RESUMEN
Understanding the impact of vaccination in a host population is essential to control infectious diseases. However, the impact of bait vaccination against wildlife diseases is difficult to evaluate. The vaccination history of host animals is generally not observable in wildlife, and it is difficult to distinguish immunity by vaccination from that caused by disease infection. For these reasons, the impact of bait vaccination against classical swine fever (CSF) in wild boar inhabiting Japan has not been evaluated accurately. In this study, we aimed to estimate the impact of the bait vaccination campaign by modelling the dynamics of CSF and the vaccination process among a Japanese wild boar population. The model was designed to estimate the impact of bait vaccination despite lack of data regarding the demography and movement of wild boar. Using our model, we solved the theoretical relationship between the impact of vaccination, the time-series change in the proportion of infected wild boar, and that of immunised wild boar. Using this derived relationship, the increase in antibody prevalence against CSF because of vaccine campaigns in 2019 was estimated to be 12.1 percentage points (95% confidence interval: 7.8-16.5). Referring to previous reports on the basic reproduction number (R0) of CSF in wild boar living outside Japan, the amount of vaccine distribution required for CSF elimination by reducing the effective reproduction number under unity was also estimated. An approximate 1.6 (when R0 = 1.5, target vaccination coverage is 33.3% of total population) to 2.9 (when R0 = 2.5, target vaccination coverage is 60.0% of total population) times larger amount of vaccine distribution would be required than the total amount of vaccine distribution in four vaccination campaigns in 2019.
Asunto(s)
Peste Porcina Clásica , Vacunas Virales , Animales , Animales Salvajes , Peste Porcina Clásica/epidemiología , Peste Porcina Clásica/prevención & control , Japón/epidemiología , Sus scrofa , Porcinos , Vacunación/veterinariaRESUMEN
African swine fever (ASF) and classical swine fever (CSF) are transboundary animal diseases (TADs) of pigs. Much effort and resources are regularly put into preventing these diseases' introduction in free areas. Passive surveillance activities bring the highest chances for the early detection of TAD incursions because they are routinely and widely conducted at farms, and because these activities focus on the time between introduction and when the first sample is sent for diagnostic testing. The authors proposed the implementation of an enhanced passive surveillance (EPS) protocol based on collecting data through participatory surveillance actions using an objective and adaptable scoring system to aid the early detection of ASF or CSF at the farm level. The protocol was applied in two commercial pig farms for ten weeks in the Dominican Republic, which is a CSF- and ASF-infected country. This study was a proof of concept, based on the EPS protocol to aid detection of substantial variations in the risk score triggering testing. One of the followed farms had score variation, which triggered testing of the animals, although the test results were negative. The study enables assessment of some of the weaknesses associated with passive surveillance and provides lessons applicable to the problem. Results demonstrate the potential for overcoming some issues preventing the broad application of EPS protocols and suggest that standardised approaches may contribute to the early detection of CSF and ASF introductions.
La peste porcine africaine (PPA) et la peste porcine classique (PPC) sont des maladies animales transfrontalières touchant les porcs. De nombreux efforts et ressources sont régulièrement alloués pour prévenir l'introduction de ces maladies dans des zones indemnes. Les activités de surveillance passive offrent les meilleures perspectives de détection précoce des incursions de maladies animales transfrontalières parce qu'elles sont menées de manière systématique et exhaustive dans les élevages, et parce qu'elles se concentrent sur la période entre l'introduction de la maladie et le moment où le premier échantillon est envoyé au laboratoire pour analyse. Les auteurs proposent la mise en oeuvre d'un protocole de surveillance passive renforcée fondé sur la collecte de données via des actions de surveillance participative utilisant un système de notation objectif et adaptable, en vue d'une détection précoce de la PPA et de la PPC dans les élevages. Ce protocole a été appliqué en République dominicaine, pays infecté par la PPA et la PPC, dans deux élevages porcins commerciaux pendant dix semaines. Cette étude était destinée à valider le principe de la méthode et se fondait sur le protocole de surveillance passive renforcée pour mieux détecter les variations substantielles de la note de risque qui conduisent à tester les animaux. L'un des élevages suivis a présenté une variation de cette note, ce qui a conduit à tester les animaux mais les tests se sont révélés négatifs. L'étude permet d'évaluer certaines des faiblesses associées à la surveillance passive et apporte des enseignements applicables à ce problème. Les résultats illustrent le potentiel de l'approche à surmonter certaines des problématiques empêchant l'application extensive des protocoles de surveillance passive renforcée. Ils suggèrent également que des approches normalisées pourraient contribuer à la détection précoce des cas d'introduction de la PPC et de la PPA.
La peste porcina africana (PPA) y la peste porcina clásica (PPC) son enfermedades animales transfronterizas que afectan al cerdo. Periódicamente se dedican grandes esfuerzos y cuantiosos recursos a evitar que estas enfermedades penetren en zonas que están exentas de ellas. Las actividades de vigilancia pasiva son las más eficaces para detectar con prontitud toda incursión de enfermedades animales transfronterizas, no solo por la regularidad y amplitud con que se llevan a cabo en las explotaciones, sino también porque inciden específicamente en el intervalo entre la penetración de una enfermedad y el momento en que se envía la primera muestra para que sea sometida a pruebas de diagnóstico. Los autores propusieron que se aplicara un protocolo de vigilancia pasiva reforzada que reposaba en la obtención de datos mediante actividades de vigilancia participativa, empleando para ello un sistema objetivo y adaptable de puntuación que ayudaba a detectar con prontitud la presencia en las explotaciones de PPA o PPC. Dicho protocolo fue aplicado a lo largo de diez semanas en dos explotaciones porcinas industriales de la República Dominicana, país en el que ambas infecciones están presentes. El estudio, que sirvió para poner a prueba la idea, pasaba por la aplicación del protocolo de vigilancia pasiva reforzada para ayudar a detectar variaciones sustanciales de la puntuación del nivel de riesgo que activa la realización de pruebas. En una de las explotaciones estudiadas se produjo una variación de la puntuación, cosa que activó la realización de pruebas en los animales, aunque estas arrojaron resultado negativo. El estudio aquí descrito permite evaluar algunos de los puntos débiles de la vigilancia pasiva y extraer enseñanzas aplicables al problema. Los resultados demuestran que es posible salvar algunas de las dificultades que impiden la aplicación generalizada de protocolos de vigilancia pasiva reforzada y dejan pensar que quizá el uso de planteamientos normalizados pueda ayudar a detectar con prontitud los casos de penetración de PPC o PPA.
Asunto(s)
Virus de la Fiebre Porcina Africana , Fiebre Porcina Africana , Peste Porcina Clásica , Enfermedades de los Porcinos , Porcinos , Animales , Peste Porcina Clásica/diagnóstico , Peste Porcina Clásica/epidemiología , Peste Porcina Clásica/prevención & control , Fiebre Porcina Africana/diagnóstico , Fiebre Porcina Africana/epidemiología , Fiebre Porcina Africana/prevención & control , Factores de Riesgo , Granjas , Sus scrofa , Enfermedades de los Porcinos/diagnósticoRESUMEN
A pilot animal disease surveillance program was implemented at four abattoirs in Phnom Penh, Cambodia, between October 2019 and January 2020. A total of 1141 samples were collected from 477 cattle and 664 swine. Serological testing was performed using commercial antibody ELISA kits for zoonotic and high-impact animal diseases, namely brucellosis, Q fever, classical swine fever (CSF), porcine reproductive and respiratory syndrome (PRRS) and African swine fever (ASF). Only two samples tested positive for Brucella antibodies (0.2%, 95% CI 0.4-0.6, n = 1141). The seroprevalence of Q fever was 0.8% (95% CI 0.3-2.1, n = 477) in the cattle samples, while CSF, PRRS and ASF in pigs were 55.4% (95% CI 51.6-59.2, n = 655), 81.2% (95% CI 78.1-84.0, n = 655) and 2.6% (95% CI 1.6-4.1, n = 664), respectively. All 38 doubtful and 17 positive ASF antibody ELISA samples were negative when tested by real-time PCR. Univariate analyses demonstrated that the factor significantly associated with positive results of ASF was the abattoir location (p-value = 0.002). Based on logistic regression models, significant risk factors for CSF were province of origin (p-value = 1.7 × 10-6), abattoir (p-value = 3.6 × 10-11) and PRRS positivity (p-value = 0.004), and for PRRS were province of origin (p-value = 0.0004) and CSF positivity (p-value = 0.001). In conclusion, the seroprevalences of zoonotic diseases in this study were very low. The high prevalence of CSF and PRRS antibodies were most likely the result of vaccination. All ASF seropositive pigs, including those that gave equivocal results, originated from large-scale Cambodian-based commercial farms, as well as Thailand, which raises questions about possible illegal vaccination or low-pathogenicity ASF variants. The pilot abattoir serological surveillance program described here has the potential to provide a sentinel for incursions of novel and endemic pathogens, although further work is required to demonstrate its capacity to provide information on the longitudinal disease trends.
Asunto(s)
Fiebre Porcina Africana , Enfermedades de los Bovinos , Peste Porcina Clásica , Síndrome Respiratorio y de la Reproducción Porcina , Fiebre Q , Enfermedades de los Porcinos , Mataderos , Fiebre Porcina Africana/epidemiología , Animales , Cambodia/epidemiología , Bovinos , Enfermedades de los Bovinos/epidemiología , Peste Porcina Clásica/epidemiología , Proyectos Piloto , Fiebre Q/veterinaria , Estudios Seroepidemiológicos , Porcinos , Zoonosis/epidemiologíaRESUMEN
Classical swine fever (CSF) is a highly contagious swine-specific disease which may have a huge economic impact for porcine production. CSF is caused by a virus belonging to the Pestivirus genus, which has expanded for the past 5 years with the discovery of new species whose genetic proximity to the CSF virus could further complicate laboratory diagnosis. The various forms of the disease, and in particular the increased frequency of attenuated forms, linked to an evolution of CSF virus strains towards a reduction in their virulence, delay clinical diagnosis. Thus, a long period may elapse before an outbreak is detected, allowing the virus to circulate longer, with the risk of spreading to distant geographical areas. Efforts must be maintained in terms of surveillance and diagnostic tools development in order to detect CSF virus infection early and thus limit the spread of the disease and facilitate control measures.
La peste porcine classique (PPC) est une maladie très contagieuse, spécifique des suidés, qui continue à constituer une menace pour la production porcine malgré un statut indemne de la plupart des pays de l'Union européenne. La PPC est causée par un virus de la famille des Flaviviridae appartenant au genre Pestivirus, en extension depuis les cinq dernières années avec la découverte de nouvelles espèces, notamment chez le porc ou autres animaux de rente dont la proximité génétique avec le virus de la PPC pourrait davantage compliquer le diagnostic de laboratoire. La diversité des formes de la maladie, et notamment la fréquence accrue des formes atténuées et inapparentes liée à une évolution des souches du virus de la PPC vers une réduction de leur virulence, retarde le diagnostic clinique. Ainsi, une longue période peut s'écouler avant la détection d'un foyer, permettant au virus de la PPC de circuler plus longuement, avec le risque de diffuser vers des zones géographiques éloignées des premiers cas d'infection. Les efforts doivent être maintenus en termes de surveillance et de développement d'outils de diagnostic afin de détecter précocement une infection par le virus de la PPC et ainsi limiter la propagation de la maladie et faciliter les mesures de contrôle.
Asunto(s)
Virus de la Fiebre Porcina Clásica , Peste Porcina Clásica , Pestivirus , Porcinos , Animales , Peste Porcina Clásica/diagnóstico , Peste Porcina Clásica/epidemiología , Peste Porcina Clásica/prevención & control , Virus de la Fiebre Porcina Clásica/genética , Brotes de EnfermedadesRESUMEN
BACKGROUND: Classical swine fever (CSF) is a contagious disease of pigs and wild boars that is transmitted through direct/indirect contact between animals or CSF virus-contaminated fomites. When the disease re-emerged in 2018 in Japan, a CSF-infected wild boar was reported shortly after the initial pig farm outbreak; subsequently, the disease spread widely. To control the disease spread among wild boars, intensive capturing, fencing, and oral bait vaccination were implemented with concomitant virological and serological surveillance. This study aimed to describe the disease spread in the wild boar population in Japan from September 2018, when the first case was reported, to March 2020, based on the surveillance data. We conducted statistical analyses using a generalized linear mixed model to identify factors associated with CSF infection among wild boars. Moreover, we descriptively assessed the effect of oral bait vaccination, which started in March 2019 in some municipalities in the affected areas. RESULTS: We observed a faster CSF infection spread in the wild boar population in Japan compared with the CSF epidemics in European countries. The infection probability was significantly higher in dead and adult animals. The influence of the multiple rounds of oral bait vaccination was not elucidated by the statistical modeling analyses. There was a decrease and increase in the proportion of infected and immune animals, respectively; however, the immunization in piglets remained insufficient after vaccination for 1 year. CONCLUSIONS: Conditions regarding the wild boar habitat, including forest continuity, higher wild boar population density, and a larger proportion of susceptible piglets, were addressed to increase the infection risk in the wild boar population. These findings could improve the national control strategy against the CSF epidemic among wild boars.
Asunto(s)
Peste Porcina Clásica/epidemiología , Sus scrofa , Vacunas Virales/administración & dosificación , Administración Oral , Animales , Anticuerpos Antivirales , Peste Porcina Clásica/inmunología , Peste Porcina Clásica/prevención & control , Virus de la Fiebre Porcina Clásica/inmunología , Brotes de Enfermedades/veterinaria , Japón/epidemiología , Porcinos , Vacunación/métodos , Vacunación/veterinaria , Vacunas Virales/inmunologíaRESUMEN
BACKGROUND: Porcine circovirus type 2 (PCV2) is one of the crucial swine viral pathogens, caused porcine circovirus associated diseases (PCVAD). Shandong province is one of the most important pork producing areas and bears a considerable economic loss due to PCVAD. However, there is limited information on epidemiology and coinfection rate of PCV2 with other critical swine diseases in this area, such as porcine reproductive and respiratory syndrome virus (PRRSV), classical swine fever virus (CSFV), Pseudorabies virus (PRV), and porcine epidemic diarrhea virus (PEDV). RESULTS: Overall, 89.59% serum samples and 36.98% tissue samples were positive for PCV2 specified ELISA and PCR positive for PCV2, respectively. The coinfection rates of PCV2 with PRRSV, PRV, CSFV, and PEDV were 26.73%, 18.37%, 13.06%, and 3.47%, respectively. Moreover, genetic characteristic of PCV2 were analyzed based on the cap genes showing that PCV2d is the dominant sub-genotype circulating in the province. CONCLUSIONS: Our findings reveal that PCV2d, as the dominant strain, is prevailing in pig farms in Shandong province at high levels. There was a high frequency of coinfection of PCV2 and PRRSV.
Asunto(s)
Infecciones por Circoviridae/veterinaria , Peste Porcina Clásica/epidemiología , Coinfección/veterinaria , Infecciones por Coronavirus/veterinaria , Síndrome Respiratorio y de la Reproducción Porcina/epidemiología , Seudorrabia/epidemiología , Enfermedades de los Porcinos/epidemiología , Animales , China/epidemiología , Infecciones por Circoviridae/epidemiología , Circovirus , Virus de la Fiebre Porcina Clásica/fisiología , Coinfección/epidemiología , Coinfección/virología , Infecciones por Coronavirus/epidemiología , Herpesvirus Suido 1/fisiología , Virus de la Diarrea Epidémica Porcina/fisiología , Virus del Síndrome Respiratorio y Reproductivo Porcino/fisiología , Porcinos , Enfermedades de los Porcinos/virologíaRESUMEN
Pork accounts for almost one-third of the meat consumed worldwide. Infectious diseases have a marked impact on pig production. Epidemiological indicators are considered the most useful criteria in decision-making; however, a health status assessment remains a challenge at the national and regional levels. This study proposes a health index including herd-losses, morbidity, fatality, and type of diseases, to rate the health situation in a region or country; it contributes to assessing the effectiveness of control, damage manifestation, and trends. It is a multidimensional index with a structure of triads and simple quantitative, semi-quantitative, and qualitative expressions that use flexible and dynamics limits. With it, we analyzed twenty-one countries in 2005-2018, focusing on African swine fever, classical swine fever, foot-mouth-disease, and porcine respiratory and reproductive syndrome, diseases that caused 72% of the morbidity. Our multidimensional approach estimates farm, local, and regional impact from infectious agents and outbreaks, and apprises trends aiming to be useful to control measures, strategic actions, and animal health policies.
Asunto(s)
Fiebre Porcina Africana/epidemiología , Peste Porcina Clásica/epidemiología , Monitoreo Epidemiológico/veterinaria , Fiebre Aftosa/epidemiología , Síndrome Respiratorio y de la Reproducción Porcina/epidemiología , Fiebre Porcina Africana/mortalidad , Fiebre Porcina Africana/virología , Animales , Peste Porcina Clásica/mortalidad , Peste Porcina Clásica/virología , Fiebre Aftosa/mortalidad , Fiebre Aftosa/virología , Síndrome Respiratorio y de la Reproducción Porcina/mortalidad , Síndrome Respiratorio y de la Reproducción Porcina/virología , Sus scrofa , PorcinosRESUMEN
Given the importance of pork in the Bhutanese diet and to enhance food security, the Government of Bhutan has generated policies to promote development of the swine sector in the country. One of the main threats to swine farming is classical swine fever (CSF), a transboundary disease of wild and domestic swine thought to be enzootic in the country. In 2018, three outbreaks of CSF were notified in Bhutan. The type of animals, their vaccine status, and the aftermath of these outbreaks highlight the interplay of epidemiological and context-specific factors that may result in CSF undermining the emerging Bhutanese swine sector. This communication reports on the CSF outbreaks of 2018, discusses some of the challenges posed by these events, and proposes some research priorities.
Asunto(s)
Peste Porcina Clásica/epidemiología , Brotes de Enfermedades/veterinaria , Porcinos , Vacunas Virales , Agricultura , Animales , Bután/epidemiología , Peste Porcina Clásica/prevención & control , Virus de la Fiebre Porcina Clásica , Brotes de Enfermedades/prevención & control , Brotes de Enfermedades/estadística & datos numéricos , Granjas , Abastecimiento de Alimentos , Enfermedades de los PorcinosRESUMEN
In September 2018, classical swine fever reemerged in Japan after 26 years, affecting domestic pigs and wild boars. The causative virus belongs to the 2.1 subgenotype, which caused repeated outbreaks in eastern and Southeast Asia. Intensive surveillance of swine and vaccination of wild boars will help control and eradicate this disease in Japan.
Asunto(s)
Virus de la Fiebre Porcina Clásica , Peste Porcina Clásica/epidemiología , Peste Porcina Clásica/virología , Animales , Peste Porcina Clásica/historia , Virus de la Fiebre Porcina Clásica/clasificación , Virus de la Fiebre Porcina Clásica/genética , Virus de la Fiebre Porcina Clásica/aislamiento & purificación , Genes Virales , Historia del Siglo XXI , Japón/epidemiología , Filogenia , Vigilancia en Salud Pública , ARN Viral , PorcinosRESUMEN
Two strains of classical swine fever virus (CSFV) (SRB/CSFV/1264/2005 and SRB/CSFV/6168/2006), producing serious clinical signs of disease during outbreaks in 2005 and 2006 in Serbia, were isolated on porcine kidney cells, and their complete genomes were determined by next-generation sequencing. This first complete genome characterization of Serbian CSFV strains provides new data about the evolution of CSFV in the Balkan region and enables further detailed phylogenetic studies of the various strains.
Asunto(s)
Virus de la Fiebre Porcina Clásica/aislamiento & purificación , Peste Porcina Clásica/virología , Genoma Viral , Animales , Secuencia de Bases , Peste Porcina Clásica/epidemiología , Virus de la Fiebre Porcina Clásica/clasificación , Virus de la Fiebre Porcina Clásica/genética , Brotes de Enfermedades , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , Filogenia , Serbia/epidemiología , Porcinos , Secuenciación Completa del GenomaRESUMEN
We report classical swine fever outbreaks occurring in naive pig herds on Jeju Island, South Korea, after the introduction of the LOM vaccine strain. Two isolates from sick pigs had >99% identity with the vaccine stain. LOM strain does not appear safe; its use in the vaccine should be reconsidered.
Asunto(s)
Virus de la Fiebre Porcina Clásica , Peste Porcina Clásica/epidemiología , Peste Porcina Clásica/virología , Brotes de Enfermedades , Animales , Peste Porcina Clásica/patología , Peste Porcina Clásica/prevención & control , Virus de la Fiebre Porcina Clásica/clasificación , Virus de la Fiebre Porcina Clásica/inmunología , República de Corea/epidemiología , Porcinos , Vacunación , Vacunas Virales/inmunologíaRESUMEN
BACKGROUND: Classical swine fever (CSF) is one of the most devastating and highly contagious viral diseases in the world. Since late 2014, outbreaks of a new sub-genotype 2.1d CSF virus (CSFV) had caused substantial economic losses in numbers of C-strain vaccinated swine farms in China. The objective of the present study was to explore the genomic characteristics and pathogenicity of the newly emerged CSFV isolates in China during 2014-2015. RESULTS: All the new 8 CSFV isolates belonged to genetic sub-genotype 2.1d. Some genomic variations or deletions were found in the UTRs and E2 of these new isolates. In addition, the pathogenicity of HLJ1 was less than Shimen, suggesting the HLJ1 of sub-genotype 2.1d may be a moderated pathogenic isolate and the C-strain vaccine can supply complete protection. CONCLUSIONS: The new CSFV isolates with unique genomic characteristics and moderate pathogenicity can be epidemic in many large-scale C-strain vaccinated swine farms. This study provides the information should be merited special attention on establishing prevention and control policies for CSF.
Asunto(s)
Virus de la Fiebre Porcina Clásica/genética , Peste Porcina Clásica/microbiología , Genoma Viral/genética , Animales , China/epidemiología , Peste Porcina Clásica/epidemiología , Peste Porcina Clásica/patología , Enfermedades Transmisibles Emergentes/epidemiología , Enfermedades Transmisibles Emergentes/veterinaria , Enfermedades Transmisibles Emergentes/virología , Filogenia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Análisis de Secuencia de ADN/veterinaria , PorcinosRESUMEN
Classical swine fever (CSF) is a globally significant disease of swine caused by classical swine fever virus. The virus affects the wild boars and pigs of all age groups, leading to acute, chronic, late-onset or in-apparent course of the disease. The disease causes great economic loss to the piggery industry due to mortality, stunted growth, poor reproductive performance, and by impeding the international trade of pig and pig products. In India, CSF outbreaks are reported from most of the states wherever pig rearing is practiced and more frequently from northeast states. In spite of the highly devastating nature and frequent outbreaks, CSF remained underestimated and neglected for decades in India. The country requires rapid and sensitive diagnostic tests for an early detection of infection to limit the spread of the disease. Also, effective prophylactics are required to help in control and eradication of the disease for the development of the piggery industry. This review looks into the economic impact; epidemiology of CSF highlighting the temporal and spatial occurrence of outbreaks in the last two decades, circulation, and emergence of the virus genotypes in and around the country; and the constraints in the disease control, with the aim to update the knowledge of current status of the disease in India. The article also emphasizes the importance of the disease and the need to develop rapid specific diagnostics and effective measures to eradicate the disease.
Asunto(s)
Peste Porcina Clásica/epidemiología , Animales , Peste Porcina Clásica/prevención & control , Peste Porcina Clásica/transmisión , Virus de la Fiebre Porcina Clásica/genética , Brotes de Enfermedades , Genotipo , India/epidemiología , PorcinosRESUMEN
For the global pig industry, classical (CSF) and African swine fever (ASF) outbreaks are a constantly feared threat. Except for Sardinia, ASF was eradicated in Europe in the late 1990s, which led to a research focus on CSF because this disease continued to be present. However, ASF remerged in eastern Europe in 2007 and the interest in the disease, its control and epidemiology increased tremendously. The similar names and the same susceptible species suggest a similarity of the two viral diseases, a related biological behaviour and, correspondingly, similar epidemiological features. However, there are several essential differences between both diseases, which need to be considered for the design of control or preventive measures. In the present review, we aimed to collate differences and similarities of the two diseases that impact epidemiology and thus the necessary control actions. Our objective was to discuss critically, if and to which extent the current knowledge can be transferred from one disease to the other and where new findings should lead to a critical review of measures relating to the prevention, control and surveillance of ASF and CSF. Another intention was to identify research gaps, which need to be closed to increase the chances of a successful eradication of ASF and therefore for a decrease of the economic threat for pig holdings and the international trade.
Asunto(s)
Virus de la Fiebre Porcina Africana/fisiología , Fiebre Porcina Africana , Virus de la Fiebre Porcina Clásica/fisiología , Peste Porcina Clásica , Fiebre Porcina Africana/epidemiología , Fiebre Porcina Africana/prevención & control , Fiebre Porcina Africana/virología , Animales , Peste Porcina Clásica/epidemiología , Peste Porcina Clásica/prevención & control , Peste Porcina Clásica/virología , PorcinosRESUMEN
Classical swine fever (CSF), a highly contagious viral disease affecting domestic and wild pigs in many developing countries, is now considered endemic in Mongolia, with 14 recent outbreaks in 2007, 2008, 2011, 2012, 2014, and 2015. For the first time, CSF viruses isolated from these 14 outbreaks were analyzed to assess their molecular epidemiology and pathogenicity in pigs. Based on the nucleotide sequences of their 5'-untranslated region, isolates were phylogenetically classified as either sub-genotypes 2.1b or 2.2, and the 2014 and 2015 isolates, which were classified as 2.1b, were closely related to isolates from China and Korea. In addition, at least three different viruses classified as 2.1b circulated in Mongolia. Experimental infection of the representative isolate in 2014 demonstrated moderate pathogenicity in 4-week-old pigs, with relatively mild clinical signs. Understanding the diversity of circulating CSF viruses gleans insight into disease dynamics and evolution, and may inform the design of effective CSF control strategies in Mongolia.
Asunto(s)
Virus de la Fiebre Porcina Clásica/clasificación , Virus de la Fiebre Porcina Clásica/genética , Virus de la Fiebre Porcina Clásica/aislamiento & purificación , Peste Porcina Clásica/epidemiología , Peste Porcina Clásica/virología , Epidemiología Molecular , Enfermedades de los Porcinos/virología , Virulencia/genética , Animales , Secuencia de Bases , Línea Celular , China , Peste Porcina Clásica/patología , Peste Porcina Clásica/fisiopatología , Modelos Animales de Enfermedad , Brotes de Enfermedades , Genotipo , Mongolia/epidemiología , Filogenia , República de Corea , Sus scrofa/virología , PorcinosRESUMEN
Classical swine fever is a viral disease of pigs that carries tremendous socio-economic impact. In outbreak situations, genetic typing is carried out for the purpose of molecular epidemiology in both domestic pigs and wild boar. These analyses are usually based on harmonized partial sequences. However, for high-resolution analyses towards the understanding of genetic variability and virus evolution, full-genome sequences are more appropriate. In this study, a unique set of representative virus strains was investigated that was collected during an outbreak in French free-ranging wild boar in the Vosges-du-Nord mountains between 2003 and 2007. Comparative sequence and evolutionary analyses of the nearly full-length sequences showed only slow evolution of classical swine fever virus strains over the years and no impact of vaccination on mutation rates. However, substitution rates varied amongst protein genes; furthermore, a spatial and temporal pattern could be observed whereby two separate clusters were formed that coincided with physical barriers.
Asunto(s)
Virus de la Fiebre Porcina Clásica/genética , Peste Porcina Clásica/virología , Evolución Molecular , Animales , Peste Porcina Clásica/epidemiología , Virus de la Fiebre Porcina Clásica/clasificación , Virus de la Fiebre Porcina Clásica/aislamiento & purificación , Brotes de Enfermedades , Europa (Continente)/epidemiología , Genotipo , Epidemiología Molecular , Filogenia , Sus scrofa , PorcinosRESUMEN
Oral mass vaccination (OMV) is considered as an efficient strategy for controlling classical swine fever (CSF) in wild boar. After the completion of vaccination, the presence of antibodies in 6-12 month-old hunted wild boars was expected to reflect a recent CSF circulation. Nevertheless, antibodies could also correspond to the long-lasting of maternal antibodies. This paper relates an experience of surveillance which lasted 4 years after the completion of OMV in a formerly vaccinated area, in north-eastern France (2010-2014). First, we conducted a retrospective analysis of the serological data collected in 6-12 month-old hunted wild boars from 2010 up to 2013, using a spatial Bayesian model accounting for hunting data autocorrelation and heterogeneity. At the level of the whole area, seroprevalence in juvenile boars decreased from 28% in 2010-2011 down to 1% in 2012-2013, but remained locally high (above 5%). The model revealed the existence of one particular seroprevalence hot-spot where a longitudinal survey of marked animals was conducted in 2013-2014, for deciphering the origin of antibodies. Eleven out of 107 captured piglets were seropositive when 3-4 months-old, but their antibody titres progressively decreased until 6-7 months of age. These results suggest piglets were carrying maternal antibodies, few of them carrying maternal antibodies lasting until the hunting season. Our study shows that OMV may generate confusion in the CSF surveillance several years after the completion of vaccination. We recommend using quantitative serological tools, hunting data modelling and capture approaches for better interpreting serological results after vaccination completion. Surveillance perspectives are further discussed.
Asunto(s)
Anticuerpos Antivirales/sangre , Virus de la Fiebre Porcina Clásica/inmunología , Monitoreo Epidemiológico/veterinaria , Vacunación Masiva/veterinaria , Sus scrofa , Administración Oral , Animales , Anticuerpos Neutralizantes/sangre , Peste Porcina Clásica/epidemiología , Peste Porcina Clásica/prevención & control , Peste Porcina Clásica/virología , Virus de la Fiebre Porcina Clásica/aislamiento & purificación , Femenino , Francia/epidemiología , Masculino , Prevalencia , Estudios Retrospectivos , Estudios Seroepidemiológicos , Porcinos , Vacunas Virales/inmunologíaRESUMEN
Current subgenotype 2.1 isolates of classical swine fever virus (CSFV) play a dominant role in CSF outbreaks in China, and a novel sub-subgenotype 2.1g of CSFV was recently identified, but the complete genome sequence of this new sub-subgenotype has not been reported. In this study, complete genome of 2.1g isolate GD19/2011 collected from Guangdong province of China in 2011 was sequenced. It was found to be 12,298 nucleotides (nt) in length, including a 375-nt 5'UTR, a 11,697-nt opening reading frame (ORF), and a 227-nt 3'UTR. GD19/2011 shared 91.0-93.7 % and 95.6-97.5 % nt and amino acid sequence identity, respectively, with other subgenotype 2.1 isolates. The topology of a phylogenetic tree constructed based on complete genome sequences of GD19/2011 and other CSFV isolates was identical to that obtained with full-length E2 gene sequences, but it was significantly different from those obtained with the 5'UTR and core sequences. Serial passages of GD9/2011 in PK-15 cells generated a highly cell-adapted virus stock with an infectious titer of 10(7.8) TCID50/ml at the 12(th) passage in which two amino acid substitutions, S476R and N2494S, were observed in comparison with the complete polyprotein sequence of the original isolate from kidney tissue, GD19/2011. This is the first report of the complete genome sequence of a 2.1g isolate, and the GD19/2011 isolate will be useful for further analysis of the evolution and virulence of CSFV isolates.
Asunto(s)
Virus de la Fiebre Porcina Clásica/genética , Peste Porcina Clásica/virología , Genoma Viral , Genotipo , Animales , China/epidemiología , Peste Porcina Clásica/epidemiología , Filogenia , PorcinosRESUMEN
BACKGROUND: Surveillance measures can only be effective if key players in the system accept them. Acceptability, which describes the willingness of persons to contribute, is often analyzed using participatory methods. Participatory epidemiology enables the active involvement of key players in the assessment of epidemiological issues. In the present study, we used a participatory method recently developed by CIRAD (Centre de Coopération Internationale en Recherche Agronomique pour le Développement) to evaluate the functionality and acceptability of Classical Swine Fever (CSF) surveillance in wild boar in Germany, which is highly dependent on the participation of hunters. The acceptability of alternative surveillance strategies was also analyzed. By conducting focus group discussions, potential vulnerabilities in the system were detected and feasible alternative surveillance strategies identified. RESULTS: Trust in the current surveillance system is high, whereas the acceptability of the operation of the system is medium. Analysis of the acceptability of alternative surveillance strategies showed how risk-based surveillance approaches can be combined to develop strategies that have sufficient support and functionality. Furthermore, some surveillance strategies were clearly rejected by the hunters. Thus, the implementation of such strategies may be difficult. CONCLUSIONS: Participatory methods can be used to evaluate the functionality and acceptability of existing surveillance plans for CSF among hunters and to optimize plans regarding their chances of successful implementation.
Asunto(s)
Peste Porcina Clásica/epidemiología , Sus scrofa , Animales , Peste Porcina Clásica/diagnóstico , Monitoreo Epidemiológico/veterinaria , Humanos , Vigilancia de la Población/métodos , Manejo de Especímenes/métodos , Manejo de Especímenes/veterinaria , PorcinosRESUMEN
The genus Pestivirus includes four species: bovine viral diarrhea virus 1, bovine viral diarrhea virus 2, classical swine fever disease virus, and ovine border disease virus. Pestiviruses infect many species of domestic and wild animals. Bovine viral diarrhea virus is a prototypical representative of the pestiviruses of ruminant animals. Recently, new candidates appeared for including in this genus: two viruses of the wild ruminant animals that have not been officially classified and one HoBi-like virus discovered for the first time in the bovine fetal serum. The circulation of the ruminant animal pestiviruses within population of domestic and wild animals, the presence of these viruses in bioproducts stimulates studies of the infection reservoirs and their influence on the effect of the bovine viral diarrhea control programs.