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1.
Sensors (Basel) ; 22(9)2022 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-35591020

RESUMO

A low-cost, scalable and reproducible approach for the mass production of screen-printed electrode (SPE) platforms that have varying percentage mass incorporations of 2D hexagonal boron nitride (2D-hBN) (2D-hBN/SPEs) is demonstrated herein. These novel 2D-hBN/SPEs are explored as a potential metal-free electrocatalysts towards oxygen reduction reactions (ORRs) within acidic media where their performance is evaluated. A 5% mass incorporation of 2D-hBN into the SPEs resulted in the most beneficial ORR catalysis, reducing the ORR onset potential by ca. 200 mV in comparison to bare/unmodified SPEs. Furthermore, an increase in the achievable current of 83% is also exhibited upon the utilisation of a 2D-hBN/SPE in comparison to its unmodified equivalent. The screen-printed fabrication approach replaces the less-reproducible and time-consuming drop-casting technique of 2D-hBN and provides an alternative approach for the large-scale manufacture of novel electrode platforms that can be utilised in a variety of applications.


Assuntos
Compostos de Boro , Técnicas Eletroquímicas , Eletrodos , Oxigênio
2.
J Vac Sci Technol A ; 38(6): 063208, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33281279

RESUMO

We report the results of a Versailles Project on Advanced Materials and Standards interlaboratory study on the intensity scale calibration of x-ray photoelectron spectrometers using low-density polyethylene (LDPE) as an alternative material to gold, silver, and copper. An improved set of LDPE reference spectra, corrected for different instrument geometries using a quartz-monochromated Al Kα x-ray source, was developed using data provided by participants in this study. Using these new reference spectra, a transmission function was calculated for each dataset that participants provided. When compared to a similar calibration procedure using the NPL reference spectra for gold, the LDPE intensity calibration method achieves an absolute offset of ∼3.0% and a systematic deviation of ±6.5% on average across all participants. For spectra recorded at high pass energies (≥90 eV), values of absolute offset and systematic deviation are ∼5.8% and ±5.7%, respectively, whereas for spectra collected at lower pass energies (<90 eV), values of absolute offset and systematic deviation are ∼4.9% and ±8.8%, respectively; low pass energy spectra perform worse than the global average, in terms of systematic deviations, due to diminished count rates and signal-to-noise ratio. Differences in absolute offset are attributed to the surface roughness of the LDPE induced by sample preparation. We further assess the usability of LDPE as a secondary reference material and comment on its performance in the presence of issues such as variable dark noise, x-ray warm up times, inaccuracy at low count rates, and underlying spectrometer problems. In response to participant feedback and the results of the study, we provide an updated LDPE intensity calibration protocol to address the issues highlighted in the interlaboratory study. We also comment on the lack of implementation of a consistent and traceable intensity calibration method across the community of x-ray photoelectron spectroscopy (XPS) users and, therefore, propose a route to achieving this with the assistance of instrument manufacturers, metrology laboratories, and experts leading to an international standard for XPS intensity scale calibration.

3.
Mikrochim Acta ; 186(3): 200, 2019 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-30796537

RESUMO

The electroanalytical detection of the neurotransmitter dopamine (DA) in the presence of uric acid (UA) is explored for the first time using commercially procured nanodiamonds (NDs). These are electrically wired via surface modification upon screen-printed graphite macroelectrodes (SPEs). The surface coverage of the NDs on the SPEs was explored in order to optimize electroanalytical outputs to result in well-resolved signals and in low limits of detection. The (electro)analytical outputs are observed to be more sensitive than those achieved at bare (unmodified) SPEs. Such responses, previously reported in the academic literature have been reported to be electrocatalytic and have been previously attributed to the presence of surface sp2 carbon and oxygenated species on the surface of the NDs. However, XPS analysis reveals the commercial NDs to be solely composed of nonconductive sp3 carbon. The low/negligible electroconductivity of the NDs was further confirmed when ND paste electrodes were fabricated and found to exhibit no electrochemical activity. The electroanalytical enhancement, when using NDs electronically wired upon SPEs, is attributed not to the NDs themselves being electrocatalytic, as reported previously, but rather changes in mass transport where the inert NDs block the underlying electroactive SPEs and create a random array of graphite microelectrodes. The electrode was applied to simultaneous sensing of DA and UA at pH 5.5. Figures of merit include (a) low working potentials of around 0.27 and 0.35 V (vs. Ag/AgCl); and (b) detection limits of 5.7 × 10-7 and 8.9 × 10-7 M for DA and UA, respectively. Graphical abstract The electroanalytical enhancement of screen-printed electrodes modified with inert/non-conductive nanodiamonds is due to a change in mass transfer where the inert nanodiamonds facilitate the production of a random microelectrode array.

4.
Phys Chem Chem Phys ; 20(30): 20010-20022, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30022207

RESUMO

We report the fabrication, characterisation (SEM/EDX, TEM, XRD, XPS and Raman spectroscopy) and electrochemical properties of graphite and graphene paste electrodes with varying lateral flake sizes. The fabricated paste electrodes are electrochemically analysed using both outer-sphere and inner-sphere redox probes, namely; hexaammineruthenium(iii) chloride, N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD), potassium ferrocyanide(ii) and ammonium ferrous(ii) sulphate. Upon comparison of different graphite paste electrodes, a clear correlation between the lateral flake sizes (La), ranging from 1.5 mm-0.5 µm, and electrochemical activity (heterogeneous electron transfer (HET) kinetics) is evident, where an improvement in the HET is observed at smaller lateral flake sizes. We infer that the beneficial response evident when employing laterally smaller flakes is due to an increased number of edge plane like-sites/defects available upon the electrode surface, facilitating electron transfer. Interestingly, given that the overall lateral flake sizes of the graphenes utilised (10.0-1.3 µm) were significantly smaller than those studied previously, an improvement in HET kinetics was also evident with the reduction of lateral flake size; the extent to which is redox-probe dependent. Improvements are observed up to a distinct point, termed the 'lateral size threshold' (ca. ≤2 µm) where the electrochemical reversible limit is approached. Further support is provided from density functional theory (DFT), exploring the electronic structure (i.e. HOMO-LUMO) as a function of flake size, which demonstrates that the coverage of edge plane like-sites/defects comprising the geometric structure of the relatively small graphene flakes is such that effectively the entire flake has become electrochemically active. In this study, the importance of lateral flake size with respect to electrochemical reactivity at carbon-based electrodes has been demonstrated alongside a structural relationship upon HET performance, a phenomenon that has not previously been described in the literature. Such work is both highly important and informative for the field of electrochemistry and electrode performance, with potential implications in a plethora of areas, ranging from novel renewable energy sources to electroanalytical sensing platforms.

5.
Analyst ; 142(10): 1756-1764, 2017 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-28418064

RESUMO

Surfactant exfoliated 2D hexagonal Boron Nitride (2D-hBN) nanosheets are explored as a potential electrochemical sensing platform and evaluated towards the electroanalytical sensing of dopamine (DA) in the presence of the common interferents, ascorbic acid (AA) and uric acid (UA). Surfactant exfoliated 2D-hBN nanosheets (2-4 layers) fabricated using sodium cholate in aqueous media are electrically wired via a drop-casting modification process onto disposable screen-printed graphite electrodes (SPEs). We critically evaluate the performance of these 2D-hBN modified SPEs and demonstrate the effect of 'mass coverage' towards the detection of DA, AA and UA. Previous studies utilising surfactant-free (pristine) 2D-hBN modified SPEs have shown a beneficial effect towards the detection of DA, AA and UA when compared to the underlying/unmodified graphite-based electrode. We show that the fabrication route utilised to prepare 2D-hBN is a vital experimental consideration, such that the beneficial effect previously reported is considerably reduced when surfactant exfoliated 2D-hBN is utilised. We demonstrate for the first time, through implementation of control experiments in the form of surfactant modified graphite electrodes, that sodium cholate is a major contributing factor to the aforementioned detrimental behaviour. The significance here is not in the material per se, but the fundamental knowledge of the surfactant and surface coverage changing the electrochemical properties of the material under investigation. Given the wide variety of ionic and non-ionic surfactants that are utilised in the manufacture of novel 2D materials, the control experiments reported herein need to be performed in order to de-convolute the electrochemical response and effectively evaluate the 'underlying surface/surfactant/2D materials' electrocatalytic contribution.


Assuntos
Compostos de Boro/química , Dopamina/análise , Técnicas Eletroquímicas , Tensoativos/química , Ácido Ascórbico , Eletrodos , Grafite , Ácido Úrico
6.
Ecol Lett ; 19(4): 443-9, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26868206

RESUMO

Demographic buffering allows populations to persist by compensating for fluctuations in vital rates, including disease-induced mortality. Using long-term data on a badger (Meles meles Linnaeus, 1758) population naturally infected with Mycobacterium bovis, we built an integrated population model to quantify impacts of disease, density and environmental drivers on survival and recruitment. Badgers exhibit a slow life-history strategy, having high rates of adult survival with low variance, and low but variable rates of recruitment. Recruitment exhibited strong negative density-dependence, but was not influenced by disease, while adult survival was density independent but declined with increasing prevalence of diseased individuals. Given that reproductive success is not depressed by disease prevalence, density-dependent recruitment of cubs is likely to compensate for disease-induced mortality. This combination of slow life history and compensatory recruitment promotes the persistence of a naturally infected badger population and helps to explain the badger's role as a persistent reservoir of M. bovis.


Assuntos
Animais Selvagens/microbiologia , Mustelidae/microbiologia , Tuberculose/veterinária , Animais , Mycobacterium bovis/fisiologia , Densidade Demográfica , Prevalência , Tuberculose/epidemiologia , Tuberculose/mortalidade
7.
Anal Chem ; 88(19): 9729-9737, 2016 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-27659497

RESUMO

Crystalline 2D hexagonal boron nitride (2D-hBN) nanosheets are explored as a potential electrocatalyst toward the electroanalytical sensing of dopamine (DA). The 2D-hBN nanosheets are electrically wired via a drop-casting modification process onto a range of commercially available carbon supporting electrodes, including glassy carbon (GC), boron-doped diamond (BDD), and screen-printed graphitic electrodes (SPEs). 2D-hBN has not previously been explored toward the electrochemical detection/electrochemical sensing of DA. We critically evaluate the potential electrocatalytic performance of 2D-hBN modified electrodes, the effect of supporting carbon electrode platforms, and the effect of "mass coverage" (which is commonly neglected in the 2D material literature) toward the detection of DA. The response of 2D-hBN modified electrodes is found to be largely dependent upon the interaction between 2D-hBN and the underlying supporting electrode material. For example, in the case of SPEs, modification with 2D-hBN (324 ng) improves the electrochemical response, decreasing the electrochemical oxidation potential of DA by ∼90 mV compared to an unmodified SPE. Conversely, modification of a GC electrode with 2D-hBN (324 ng) resulted in an increased oxidation potential of DA by ∼80 mV when compared to the unmodified electrode. We explore the underlying mechanisms of the aforementioned examples and infer that electrode surface interactions and roughness factors are critical considerations. 2D-hBN is utilized toward the sensing of DA in the presence of the common interferents ascorbic acid (AA) and uric acid (UA). 2D-hBN is found to be an effective electrocatalyst in the simultaneous detection of DA and UA at both pH 5.0 and 7.4. The peak separations/resolution between DA and UA increases by ∼70 and 50 mV (at pH 5.0 and 7.4, respectively, when utilizing 108 ng of 2D-hBN) compared to unmodified SPEs, with a particularly favorable response evident in pH 5.0, giving rise to a significant increase in the peak current of DA. The limit of detection (3σ) is found to correspond to 0.65 µM for DA in the presence of UA. However, it is not possible to deconvolute the simultaneous detection of DA and AA. The observed electrocatalytic effect at 2D-hBN has not previously been reported in the literature when supported upon carbon or any other electrode. We provide valuable insights into the modifier-substrate interactions of this material, essential for those designing, fabricating, and consequently performing electrochemical experiments utilizing 2D-hBN and related 2D materials.


Assuntos
Compostos de Boro/química , Dopamina/análise , Técnicas Eletroquímicas , Ácido Ascórbico/análise , Tamanho da Partícula , Propriedades de Superfície
8.
Anal Chem ; 87(23): 11666-72, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26561992

RESUMO

A reagentless pH sensor based upon disposable and economical graphite screen-printed electrodes (GSPEs) is demonstrated for the first time. The voltammetric pH sensor utilizes GSPEs which are chemically pretreated to form surface immobilized oxygenated species that, when their redox behavior is monitored, give a Nernstian response over a large pH range (1-13). An excellent experimental correlation is observed between the voltammetric potential and pH over the entire pH range of 1-13 providing a simple approach with which to monitor solution pH. Such a linear response over this dynamic pH range is not usually expected but rather deviation from linearity is encountered at alkaline pH values; absence of this has previously been attributed to a change in the pKa value of surface immobilized groups from that of solution phase species. This non-deviation, which is observed here in the case of our facile produced reagentless pH sensor and also reported in the literature for pH sensitive compounds immobilized upon carbon electrodes/surfaces, where a linear response is observed over the entire pH range, is explained alternatively for the first time. The performance of the GSPE pH sensor is also directly compared with a glass pH probe and applied to the measurement of pH in "real" unbuffered samples where an excellent correlation between the two protocols is observed validating the proposed GSPE pH sensor.

9.
Environ Microbiol ; 16(12): 3753-63, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24119163

RESUMO

American foulbrood (AFB), caused by Paenibacillus larvae, is the most damaging bacterial brood disease of the honeybee (Apis mellifera), causing colony deaths on all continents where honeybees are managed. AFB has been a persistent problem in the UK for over 70 years, with a fluctuating number of cases discovered annually. Once diseased colonies are identified, they are destroyed to reduce pathogen spread. We investigated the pattern of AFB cases recorded over the period 1994 to 2012 using spatial-statistical approaches, with a view to identifying the nature of spread across England and Wales. Our results indicated that AFB exhibits significant spatial aggregation at distances from 10 to 30 km, with aggregations lasting between 1 and 5 years. Kernel smoothing indicated areas of elevated relative risk in different years, and these were further detailed by spatial-scan statistics. We identified disease clusters and successfully estimated their size, location and duration. The majority of clusters did not persist in all years, indicating that management measures may lead to localized extinction of the disease. Whilst less common, persistent clusters likely indicate potential endemic or exotic risk points. The application of robust epidemiological approaches to improve the control of AFB is discussed.


Assuntos
Abelhas/microbiologia , Paenibacillus , Animais , Análise por Conglomerados , Inglaterra/epidemiologia , Incidência , Larva/microbiologia , País de Gales/epidemiologia
10.
Proc Biol Sci ; 281(1790)2014 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-25056621

RESUMO

In animal populations, males are commonly more susceptible to disease-induced mortality than females. However, three competing mechanisms can cause this sex bias: weak males may simultaneously be more prone to exposure to infection and mortality; being 'male' may be an imperfect proxy for the underlying driver of disease-induced mortality; or males may experience increased severity of disease-induced effects compared with females. Here, we infer the drivers of sex-specific epidemiology by decomposing fixed mortality rates into mortality trajectories and comparing their parameters. We applied Bayesian survival trajectory analysis to a 22-year longitudinal study of a population of badgers (Meles meles) naturally infected with bovine tuberculosis (bTB). At the point of infection, infected male and female badgers had equal mortality risk, refuting the hypothesis that acquisition of infection occurs in males with coincidentally high mortality. Males and females exhibited similar levels of heterogeneity in mortality risk, refuting the hypothesis that maleness is only a proxy for disease susceptibility. Instead, sex differences were caused by a more rapid increase in male mortality rates following infection. Males are indeed more susceptible to bTB, probably due to immunological differences between the sexes. We recommend this mortality trajectory approach for the study of infection in animal populations.


Assuntos
Mustelidae/microbiologia , Caracteres Sexuais , Tuberculose Bovina/epidemiologia , Tuberculose Bovina/mortalidade , Animais , Teorema de Bayes , Bovinos , Feminino , Estudos Longitudinais , Masculino , Mustelidae/genética , Mustelidae/imunologia , Mycobacterium bovis/imunologia , Análise de Sobrevida
11.
J Am Coll Emerg Physicians Open ; 5(1): e13100, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38260004

RESUMO

Objective: Intranasal medications have been proposed as adjuncts to out-of-hospital cardiac arrest (OHCA) care. We sought to quantify the effects of intranasal medication administration (INMA) in OHCA workflows. Methods: We conducted separate randomized OHCA simulation trials with lay rescuers (LRs) and first responders (FRs). Participants were randomized to groups performing hands-only cardiopulmonary resuscitation (CPR)/automated external defibrillator with or without INMA during the second analysis phase. Time to compression following the second shock (CPR2) was the primary outcome and compression quality (chest compression rate (CCR) and fraction (CCF)) was the secondary outcome. We fit linear regression models adjusted for CPR training in the LR group and service years in the FR group. Results: Among LRs, INMA was associated with a significant increase in CPR2 (mean diff. 44.1 s, 95% CI: 14.9, 73.3), which persisted after adjustment (p = 0.005). We observed a significant decrease in CCR (INMA 95.1 compressions per min (cpm) vs control 104.2 cpm, mean diff. -9.1 cpm, 95% CI -16.6, -1.6) and CCF (INMA 62.4% vs control 69.8%, mean diff. -7.5%, 95% CI -12.0, -2.9). Among FRs, we found no significant CPR2 delays (mean diff. -2.1 s, 95% CI -15.9, 11.7), which persisted after adjustment (p = 0.704), or difference in quality (CCR INMA 115.5 cpm vs control 120.8 cpm, mean diff. -5.3 cpm, 95% CI -12.6, 2.0; CCF INMA 79.6% vs control 81.2% mean diff. -1.6%, 95% CI -7.4, 4.3%). Conclusions: INMA in LR resuscitation was associated with diminished resuscitation performance. INMA by FR did not impede key times or quality.

12.
Nat Genet ; 30(2): 215-20, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11799392

RESUMO

Schimke immuno-osseous dysplasia (SIOD, MIM 242900) is an autosomal-recessive pleiotropic disorder with the diagnostic features of spondyloepiphyseal dysplasia, renal dysfunction and T-cell immunodeficiency. Using genome-wide linkage mapping and a positional candidate approach, we determined that mutations in SMARCAL1 (SWI/SNF2-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a-like 1), are responsible for SIOD. Through analysis of data from persons with SIOD in 26 unrelated families, we observed that affected individuals from 13 of 23 families with severe disease had two alleles with nonsense, frameshift or splicing mutations, whereas affected individuals from 3 of 3 families with milder disease had a missense mutation on each allele. These observations indicate that some missense mutations allow retention of partial SMARCAL1 function and thus cause milder disease.


Assuntos
DNA Helicases/genética , Síndromes de Imunodeficiência/genética , Mutação , Osteocondrodisplasias/genética , Adolescente , Adulto , Alelos , Sequência de Aminoácidos , Animais , Sequência de Bases , Criança , Pré-Escolar , Consanguinidade , Sequência Conservada , DNA/genética , Análise Mutacional de DNA , Feminino , Genes Recessivos , Humanos , Masculino , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Linhagem , Fenótipo , Insuficiência Renal/genética , Homologia de Sequência de Aminoácidos , Especificidade da Espécie , Linfócitos T/imunologia
13.
J Am Coll Emerg Physicians Open ; 4(3): e12974, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37229183

RESUMO

Objective: In the United States, police are often important co-responders to 911 calls with emergency medical services for medical emergencies. To date, there remains a lack of a comprehensive understanding of the mechanisms by which police response modifies time to in-hospital medical care for traumatically injured patients. Further, it remains unclear if differentials exist within or between communities. A scoping review was performed to identify studies evaluating prehospital transport of traumatically injured patients and the role or impact of police involvement. Methods: PubMed, SCOPUS, and Criminal Justice Abstracts databases were utilized to identify articles. English-language, US-based, peer-reviewed articles published on or prior to March 30, 2022 were eligible for inclusion. Results: Of 19,437 articles initially identified, 70 articles were selected for full review and 17 for final inclusion. Key findings included (1) current law enforcement practices involving scene clearance introduce the potential for delayed patient transport but to date there is little research quantifying delays; (2) police transport protocols may decrease transport times; and (3) there are no studies examining the potential impact of scene clearance practices at the patient or community level. Conclusions: Our results highlight that police are often the first on scene when responding to traumatic injuries and have an active role via scene clearance or, in some systems, patient transport. Despite the significant potential for impact on patient well-being, there remains a paucity of data examining and driving current practices.

14.
BMC Vet Res ; 8: 79, 2012 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-22709848

RESUMO

BACKGROUND: Rabies is a fatal viral disease that potentially can affect all mammals. Terrestrial rabies is not present in the United Kingdom and has been eliminated from Western Europe. Nevertheless the possibility remains that rabies could be introduced to England, where it would find two potentially suitable hosts, red foxes and badgers. With the aim to analyse the spread and emergency control of rabies in this two species host community, a simulation model was constructed. Different control strategies involving anti-rabies vaccination and population culling were developed, considering control application rates, spatial extent and timing. These strategies were evaluated for efficacy and feasibility to control rabies in hypothetical rural areas in the South of England immediately after a disease outbreak. RESULTS: The model confirmed that both fox and badger populations, separately, were competent hosts for the spread of rabies. Realistic vaccination levels were not sufficient to control rabies in high-density badger populations. The combined species community was a very strong rabies host. However, disease spread within species appeared to be more important than cross-species infection. Thus, the drivers of epidemiology depend on the potential of separate host species to sustain the disease. To control a rabies outbreak in the two species, both species had to be targeted. Realistic and robust control strategies involved vaccination of foxes and badgers, but also required badger culling. Although fox and badger populations in the UK are exceptionally dense, an outbreak of rabies can be controlled with a higher than 90% chance, if control response is quick and follows a strict regime. This requires surveillance and forceful and repeated control campaigns. In contrast, an uncontrolled rabies outbreak in the South of England would quickly develop into a strong epizootic involving tens of thousands of rabid foxes and badgers. CONCLUSIONS: If populations of both host species are sufficiently large, epizootics are driven by within-species transmission, while cross-species-infection appears to be of minor importance. Thus, the disease control strategy has to target both host populations.


Assuntos
Raposas , Modelos Biológicos , Mustelidae , Vacina Antirrábica/imunologia , Raiva/veterinária , Animais , Controle de Doenças Transmissíveis/métodos , Simulação por Computador , Surtos de Doenças , Reservatórios de Doenças , Emergências/veterinária , Inglaterra/epidemiologia , Densidade Demográfica , Raiva/prevenção & controle , Especificidade da Espécie
15.
Stud Health Technol Inform ; 291: 17-26, 2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35593755

RESUMO

The 21st century has seen an enormous growth in emergency medical services (EMS) information technology systems, with corresponding accumulation of large volumes of data. Despite this growth, integration efforts between EMS-based systems and electronic health records, and public-sector databases have been limited due to inconsistent data structure, data missingness, and policy and regulatory obstacles. Efforts to integrate EMS systems have benefited from the evolving science of entity resolution and record linkage. In this chapter, we present the history and fundamentals of record linkage techniques, an overview of past uses of this technology in EMS, and a look into the future of record linkage techniques for integrating EMS data systems including the use of machine learning-based techniques.


Assuntos
Serviços Médicos de Emergência , Troca de Informação em Saúde , Bases de Dados Factuais , Registros Eletrônicos de Saúde , Sistemas de Informação
16.
Prev Vet Med ; 204: 105635, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35453089

RESUMO

In wildlife disease management there are few diseases for which vaccination is a viable option. The human vaccine BCG has been used for the control of bovine tuberculosis in badgers since 2010 and is expected to increase. Understanding the long-term effects of repeated vaccination campaigns on disease prevalence is vital, but modelling thus far has generally assumed that a vaccine provides perfect protection to a proportion of the population, and that animals exposed to a repeated vaccination have a second independent chance of becoming protected. We held a workshop with experts in the field to obtain consensus over the main pathways for partial protection in the badger, and then simulated these using an established model. The available data supported the possibility that some individuals receive no benefit from the BCG vaccine, others may result in a delayed disease progression and in the remaining animals, vaccine protected the individual from any onward transmission. Simulating these pathways using different levels of overall efficacy demonstrated that partial protection leads to a reduced effect of vaccination, but in all of the identified scenarios it was still possible to eradicate disease in an isolated population with no disease introduction. We also identify those potential vaccination failures that require further investigation to determine which of our proposed pathways is the more likely.


Assuntos
Doenças dos Bovinos , Mustelidae , Mycobacterium bovis , Tuberculose Bovina , Animais , Animais Selvagens , Vacina BCG , Bovinos , Tuberculose Bovina/epidemiologia , Vacinação/veterinária
17.
Transbound Emerg Dis ; 69(4): e104-e118, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34333857

RESUMO

The incidence of bovine tuberculosis (TB, caused by Mycobacterium bovis) in cattle has been associated with TB in badgers (Meles meles) in parts of England. The aim was to identify badger-associated M. bovis reservoirs in the Edge Area, between the High- and Low-Risk Areas for cattle TB. Data from badger TB surveys were sparse. Therefore, a definition for a local M. bovis reservoir potentially shared by cattle and badgers was developed using cattle TB surveillance data. The performance of the definition was estimated through Latent Class Analysis using badger TB survey data. Spatial units (25 km2 ) in the Edge Area were classified as having a reservoir if they had (i) at least one TB incident in at least three of the previous 7 years, (ii) at least one TB incident in a cattle herd confirmed by post-mortem tests as due to M. bovis infection and not attributable to cattle movements in the previous 2 years and (iii) more confirmed TB incidents than un-confirmed in the previous 2 years. Approximately 20% of the Edge Area was classified as having a local M. bovis reservoir using the cattle-based definition. Assuming 15% TB prevalence in Edge Area badgers, sensitivity for the local M. bovis reservoir definition varied from 25.7% [95% credible interval (CrI): 10.7%-85.1%] to 64.8% (95% CrI: 48.1%-88.0%). Specificity was 91.9% (CrI: 83.6%-97.4%). Over 90% of the local reservoir was in stable endemic TB areas identified through previous work and its spatial distribution was largely consistent with local veterinary knowledge. Uncertainty in the reservoir spatial distribution was explored through its recalculation in spatial units shifted in different directions. We recommend that the definition is re-evaluated as further data on badger infection with M. bovis become available.


Assuntos
Doenças dos Bovinos , Mustelidae , Mycobacterium bovis , Tuberculose Bovina , Animais , Bovinos , Reservatórios de Doenças/microbiologia , Reservatórios de Doenças/veterinária , Incidência , Mustelidae/microbiologia , Prevalência , Tuberculose Bovina/epidemiologia
18.
Proc Biol Sci ; 278(1713): 1913-20, 2011 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-21123260

RESUMO

Control of bovine tuberculosis (TB) in cattle has proven particularly challenging where reservoirs of infection exist in wildlife populations. In Britain and Ireland, control is hampered by a reservoir of infection in Eurasian badgers (Meles meles). Badger culling has positive and negative effects on bovine TB in cattle and is difficult, costly and controversial. Here we show that Bacillus Calmette-Guérin (BCG) vaccination of captive badgers reduced the progression, severity and excretion of Mycobacterium bovis infection after experimental challenge. In a clinical field study, BCG vaccination of free-living badgers reduced the incidence of positive serological test results by 73.8 per cent. In common with other species, BCG did not appear to prevent infection of badgers subjected to experimental challenge, but did significantly reduce the overall disease burden. BCG vaccination of badgers could comprise an important component of a comprehensive programme of measures to control bovine TB in cattle.


Assuntos
Vacina BCG/uso terapêutico , Reservatórios de Doenças/veterinária , Mustelidae/imunologia , Tuberculose Bovina/prevenção & controle , Animais , Vacina BCG/imunologia , Bovinos , Inglaterra , Mustelidae/sangue , Mustelidae/microbiologia , Mycobacterium bovis/imunologia , Mycobacterium bovis/patogenicidade , Tuberculose Bovina/transmissão
19.
PLoS One ; 16(3): e0248426, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33735292

RESUMO

Industry-led culling of badgers has occurred in England to reduce the incidence of bovine tuberculosis in cattle for a number of years. Badger vaccination is also possible, and a move away from culling was "highly desirable" in a recent report to the UK government. Here we used an established simulation model to examine badger control option in a post-cull environment in England. These options included no control, various intermittent culling, badger vaccination and use of a vaccine combined with fertility control. The initial simulated cull led to a dramatic reduction in the number of infected badgers present, which increased slowly if there was no further badger management. All three approaches led to a further reduction in the number of infected badgers, with little to choose between the strategies. We do note that of the management strategies only vaccination on its own leads to a recovery of the badger population, but also an increase in the number of badgers that need to be vaccinated. We conclude that vaccination post-cull, appears to be particularly effective, compared to vaccination when the host population is at carrying capacity.


Assuntos
Abate de Animais/métodos , Reservatórios de Doenças/veterinária , Mustelidae/microbiologia , Tuberculose Bovina/prevenção & controle , Vacinação/métodos , Abate de Animais/estatística & dados numéricos , Animais , Bovinos , Simulação por Computador , Inglaterra , Incidência , Modelos Estatísticos , Mycobacterium bovis/imunologia , Mycobacterium bovis/isolamento & purificação , Mycobacterium bovis/patogenicidade , Controle da População/métodos , Controle da População/estatística & dados numéricos , Tuberculose Bovina/transmissão , Vacinação/estatística & dados numéricos
20.
Arch Dis Child ; 106(4): 384-386, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-32241783

RESUMO

AIMS: To investigate access to paediatric renal transplantation and examine potential barriers within the process. METHODS: Cross-sectional, multicentre, observational study where paediatric nephrology centres in the UK were requested to provide data on transplantation plans for all children (<18 years) with end-stage kidney disease (ESKD). RESULTS: 308 children with ESKD were included in this study from 12 out of 13 UK paediatric nephrology centres. 139 (45%) were being prepared for living donor transplantation and 82 (27%) were listed for deceased donor transplantation. The most common cited factors delaying transplantation from occurring in children were disease factors (36%), donor availability (27%) and size of the child (20%). Psychosocial factors were listed as a barrier in 19% of children. CONCLUSIONS: In this study we have documented the main barriers to renal transplantation in children. Some identified factors may be modifiable through local or national intervention, including donor availability and patient psychosocial factors.


Assuntos
Falência Renal Crônica/diagnóstico , Transplante de Rim/métodos , Doadores Vivos/estatística & dados numéricos , Psicologia/estatística & dados numéricos , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Acessibilidade aos Serviços de Saúde , Humanos , Falência Renal Crônica/epidemiologia , Falência Renal Crônica/fisiopatologia , Transplante de Rim/estatística & dados numéricos , Doadores Vivos/provisão & distribuição , Reino Unido/epidemiologia
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