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Disentangling the impact of the weather on transmission of infectious diseases is crucial for health protection, preparedness and prevention. Because weather factors are co-incidental and partly correlated, we have used geography to separate out the impact of individual weather parameters on other seasonal variables using campylobacteriosis as a case study. Campylobacter infections are found worldwide and are the most common bacterial food-borne disease in developed countries, where they exhibit consistent but country specific seasonality. We developed a novel conditional incidence method, based on classical stratification, exploiting the long term, high-resolution, linkage of approximately one-million campylobacteriosis cases over 20 years in England and Wales with local meteorological datasets from diagnostic laboratory locations. The predicted incidence of campylobacteriosis increased by 1 case per million people for every 5° (Celsius) increase in temperature within the range of 8°-15°. Limited association was observed outside that range. There were strong associations with day-length. Cases tended to increase with relative humidity in the region of 75-80%, while the associations with rainfall and wind-speed were weaker. The approach is able to examine multiple factors and model how complex trends arise, e.g. the consistent steep increase in campylobacteriosis in England and Wales in May-June and its spatial variability. This transparent and straightforward approach leads to accurate predictions without relying on regression models and/or postulating specific parameterisations. A key output of the analysis is a thoroughly phenomenological description of the incidence of the disease conditional on specific local weather factors. The study can be crucially important to infer the elusive mechanism of transmission of campylobacteriosis; for instance, by simulating the conditional incidence for a postulated mechanism and compare it with the phenomenological patterns as benchmark. The findings challenge the assumption, commonly made in statistical models, that the transformed mean rate of infection for diseases like campylobacteriosis is a mere additive and combination of the environmental variables.
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Infecções por Campylobacter , Campylobacter , Doenças Transmissíveis , Gastroenterite , Humanos , Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/microbiologia , País de Gales/epidemiologia , Tempo (Meteorologia) , Estações do Ano , Inglaterra/epidemiologia , Incidência , Doenças Transmissíveis/epidemiologiaRESUMO
Vaccination is an important disease prevention and control measure; however, vaccine adoption by livestock farmers in Tanzania is still low. This cross-sectional study examined the challenges to vaccine use faced by livestock owners and animal health professionals (AHPs) in Tanzania. A questionnaire was administered to 216 households that kept small ruminants and poultry and 19 AHPs' data were collected electronically via the survey platform Qualtrics, and descriptive statistics were performed. Households with poultry reported vaccinating mostly against Newcastle disease (91.7%), fowl pox (48.1%) and Gumboro disease (37.0%), whilst households with small ruminants reported contagious caprine pleuropneumonia (62.2%), sheep and goat pox (17.1%), foot-and-mouth disease (7.3%) and peste des petits ruminants (7.3%). The households' decision to vaccinate was mostly influenced by knowledge of diseases (82.4%), disease history on the farm (69.4%) and vaccine price (63.4%). Most households (54.6%) experienced challenges when purchasing vaccines, including high vaccine cost (78.0%), long distance from vaccine source (61.0%) and vaccine unavailability (21.2%). The findings suggest that improving the knowledge of livestock owners regarding the priority diseases and the benefits of vaccination, establishing more vaccine suppliers, improving vaccine distribution and access and training AHPs and households on appropriate vaccine storage and handling are necessary to improve vaccine adoption and ensure vaccine quality and effectiveness.
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Aves Domésticas , Vacinas Virais , Animais , Estudos Transversais , Cabras , Gado , Ovinos , Tanzânia/epidemiologiaRESUMO
Peste des petits ruminants (PPR) is a major constraint to the productivity of small ruminants in Nigeria. Understanding of the current epidemiological status of PPR is crucial to its effective control. A review of the epidemiology of PPR in Nigeria was performed and research gaps were identified. Thirty-seven eligible articles were reviewed: these presented information from 30 of the 36 states of Nigeria. Most studies focused on goats and/or sheep (n = 33) but camels (n = 4), cattle (n = 1) and wild ruminants (n = 2) were also considered. Fourteen (37.8%) of the articles reported seroprevalence in small ruminants, which varied from 0.0% to 77.5% where more than 10 animals were sampled. Molecular characterization and phylogenetic analysis were performed in 6 studies, with lineages II and IV, detected in sheep and goats. In one study in small ruminants, sequences clustering into lineage I showed a similarity to the vaccine strain, Nigeria 75/1, based on phylogenetic analysis of F gene sequences. However, if the preferred method of sequencing the N gene had been performed, this isolate would have been grouped into lineage II. According to N gene phylogenetic analysis in the other studies, sequences were identified that clustered with clade II-NigA, II-NigB (closely related to the Nigeria 75/1 vaccine strain), and others which were well separated, suggesting a high diversity of PPRV in Nigeria. Five articles reported the detection of lineage IV in 22/36 states, with IV-NigA and IV-NigB detected, highlighting its widespread distribution in Nigeria. Risk factors for PPRV seropositivity were reported in 10/37 (27.0%) articles, with a higher seroprevalence observed in female animals, although differing results were observed when considering species and age separately. There were inconsistencies in study design and data reporting between studies which precluded conduct of a meta-analysis. Nevertheless, several research gaps were identified including the need to investigate the low uptake of PPRV vaccine, and the economic benefits of PPR control measures to small ruminant farmers. Such data will inform PPR control strategies in Nigeria and subsequently contribute to the global 2030 PPR eradication strategy.
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Pastoral and agro-pastoral farming are extensively practised in Ethiopia, and the main livestock kept are cattle, goats, sheep, poultry, and camels. The livestock sector is faced with complex challenges including limited availability of well-trained and skilled animal health professionals. The objective of this study was to identify and prioritise areas for training with the goal of providing evidence to guide strategies to improve the skills, delivery, and governance of veterinary services across Ethiopia. A cross-sectional survey was developed and administered electronically to veterinary professionals in Ethiopia using the Qualtrics platform. Data were collected on select parameters including demographics, diseases of economic significance, diagnosis, disease prevention, biosecurity, disease control, treatment, epidemiology, One Health, disease reporting, and the participants' opinions about training. The survey data was downloaded in Microsoft Excel and descriptive statistics performed. A total of 234 veterinary professionals completed the survey. Most participants were male (89.7%) and aged between 26 and 35 years (81.2%). Of the total respondents, 56.4% worked in government and 8.5% in private practice. Most participants perceived training on laboratory diagnostic testing, disease prevention, antimicrobial resistance, antibiotic sensitivity testing, basic epidemiology, and clinical procedures, as most beneficial. In addition, most respondents would like to receive training on diseases affecting cattle, poultry, and small ruminants. The findings from this study provide baseline information on priority training areas for veterinary professionals and could potentially contribute to national efforts to develop and implement a continuing professional development programme in the veterinary domain, in view of improving veterinary service delivery.
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Biosseguridade , Gado , Animais , Bovinos , Estudos Transversais , Etiópia/epidemiologia , Masculino , Avaliação das Necessidades , OvinosRESUMO
In Uganda, delivery of veterinary services is vital to animal health and productivity, and is heavily dependent on well-trained and skilled animal health professionals. The purpose of this study was to identify and prioritize areas for refresher training and continuous professional development of animal health professionals (veterinarians and veterinary paraprofessionals), with the overarching aim of improving veterinary service delivery in Uganda. A survey was administered electronically to 311 animal health professionals during the period November 14-30, 2019. Data were collected on relevant parameters including demographics, knowledge on preventive medicine, diagnostics, disease control and treatment, epidemiology, and One Health, as well as participants' opinions on training priorities, challenges faced, and constraints to veterinary service delivery. Most respondents were veterinarians 26-35 years old, were male, and worked in clinical practice. Lowest perceived knowledge was reported on subjects relating to laboratory diagnostics, antimicrobial resistance (AMR), and nutrition. Training topics considered to be of most benefit to respondents included laboratory diagnostics, treatment of common livestock diseases, AMR, and practical clinical skills in reproductive and preventive medicine. Participants preferred to receive training in the form of practical workshops, in-practice training, and external training. This study highlights the need to prioritize training in practical clinical skills, laboratory diagnostics, and AMR. Wet labs and hands-on practical clinical and laboratory skills should be incorporated to enhance training. Provision of targeted and successful trainings will be dependent on the allocation of adequate resources and support by relevant public and private stakeholders across the veterinary sector.
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Educação em Veterinária , Médicos Veterinários , Animais , Educação Continuada , Feminino , Humanos , Masculino , Avaliação das Necessidades , UgandaRESUMO
Poultry production is a major component of the livestock sector in Nigeria and continues to expand rapidly; however, it is still constrained by low productivity. A farm survey was conducted to provide a baseline assessment of poultry production (products generated, farm costs, and revenue), pharmaceutical use, and related challenges faced by farmers on 44 commercial poultry farms in Oyo and Kano states of Nigeria. Live spent layers, eggs, and used beddings were the most frequently sold products for revenue. Antibiotic products were widely used, the most reported were Doxygen, Tylosin, and Conflox. Overall, 40% of farms used feed additives (including toxin binders, minerals, and vitamins) and 12% used coccidiostats. Access to pharmaceutical products was a key challenge and appeared to disproportionally affect farmers in the northern part (Kano) of Nigeria. Other challenges included perceived antibiotic ineffectiveness, high cost of drugs, and long distances to pharmaceutical suppliers. Challenges related to vaccine use were unavailability, distance to the supplier, and health issues interfering with the vaccination schedule. Study findings highlight the need for improved access to veterinary pharmaceuticals, particularly in the northern states. Further investigations into the causes of antibiotic ineffectiveness and strategies for distribution of high-quality, effective pharmaceuticals are also necessary.
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Background: Despite the investments made in veterinary diagnostic laboratory service delivery in Uganda, the scope and level of utilization remains low. This study aimed to determine the priority livestock diseases for which farmers and animal health professionals require veterinary diagnostic laboratory services, document the perceptions and opinions of key stakeholders on veterinary diagnostic laboratory services, and determine the factors that influence the delivery and utilization of animal disease diagnostic services in Uganda. Methods: A qualitative study approach involving a survey and key informant interviews was used to collect relevant data from four stakeholder groups: animal health workers, laboratory technologists and technicians, farmers, and key informants. The survey data were exported to excel, and descriptive statistics performed. The key informant interview recordings were transcribed, and thematic analysis performed. Results: The most reported diseases and conditions for which diagnostic services were needed were hemoparasites (including East Coast fever, anaplasmosis, babesiosis, and trypanosomosis), viral (including Foot and mouth disease, lumpy skin disease, rift valley fever, and papillomatosis), bacteria (including brucellosis, colibacillosis, anthrax, leptospirosis, and paratuberculosis) and protozoa diseases (coccidiosis), endoparasites (helminths), and mastitis. The most common diagnostic laboratory tests requested by clients, but laboratories were unable to provide included: rapid tests for contagious bovine pleuropneumonia, Foot and mouth disease, Newcastle disease, acaricide analysis, culture and antimicrobial sensitivity test, serology, and complete blood count. The most frequently reported challenges to providing diagnostic laboratory services were poor or lack of relevant equipment, insufficient or lack of supplies and reagents, high cost of reagents, inadequate or lack of laboratory staff to perform tests, and inadequate training of laboratory staff. Conclusions: This study highlighted the need to improve provision of laboratory diagnostic services to meet the prioritized diagnostic needs of farmers and animal health professionals. Increased intersectoral engagement and funding support from the private, industry, and government sectors is necessary to help address the observed challenges to provision of diagnostic laboratory services, including equipping of the laboratories, provision of supplies, and hiring and training of laboratory staff. Finally, the findings also suggest that the education of farmers and animal health workers on the value and benefits of laboratory diagnostic services may contribute to increase in sample submission and subsequent demand for diagnostic laboratory services.
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An owner's ability to detect changes in the behavior of a dog afflicted with osteoarthritis (OA) may be a barrier to presentation, clinical diagnosis and initiation of treatment. Management of OA also relies upon an owner's ability to accurately monitor improvement following a trial period of pain relief. The changes in behavior that are associated with the onset and relief of pain from OA can be assessed to determine the dog's health-related quality of life (HRQOL). HRQOL assessments are widely used in human medicine and if developed correctly can be used in the monitoring of disease and in clinical trials. This study followed established guidelines to construct a conceptual framework of indicators of HRQOL in dogs with OA. This generated items that can be used to develop a HRQOL assessment tool specific to dogs with OA. A systematic review was conducted using Web of Science, PubMed and Scopus with search terms related to indicators of HRQOL in dogs with osteoarthritis. Eligibility and quality assessment criteria were applied. Data were extracted from eligible studies using a comprehensive data charting table. Resulting domains and items were assessed at a half-day workshop attended by experts in canine osteoarthritis and quality of life. Domains and their interactions were finalized and a visual representation of the conceptual framework was produced. A total of 1,264 unique articles were generated in the database searches and assessed for inclusion. Of these, 21 progressed to data extraction. After combining synonyms, 47 unique items were categorized across six domains. Review of the six domains by the expert panel resulted in their reduction to four: physical appearance, capability, behavior, and mood. All four categories were deemed to be influenced by pain from osteoarthritis. Capability, mood, and behavior were all hypothesized to impact on each other while physical appearance was impacted by, but did not impact upon, the other domains. The framework has potential application to inform the development of valid and reliable instruments to operationalize measurement of HRQOL in canine OA for use in general veterinary practice to guide OA management decisions and in clinical studies to evaluate treatment outcomes.
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The growth of the poultry industry in Nigeria is constrained by major poultry diseases, despite the implementation of vaccination programs. This study aimed to assess the level of protection against Newcastle disease (ND), infectious bursal disease (IBD), and avian infectious bronchitis (IB) afforded by current vaccination schedules and characterize the circulating virus strains in commercial poultry flocks in Nigeria. A cross-sectional study was conducted on 44 commercial poultry farms in Oyo and Kano states of Nigeria. Serum and tissue samples and data on flock, clinical and vaccination records were collected on each farm. Farms were classified as being protected or not protected against ND, IBD and IB based on a defined criterion. Real-time reverse transcription polymerase chain reaction (rRT-PCR) testing was performed for each target virus on tissue samples and positive samples were sequenced. A total of 15/44 (34.1%), 35/44 (79.5%), and 1/44 (2.3%) farms were considered to be protected against ND, IBD, and IB, respectively, at the time of sampling. NDV RNA was detected on 7/44 (15.9%) farms and sequences obtained from 3/7 farms were characterized as the lentogenic strain. Infectious bursal disease virus (IBDV) RNA was detected on 16/44 (36.4%) farms tested; very virulent (vv) IBDV and non-virulent (nv) IBDV strains were both detected in 3/16 (18.8%) positive samples. Sequences of IBDV isolates were either clustered with a group of genotype 3 virulent IBDV strains or were related to vaccine strains MB and D78 strains. IBV RNA was detected on 36/44 (81.8%) farms, with variant02, Massachusetts, 4/91, and Q1 variants detected. Sequences of IBV isolates were either clustered with the vaccines strains Massachusetts M41 and H120 or were most closely related to the D274-like strains or a clade of sequences reported in Nigeria and Niger in 2006 and 2007. This study revealed that most study farms in Oyo and Kano states did not have adequate protective antibody titers against IBV and NDV and were therefore at risk of field challenge. Infectious bursal disease virus and IBV RNA were detected on farms with a history of vaccination suggesting potential vaccination failure, or that the vaccine strains used mismatch with the circulating strains and are therefore not protective.
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Peste des petits ruminants (PPR) is a highly contagious viral disease of sheep and goats with high mortality. The disease is of considerable economic importance in countries such as Tanzania, where small ruminant products are important for sustainable livelihoods. This review assesses current knowledge regarding the epidemiology of PPRV in Tanzania, highlighting the challenges with respect to control and suggesting possible interventions. Thirty-three articles were identified after literature searches using Google Scholar and PubMed. Studies revealed that PPRV is endemic in sheep and goats in Tanzania, although seropositivity has also been reported in cattle, camels, buffalo, Grant's gazelle, wildebeest and impala, but with no clinical manifestation. Three lineages (lineage II to IV) of PPRV have been identified in Tanzania, implying at least two separate introductions of the virus. Diagnosis of PPR in Tanzania is mostly by observation of clinical signs and lesions at post mortem. Risk factors in Tanzania include age, sex, species, and close contact of animals from different farms/localities. Although there is an efficacious vaccine available for PPR, poor disease surveillance, low vaccine coverage, and uncontrolled animal movements have been the bane of control efforts for PPR in Tanzania. There is need for collaborative efforts to develop interventions to control and eradicate the disease. The establishment of a national reference laboratory for PPR, conduct of surveillance, the development of high-quality DIVA vaccines, as well as execution of a carefully planned national vaccination campaign may be key to the control and subsequent eradication of PPR in Tanzania and achieving the global goal of eradicating PPR by 2030.
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Antimicrobial resistance (AMR) is a global health concern and the inappropriate use of antibiotics in animals and humans is considered a contributing factor. A cross-sectional survey to assess the knowledge, attitudes and practices of veterinarians regarding AMR and antimicrobial stewardship was conducted in Nigeria. A total of 241 respondents completed an online survey. Only 21% of respondents correctly defined the term antimicrobial stewardship and 59.8% were unaware of the guidelines provided by the Nigeria AMR National Action Plan. Over half (51%) of the respondents indicated that prophylactic antibiotic use was appropriate when farm biosecurity was poor. Only 20% of the respondents conducted antimicrobial susceptibility testing (AST) frequently, and the unavailability of veterinary laboratory services (82%) and the owner's inability to pay (72%) were reported as key barriers to conducting AST. The study findings suggest strategies focusing on the following areas may be useful in improving appropriate antibiotic use and antimicrobial stewardship among veterinarians in Nigeria: increased awareness of responsible antimicrobial use among practicing and newly graduated veterinarians, increased dissemination of regularly updated antibiotic use guidelines, increased understanding of the role of good biosecurity and vaccination practices in disease prevention, and increased provision of laboratory services and AST at affordable costs.
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OBJECTIVES: We contribute a new methodological approach to the ongoing efforts towards evaluating public health surveillance. Specifically, we apply a descriptive framework, grounded in prospect theory (PT), for the evaluation of decisions on disease surveillance deployment. We focus on two attributes of any surveillance system: timeliness, and false positive rate (FPR). METHODS: In a sample of 69 health professionals from a number of health related networks polled online, we elicited PT preferences, specifically respondents' attitudes towards gains, losses and probabilities (i.e., if they overweight or underweight extreme probabilities) by means of a series of lotteries for either timeliness or FPR. Moreover, we estimated willingness to pay (WTP) for improvements in the two surveillance attributes. For contextualization, we apply our framework to rabies surveillance. RESULTS: Our data reveal considerable probability weighting, both for gains and losses. In other words, respondents underestimate their chances of getting a good outcome in uncertain situations, and they overestimate their chances of bad outcomes. Moreover, there is convex utility for losses and loss aversion, that is, losses loom larger than gains of the same absolute magnitude to the respondents. We find no differences between the estimated parameters for timeliness and FPR. The median WTP is $7,250 per day gained in detection time and $30 per 1/10,000 reduction in FPR. CONCLUSION: Our results indicate that the biases described by PT are present among public health professionals, which highlights the need to incorporate a PT framework when eliciting their preferences for surveillance systems.
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Métodos Epidemiológicos , Vigilância da População/métodos , Saúde Pública/métodos , Vigilância de Evento Sentinela , Doença/economia , Humanos , Saúde Pública/economiaRESUMO
This study presents British farmers' perception of, and barriers to, implementing Salmonella control on pig farms. Four farms that had implemented interventions and their 33 close contacts (known to the intervention farmers) took part in interviews before (phase 1) and after (phase 2) intervention trials to assess the difference in perception over time. Their results were compared against those from nine randomly selected control farms. The hypothesis was that farms implementing interventions whether or not successful, would influence their close contacts' opinion over time. Based on a 'pathway to disease control' model, three intrinsic factors known to influence motivation - attitudes, social norms and self-efficacy - were evaluated. Farmers mentioned that successful interventions on a farm would attract their attention. The use of an appropriate communication strategy is therefore recommended to stimulate farmers' intent to implement control measures. Both before and after the intervention trials, all farmers had a positive attitude towards Salmonella control and felt that their peers and authorities were supportive of controlling Salmonella on farms. In phase 2, however, farmers were more likely to want to share the burden of control with other stakeholders along the food chain and their belief in self-efficacy had weakened. Whilst social norms were not associated with an intention to take action on control, a positive attitude towards Salmonella control and a belief in self-efficacy were more likely to result in an intent to control. In phase 2, farmers with an intent to implement an intervention appeared to have a greater, but not significant positive belief in self-efficacy (p=0.108). This study confirmed that farmers recognised their responsibility for controlling Salmonella in pork - even though their confidence in their ability to control Salmonella decreased over time - and believed that responsibility should be shared with the rest of the production chain. It showed that farmers trusted their veterinarian as a source of advice to guide them during the process of implementing change, though an increase in farms' Salmonella seroprevalence score (Zoonosis National Control Programme (ZNCP) score) especially for those with a low ZNCP score was also likely to influence their behaviour. Getting concrete feedback from customers or a tangible benefit from their action was a strong incentive especially for farms with a ZNCP score higher than 50%. The study also revealed a need to validate which measures are effective as farmers did not perceive that the current advised interventions were worth the additional effort.
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Criação de Animais Domésticos/métodos , Motivação , Percepção , Salmonelose Animal/prevenção & controle , Doenças dos Suínos/prevenção & controle , Animais , Inglaterra , Humanos , Salmonella/fisiologia , Salmonelose Animal/microbiologia , Suínos , Doenças dos Suínos/microbiologiaAssuntos
Criação de Animais Domésticos/organização & administração , Doenças dos Bovinos/prevenção & controle , Tomada de Decisões , Comportamento de Ajuda , Paratuberculose/prevenção & controle , Animais , Bovinos , Doenças dos Bovinos/microbiologia , Humanos , Mycobacterium avium subsp. paratuberculosis/isolamento & purificação , Paratuberculose/microbiologiaRESUMO
Bovine neonatal pancytopenia (BNP; previously known as idiopathic haemorrhagic diathesis and commonly known as bleeding calf syndrome) is a novel haemorrhagic disease of young calves which has emerged in a number of European countries during recent years. Data were retrospectively collected during June to November 2010 for 56 case calves diagnosed with BNP between 17 March and 7 June of the same year. These were compared with 58 control calves randomly recruited from herds with no history of BNP. Multivariable logistic regression analysis showed that increased odds of a calf being a BNP case were associated with its dam having received PregSure® BVD (Pfizer Animal Health) vaccination prior to the birth of the calf (odds ratio (OR) 40.78, p<0.001) and its herd of origin being located in Scotland (OR 9.71, pâ=â0.006). Decreased odds of a calf being a BNP case were associated with the calf having been kept outside (OR 0.11, pâ=â0.006). The longer that a cattle herd had been established on the farm was also associated with decreased odds of a calf in that herd being a BNP case (OR 0.97, pâ=â0.011).
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Doenças dos Bovinos/etiologia , Pancitopenia/veterinária , Animais , Animais Recém-Nascidos , Estudos de Casos e Controles , Bovinos , Vírus da Diarreia Viral Bovina/imunologia , Feminino , Modelos Logísticos , Masculino , Pancitopenia/etiologia , Gravidez , Estudos Retrospectivos , Fatores de Risco , Reino Unido , Vacinação/efeitos adversos , Vacinação/veterinária , Vacinas Virais/administração & dosagem , Vacinas Virais/efeitos adversosRESUMO
Control of endemic, exotic, and emerging animal diseases critically depends on their early detection and timely management. This paper proposes a novel approach to evaluate alternative surveillance programs based on info-gap theory. A general modeling framework is developed explicitly accounting for severe uncertainty about the incursion, detection, spread, and control of exotic and emergent diseases. The model is illustrated by an evaluation of bluetongue disease surveillance strategies. Key results indicate that, when available, vaccination of the entire population is the most robust strategy. If vaccines are not available then active reporting of suspect clinical signs by farmers is a very robust surveillance policy.
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Bluetongue/epidemiologia , Doenças Transmissíveis Emergentes/veterinária , Modelos Biológicos , Animais , Bluetongue/diagnóstico , Bluetongue/prevenção & controle , Controle de Doenças Transmissíveis/métodos , Doenças Transmissíveis Emergentes/diagnóstico , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/prevenção & controle , Técnicas de Apoio para a Decisão , Inglaterra/epidemiologia , Vigilância da População/métodos , Ovinos , Incerteza , País de Gales/epidemiologiaRESUMO
This study presents a method for evaluation of surveillance for avian influenza (AI) in wild birds and compares surveillance activities before and after changes in surveillance strategy in Great Britain (GB). In October 2008 the AI Wild Bird Surveillance (AIWBS) system in GB was modified to focus on passive surveillance (birds found dead), including those found during warden patrols of wetlands and wildlife reserves, with less emphasis on public reporting of birds found dead. The number of birds sampled by active surveillance (birds live-trapped or shot) was also reduced. In the present study the impact of these changes was investigated by comparing the 12 mo prior to October 2008 with the subsequent 12 mo. Four factors were considered for each surveillance system component: 1) the number of wild birds tested; 2) whether the tested wild birds were considered "higher risk species" (HRS) for being infected with AI; 3) the location of the birds tested with respect to counties designated as a priority for surveillance; and 4) the probability that the birds tested might yield a positive AI virus result based on surveillance results in wild birds across Europe. The number of birds tested by both surveillance types was greatly reduced after the strategy change. The proportion of birds sampled in priority counties also significantly decreased in the second year for both active and passive surveillance. However, the proportion of HRS sampled by active surveillance significantly increased, while a significant decrease in these species was seen for passive surveillance in the second year. The derived probability scores for detecting AI based on European surveillance results indicated a reduction in sensitivity for H5N1 highly pathogenic AI detection by passive surveillance. The methods developed to evaluate AIWBS in GB may be applicable to other European Union countries. The results also reflect the complex issues associated with evaluation of disease surveillance in wildlife populations in which the disease ecology is only partially understood.
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Animais Selvagens , Influenza Aviária/epidemiologia , Animais , Aves , Vigilância da População , Fatores de Tempo , Reino Unido/epidemiologiaRESUMO
BACKGROUND: New and emerging diseases of livestock may impact animal welfare, trade and public health. Early detection of outbreaks can reduce the impact of these diseases by triggering control measures that limit the number of cases that occur. The aim of this study was to investigate whether prospective spatiotemporal methods could be used to identify outbreaks of new and emerging diseases in scanning surveillance data. SaTScan was used to identify clusters of unusually high levels of submissions where a diagnosis could not be reached (DNR) using different probability models and baselines. The clusters detected were subjected to a further selection process to reduce the number of false positives and a more detailed epidemiological analysis to ascertain whether they were likely to represent real outbreaks. RESULTS: 187,925 submissions of clinical material from cattle were made to the Regional Laboratory of the Veterinary Laboratories Agency (VLA) between 2002 and 2007, and the results were stored on the VLA FarmFile database. 16,925 of these were classified as DNRs and included in the analyses. Variation in the number and proportion of DNRs was found between syndromes and regions, so a spatiotemporal analysis for each DNR syndrome was done. Six clusters were identified using the Bernoulli model after applying selection criteria (e.g. size of cluster). The further epidemiological analysis revealed that one of the systemic clusters could plausibly have been due to Johne's disease. The remainder were either due to misclassification or not consistent with a single diagnosis. CONCLUSIONS: Our analyses have demonstrated that spatiotemporal methods can be used to detect clusters of new or emerging diseases, identify clusters of known diseases that may not have been diagnosed and identify misclassification in the data, and highlighted the impact of data quality on the ability to detect outbreaks. Spatiotemporal methods should be used alongside current temporal methods for analysis of scanning surveillance data. These statistical analyses should be followed by further investigation of possible outbreaks to determine whether cases have common features suggesting that these are likely to represent real outbreaks, or whether issues with the collection or processing of information have resulted in false positives.
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Doenças dos Bovinos/diagnóstico , Doenças Transmissíveis Emergentes/veterinária , Surtos de Doenças/veterinária , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças Transmissíveis Emergentes/epidemiologia , Bases de Dados Factuais , Paratuberculose/epidemiologia , Vigilância da População/métodos , Estudos Prospectivos , Reprodutibilidade dos Testes , Conglomerados Espaço-Temporais , Reino Unido/epidemiologiaRESUMO
Surveillance of wild birds for avian influenza viruses has been compulsory in the European Union (EU) since 2005, primarily as a means of detecting H5N1 highly pathogenic avian influenza (HPAI) virus and of monitoring the circulation of low pathogenicity avian influenza (LPAI) virus H5 and H7 strains. In 2007, 79,392 wild birds were tested throughout the EU. H5N1 HPAI was detected in 329 birds from four Member States (MS); affected birds were almost entirely of the orders Podicipediformes (grebes) and Anseriformes (waterfowl) during the summer months. LPAI was detected in 1485 wild birds among 21 MS. A total of 1250 birds were positive for influenza A but were not discriminated any further; LPAI H5 was detected in 105 birds, exclusively of the order Anseriformes. LPAI H7 was detected in seven birds. LPAI of other subtypes was found in 123 birds. Epidemiologic evidence and phylogenetic analysis of H5N1 viruses indicate that H5N1 did not appear to persist in the EU from 2006 but was reintroduced, probably from the Middle East.