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Bovine brucellosis is a worldwide zoonotic contagious disease. According to World Animal Health Information System reports Ecuador has presented an increasing number of bovine brucellosis outbreaks in the continental territory over the past years (756 in 2018 versus 964 in 2021), generating economic losses for producers and causing a risk to public health. A cross-sectional study was conducted to investigate the seroprevalence of bovine brucellosis and associated risk or protective factors between May and June 2018. This stratified random study was implemented in 290 cattle herds located in the 23 provinces of continental Ecuador, which represents a total of 3737 cows aged 24 months or older. A competitive ELISA was used to detect Brucella antibodies. Simultaneously, an epidemiological survey was implemented to assess the brucellosis risk or protective factors. The apparent prevalence of bovine brucellosis at the herd level was 21.3% (95% CI: 16.8-26.6) and 6.2% (95% CI: 5.5-7) at the animal level. Univariate and multivariate logistic regression analyses were performed to determine the relationship between the potential factors associated with the presence of bovine brucellosis. The risk factors identified after multivariate analysis were a surface in ha per herd > 70 ha (OR = 2.73; 95% CI: 1.18-6.32) and the number of parturitions per animal (two or more with OR ≥ 1.8 and p-value ≤ 0.047). On the contrary, the protective factors were the region (farms located in the eastern region) and the absence of reported clinical signs. In addition, in herds where extensive production predominates, farmers have a low level of knowledge, and the farm biosecurity level is low. These results can guide the authorities in managing the risk factors identified, understanding the current epidemiological situation in Ecuador, improving the bovine brucellosis control program and food safety, as well as increase the one-health approach.
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Foot and mouth disease was the first disease for which, in 1996, the World Organisation for Animal Health (WOAH; founded as OIE) established an official list of disease-free territories, which has helped to facilitate the trade of animals and animal products from those territories. Since that year, there have been a number of suspensions of FMD-free status which have impacted the livestock industry of the territories affected. The objective of this study is to identify factors associated with the time taken to recover FMD-free status after suspension. Historical applications submitted (between 1996 and the first semester of 2020) by WOAH Members for recognition and recovery of FMD-free status were used as the main source of data. Only FMD-free status suspensions caused by outbreaks were considered. Data on the Member's socio-economic characteristics, livestock production systems, FMD outbreak characteristics, and control strategies were targeted for the analysis. The period of time taken to recover FMD-free status was estimated using Kaplan-Meier survival curves. A Cox proportional hazard model was used to identify factors associated with the time taken to recover FMD-free status after suspension. A total of 163 territories were granted official FMD-free status during the study period. The study sample consisted of 45 FMD-free status suspensions. Africa and the Americas accounted for over 50% of FMD-free status suspensions, while over 70% of these occurred in formerly FMD-free territories where vaccination was not practiced. The study noted that implementing a stamping-out or vaccination and remove policy shortened the time to recover FMD-free status, compared with a vaccination and retain policy. Other variables associated with the outcome were the income level of the Member, Veterinary Service capacity, time taken to implement control measures, time taken until the disposal of the last FMD case, whether the territory bordered FMD-infected territories, and time elapsed since FMD freedom. This analysis will contribute toward the understanding of the main determinants affecting the time to recover the FMD free status of WOAH Members and policy processes for FMD control and elimination.
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OBJECTIVE: Determine and characterize potential risk areas for the occurrence of cutaneous leishmaniasis (CL) in Latin America (LA). METHOD: Ecological observational study with observation units defined by municipalities with CL transmission between 2014-2018. Environmental and socioeconomic variables available for at least 85% of the municipalities were used, combined in a single database, utilizing the R software. The principal component analysis methodology was combined with a hierarchical cluster analysis to group clusters of municipalities based on their similarity. The V-test was estimated to define the positive or negative association of the variables with the clusters and separation by natural breaks was used to determine which ones contributed the most to each cluster. Information on cases was also incorporated in the analyses to attribute CL risk for each cluster. RESULTS: This study included 4,951 municipalities with CL transmission (36.5% of the total in LA) and seven clusters were defined by their association with 18 environmental and socioeconomic variables. The historical risk of CL is positively associated with the Amazonian, Andean and Savannah clusters in a decreasingly manner; and negatively associated with the Forest evergreen, Forest/crop and Forest/populated clusters. The Agricultural cluster did not reveal any association with the CL cases. CONCLUSIONS: The study made it possible to identify and characterize the CL risk by clusters of municipalities and to recognize the epidemiological distribution pattern of transmission, which provides managers with better information for intersectoral interventions to control CL.
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OBJECTIVE: Determine and characterize areas at potential risk for the occurrence of cutaneous leishmaniasis (CL) in Latin America. METHOD: Ecological observational study with observation units defined by municipalities with CL transmission during 2014-2018. Environmental and socioeconomic variables available for at least 85% of municipalities were combined in a single database, using R software. Principal component analysis was combined with hierarchical cluster analysis for the formation of clusters of municipalities according to their similarity. The V-test was used to define positive or negative association of variables with clusters and separation by natural divisions to determine which contributed more to each cluster. Cases were included to attribute CL risk for each cluster. RESULTS: The study included 4 951 municipalities with CL transmission (36.5% of municipalities in Latin America); seven clusters were defined by their association with 18 environmental and socioeconomic variables. Historical risk of CL is associated positively and in descending order with the Amazonian, Andean, and Savanna clusters; and negatively with the Forest/perennial, Forest/cultivated, and Forest/populated clusters. The Agricultural cluster showed no association with CL cases. CONCLUSIONS: The study made it possible to identify and characterize CL risk by clusters of municipalities and to understand the characteristic epidemiological distribution patterns of transmission, providing program managers with better information for intersectoral interventions to control CL.
OBJETIVO: Determinar e caracterizar as áreas de risco de ocorrência de leishmaniose cutânea na América Latina. MÉTODO: Estudo observacional ecológico com unidades de observação definidas por municípios com transmissão de leishmaniose cutânea entre 2014 e 2018. Foram usadas as variáveis ambientais e socioeconômicas disponíveis em 85% ou mais dos municípios, reunidas em uma única base de dados com o uso do software R. A metodologia de análise de componentes principais foi combinada a uma análise de conglomerados com agrupamento hierárquico para formar conglomerados de municípios por semelhança. O teste V foi usado para estabelecer a associação (positiva ou negativa) das variáveis com os conglomerados e uma separação por divisões naturais foi usada para determinar as variáveis que mais contribuíram em cada conglomerado. Os casos foram incluídos para avaliar o risco de leishmaniose cutânea em cada conglomerado. RESULTADOS: A amostra do estudo compreendeu 4.951 municípios com transmissão de leishmaniose cutânea (36,5% do total na América Latina). Foram definidos sete conglomerados por apresentarem associação com 18 variáveis ambientais e socioeconômicas. Foi observada associação positiva e decrescente do risco histórico de leishmaniose cutânea com os conglomerados Amazônico, Andino e Savana e negativa com os conglomerados Mata/perene, Mata/cultivo e Mata/povoado. O conglomerado Agrícola não demonstrou associação com casos de leishmaniose cutânea. CONCLUSÕES: Este estudo permitiu identificar e caracterizar o risco de leishmaniose cutânea por conglomerados de municípios e conhecer o padrão epidemiológico de distribuição da transmissão da doença, oferecendo às autoridades dados melhores para subsidiar as intervenções intersetoriais para o controle da leishmaniose cutânea.
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RESUMEN Objetivo. Determinar y caracterizar áreas de riesgo potencial de la ocurrencia de leishmaniasis cutánea (LC) en América Latina (AL). Método. Estudio observacional ecológico con unidades de observación definidas por municipios con transmisión de LC entre 2014-2018. Se utilizaron variables medioambientales y socioeconómicas disponibles para al menos 85% de los municipios, combinados en una sola base de datos, a través del software R. Se combinó la metodología de análisis de componentes principales con un análisis de conglomerados jerárquicos para la formación de conglomerados de municipios en función de su similitud. Se estimó el V-test para definir la asociación positiva o negativa de las variables con los conglomerados y separación por divisiones naturales para determinar cuáles contribuyeron más a cada conglomerado. Se incorporaron los casos para atribuir el riesgo de LC para cada conglomerado. Resultados. Se incluyeron en el estudio 4 951 municipios con transmisión de LC (36,5% del total en AL) y se definieron siete conglomerados por su asociación con 18 variables medioambientales y socioeconómicas. El riesgo histórico de LC se asocia de manera positiva y en forma decreciente con los conglomerados Amazónico, Andino y Sabana; y de manera negativa con los conglomerados Boscoso/perenne, Boscoso/cultivo y Boscoso/poblado. El conglomerado Agrícola no reveló ninguna asociación con los casos de LC. Conclusiones. El estudio permitió identificar y caracterizar el riesgo de LC por conglomerados de municipios y conocer el patrón propio epidemiológico de distribución de la transmisión, lo que proporciona a los gestores una mejor información para las intervenciones intersectoriales para el control de la LC.
ABSTRACT Objective. Determine and characterize areas at potential risk for the occurrence of cutaneous leishmaniasis (CL) in Latin America. Method. Ecological observational study with observation units defined by municipalities with CL transmission during 2014-2018. Environmental and socioeconomic variables available for at least 85% of municipalities were combined in a single database, using R software. Principal component analysis was combined with hierarchical cluster analysis for the formation of clusters of municipalities according to their similarity. The V-test was used to define positive or negative association of variables with clusters and separation by natural divisions to determine which contributed more to each cluster. Cases were included to attribute CL risk for each cluster. Results. The study included 4 951 municipalities with CL transmission (36.5% of municipalities in Latin America); seven clusters were defined by their association with 18 environmental and socioeconomic variables. Historical risk of CL is associated positively and in descending order with the Amazonian, Andean, and Savanna clusters; and negatively with the Forest/perennial, Forest/cultivated, and Forest/populated clusters. The Agricultural cluster showed no association with CL cases. Conclusions. The study made it possible to identify and characterize CL risk by clusters of municipalities and to understand the characteristic epidemiological distribution patterns of transmission, providing program managers with better information for intersectoral interventions to control CL.
RESUMO Objetivo. Determinar e caracterizar as áreas de risco de ocorrência de leishmaniose cutânea na América Latina. Método. Estudo observacional ecológico com unidades de observação definidas por municípios com transmissão de leishmaniose cutânea entre 2014 e 2018. Foram usadas as variáveis ambientais e socioeconômicas disponíveis em 85% ou mais dos municípios, reunidas em uma única base de dados com o uso do software R. A metodologia de análise de componentes principais foi combinada a uma análise de conglomerados com agrupamento hierárquico para formar conglomerados de municípios por semelhança. O teste V foi usado para estabelecer a associação (positiva ou negativa) das variáveis com os conglomerados e uma separação por divisões naturais foi usada para determinar as variáveis que mais contribuíram em cada conglomerado. Os casos foram incluídos para avaliar o risco de leishmaniose cutânea em cada conglomerado. Resultados. A amostra do estudo compreendeu 4.951 municípios com transmissão de leishmaniose cutânea (36,5% do total na América Latina). Foram definidos sete conglomerados por apresentarem associação com 18 variáveis ambientais e socioeconômicas. Foi observada associação positiva e decrescente do risco histórico de leishmaniose cutânea com os conglomerados Amazônico, Andino e Savana e negativa com os conglomerados Mata/perene, Mata/cultivo e Mata/povoado. O conglomerado Agrícola não demonstrou associação com casos de leishmaniose cutânea. Conclusões. Este estudo permitiu identificar e caracterizar o risco de leishmaniose cutânea por conglomerados de municípios e conhecer o padrão epidemiológico de distribuição da transmissão da doença, oferecendo às autoridades dados melhores para subsidiar as intervenções intersetoriais para o controle da leishmaniose cutânea.
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Humanos , Leishmaniose Cutânea/epidemiologia , Fatores Socioeconômicos , Análise por Conglomerados , Medição de Risco , América Latina/epidemiologiaRESUMO
: Rabies virus (RABV) is the only lyssavirus known to be present within the Caribbean. The island of Trinidad, is richly diverse in chiropteran fauna and endemic for bat-transmitted rabies with low RABV isolation rates observed in this population. We aimed to determine the seroprevalence of rabies virus neutralizing antibodies (RVNA) in light of spatio-temporal and bat demographic factors to infer the extent of natural exposure to RABV in the Trinidadian bat population. RVNA titers were determined by the RABV micro-neutralization test on 383 bat samples representing 21 species, comprising 30.9% of local bat diversity, from 31 locations across the island over 5 years. RVNA was positively detected in 33 samples (8.6%) representing 6 bat species (mainly frugivorous) with titers ranging from 0.1 to 19 IU/mL (mean 1.66 IU/mL). The analyses based on a multivariable binomial generalised linear mixed-effects model showed that bat age and year of capture were significant predictors of seropositivity. Thus, juvenile bats were more likely to be seropositive when compared to adults (estimate 1.13; p = 0.04) which may suggest early exposure to the RABV with possible implications for viral amplification in this population. Temporal variation in rabies seropositivity, 2012-2014 versus 2015-2017 (estimate 1.07; p = 0.03) may have been related to the prevailing rabies epizootic situation. Regarding other factors investigated, RVNA was found in bats from both rural and non-rural areas, as well as in both hematophagous and non-hematophagous bat species. The most common seropositive species, Artibeusjamaicensisplanirostris is ubiquitous throughout the island which may potentially facilitate human exposure. The findings of this study should be factored into public health assessments on the potential for rabies transmission by non-hematophagous bats in Trinidad.
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Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Quirópteros/imunologia , Raiva/imunologia , Raiva/veterinária , Animais , Quirópteros/virologia , Feminino , Masculino , Raiva/epidemiologia , Vírus da Raiva/imunologia , Estudos Soroepidemiológicos , Trinidad e Tobago/epidemiologiaRESUMO
BACKGROUND: Visceral Leishmaniasis (VL) is the most severe form of leishmaniasis because it can lead to death. In the Americas, 96% of cases are in Brazil, and despite efforts, the fatality rate has increased in the past years. We analyzed deaths associated to VL in Brazil and investigated the factors that could influence on the timeliness of fatal outcome with emphasis on time (tStoD). METHODOLOGY: The registered deaths by VL were sourced from the Brazilian National Notification System from 2007-2014. Through a retrospective cohort study, univariate and multivariable Cox proportional hazards model analysis were performed and investigated the factors that could influence the time (tStoD). These factors were analyzed through survival models. RESULTS: Out of the 1,589 reported deaths, the median for onset of the symptoms and the case notification date (tStoN) is 25 days (10-61), and for date of case notification and death (tNotD) is 9 days (4-17). The time (tStoN) to event investigation for HIV non-infected individuals was 1.4 (1.16-1.68) greater than the HIV positive group. At the same time peri-urban and urban area were 0.83 (0.47-1.44) and 1.33 (1.16-1.52), respectively. The explorations revealed apparent differences between the time to event investigation (both for tStoN and tNotD) and the age at the onset of the symptoms. According to the tStoN the rate of notification is 1.73 times greater in patients under 5 years old at the onset of the clinical symptoms compared to older patients. CONCLUSION: VL patients under 5 years old were diagnosed earlier and had shorter survival. It could mean that in younger population, although properly diagnosed, the fatality pattern might be related to the severity of the disease. Main host characteristics were evaluated, and age and co-infections seem to have an impact in the disease progression.
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Leishmaniose Visceral/mortalidade , Mortalidade Prematura , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Brasil , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Análise de Sobrevida , Adulto JovemRESUMO
Vampire bat-transmitted human rabies was first recognized in Trinidad during a major outbreak during the first half of the 20th century. To date, Trinidad is the only Caribbean island with vampire bat-transmitted rabies. Herein, we summarized the epidemiological situation of rabies in Trinidad during the period 1971-2015 through the analysis of field and laboratory records. During the study period, 259 domestic and wild animal rabies cases were laboratory confirmed with an annual median of 2 animal rabies cases. Over the 45 years, five significant epizootic events occurred (in 1974, 1997-1998, 2000, 2010 and 2012-2013) over which there was a significant increasing trend for the occurrence of rabies cases. The highest number of cases (87 cases) occurred during the 1997-1998 event, and the rabies positive proportion, was highest (0.7, 95% CI 0.52-0.84) for the year 2000. Rabies risk was highest for cattle (negative binomial parameter estimate 4.84, 95% CI 3.45-6.76), although numerous rabies cases were seen in the caprine population during the study period. In light of this finding, consideration should be given to including the small ruminant population in the national rabies vaccination program. Outbreaks affected mainly the counties of St. Patrick and St. George East, with epidemic progression outwards, and these areas should be prioritized for prevention and control efforts.
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Quirópteros/virologia , Surtos de Doenças/veterinária , Gado/virologia , Vírus da Raiva/fisiologia , Raiva/veterinária , Animais , Animais Domésticos , Animais Selvagens , Humanos , Raiva/epidemiologia , Raiva/prevenção & controle , Raiva/virologia , Trinidad e Tobago/epidemiologia , Vacinação/veterinária , ZoonosesRESUMO
OBJECTIVE: To compare the performance of polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) tests for diagnosing Echinococcus granulosus in dog feces among national reference laboratories in Argentina, Chile, Peru, and Uruguay. METHODS: National laboratories affiliated with the Ministry of Health/Agriculture of each country exchanged panels of 10 positive/negative samples obtained from their regular national surveillance programs in November 2015 - November 2016. All laboratories applied PCR; two also applied ELISA techniques. Sensitivity and specificity were determined for each laboratory and concordance of results among the laboratories was evaluated by Cohen Kappa coefficient. RESULTS: Poor concordance (3 of 10 paired comparisons had values of Kappa > 0.4), low sensitivity and specificity across all laboratories, and poor performance of both techniques in detecting E. granulosus in canine feces was demonstrated in this study. An ex-post comparison of the laboratories' test protocols showed substantial heterogeneity that could partially explain poor concordance of results. CONCLUSION: The results underscore the heterogeneity of canine echinococcosis diagnosis across the region and indicate possible sources of variability. Efforts to standardize canine echinococcosis testing must be included in the plan of action for the Regional Initiative for the Control of Cystic Echinococcosis. Future comparisons with fecal samples of known parasite load are needed.
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BACKGROUND: In the Americas, leishmaniasis is endemic in 18 countries, and from 2001 through 2015, 17 countries reported 843,931 cases of cutaneous and mucocutaneous leishmaniasis, and 12 countries reported 52,176 cases of visceral leishmaniasis. A Regional Information System (SisLeish) was created in order to provide knowledge of the distribution and tendency of this disease to analyze and monitor the leishmaniasis status. This article analyses the performance and progress of SisLeish from 2012-2015. METHODOLOGY: The performance of SisLeish was evaluated by country adhesion, data completeness and delay in entering the data, and also by the SWOT technique. Furthermore, we outlined the structure and modus operandi of the system and indicators utilized. RESULTS: In 2012, only 18% of the countries entered the data in SisLeish before the deadline, where 66.7% and 50% of the countries with autochthonous CL/ML and VL reported their cases to the system, respectively. Whereas in 2015, 59% of the countries reached the deadline, where 94.4% and 58.3% of the countries reported their CL/ML and VL data, respectively. Regarding data completeness, there was great progress for different variables since its launch, such as gender, which had an approximately 100% improvement from 2012 to 2015. The SWOT analysis of SisLeish showed 12 strengths, 11 opportunities, seven weaknesses and six threats. CONCLUSIONS: From 2012-2015 there has been an improvement in the adhesion, quality and data completeness, showing the effort of the majority of the countries to enhance their national database. The SWOT analysis demonstrated that strengths and opportunities exceed weaknesses and threats; however, it highlighted the system frailties and challenges that need to be addressed. Furthermore, it has stimulated several National Programs to advance their surveillance system. Therefore, SisLeish has become an essential tool to prioritize areas, assist in decision-making processes, and to guide surveillance and control actions.
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Monitoramento Epidemiológico , Pesquisa sobre Serviços de Saúde , Sistemas de Informação/organização & administração , Sistemas de Informação/normas , Leishmaniose/epidemiologia , América/epidemiologia , Humanos , Cooperação InternacionalRESUMO
Foot-and-Mouth Disease serotype O circulated endemically in Ecuador for many years, with an upsurge occurring in 2009. This manuscript describes retrospectively in vitro and in vivo laboratory studies to predict the field effectiveness of a commercial FMD vaccine to protect against the field strain, and explains the key actions and epidemiological strategies followed by the country to control the disease. The results established that the use of a good quality oil vaccine, manufactured with strains that were isolated long ago: O1 Campos Br/58 and A24 Cruzeiro Br/55; combined with the correct epidemiological strategies, are useful to control field strains when used in periodic biannual vaccination campaigns.
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Doenças dos Bovinos/prevenção & controle , Febre Aftosa/prevenção & controle , Vacinas Virais/uso terapêutico , Sequência de Aminoácidos , Animais , Anticorpos Antivirais/sangue , Proteínas do Capsídeo/genética , Bovinos , Doenças dos Bovinos/virologia , Proteção Cruzada , Equador , Vírus da Febre Aftosa/classificação , Vacinação/veterinária , Vacinas Virais/imunologiaAssuntos
Controle de Doenças Transmissíveis/métodos , Reservatórios de Doenças/veterinária , Doenças do Cão/prevenção & controle , Leishmaniose Visceral/prevenção & controle , Leishmaniose Visceral/veterinária , Zoonoses/prevenção & controle , Animais , Região do Caribe/epidemiologia , Cães , Europa (Continente)/epidemiologia , Humanos , América Latina/epidemiologia , Leishmaniose Visceral/epidemiologia , Vigilância da População/métodosRESUMO
Liver fluke is a manifestation of bovine fasciolosis and its presence is compulsorily investigated as part of routine official abattoir inspections. It is known that the presence of fasciolosis negatively influences beef production, interfering with weight gain and fertility. Recent reports suggest increased occurrence of this parasite worldwide. This paper aims to investigate the impact of fasciolosis on beef cattle performance by examining the association of liver fluke with carcase characteristics and its value. Cattle slaughtered between 2005 and 2010 (328, 137 cattle (of which 12.6% were positive to liver fluke) sourced from 2278 farms) are analysed adjusting for the effect of gender, age, breed, season and year. Carcases with liver fluke have lower cold weight than those carcases free of fluke, estimated coefficient -0.63 kg (95% confidence intervals (CI) -0.93, -0.33). Carcases with liver fluke have lower price than those carcases free of fluke, estimated coefficient -£1.5 (95% CI -2.24, -0.74). The presence of liver fluke is associated with lower carcase conformation scores compared to carcases with fluke absence, proportional odds ratio (POR) 0.89 (95% CI 0.87-0.91). Similarly, the presence of liver fluke is associated with lower levels of fat in the carcase compared to carcases with fluke absence, POR 0.97 (95% CI 0.95-0.99). These results indicate a potential negative effect of the parasitism on carcase performance. The downgrading of the carcase impacts its value and therefore the price paid to the farmer. Both farmers and abattoir operators share a common interest in the control of fasciolosis in order to optimise the profitability of beef production. This study shows the utility of abattoir post-mortem inspection as a tool to monitoring animal health and production.
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Doenças dos Bovinos/parasitologia , Fasciolíase/veterinária , Carne/normas , Animais , Composição Corporal , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/patologia , Fasciolíase/epidemiologia , Fasciolíase/patologia , Feminino , Masculino , Escócia/epidemiologiaRESUMO
BACKGROUND: Abattoir detected pathologies are of crucial importance to both pig production and food safety. Usually, more than one pathology coexist in a pig herd although it often remains unknown how these different pathologies interrelate to each other. Identification of the associations between different pathologies may facilitate an improved understanding of their underlying biological linkage, and support the veterinarians in encouraging control strategies aimed at reducing the prevalence of not just one, but two or more conditions simultaneously. RESULTS: Multi-dimensional machine learning methodology was used to identify associations between ten typical pathologies in 6485 batches of slaughtered finishing pigs, assisting the comprehension of their biological association. Pathologies potentially associated with septicaemia (e.g. pericarditis, peritonitis) appear interrelated, suggesting on-going bacterial challenges by pathogens such as Haemophilus parasuis and Streptococcus suis. Furthermore, hepatic scarring appears interrelated with both milk spot livers (Ascaris suum) and bacteria-related pathologies, suggesting a potential multi-pathogen nature for this pathology. CONCLUSIONS: The application of novel multi-dimensional machine learning methodology provided new insights into how typical pig pathologies are potentially interrelated at batch level. The methodology presented is a powerful exploratory tool to generate hypotheses, applicable to a wide range of studies in veterinary research.
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Inteligência Artificial , Doenças dos Suínos/patologia , Matadouros , Animais , Teorema de Bayes , Modelos Biológicos , Fatores de Risco , SuínosRESUMO
Ascaris suum is the most important internal parasite in farmed pigs world-wide. In England, the BPEX Pig Health Scheme (BPHS) monitors the prevalence of ascariosis in slaughtered finished pigs by identifying milk spots - the healing lesions caused by A. suum larvae migration through the liver. This study investigates the trend of milk spot lesions from July 2005 to December 2010 to identify the progress made by the industry in controlling this parasitic disease. For visual explorations, the monthly prevalence for milk spots was modelled using "STL", a seasonal-trend decomposition method based on locally weighted regression. Random effects binomial modelling accounting for clustering at batch level was used to test the significance of the trend and seasonality. Additionally, the differences in the milk spot prevalence trends for BPHS members (those that joined the scheme) and non-members were investigated and tested. A mean of 12,442 pigs was assessed per month (in 290 batches) across 12 pig abattoirs over the study period, from which a monthly mean of 7102 pigs (159 batches) came from BPHS members. A mild overall decrease in prevalence of milk spots over the monitored period was identified as well as a seasonal variation which showed peaks in summer and at the beginning of autumn. BPHS members maintained a lower prevalence than non-members. The results from this work illustrate ascariosis as a persistent problem in current farm production.
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Matadouros , Ascaríase/veterinária , Fígado/patologia , Estações do Ano , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/patologia , Animais , Ascaríase/epidemiologia , Ascaríase/patologia , Ascaríase/prevenção & controle , Ascaris suum/fisiologia , Inglaterra/epidemiologia , Prevalência , Suínos , Doenças dos Suínos/prevenção & controleRESUMO
Enzootic pneumonia (EP) is responsible for considerable economic losses in pig production. This study analyses temporal variations of pneumonic lesions present in slaughtered finishing pigs utilising a novel analytical tool - STL decomposition. Using data collected over a 6-year period starting in July 2005, time-series analyses were conducted to identify trend and the presence of seasonal variations to support industry led measures to monitor and control this important respiratory disease. In England, the BPEX Pig Health Scheme monitors the occurrence of EP in slaughtered finished pigs by identifying its gross pathology, enzootic pneumonia-like (EP-like) lesions. For visual analytics, the monthly prevalence for EP-like lesions was modelled using STL, a seasonal-trend decomposition method based on locally-weighted regression. A binomial generalised linear mixed-effects model (GLMM), accounting for clustering at batch level, was used to test the significance of the trend and seasonality. A mean of 12,370 pigs was assessed per month across 12 pig abattoirs over the study period. A trend toward reduction in prevalence of EP-like lesions during the first 3 years of BPHS, followed by an increasing trend, was identified with STL. This feature was consistent with the presence of a statistically significant positive quadratic term ("U" shape) as identified using the GLMM inference model. November and December appeared in the STL explorations as higher seasonal peaks of the occurrence of EP-like lesions. These 2 months had a significantly higher risk of this disease (OR=1.38, 95% CI: 1.24-1.54 and OR=1.4, 95% CI: 1.25-1.58, respectively, with July taken as baseline). The results were reported back to the pig industry as part of the national monitoring investigations.
Assuntos
Carne , Modelos Estatísticos , Pneumonia/veterinária , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/prevenção & controle , Matadouros , Animais , Demografia , Inglaterra/epidemiologia , Pneumonia/epidemiologia , Pneumonia/prevenção & controle , Prevalência , Estações do Ano , Suínos , Doenças dos Suínos/etiologiaRESUMO
Ascariosis is the most important internal parasitism present worldwide in farmed pigs. Milk spots are healing lesions occurring when Ascaris suum larvae migrate through the liver. This study aimed to identify current husbandry practices (e.g. wet/compound feeding, outdoors/indoors production, bedded/slatted floors) that influence the prevalence of milk spots in batches of slaughtered pigs, accounting for geographical locations and seasonality. Farm information was accessed through the British farm quality assurance programmes (QAPs) and information on milk spots was obtained from the pig abattoir based health schemes. Two working datasets were created. The first consisted of 505 farms recruited from the whole of Great Britain (GB). The second combined 338 farms from England and Wales (EW) with housing and feed category-specific information (e.g. for growers and finishers separately), which was not fully available for inclusion in the previous dataset. The variables were studied in multivariable beta-binomial models with the presence of milk spots being the response variable. Solid floor with bedding appeared as a risk factor, OR 1.52 (95% confidence intervals (CI) 1.26-1.85) for the GB sample, and OR 1.47 (CI 1.19-1.81) for the EW subset. Those GB herds that had all the stages of production indoors appeared to be at lower risk of milk spots (OR 0.4, CI 0.32-0.49). Changes were detected within year, with higher risk of milk spots in the second 6 months of the year OR 1.17 (CI 1.02-1.35) in the GB sample and 1.21 (95% CI 1.04-1.41) in EW farms. Overall this study suggests that those husbandry practices facilitating optimal levels of hygiene posed lower risk of milk spots in slaughtered pigs, potentially reflecting lower levels of ascariosis in the later stages of production.