill. This is consistent with previous work suggesting the LMM performs better in epidemic than in endemic regions. A method for interpreting hindcast validation results as uncertainty quantification is then presented. Finally, the uncertainty in the relationship between seasonal average climate and malaria risk is analysed, using the LMM driven by the 20th century reanalysis dataset. The relationship parameters describing seasonal average climate and malaria risk is explored and impact surfaces are created, relating seasonal average temperature and precipitation to average seasonal malaria incidence. The robustness of these impact surfaces is investigated by comparing the surfaces associated with different LMM survival schemes. A method of combining impact surfaces based on tercile categories is described and implemented and it is demonstrated how the resulting graphic could be integrated with a seasonal ensemble forecast system. Such a tool is potentially useful for decision-makers, allowing an intuitive visual communication of the quantified uncertainty in predicting climate-driven disease risk at seasonal timescales.
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- 2013
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248. Assessing the suitability for Aedes albopictus and dengue transmission risk in China with a delay differential equation model.
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Metelmann, Soeren, Liu, Xiaobo, Lu, Liang, Caminade, Cyril, Liu, Keke, Cao, Lina, Medlock, Jolyon M., Baylis, Matthew, Morse, Andrew P., and Liu, Qiyong
- Subjects
- *
DELAY differential equations , *AEDES albopictus , *DENGUE , *DENGUE viruses , *CLIMATIC zones - Abstract
Dengue is considered non-endemic to mainland China. However, travellers frequently import the virus from overseas and local mosquito species can then spread the disease in the population. As a consequence, mainland China still experiences large dengue outbreaks. Temperature plays a key role in these outbreaks: it affects the development and survival of the vector and the replication rate of the virus. To better understand its implication in the transmission risk of dengue, we developed a delay differential equation model that explicitly simulates temperature-dependent development periods and tested it with collected field data for the Asian tiger mosquito, Aedes albopictus. The model predicts mosquito occurrence locations with a high accuracy (Cohen's κ of 0.78) and realistically replicates mosquito population dynamics. Analysing the infection dynamics during the 2014 dengue outbreak that occurred in Guangzhou showed that the outbreak could have lasted for another four weeks if mosquito control interventions had not been undertaken. Finally, we analyse the dengue transmission risk in mainland China. We find that southern China, including Guangzhou, can have more than seven months of dengue transmission per year while even Beijing, in the temperate north, can have dengue transmission during hot summer months. The results demonstrate the importance of using detailed vector and infection ecology, especially when vector-borne disease transmission risk is modelled over a broad range of climatic zones. Author summary: Dengue is a mosquito-borne disease and the transmission of its virus depends on four factors: The presence of 1) the virus, 2) the human host, 3) the mosquito vector, and 4) the suitability of environmental conditions. Mainland China faces regular dengue outbreaks. Because the virus is constantly imported by infected travellers into the susceptible populations of Chinese metropolises, factors 1) and 2) are almost always met. We now investigate factors 3) and 4) to see when and where the risk for outbreaks is greatest. We use a novel model that considers the development of both the mosquitoes and the viruses under different climate conditions. Our findings suggest that the Asian tiger mosquito (Aedes albopictus) can potentially transmit dengue virus over large parts of mainland China; the biggest transmission risk is simulated over southern China where large outbreaks have occurred historically, but also over the temperate north, as far as Beijing, where smaller dengue outbreaks could occur during hot summer months. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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249. Torix Rickettsia are widespread in arthropods and reflect a neglected symbiosis.
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Pilgrim, Jack, Thongprem, Panupong, Davison, Helen R, Siozios, Stefanos, Baylis, Matthew, Zakharov, Evgeny V, Ratnasingham, Sujeevan, deWaard, Jeremy R, Macadam, Craig R, Smith, M Alex, and Hurst, Gregory D D
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- *
RICKETTSIA , *MITOCHONDRIAL DNA , *AQUATIC insects , *AQUATIC invertebrates , *STINKBUGS , *SYMBIOSIS , *DISEASE vectors , *ARTHROPODA - Abstract
Background Rickettsia are intracellular bacteria best known as the causative agents of human and animal diseases. Although these medically important Rickettsia are often transmitted via haematophagous arthropods, other Rickettsia , such as those in the Torix group, appear to reside exclusively in invertebrates and protists with no secondary vertebrate host. Importantly, little is known about the diversity or host range of Torix group Rickettsia. Results This study describes the serendipitous discovery of Rickettsia amplicons in the Barcode of Life Data System (BOLD), a sequence database specifically designed for the curation of mitochondrial DNA barcodes. Of 184,585 barcode sequences analysed, Rickettsia is observed in ∼0.41% of barcode submissions and is more likely to be found than Wolbachia (0.17%). The Torix group of Rickettsia are shown to account for 95% of all unintended amplifications from the genus. A further targeted PCR screen of 1,612 individuals from 169 terrestrial and aquatic invertebrate species identified mostly Torix strains and supports the "aquatic hot spot" hypothesis for Torix infection. Furthermore, the analysis of 1,341 SRA deposits indicates that Torix infections represent a significant proportion of all Rickettsia symbioses found in arthropod genome projects. Conclusions This study supports a previous hypothesis that suggests that Torix Rickettsia are overrepresented in aquatic insects. In addition, multiple methods reveal further putative hot spots of Torix Rickettsia infection, including in phloem-feeding bugs, parasitoid wasps, spiders, and vectors of disease. The unknown host effects and transmission strategies of these endosymbionts make these newly discovered associations important to inform future directions of investigation involving the understudied Torix Rickettsia. [ABSTRACT FROM AUTHOR]
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- 2021
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250. Does Fasciola hepatica infection increase the susceptibility of cattle to infection with other pathogens normally controlled by a Th1 or pro-inflammatory response?
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Claridge, Jennifer, Williams, Diana, and Baylis, Matthew
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636.2 - Abstract
Fasciola hepatica is a trematode parasite with wide geographical and host ranges, primarily affecting ruminants in the United Kingdom. Infection of host animals leads to significant economic losses in production, with reduced weight gains and milk quality and quantity. Clinical disease, known as fasciolosis, is expensive to treat and causes significant morbidity and mortality. More than three quarters of dairy herds surveyed in England and Wales have been exposed to this parasite, and the number of diagnoses of fasciolosis, made by the Animal Health Veterinary Laboratories Agency, has increased dramatically in the last fifteen years. Experimental studies have demonstrated failure to diagnose bovine tuberculosis (BTB) when co-infection with F. hepatica is present. In Chapter 2, we demonstrate a novel method for estimating the prevalence of BTB in England and Wales and show that, in light of the imperfect diagnostic test for BTB, the prevalence may be significantly higher than currently reported. In Chapter 3, a logistic regression model for the presence or absence of BTB on farms in England and Wales is designed, based upon those previously published. The addition of a variable to describe the burden of F. hepatica found in the locality of each farm significantly increases the predictive power of the model and may help to explain the under-diagnosis of BTB suggested in Chapter 2. A significant, negative association is demonstrated between F. hepatica exposure and the BTB status of the farm. The difference between the model predictions for BTB status made with F. hepatica exposure as tested and the predictions made assuming F. hepatica exposure is negative is then calculated to provide an estimate of the missing BTB diagnoses due to co-infection. We show this under-ascertainment to be over one third of cases. The significant, negative association between F. hepatica exposure and BTB diagnosis described at the herd level in Chapter 3, is then tested on an animal level. In Chapter 4, milk samples from individual animals testing negative and inconclusive, or negative and positive to the BTB test are assessed using the anti-F. hepatica antibody ELISA and an exposure value obtained. Significantly higher exposure to F. hepatica was not found in either pairing of BTB outcome-cattle and potential reasons for this are discussed. Chapter 5 investigates the association between F. hepatica exposure and other infectious diseases such as Bovine Viral Diarrhoea virus (BVDv), Leptospira spp, Infectious Bovine Rhinotracheitis, Johnes Disease and Neospora caninum. A random effects model is constructed using information collected about animal and farm parameters, to predict F. hepatica exposure. Vaccination against BVDv and Leptospira spp are shown to be significantly associated, the former being positively and the latter being negatively correlated. Johnes Disease prevalence is negatively associated with F. hepatica exposure and Salmonella Dublin prevalence is positively associated. Farm management and husbandry variables were also found to be significantly associated with F. hepatica exposure. In total, this thesis adds to the growing realisation that co-infection with this pathogen can have significant repercussions on the diagnostic ability of the BTB test and on the health and welfare of the national herd.
- Published
- 2012
- Full Text
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