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Shaw C, McLure A, Glass K. Modelling African swine fever introduction in diverse Australian feral pig populations. Prev Vet Med 2024; 228:106212. [PMID: 38704921 DOI: 10.1016/j.prevetmed.2024.106212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/21/2023] [Accepted: 04/25/2024] [Indexed: 05/07/2024]
Abstract
African swine fever (ASF) is a viral disease that affects domestic and feral pigs. While not currently present in Australia, ASF outbreaks have been reported nearby in Indonesia, Timor-Leste, and Papua New Guinea. Feral pigs are found in all Australian states and territories and are distributed in a variety of habitats. To investigate the impacts of an ASF introduction event in Australia, we used a stochastic network-based metapopulation feral pig model to simulate ASF outbreaks in different regions of Australia. Outbreak intensity and persistence in feral pig populations was governed by local pig recruitment rates, population size, carcass decay period, and, if applicable, metapopulation topology. In Northern Australia, the carcass decay period was too short for prolonged persistence, while endemic transmission could possibly occur in cooler southern areas. Populations in Macquarie Marshes in New South Wales and in Namadgi National Park in the Australian Capital Territory had the highest rates of persistence. The regions had different modes of transmission that led to long-term persistence. Endemic Macquarie Marshes simulations were characterised by rapid transmission caused by high population density that required a fragmented metapopulation to act as a bottleneck to slow transmission. Endemic simulations in Namadgi, with low density and relatively slow transmission, relied on large, well-connected populations coupled with long carcass decay times. Despite the potential for endemic transmission, both settings required potentially unlikely population sizes and dynamics for prolonged disease survival.
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Affiliation(s)
- Callum Shaw
- National Centre for Epidemiology and Population Health, Australian National University, Canberra, ACT, Australia.
| | - Angus McLure
- National Centre for Epidemiology and Population Health, Australian National University, Canberra, ACT, Australia
| | - Kathryn Glass
- National Centre for Epidemiology and Population Health, Australian National University, Canberra, ACT, Australia
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2
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Nie W, Liu C. Assessing food safety risks based on a geospatial analysis: toward a cross-regional food safety management. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2023; 103:6654-6663. [PMID: 37261721 DOI: 10.1002/jsfa.12761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 04/22/2023] [Accepted: 06/01/2023] [Indexed: 06/02/2023]
Abstract
BACKGROUND Food safety risks (FSRs) are increasingly characterized by geographical complexity along with rapid urbanization, changing dietary pattern, and the modernization of the food industry. These factors pose challenges for food risk control in developing economies, more so during the global COVID-19 pandemic. The accurate assessment of risk source and transfer path is a crucial step toward enhancing cross-regional food safety management. This study aims to examine the spatial distribution, transfer path and driving factors of FSRs in China, provided with a national food safety database collected from 8.63 million batches of food sampling inspections for 33 different types of foods across 30 provinces. RESULTS The findings reveal significant regional disparities in FSRs, which is the highest in the west with small-scale sampling inspection and the lowest in the east with intensive sampling inspection. Catering and processed foods with higher daily consumption suffer more profound FSR than agricultural products. As evidenced by the shrinking low-low agglomeration areas, the local FSRs have been effectively controlled. The high-high agglomeration areas playing positive impacts on risk control are expanding while distributed discretely. CONCLUSION The spatial transfer of FSRs is significantly driven by multiple drivers: regulatory capacity and intensity, information disclosure, food industry, regional economy, and food consumption. Assessing FSRs based on a geospatial analysis contributes to identifying risk sources, optimizing risk management, and constructing a sustainable food safety system. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Wenjing Nie
- College of Humanities and Social Development, Nanjing Agricultural University, Nanjing, China
| | - Chunhui Liu
- College of Humanities and Social Development, Nanjing Agricultural University, Nanjing, China
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3
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Ito S, Kawaguchi N, Bosch J, Aguilar-Vega C, Sánchez-Vizcaíno JM. What can we learn from the five-year African swine fever epidemic in Asia? Front Vet Sci 2023; 10:1273417. [PMID: 37841468 PMCID: PMC10569053 DOI: 10.3389/fvets.2023.1273417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Accepted: 09/11/2023] [Indexed: 10/17/2023] Open
Abstract
Today's global swine industry is exposed to the unprecedented threat of African swine fever (ASF). Asia, the site of the most recent epidemics, could serve as a huge viral reservoir for the rest of the world given the severity of the damage, the huge swine industry, and the high volume of trade with other countries around the world. As the majority of ASF notifications in Asia today originate from pig farms, the movement of live pigs and associated pork products are considered critical control points for disease management. Particularly, small-scale or backyard farms with low biosecurity levels are considered major risk factors. Meanwhile, wild boars account for most notified cases in some countries and regions, which makes the epidemiological scenario different from that in other Asian countries. As such, the current epidemic situation and higher risk factors differ widely between these countries. A variety of studies on ASF control have been conducted and many valuable insights have been obtained in Asia; nevertheless, the overall picture of the epidemic is still unclear. The purpose of this review is to provide an accurate picture of the epidemic situation across Asia, focusing on each subregion to comprehensively explain the disease outbreak. The knowledge gained from the ASF epidemics experienced in Asia over the past 5 years would be useful for disease control in areas that are already infected, such as Europe, as well as for non-affected areas to address preventive measures. To this end, the review includes two aspects: a descriptive analytical review based on publicly available databases showing overall epidemic trends, and an individualized review at the subregional level based on the available literature.
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Affiliation(s)
- Satoshi Ito
- VISAVET Health Surveillance Center, Complutense University of Madrid, Madrid, Spain
- Department of Animal Health, Faculty of Veterinary Medicine, Complutense University of Madrid, Madrid, Spain
| | - Nijiho Kawaguchi
- VISAVET Health Surveillance Center, Complutense University of Madrid, Madrid, Spain
- Department of Animal Health, Faculty of Veterinary Medicine, Complutense University of Madrid, Madrid, Spain
- Division of Molecular Pathobiology, Hokkaido University International Institute for Zoonosis Control, Sapporo, Japan
| | - Jaime Bosch
- VISAVET Health Surveillance Center, Complutense University of Madrid, Madrid, Spain
- Department of Animal Health, Faculty of Veterinary Medicine, Complutense University of Madrid, Madrid, Spain
| | - Cecilia Aguilar-Vega
- VISAVET Health Surveillance Center, Complutense University of Madrid, Madrid, Spain
- Department of Animal Health, Faculty of Veterinary Medicine, Complutense University of Madrid, Madrid, Spain
| | - Jose Manuel Sánchez-Vizcaíno
- VISAVET Health Surveillance Center, Complutense University of Madrid, Madrid, Spain
- Department of Animal Health, Faculty of Veterinary Medicine, Complutense University of Madrid, Madrid, Spain
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4
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Kim Y, Nouvellet P, Rogoll L, Staubach C, Schulz K, Sauter-Louis C, Pfeiffer DU, Fournié G. Contrasting seasonality of African swine fever outbreaks and its drivers. Epidemics 2023; 44:100703. [PMID: 37385853 DOI: 10.1016/j.epidem.2023.100703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 05/30/2023] [Accepted: 06/12/2023] [Indexed: 07/01/2023] Open
Abstract
The seasonality of African swine fever (ASF) outbreaks in domestic pigs differs between temperate and subtropical/tropical regions. We hypothesise that variations in the importance of wild boar-to-farm and farm-to-farm transmission routes shape these contrasting patterns, and we emphasise the implications for effective ASF control.
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Affiliation(s)
| | - Pierre Nouvellet
- University of Sussex, Brighton, UK; Imperial College London, London, UK
| | - Lisa Rogoll
- Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | | | - Katja Schulz
- Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | | | - Dirk Udo Pfeiffer
- The Royal Veterinary College, London, UK; City University of Hong Kong, Hong Kong SAR, Hong Kong
| | - Guillaume Fournié
- The Royal Veterinary College, London, UK; Université de Lyon, INRAE, VetAgro Sup, UMR EPIA, Marcy l'Etoile, France; Université Clermont Auvergne, INRAE, VetAgro Sup, UMR EPIA, Saint-Gènes-Champanelle, France.
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Gilbert M, Dvornicky-Raymond Z, Bodgener J. Disease threats to tigers and their prey. Front Ecol Evol 2023. [DOI: 10.3389/fevo.2023.1135935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023] Open
Abstract
The contraction of the global tiger population over the last 100 years into small, often isolated subpopulations has made them increasingly vulnerable to the impact of disease. Despite this, the health of wild tigers continues to be insufficiently funded and explored. For example, canine distemper virus (CDV), has been associated with localized declines and increased risk of extinction, and yet has received little research attention in most tiger range countries. The emergence of new pathogenic threats has posed fresh challenges, including African swine fever virus (ASFV), which has the potential to devastate wild boar populations, and severe acute respiratory syndrome coronavirus (SARS-CoV2) with implications for tiger conservation that remain unknown. The objective of this review is to synthesize current research on the health of tigers and their prey that impacts the conservation of tigers in the wild. Published sources are interpreted based on three mechanisms through which disease can affect the viability of tiger populations: (1) by reducing the survival of adult tigers, (2) by reducing breeding productivity, and (3) by reducing the carrying capacity of tiger habitat through decreased prey abundance. Examples of CDV, SARS-CoV2, carnivore protoparvovirus 1 and ASFV are used to illustrate these processes and inform discussion of research and mitigation priorities.
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Three Years of African Swine Fever in South Korea (2019–2021): A Scoping Review of Epidemiological Understanding. Transbound Emerg Dis 2023. [DOI: 10.1155/2023/4686980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
African swine fever (ASF) is a highly contagious viral disease in domestic pigs and wild boar that causes tremendous socioeconomic damage in related industries. In 2019, the virus emerged in South Korea, which has since reported 21 outbreaks in domestic pig farms and over 2,600 cases in wild boar. In this review, we synthesize the epidemiological knowledge generated on ASF in South Korea during the first three years of the epidemic (2019–2021). We searched four international and one domestic Korean database to identify scientific articles published since 2019 and describing ASF epidemiology in South Korea. Fourteen articles met our selection criteria and were used to synthesize the origin of ASF in South Korea, the risk factors of disease occurrence, the effectiveness of the surveillance and intervention measures that were implemented, and the viral transmission dynamics. We found that timely intensive surveillance and interventions on domestic pig farms successfully blocked between-farm transmission. However, in wild boar, the ASF virus has spread massively towards the south primarily along the mountain ranges despite ongoing fence erection and intensive depopulation efforts, endangering domestic pig farms across the country. The current devastating epidemic is suspected to be the consequence of an ASF control strategy unaligned to the epidemiological context, the challenging implementation of control measures hindered by topological complexities, and inappropriate biosecurity by field workers. To improve our understanding of ASF epidemiology in South Korea and enhance disease management, future research studies should specify the ecological drivers of disease distribution and spread and devise effective control strategies, particularly in relation to Korean topography, and the latent spread of the virus in wild boar populations. Additionally, research studies should explore the psychosocial factors for ASF management, and develop tools to support evidence-based decision-making for managing ASFV in wild boar.
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Oberin M, Hillman A, Ward MP, Holley C, Firestone S, Cowled B. The Potential Role of Wild Suids in African Swine Fever Spread in Asia and the Pacific Region. Viruses 2022; 15:61. [PMID: 36680101 PMCID: PMC9867030 DOI: 10.3390/v15010061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Revised: 10/28/2022] [Accepted: 12/21/2022] [Indexed: 12/28/2022] Open
Abstract
African swine fever (ASF) in Asia and the Pacific is currently dominated by ASF virus transmission within and between domestic pig populations. The contribution made by wild suids is currently not well understood; their distribution, density and susceptibility to the virus has raised concerns that their role in the epidemiology of ASF in the region might be underestimated. Whilst in the Republic of Korea wild suids are considered important in the spread and maintenance of ASF virus, there is an apparent underreporting to official sources of the disease in wild suids from other countires and regions. A review of the current literature, an analysis of the official reporting resources and a survey of the World Organisation of Animal Health Member delegates in Asia and the Pacific were used to assess the potential role of wild suids in ASF outbreaks, and also to gain insight into what ASF management or control strategies are currently implemented for wild suids. Applying appropriate population control and management strategies can be increased in some areas, especially to assist in the conservation of endangered endemic wild suids in this region.
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Affiliation(s)
- Madalene Oberin
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3010, Australia
- Ausvet, Canberra, ACT 2617, Australia
| | - Alison Hillman
- Ausvet, Canberra, ACT 2617, Australia
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA 6150, Australia
| | - Michael P. Ward
- Sydney School of Veterinary Science, The University of Sydney, Camden, NSW 2570, Australia
| | - Caitlin Holley
- The World Organisation for Animal Health, Tokyo 113-8657, Japan
| | - Simon Firestone
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Brendan Cowled
- Ausvet, Canberra, ACT 2617, Australia
- Sydney School of Veterinary Science, The University of Sydney, Camden, NSW 2570, Australia
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Truong AD, Kang S, Dang HV, Hong Y, Vu TH, Heo J, Chu NT, Nguyen HT, Tran HTT, Hong YH. Small RNA sequencing and profiling of serum-derived exosomes from African swine fever virus-infected pigs. J Anim Sci 2022; 101:6881709. [PMID: 36478238 PMCID: PMC9940739 DOI: 10.1093/jas/skac400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
African swine fever (ASF) virus (ASFV) is responsible for one of the most severe swine diseases worldwide, with a morbidity rate of up to 100%; no vaccines or antiviral medicines are available against the virus. Exosomal miRNAs from individual cells can regulate the immune response to infectious diseases. In this study, pigs were infected with an ASFV Pig/HN/07 strain that was classified as acute form, and exosomal miRNA expression in the serum of infected pigs was analyzed using small RNA sequencing (small RNA-seq). Twenty-seven differentially expressed (DE) miRNAs were identified in the ASFV-infected pigs compared to that in the uninfected controls. Of these, 10 were upregulated and 17 were downregulated in the infected pigs. All DE miRNAs were analyzed using gene ontology (GO) terms and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, and the DE miRNAs were found to be highly involved in T-cell receptor signaling, cGMP-PKG signaling, Toll-like receptor, MAPK signaling, and mTOR signaling pathways. Furthermore, the Cytoscape network analysis identified the network of interactions between DE miRNAs and target genes. Finally, the transcription levels of four miRNA genes (ssc-miR-24-3p, ssc-miR-130b-3p, ssc-let-7a, and ssc-let-7c) were examined using quantitative real-time PCR (qRT-PCR) and were found to be consistent with the small RNA-seq data. These DE miRNAs were associated with cellular genes involved in the pathways related to immune response, virus-host interactions, and several viral genes. Overall, our findings provide an important reference and improve our understanding of ASF pathogenesis and the immune or protective responses during an acute infection in the host.
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Affiliation(s)
| | | | | | - Yeojin Hong
- Department of Animal Science and Technology, Chung-Ang University, Anseong 17546, Republic of Korea
| | - Thi Hao Vu
- Department of Animal Science and Technology, Chung-Ang University, Anseong 17546, Republic of Korea
| | - Jubi Heo
- Department of Animal Science and Technology, Chung-Ang University, Anseong 17546, Republic of Korea
| | - Nhu Thi Chu
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi 100000, Vietnam
| | - Huyen Thi Nguyen
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi 100000, Vietnam
| | - Ha Thi Thanh Tran
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi 100000, Vietnam
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Zhang P, Nie T, Ma J, Chen H. Identification of suitable areas for African swine fever occurrence in china using geographic information system-based multi-criteria analysis. Prev Vet Med 2022; 209:105794. [DOI: 10.1016/j.prevetmed.2022.105794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 09/28/2022] [Accepted: 10/28/2022] [Indexed: 11/06/2022]
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10
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Bacigalupo SA, Chang Y, Dixon LK, Gubbins S, Kucharski AJ, Drewe JA. The importance of fine-scale predictors of wild boar habitat use in an isolated population. Ecol Evol 2022; 12:e9031. [PMID: 35784084 PMCID: PMC9217887 DOI: 10.1002/ece3.9031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 05/19/2022] [Accepted: 05/27/2022] [Indexed: 12/30/2022] Open
Abstract
Predicting the likelihood of wildlife presence at potential wildlife-livestock interfaces is challenging. These interfaces are usually relatively small geographical areas where landscapes show large variation over small distances. Models of wildlife distribution based on coarse data over wide geographical ranges may not be representative of these interfaces. High-resolution data can help identify fine-scale predictors of wildlife habitat use at a local scale and provide more accurate predictions of species habitat use. These data may be used to inform knowledge of interface risks, such as disease transmission between wildlife and livestock, or human-wildlife conflict.This study uses fine-scale habitat use data from wild boar (Sus scrofa) based on activity signs and direct field observations in and around the Forest of Dean in Gloucestershire, England. Spatial logistic regression models fitted using a variant of penalized quasi-likelihood were used to identify habitat-based and anthropogenic predictors of wild boar signs.Our models showed that within the Forest of Dean, wild boar signs were more likely to be seen in spring, in forest-type habitats, closer to the center of the forest and near litter bins. In the area surrounding the Forest of Dean, wild boar signs were more likely to be seen in forest-type habitats and near recreational parks and less likely to be seen near livestock.This approach shows that wild boar habitat use can be predicted using fine-scale data over comparatively small areas and in human-dominated landscapes, while taking account of the spatial correlation from other nearby fine-scale data-points. The methods we use could be applied to map habitat use of other wildlife species in similar landscapes, or of movement-restricted, isolated, or fragmented wildlife populations.
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Affiliation(s)
| | - Yu‐mei Chang
- Royal Veterinary CollegeUniversity of LondonHatfieldUK
| | | | | | - Adam J. Kucharski
- London School of Hygiene & Tropical MedicineUniversity of LondonLondonUK
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11
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African swine fever virus: A raised global upsurge and a continuous threaten to pig husbandry. Microb Pathog 2022; 167:105561. [DOI: 10.1016/j.micpath.2022.105561] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 04/01/2022] [Accepted: 04/27/2022] [Indexed: 11/21/2022]
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Cadenas-Fernández E, Ito S, Aguilar-Vega C, Sánchez-Vizcaíno JM, Bosch J. The Role of the Wild Boar Spreading African Swine Fever Virus in Asia: Another Underestimated Problem. Front Vet Sci 2022; 9:844209. [PMID: 35573420 PMCID: PMC9093143 DOI: 10.3389/fvets.2022.844209] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 03/22/2022] [Indexed: 11/13/2022] Open
Abstract
African swine fever (ASF) is a highly lethal infectious disease in naive populations of domestic pigs and wild boar. In Asia, from the first outbreak in August 2018 until the end of November 2021, ASF has been reported in 16 Asian countries. The ASF virus (ASFV) circulation in domestic pigs is considered the main problem in Asia. On the other hand, there are very few reports of ASF in wild boar in this region. However, considering the high wild boar density within the same area of smallholder domestic pig farms in Asia, the occurrence of ASFV infection in wild boar may be underestimated. The role of the wild boar in other ASF epidemiological scenarios, such as Europe, is a key for the maintenance and transmission of the disease. Hence, we performed a preliminary study estimating the extent of ASFV infection in the Asian wild boar population. The potential risk area of ASF-infected wild boar was calculated based on the habitat suitability for wild boar, the kernel density of ASF notification in smallholder farms and wild boar, and the ASFV transmission rate of wild boar. As a result of the analysis, high-, medium-, and low-risk areas were identified throughout Southeast and East Asia. The highest risk area was detected in China, followed by Myanmar, Far East Russia, Thailand, Vietnam, Laos, Cambodia, and the Philippines. Additionally, another risk area was detected from northeastern China to the Korean Peninsula, including Far East Russia. This study shows hot spots where a high risk of infection in wild boar is most likely to occur, helping to control ASF.
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Affiliation(s)
- Estefanía Cadenas-Fernández
- VISAVET Health Surveillance Center, Complutense University of Madrid, Madrid, Spain
- Department of Animal Health, Faculty of Veterinary, Complutense University of Madrid, Madrid, Spain
- *Correspondence: Estefanía Cadenas-Fernández
| | - Satoshi Ito
- VISAVET Health Surveillance Center, Complutense University of Madrid, Madrid, Spain
- Department of Animal Health, Faculty of Veterinary, Complutense University of Madrid, Madrid, Spain
| | - Cecilia Aguilar-Vega
- VISAVET Health Surveillance Center, Complutense University of Madrid, Madrid, Spain
- Department of Animal Health, Faculty of Veterinary, Complutense University of Madrid, Madrid, Spain
| | - José Manuel Sánchez-Vizcaíno
- VISAVET Health Surveillance Center, Complutense University of Madrid, Madrid, Spain
- Department of Animal Health, Faculty of Veterinary, Complutense University of Madrid, Madrid, Spain
| | - Jaime Bosch
- VISAVET Health Surveillance Center, Complutense University of Madrid, Madrid, Spain
- Department of Animal Health, Faculty of Veterinary, Complutense University of Madrid, Madrid, Spain
- Jaime Bosch
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Nguyen VT, Cho KH, Mai NTA, Park JY, Trinh TBN, Jang MK, Nguyen TTH, Vu XD, Nguyen TL, Nguyen VD, Ambagala A, Kim YJ, Le VP. Multiple variants of African swine fever virus circulating in Vietnam. Arch Virol 2022; 167:1137-1140. [PMID: 35190886 DOI: 10.1007/s00705-022-05363-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 12/04/2021] [Indexed: 11/29/2022]
Abstract
African swine fever (ASF) is a contagious and deadly viral disease affecting swine of all ages. ASF was first reported in Vietnam in February 2019, and it is now considered endemic in Vietnam. In this study, 122 ASF-positive samples collected from domestic pigs in 28 different provinces of northern, central, and southern Vietnam during outbreaks in 2019-2021 were genetically characterized. The findings confirmed that all ASF virus (ASFV) strains circulating in Vietnam belonged to p72 genotype II, p54 genotype II, CD2v serogroup 8, and CVR gene variant type I. However, further analysis based on the tandem repeat sequences located between I73R and I329L genes revealed that there were three different variants of ASFV, IGR I, II, and III, circulating in the domestic pig population in Vietnam. The IGR II variants were the most prevalent (117/122 strains) and were detected in pigs in all of the provinces tested, followed by IGR III (4/122 strains) and IGR I (1/122 strains). This study confirms for the first time the presence of IGR III variants in Vietnam.
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Affiliation(s)
- Van Tam Nguyen
- College of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Ki-Hyun Cho
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Gimcheon, South Korea
| | - Nguyen Tuan Anh Mai
- College of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Jee-Yong Park
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Gimcheon, South Korea
| | - Thi Bich Ngoc Trinh
- College of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Min-Kyung Jang
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Gimcheon, South Korea
| | - Thi Thu Huyen Nguyen
- College of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam.,Bac Giang Agriculture and Forestry University, Bac Giang, Vietnam
| | - Xuan Dang Vu
- College of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Thi Lan Nguyen
- College of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Van Diep Nguyen
- College of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Aruna Ambagala
- National Centre for Foreign Animal Disease, Canadian Food Inspection Agency, Winnipeg, MB, Canada
| | - Yong-Joo Kim
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Gimcheon, South Korea.
| | - Van Phan Le
- College of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam.
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Tran HTT, Truong AD, Chu NT, Vu HN, Nguyen HT, Nguyen T, Siti F, Lee H, Leon AD, Yersin AG, Dang HV. Inhibition of African swine fever virus replication by β-glucan. Open Vet J 2022; 12:1027-1034. [PMID: 36650869 PMCID: PMC9805760 DOI: 10.5455/ovj.2022.v12.i6.31] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 11/22/2022] [Indexed: 12/30/2022] Open
Abstract
Background African swine fever (ASF) is one of the most important diseases in pigs because of its effects on all ages and breeds. To date, commercial vaccines and drugs for the prevention of ASF are lacking in the market and the survival of African swine fever virus (ASFV) in various environmental, farm, and or feed matrices has allowed the virus to remain, causing new outbreaks in the pig population. Besides biosecurity and animal husbandry management practices, the improvement of the host immune responses is critical to control, managing, and preventing ASF. Aim In this study, we investigated the protective role of β-glucan against ASFV infection using a porcine alveolar macrophage (PAM) model. Methods The effects of β-glucan on cell proliferation were evaluated by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The potential effects of β-glucan against a field ASFV strain isolated in Vietnam were further examined by real-time PCR and hemadsorption assays. The interferon (IFN)-α and interleukin (IL)-6 protein production induced by β-glucan was determined using a sandwich enzyme-linked immunosorbent assay. Results Our results demonstrated that the β-glucan additive possessed an immune stimulus factor against ASFV. Specifically, protection of PAMs against ASFV infection in vitro was observed at 12 hours (p < 0.05) at the tested doses (30 and 50 µg/ml) as induced by incubation with β-glucan for 2 hours. These effects remained until 24 hours after post-infection. Additionally, at a high dose (50 µg/ml), pre-treatment with the β-glucan statistically increased the expression levels of IFNα and IL-6 when compared to untreated groups or only ASFV infection. Conclusion Together, these findings indicated that the β-glucan may protect the host against ASFV infection via the multiple cellular immune mechanisms.
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Affiliation(s)
- Ha Thi Thanh Tran
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi 100000, Vietnam,Both authors contributed equally to this work
| | - Anh Duc Truong
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi 100000, Vietnam,Both authors contributed equally to this work
| | - Nhu Thi Chu
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi 100000, Vietnam
| | - Hoai Nam Vu
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi 100000, Vietnam
| | - Huyen Thi Nguyen
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi 100000, Vietnam
| | - Tinh Nguyen
- Kemin Animal Nutrition and Health, Asia Pacific 12 Senoko Drive, 758200 Singapore
| | - Fatimah Siti
- Kemin Animal Nutrition and Health, Asia Pacific 12 Senoko Drive, 758200 Singapore
| | - Hans Lee
- Kemin Animal Nutrition and Health, Asia Pacific 12 Senoko Drive, 758200 Singapore
| | - Alexander De Leon
- Kemin Animal Nutrition and Health, Asia Pacific 12 Senoko Drive, 758200 Singapore
| | | | - Hoang Vu Dang
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, 86 Truong Chinh, Dong Da, Hanoi 100000, Vietnam,Corresponding Author: Hoang Vu Dang. Department of Biochemistry and Immunology, National Institute of Veterinary Research, Hanoi, Vietnam.
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15
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Abstract
Next-generation sequencing (NGS) technologies have been powerfully applied in both research and clinical settings for the understanding and control of infectious disease. It enables high-resolution characterization of viral pathogens in terms of properties that include molecular epidemiology, genotype, serotype, and virulence. However, a beginner's NGS protocol for characterization of African swine fever virus (ASFV) is lacking. Here, we present detailed step-by-step methods for obtaining NGS data from ASF virus (ASFV) using the Illumina platform. The protocol has been performed with respect to ASFV DNA genome extraction, qualification of DNA, library preparation, quality control, de novo assembly, and data quality control. The protocol represents a step-by-step and reproducible method for producing high-quality sequencing data. The key advantages of this protocol include the protocol being very simple for users with no experience of genome sequencing and reproducibility of the protocol for other DNA genome viruses.
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Affiliation(s)
- Ha Thi Thanh Tran
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, Hanoi, Vietnam
| | - Anh Duc Truong
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, Hanoi, Vietnam
| | - Hoang Vu Dang
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, Hanoi, Vietnam.
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16
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Lim JS, Kim E, Ryu PD, Pak SI. Basic reproduction number of African swine fever in wild boars ( Sus scrofa) and its spatiotemporal heterogeneity in South Korea. J Vet Sci 2021; 22:e71. [PMID: 34553516 PMCID: PMC8460458 DOI: 10.4142/jvs.2021.22.e71] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 07/29/2021] [Accepted: 08/05/2021] [Indexed: 11/21/2022] Open
Abstract
Background African swine fever (ASF) is a hemorrhagic fever occurring in wild boars (Sus scrofa) and domestic pigs. The epidemic situation of ASF in South Korean wild boars has increased the risk of ASF in domestic pig farms. Although basic reproduction number (R0) can be applied for control policies, it is challenging to estimate the R0 for ASF in wild boars due to surveillance bias, lack of wild boar population data, and the effect of ASF-positive wild boar carcass on disease dynamics. Objectives This study was undertaken to estimate the R0 of ASF in wild boars in South Korea, and subsequently analyze the spatiotemporal heterogeneity. Methods We detected the local transmission clusters using the spatiotemporal clustering algorithm, which was modified to incorporate the effect of ASF-positive wild boar carcass. With the assumption of exponential growth, R0 was estimated for each cluster. The temporal change of the estimates and its association with the habitat suitability of wild boar were analyzed. Results Totally, 22 local transmission clusters were detected, showing seasonal patterns occurring in winter and spring. Mean value of R0 of each cluster was 1.54. The estimates showed a temporal increasing trend and positive association with habitat suitability of wild boar. Conclusions The disease dynamics among wild boars seems to have worsened over time. Thus, in areas with a high elevation and suitable for wild boars, practical methods need to be contrived to ratify the control policies for wild boars.
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Affiliation(s)
- Jun-Sik Lim
- College of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea
| | - Eutteum Kim
- College of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea
| | - Pan-Dong Ryu
- College of Veterinary Medicine, Seoul National University, Seoul 08732, Korea
| | - Son-Il Pak
- College of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea.
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17
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Denstedt E, Porco A, Hwang J, Nga NTT, Ngoc PTB, Chea S, Khammavong K, Milavong P, Sours S, Osbjer K, Tum S, Douangngeun B, Theppanya W, Van Long N, Thanh Phuong N, Tin Vinh Quang L, Van Hung V, Hoa NT, Le Anh D, Fine A, Pruvot M. Detection of African swine fever virus in free-ranging wild boar in Southeast Asia. Transbound Emerg Dis 2021; 68:2669-2675. [PMID: 33351995 PMCID: PMC8518571 DOI: 10.1111/tbed.13964] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/06/2020] [Accepted: 12/18/2020] [Indexed: 12/01/2022]
Abstract
African Swine Fever (ASF) is a highly contagious and fatal viral disease affecting both domestic and wild suids. The virus was introduced to Southeast Asia in early 2019 and has since spread rapidly throughout the region. Although significant efforts have been made to track and diagnose the disease in domestic pigs, very little is known about ASF in free-ranging wild boar and their potential role in maintaining the disease within Southeast Asia. Through a collaboration between government and non-government actors in Laos, Viet Nam, and Cambodia, investigations were conducted to (a) characterize the interface between domestic pigs and wild boar, (b) document risk factors for likely ASF spillover into wild boar populations by way of this interface, and (c) determine whether ASF in wild boar could be detected in each country. An extensive overlap between wild boar habitat and domestic pig ranging areas was found around villages bordering forests in all three countries, creating a high-risk interface for viral spillover between domestic pig and wild boar populations. Fifteen and three wild boar carcasses were detected through passive reporting in Laos and Viet Nam, respectively, in 2019 and early 2020. Four of five carcasses screened in Laos and two of three in Viet Nam were confirmed positive for African swine fever virus using real-time PCR. There were no confirmed reports of wild boar carcasses in Cambodia. This is the first confirmation of ASF in wild boar in Southeast Asia, the result of a probable viral spillover from domestic pigs, which highlights the importance of early reporting and monitoring of ASF in wild boar to enable the implementation of appropriate biosecurity measures.
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Affiliation(s)
- Emily Denstedt
- Wildlife Conservation SocietyLao PDR Country ProgramVientianeLaos
- Wildlife Conservation SocietyHealth ProgramBronxNYUSA
| | - Alice Porco
- Wildlife Conservation SocietyHealth ProgramBronxNYUSA
- Wildlife Conservation SocietyCambodia Country ProgramPhnom PenhCambodia
| | - Jusun Hwang
- Wildlife Conservation SocietyHealth ProgramBronxNYUSA
- Wildlife Conservation SocietyViet Nam Country ProgramHanoiViet Nam
- Biosafety Research TeamEnvironmental Health Research DepartmentNational Institute of Environmental ResearchIncheonSouth Korea
| | | | | | - Sokha Chea
- Wildlife Conservation SocietyCambodia Country ProgramPhnom PenhCambodia
| | | | | | - Sreyem Sours
- Wildlife Conservation SocietyCambodia Country ProgramPhnom PenhCambodia
| | - Kristina Osbjer
- Emergency Center for Transboundary Animal DiseasesFood and Agriculture Organization of the United NationsPhnom PenhCambodia
- Department of Clinical SciencesSwedish University of Agricultural SciencesUppsalaSweden
| | - Sothyra Tum
- Cambodian National Animal Health and Production Research InstitutePhnom PenhCambodia
| | - Bounlom Douangngeun
- Department of Livestock and FisheriesNational Animal Health LaboratoryVientianeLaos
| | - Watthana Theppanya
- Department of Livestock and FisheriesNational Animal Health LaboratoryVientianeLaos
| | - Nguyen Van Long
- Department of Animal HealthMinistry of Agricultural and Rural Development of Viet NamHanoiViet Nam
| | | | | | - Vo Van Hung
- Regional Animal Health Office No. 6Ho Chi Minh CityViet Nam
| | - Nguyen Thi Hoa
- Viet Nam National University of AgricultureHanoiViet Nam
| | - Dao Le Anh
- Viet Nam National University of AgricultureHanoiViet Nam
| | - Amanda Fine
- Wildlife Conservation SocietyHealth ProgramBronxNYUSA
- Wildlife Conservation SocietyViet Nam Country ProgramHanoiViet Nam
| | - Mathieu Pruvot
- Wildlife Conservation SocietyHealth ProgramBronxNYUSA
- Faculty of Veterinary MedicineUniversity of CalgaryCalgaryAlbertaCanada
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18
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Barroso-Arévalo S, Barasona JA, Cadenas-Fernández E, Sánchez-Vizcaíno JM. The Role of Interleukine-10 and Interferon-γ as Potential Markers of the Evolution of African Swine Fever Virus Infection in Wild Boar. Pathogens 2021; 10:pathogens10060757. [PMID: 34203976 PMCID: PMC8232672 DOI: 10.3390/pathogens10060757] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/03/2021] [Accepted: 06/11/2021] [Indexed: 12/24/2022] Open
Abstract
African swine fever virus (ASFv) is one of the most challenging pathogens to affect both domestic and wild pigs. The disease has now spread to Europe and Asia, causing great damage to the pig industry. Although no commercial vaccine with which to control the disease is, as yet, available, some potential vaccine candidates have shown good results in terms of protection. However, little is known about the host immune mechanisms underlying that protection, especially in wild boar, which is the main reservoir of the disease in Europe. Here, we study the role played by two cytokines (IL-10 and IFN-γ) in wild boar orally inoculated with the attenuated vaccine candidate Lv17/WB/Rie1 and challenged with a virulent ASFv genotype II isolate. A group of naïve wild boar challenged with the latter isolate was also established as a control group. Our results showed that both cytokines play a key role in protecting the host against the challenge virus. While high levels of IL-10 in serum may trigger an immune system malfunctioning in challenged animals, the provision of stable levels of this cytokine over time may help to control the disease. This, together with high and timely induction of IFN-γ by the vaccine candidate, could help protect animals from fatal outcomes. Further studies should be conducted in order to support these preliminary results and confirm the role of these two cytokines as potential markers of the evolution of ASFV infection.
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Affiliation(s)
- Sandra Barroso-Arévalo
- VISAVET Health Surveillance Center, Complutense University of Madrid, 28040 Madrid, Spain; (J.A.B.); (E.C.-F.); (J.M.S.-V.)
- Department of Animal Health, Faculty of Veterinary, Complutense University of Madrid, 28040 Madrid, Spain
- Correspondence:
| | - Jose A. Barasona
- VISAVET Health Surveillance Center, Complutense University of Madrid, 28040 Madrid, Spain; (J.A.B.); (E.C.-F.); (J.M.S.-V.)
- Department of Animal Health, Faculty of Veterinary, Complutense University of Madrid, 28040 Madrid, Spain
| | - Estefanía Cadenas-Fernández
- VISAVET Health Surveillance Center, Complutense University of Madrid, 28040 Madrid, Spain; (J.A.B.); (E.C.-F.); (J.M.S.-V.)
- Department of Animal Health, Faculty of Veterinary, Complutense University of Madrid, 28040 Madrid, Spain
| | - Jose M. Sánchez-Vizcaíno
- VISAVET Health Surveillance Center, Complutense University of Madrid, 28040 Madrid, Spain; (J.A.B.); (E.C.-F.); (J.M.S.-V.)
- Department of Animal Health, Faculty of Veterinary, Complutense University of Madrid, 28040 Madrid, Spain
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19
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Yoon H, Hong SK, Lee I, Choi DS, Lee JH, Lee E, Wee SH. Arthropods as potential vectors of African swine fever virus outbreaks in pig farms in the Republic of Korea. Vet Med Sci 2021; 7:1841-1844. [PMID: 34085400 PMCID: PMC8464277 DOI: 10.1002/vms3.545] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 03/30/2021] [Accepted: 05/03/2021] [Indexed: 11/25/2022] Open
Abstract
The seasonality of African swine fever (ASF) in the summers and outbreaks in farms with high biosecurity levels suggest that the ASF virus (ASFV) may be transmitted by arthropod vectors. Arthropods were collected in this study from 14 pig farms with ASF outbreaks in Korea in 2019 to explore the role of arthropods as potential ASFV vectors. A total of 28,729 arthropods, including 28,508 (99.2%) Diptera, were collected using blacklight traps, insect nets and yellow sticky strips. All arthropod samples were negative for ASFV genomic DNA according to laboratory tests using real‐time polymerase chain reaction. This result may reflect the effects of immediate control measures following the detection of farms with ASF outbreaks in the early phase of infection in Korea. We collected 28,729 arthropods in 14 outbreaks pig farms in Korea to know the possibility that ASF may be transmitted by arthropod vector.
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Affiliation(s)
- Hachung Yoon
- Veterinary Epidemiology Division, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
| | - Seong-Keun Hong
- Veterinary Epidemiology Division, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
| | - Ilseob Lee
- Veterinary Epidemiology Division, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
| | - Deuk-Soo Choi
- Plant Quarantine Technology Center, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
| | - Jong-Ho Lee
- Plant Pest Control Division, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
| | - Eunesub Lee
- Veterinary Epidemiology Division, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
| | - Sung-Hwan Wee
- Department of Animal Disease Control and Quarantine, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
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20
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Jo YS, Gortázar C. African Swine Fever in wild boar: Assessing interventions in South Korea. Transbound Emerg Dis 2021; 68:2878-2889. [PMID: 33844467 DOI: 10.1111/tbed.14106] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/05/2021] [Accepted: 04/07/2021] [Indexed: 11/25/2022]
Abstract
African Swine Fever (ASF) was detected in South Korean pig farms in September 2019. Currently, ASF occurs mostly in wild boar (Sus scrofa). We describe the ASF dynamics in wild boar in South Korea from October 2019 to October 2020 and use case studies to evidence the advantages and limitations of the control measures applied. During 2019, ASF remained confined in fenced areas of three counties. Since January 2020 however, the ASF management policy changed from fencing with limited disturbance to culling (with more disturbance), and ASF spread east and south. Until 31 October 2020, a total of 775 wild boar ASF cases have been confirmed, affecting 9 counties. Interventions for ASF control in wild boar included silent (trapping) and non-silent (shooting) population control, local and large-scale fencing, and carcass destruction. Pre-ASF wild boar densities were closed to 10 per km2 . Biosafety risks arose from the movements of people and vehicles, swill feeding of wild boar, destroying pig herds, handling wild boar during trapping and hunting, and searching for and disposing of carcasses. Despite training efforts, biosafety regulations were sometimes ignored. We observed differences between counties regarding disease control. While interventions apparently succeeded in controlling ASF in one site where geographical features and fast decision making facilitated an early and efficient fencing, and culling was performed silently, biosafety problems and habitat- and management-related delays hindered ASF control in other situations. Given that carcass, destruction faces specific limitations in South Korea, fencing and trapping (under appropriate biosafety conditions) might represent the most effective intervention option.
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Affiliation(s)
- Yeong-Seok Jo
- Department of Biology Education, Daegu University, Gyeongsan, South Korea
| | - Christian Gortázar
- SaBio Instituto de Investigación en Recursos Cinegéticos IREC, Universidad de Castilla-La Mancha & CSIC, Ciudad Real, Spain
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21
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Lim JS, Vergne T, Pak SI, Kim E. Modelling the Spatial Distribution of ASF-Positive Wild Boar Carcasses in South Korea Using 2019-2020 National Surveillance Data. Animals (Basel) 2021; 11:ani11051208. [PMID: 33922261 PMCID: PMC8145688 DOI: 10.3390/ani11051208] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/19/2021] [Accepted: 04/19/2021] [Indexed: 11/18/2022] Open
Abstract
Simple Summary Since African swine fever (ASF) virus in wild boar populations can spill over to domestic pigs, it is crucial to understand the disease determinants in the wild compartment. However, the imperfect detection sensitivity of wild boar surveillance jeopardizes our ability to understand ASF spatial distribution. In this study, we used national surveillance data of ASF in wild boars collected in the Republic of Korea from 2019–2020 to model the spatial distribution of ASF-positive carcasses for two successive study periods associated with different surveillance intensity. The model allowed us to identify disease risk factors in the Republic of Korea, determine the spatial distribution of the risk of ASF, and estimate the sensitivity of surveillance. The outputs of this study are relevant to policy makers for developing and improving risk-based surveillance programs for ASF in wild boars. Abstract In September 2019, African swine fever (ASF) was reported in South Korea for the first time. Since then, more than 651 ASF cases in wild boars and 14 farm outbreaks have been notified in the country. Despite the efforts to eradicate ASF among wild boar populations, the number of reported ASF-positive wild boar carcasses have increased recently. The purpose of this study was to characterize the spatial distribution of ASF-positive wild boar carcasses to identify the risk factors associated with the presence and number of ASF-positive wild boar carcasses in the affected areas. Because surveillance efforts have substantially increased in early 2020, we divided the study into two periods (2 October 2019 to 19 January 2020, and 19 January to 28 April 2020) based on the number of reported cases and aggregated the number of reported ASF-positive carcasses into a regular grid of hexagons of 3-km diameter. To account for imperfect detection of positive carcasses, we adjusted spatial zero-inflated Poisson regression models to the number of ASF-positive wild boar carcasses per hexagon. During the first study period, proximity to North Korea was identified as the major risk factor for the presence of African swine fever virus. In addition, there were more positive carcasses reported in affected hexagons with high habitat suitability for wild boars, low heat load index (HLI), and high human density. During the second study period, proximity to an ASF-positive carcass reported during the first period was the only significant risk factor for the presence of ASF-positive carcasses. Additionally, low HLI and elevation were associated with an increased number of ASF-positive carcasses reported in the affected hexagons. Although the proportion of ASF-affected hexagons increased from 0.06 (95% credible interval (CrI): 0.05–0.07) to 0.09 (95% CrI: 0.08–0.10), the probability of reporting at least one positive carcass in ASF-affected hexagons increased from 0.49 (95% CrI: 0.41–0.57) to 0.73 (95% CrI: 0.66–0.81) between the two study periods. These results can be used to further advance risk-based surveillance strategies in the Republic of Korea.
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Affiliation(s)
- Jun-Sik Lim
- College of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea; (J.-S.L.); (S.-I.P.)
| | - Timothée Vergne
- UMR ENVT-INRAE 1225, Ecole Nationale Vétérinaire de Toulouse, 31300 Toulouse, France;
| | - Son-Il Pak
- College of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea; (J.-S.L.); (S.-I.P.)
| | - Eutteum Kim
- College of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea; (J.-S.L.); (S.-I.P.)
- Correspondence:
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22
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Hayes BH, Andraud M, Salazar LG, Rose N, Vergne T. Mechanistic modelling of African swine fever: A systematic review. Prev Vet Med 2021; 191:105358. [PMID: 33930624 DOI: 10.1016/j.prevetmed.2021.105358] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 04/06/2021] [Accepted: 04/13/2021] [Indexed: 12/11/2022]
Abstract
The spread of African swine fever (ASF) poses a grave threat to the global swine industry. Without an available vaccine, understanding transmission dynamics is essential for designing effective prevention, surveillance, and intervention strategies. These dynamics can often be unraveled through mechanistic modelling. To examine the assumptions on transmission and objectives of the mechanistic models of ASF, a systematic review of the scientific literature was conducted. Articles were examined across multiple epidemiological and model characteristics, with filiation between models determined through the creation of a neighbor-joined tree using phylogenetic software. Thirty-four articles qualified for inclusion, with four main modelling objectives identified: estimating transmission parameters (11 studies), assessing determinants of transmission (7), examining consequences of hypothetical outbreaks (5), assessing alternative control strategies (11). Population-based (17), metapopulation (5), and individual-based (12) model frameworks were represented, with population-based and metapopulation models predominantly used among domestic pigs, and individual-based models predominantly represented among wild boar. The majority of models (25) were parameterized to the genotype II isolates currently circulating in Europe and Asia. Estimated transmission parameters varied widely among ASFV strains, locations, and transmission scale. Similarly, parameter assumptions between models varied extensively. Uncertainties on epidemiological and ecological parameters were usually accounted for to assess the impact of parameter values on the modelled infection trajectory. To date, almost all models are host specific, being developed for either domestic pigs or wild boar despite the fact that spillover events between domestic pigs and wild boar are evidenced to play an important role in ASF outbreaks. Consequently, the development of more models incorporating such transmission routes is crucial. A variety of codified and hypothetical control strategies were compared however they were all a priori defined interventions. Future models, built to identify the optimal contributions across many control methods for achieving specific outcomes should provide more useful information for policy-makers. Further, control strategies were examined in competition with each other, which is opposed to how they would actually be synergistically implemented. While comparing strategies is beneficial for identifying a rank-order efficacy of control methods, this structure does not necessarily determine the most effective combination of all available strategies. In order for ASFV models to effectively support decision-making in controlling ASFV globally, these modelling limitations need to be addressed.
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Affiliation(s)
- Brandon H Hayes
- UMR ENVT-INRAE IHAP, National Veterinary School of Toulouse, 31000, Toulouse, France; Epidemiology Health and Welfare Department, Ploufragan-Plouzané-Niort Laboratory, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), 22440, Ploufragan, France.
| | - Mathieu Andraud
- Epidemiology Health and Welfare Department, Ploufragan-Plouzané-Niort Laboratory, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), 22440, Ploufragan, France
| | - Luis G Salazar
- Epidemiology Health and Welfare Department, Ploufragan-Plouzané-Niort Laboratory, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), 22440, Ploufragan, France
| | - Nicolas Rose
- Epidemiology Health and Welfare Department, Ploufragan-Plouzané-Niort Laboratory, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), 22440, Ploufragan, France
| | - Timothée Vergne
- UMR ENVT-INRAE IHAP, National Veterinary School of Toulouse, 31000, Toulouse, France
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23
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Tran HTT, Truong AD, Dang AK, Ly DV, Nguyen CT, Chu NT, Hoang TV, Nguyen HT, Dang HV. Circulation of two different variants of intergenic region (IGR) located between the I73R and I329L genes of African swine fever virus strains in Vietnam. Transbound Emerg Dis 2021; 68:2693-2695. [PMID: 33471420 DOI: 10.1111/tbed.13996] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 12/06/2020] [Accepted: 01/16/2021] [Indexed: 12/19/2022]
Abstract
Since African swine fever virus (ASFV) introduction into Vietnam in 2019, most ASFV strains detected in this country belong to the p72 genotype II and intergenic region (IGR) II variant. Further investigation of the intergenic region of ASFVs isolated in the Capital Hanoi region showed two different variants, IGR I and IGR II, which were located between the I73R and I329L genes of the p72 genotype II ASFV strains. This finding suggests co-circulation of two ASFV variants in the domestic pig population in Vietnam.
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Affiliation(s)
- Ha Thi Thanh Tran
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, Hanoi, Vietnam
| | - Anh Duc Truong
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, Hanoi, Vietnam
| | - Anh Kieu Dang
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, Hanoi, Vietnam
| | - Duc Viet Ly
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, Hanoi, Vietnam
| | - Chinh Thi Nguyen
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, Hanoi, Vietnam
| | - Nhu Thi Chu
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, Hanoi, Vietnam
| | - Tuan Van Hoang
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, Hanoi, Vietnam
| | - Huyen Thi Nguyen
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, Hanoi, Vietnam
| | - Hoang Vu Dang
- Department of Biochemistry and Immunology, National Institute of Veterinary Research, Hanoi, Vietnam
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24
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Luskin MS, Meijaard E, Surya S, Sheherazade, Walzer C, Linkie M. African Swine Fever threatens Southeast Asia's 11 endemic wild pig species. Conserv Lett 2020. [DOI: 10.1111/conl.12784] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
- Matthew Scott Luskin
- School of Biological Sciences University of Queensland Brisbane Queensland Australia
| | - Erik Meijaard
- Borneo Futures Bandar Seri Begawan Brunei Darussalam
- Durrell Institute of Conservation and Ecology University of Kent Canterbury Kent UK
| | - Selly Surya
- Wildlife Conservation Society, Indonesia Program Bogor West Java Indonesia
| | - Sheherazade
- Wildlife Conservation Society, Indonesia Program Bogor West Java Indonesia
| | - Chris Walzer
- Wildlife Conservation Society, The Bronx New York
- Research Institute of Wildlife Ecology University of Veterinary Medicine Vienna Austria
| | - Matthew Linkie
- Wildlife Conservation Society, Indonesia Program Bogor West Java Indonesia
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