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Penrith ML, van Emmenes J, Hakizimana JN, Heath L, Kabuuka T, Misinzo G, Odoom T, Wade A, Zerbo HL, Luka PD. African Swine Fever Diagnosis in Africa: Challenges and Opportunities. Pathogens 2024; 13:296. [PMID: 38668251 PMCID: PMC11054189 DOI: 10.3390/pathogens13040296] [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: 02/07/2024] [Revised: 03/18/2024] [Accepted: 03/29/2024] [Indexed: 04/29/2024] Open
Abstract
The global spread of African swine fever (ASF) in recent decades has led to the need for technological advances in sampling and diagnostic techniques. The impetus for these has been the need to enable sampling by lay persons and to obtain at least a preliminary diagnosis in the field for early control measures to be put in place before final laboratory confirmation. In rural Africa, rapid diagnosis is hampered by challenges that include lack of infrastructure as well as human and financial resources. Lack of animal health personnel, access to affordable means to transport field samples to a laboratory, and lack of laboratories with the capacity to make the diagnosis result in severe under-reporting of ASF, especially in endemic areas. This review summarizes the challenges identified in gap analyses relevant to low- and middle-income countries, with a focus on Africa, and explore the opportunities provided by recent research to improve field diagnosis and quality of diagnostic samples used. Sampling techniques include invasive sampling techniques requiring trained personnel and non-invasive sampling requiring minimal training, sampling of decomposed carcass material, and preservation of samples in situations where cold chain maintenance cannot be guaranteed. Availability and efficacy of point-of-care (POC) tests for ASF has improved considerably in recent years and their application, as well as advantages and limitations, are discussed. The adequacy of existing laboratory diagnostic capacity is evaluated and opportunities for networking amongst reference and other laboratories offering diagnostic services are discussed. Maintaining laboratory diagnostic efficiency in the absence of samples during periods of quiescence is another issue that requires attention, and the role of improved laboratory networking is emphasized. Early diagnosis of ASF is key to managing the disease spread. Therefore, the establishment of the Africa Chapter of the Global African Swine Fever Research Alliance (GARA) increases opportunities for collaboration and networking among the veterinary diagnostic laboratories in the region.
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Affiliation(s)
- Mary-Louise Penrith
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0110, South Africa
| | - Juanita van Emmenes
- Transboundary Animal Diseases, Onderstepoort Veterinary Institute, Agricultural Research Council, Pretoria 0110, South Africa; (J.v.E.); (L.H.)
| | - Jean N. Hakizimana
- SACIDS Africa Centre of Excellence for Infectious Diseases, SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro P.O. Box 3297, Tanzania; (J.N.H.); (G.M.)
| | - Livio Heath
- Transboundary Animal Diseases, Onderstepoort Veterinary Institute, Agricultural Research Council, Pretoria 0110, South Africa; (J.v.E.); (L.H.)
| | - Tonny Kabuuka
- National Livestock Resources Research Institute, National Agricultural Research Organization, Entebbe P.O. Box 295, Uganda;
| | - Gerald Misinzo
- SACIDS Africa Centre of Excellence for Infectious Diseases, SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro P.O. Box 3297, Tanzania; (J.N.H.); (G.M.)
- Department of Veterinary Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro P.O. Box 3019, Tanzania
| | - Theophilus Odoom
- Veterinary Services Directorate, Accra Veterinary Laboratory, Accra P.O. Box M161, Ghana;
| | - Abel Wade
- National Veterinary Laboratory (LANAVET), Garoua P.O. Box 503, Cameroon;
| | - Habibata L. Zerbo
- Ministry of Agriculture, Animal and Fisheries Resources, Ouagadougou 03 BP 907, Burkina Faso;
| | - Pam D. Luka
- Biotechnology Centre, National Veterinary Research Institute, PMB 1, Vom 930103, Nigeria
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Kayaga EB, Wampande EM, Ekakoro JE, Okwasiimire R, Nassali A, Ochoa K, Hauser C, Ndoboli D, Havas KA. Detection of antibodies against Ornithodoros moubata salivary antigens and their association with detection of African swine fever virus in pigs slaughtered in central Uganda. Front Vet Sci 2024; 11:1328040. [PMID: 38605921 PMCID: PMC11007201 DOI: 10.3389/fvets.2024.1328040] [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: 10/26/2023] [Accepted: 03/14/2024] [Indexed: 04/13/2024] Open
Abstract
Introduction African swine fever (ASF) is an important disease of pigs in sub-Saharan Africa and Uganda and is threatening the pig population and agricultural economy of other continents. ASF virus (ASFV) can be transmitted from wild suids to domestic pigs through soft ticks of the Ornithodoros species. The aim of this study was to understand the relationship between domestic pigs' O. moubata tick exposure and ASFV status. Methods Pigs were sampled from six abattoirs in the Kampala metropolitan area of Uganda from May 2021 through June 2022. Blood, serum, and tissue samples were collected. Serum was tested for antibodies against the rtTSGP1 salivary antigens of O. moubata ticks using an indirect ELISA assay. Blood and tissue samples from pigs were tested to detect ASFV using qPCR. Probability of tick exposure was categorized based on sample-to-positive ratio cut-off points. Results Out of 1,328 serum samples tested, there were 828 (62.3%) samples with a negligible probability; 369 (27.8%) with a medium probability; 90 (6.8%) with a high probability, and 41 (3.1%) with a very high probability of exposure to the O. moubata salivary antigen. There was a statistically significant association between the pigs' O. moubata exposure and ASFV status with a higher proportion of pigs having a very high probability of infection if they were ASFV positive by blood, tonsil, and lymph nodes. Discussion These results suggested that tick exposure was associated with ASFV transmission in Uganda. There were ASFV qPCR positive pigs that had no O. moubata exposure as well, which highlights that pig-to-pig and indirect contact transmission still play a significant role. This work highlights the need for further work in Uganda to investigate these transmission factors related to the O. moubata tick and ASFV transmission.
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Affiliation(s)
- Edrine B. Kayaga
- Central Diagnostic Laboratory, College of Veterinary Medicine, Animal Resources, and Biosecurity, Makerere University, Kampala, Uganda
| | - Eddie M. Wampande
- Central Diagnostic Laboratory, College of Veterinary Medicine, Animal Resources, and Biosecurity, Makerere University, Kampala, Uganda
| | - John E. Ekakoro
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
| | - Rodney Okwasiimire
- Central Diagnostic Laboratory, College of Veterinary Medicine, Animal Resources, and Biosecurity, Makerere University, Kampala, Uganda
| | - Aisha Nassali
- Central Diagnostic Laboratory, College of Veterinary Medicine, Animal Resources, and Biosecurity, Makerere University, Kampala, Uganda
| | - Krista Ochoa
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
| | - Cole Hauser
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
| | - Dickson Ndoboli
- Central Diagnostic Laboratory, College of Veterinary Medicine, Animal Resources, and Biosecurity, Makerere University, Kampala, Uganda
| | - Karyn A. Havas
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
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Okwasiimire R, Kayaga EB, Ekakoro JE, Ndoboli D, Schumann K, Faburay B, Nassali A, Hauser C, Ochoa K, Wampande EM, Havas KA. Spatiotemporal description of African swine fever virus nucleic acid and antibodies detected in pigs sampled at abattoirs in the greater Kampala metropolitan area, Uganda from May 2021 through June 2022. Porcine Health Manag 2023; 9:51. [PMID: 37919811 PMCID: PMC10623799 DOI: 10.1186/s40813-023-00345-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 10/25/2023] [Indexed: 11/04/2023] Open
Abstract
BACKGROUND African swine fever virus (ASFV) infections in Africa cause hemorrhagic disease in domestic pigs and is maintained by a sylvatic cycle in warthogs. It is endemic in Uganda, leading to significant economic losses. Previous studies performed in rural areas and in Kampala had differing diagnostic results. The purpose of this study was to provide a robust spatial, temporal, and diagnostic summary of pigs slaughtered in the greater Kampala metropolitan area over the course of one year. This study characterized 1208 to 1323 serum, blood, and tissue samples collected from pigs at six abattoirs in the greater Kampala metropolitan area of Uganda monthly from May 2021 through June 2022. Validated and standardized serologic and molecular diagnostics were used. RESULTS Only 0.15% of pigs had detectable antibodies against ASFV, suggesting low survival rates or pre-clinical diagnosis. Yet, 59.5% of pigs were positive for ASFV DNA. Blood had the lowest detection rate (15.3%) while tonsil and lymph nodes had the highest (38% and 37.5%, respectively), spleen samples (31.5%) were in between. Agreement between sample types was fair to moderate overall. A significant seasonality of ASFV infections emerged with infections found predominately in the dry seasons. Spatial assessments revealed that the greater Kampala metropolitan area abattoirs have a catchment area that overlaps with Uganda's most pig dense regions. CONCLUSIONS Pigs at greater Kampala metropolitan area abattoirs can be sentinels for acute disease throughout the pig dense region of Uganda, particularly in the dry seasons. The high prevalence detected suggests that pigs are sold in response to local reports of ASFV infections (panic sales). Serological surveillance is not useful, as very few pigs seroconverted in this study prior to slaughter. In contrast, tissue samples of pigs can be used to detect disease using qPCR methods.
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Affiliation(s)
- Rodney Okwasiimire
- Central Diagnostic Laboratory, College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, P.O.Box 7062, Kampala, Uganda
| | - Edrine B Kayaga
- Central Diagnostic Laboratory, College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, P.O.Box 7062, Kampala, Uganda
| | - John E Ekakoro
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853-6401, USA
| | - Dickson Ndoboli
- Central Diagnostic Laboratory, College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, P.O.Box 7062, Kampala, Uganda
| | - Kate Schumann
- Foreign Animal Disease Diagnostic Laboratory, Veterinary Services, Animal and Plant Health Inspection Services, United States Department of Agriculture, National Veterinary Services Laboratories, Greenport, NY, USA
| | - Bonto Faburay
- Foreign Animal Disease Diagnostic Laboratory, Veterinary Services, Animal and Plant Health Inspection Services, United States Department of Agriculture, National Veterinary Services Laboratories, Greenport, NY, USA
| | - Aisha Nassali
- Central Diagnostic Laboratory, College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, P.O.Box 7062, Kampala, Uganda
| | - Cole Hauser
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853-6401, USA
| | - Krista Ochoa
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853-6401, USA
| | - Eddie M Wampande
- Central Diagnostic Laboratory, College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, P.O.Box 7062, Kampala, Uganda
| | - Karyn A Havas
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853-6401, USA.
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Erika C, Susanna SL, Tonny A, Karl S, Klara F. Co-created community contracts support biosecurity changes in a region where African swine fever is endemic - Part I: The methodology. Prev Vet Med 2023; 212:105840. [PMID: 36640661 DOI: 10.1016/j.prevetmed.2023.105840] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 11/08/2022] [Accepted: 01/08/2023] [Indexed: 01/12/2023]
Abstract
In Northern Uganda more people live in poverty than elsewhere in the country. Small-scale pig-keeping is common and African swine fever (ASF) is endemic, spreading along the smallholder value chain. Biosecurity measures remain the only way to prevent and control the spread of ASF in this context. Previous research in the study area has shown that many stakeholders are aware of ASF, how it is spread and methods for prevention and control, but biosecurity implementation remains limited. Participatory approaches have been suggested in order to increase community engagement in relation to animal disease control, ensuring that disease prevention or control actions are guided by local people's priorities and the promotion of local ownership of disease control. The objective of this study was to investigate the capacity of participatory action at community level with a broad inclusion of stakeholders to initiate change and greater stakeholder ownership to improve biosecurity in the smallholder pig value chain. Specific attention was paid to the feasibility of co-created community contracts for this purpose. The study was carried out in Northern Uganda in six purposively selected villages and included both farmers and traders. Centred on co-created community contracts on biosecurity, the study comprised repeated group discussions, semi-structured and structured group and individual interviews, as well as field observations. At the first meeting, participants were presented with suggested biosecurity measures adapted for farmers and traders respectively. Participants discussed each measure, agreed which ones to implement for one year, and co-created a community contract to this effect. During the study period, repeated interviews were undertaken and implementation support was provided. Interview data was coded and thematically analysed. Great diversity was observed between communities with regard to which and how many measures were selected, illustrating heterogeneity in the possibilities of biosecurity implementation and the complexity of livelihood challenges. The methodology appeared to be effective at instigating change, with all the communities changing some of their biosecurity behaviour during the study period. The intensified communication and cooperation around pigs in the communities reinforced the sense of group identity and the capacity-building offered at the first meeting supported implementation and appeared to be more important than the physical contract. Participants reported feeling empowered and described how they shared their knowledge, educated their peers and acted as catalysts for wider biosecurity change in their communities. These are promising results and indicate a positive attitude to both the agreed measures and the methodology.
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Affiliation(s)
- Chenais Erika
- Department of Disease Control and Epidemiology, National Veterinary Institute, Uppsala, Sweden.
| | - Sternberg Lewerin Susanna
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Aliro Tonny
- Faculty of Agriculture and Environment, Gulu University, Gulu, Uganda
| | - Ståhl Karl
- Department of Disease Control and Epidemiology, National Veterinary Institute, Uppsala, Sweden
| | - Fischer Klara
- Department of Urban and Rural Development, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Penrith ML, van Heerden J, Pfeiffer DU, Oļševskis E, Depner K, Chenais E. Innovative Research Offers New Hope for Managing African Swine Fever Better in Resource-Limited Smallholder Farming Settings: A Timely Update. Pathogens 2023; 12:355. [PMID: 36839627 PMCID: PMC9963711 DOI: 10.3390/pathogens12020355] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/17/2023] [Accepted: 02/19/2023] [Indexed: 02/23/2023] Open
Abstract
African swine fever (ASF) in domestic pigs has, since its discovery in Africa more than a century ago, been associated with subsistence pig keeping with low levels of biosecurity. Likewise, smallholder and backyard pig farming in resource-limited settings have been notably affected during the ongoing epidemic in Eastern Europe, Asia, the Pacific, and Caribbean regions. Many challenges to managing ASF in such settings have been identified in the ongoing as well as previous epidemics. Consistent implementation of biosecurity at all nodes in the value chain remains most important for controlling and preventing ASF. Recent research from Asia, Africa, and Europe has provided science-based information that can be of value in overcoming some of the hurdles faced for implementing biosecurity in resource-limited contexts. In this narrative review we examine a selection of these studies elucidating innovative solutions such as shorter boiling times for inactivating ASF virus in swill, participatory planning of interventions for risk mitigation for ASF, better understanding of smallholder pig-keeper perceptions and constraints, modified culling, and safe alternatives for disposal of carcasses of pigs that have died of ASF. The aim of the review is to increase acceptance and implementation of science-based approaches that increase the feasibility of managing, and the possibility to prevent, ASF in resource-limited settings. This could contribute to protecting hundreds of thousands of livelihoods that depend upon pigs and enable small-scale pig production to reach its full potential for poverty alleviation and food security.
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Affiliation(s)
- Mary-Louise Penrith
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0110, South Africa
| | - Juanita van Heerden
- Transboundary Animal Diseases, Onderstepoort Veterinary Research, Agricultural Research Council, Pretoria 0110, South Africa
| | - Dirk U. Pfeiffer
- Centre for Applied One Health Research and Policy Advice, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong SAR, China
- Department of Pathobiology and Population Sciences, Veterinary Epidemiology, Economics, and Public Health Group, Royal Veterinary College, Hatfield AL9 7TA, UK
| | - Edvīns Oļševskis
- Food and Veterinary Service, LV-1050 Riga, Latvia
- Institute of Food Safety, Animal Health and Environment, “BIOR“, LV-1076 Riga, Latvia
| | - Klaus Depner
- Friedrich-Loeffler-Institute, Greifswald-Insel Riems, 17493 Greifswald, Germany
| | - Erika Chenais
- Department of Disease Control and Epidemiology, National Veterinary Institute, S-751 89 Uppsala, Sweden
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Hasahya E, Thakur K, Dione MM, Kerfua SD, Mugezi I, Lee HS. Analysis of patterns of livestock movements in the Cattle Corridor of Uganda for risk-based surveillance of infectious diseases. Front Vet Sci 2023; 10:1095293. [PMID: 36756309 PMCID: PMC9899994 DOI: 10.3389/fvets.2023.1095293] [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: 11/11/2022] [Accepted: 01/03/2023] [Indexed: 01/24/2023] Open
Abstract
Introduction The knowledge of animal movements is key to formulating strategic animal disease control policies and carrying out targeted surveillance. This study describes the characteristics of district-level cattle, small ruminant, and pig trade networks in the Cattle Corridor of Uganda between 2019 and 2021. Methodology The data for the study was extracted from 7,043 animal movement permits (AMPs) obtained from the Ministry of Agriculture, Animal Industry and Fisheries (MAAIF) of Uganda. Most of the data was on cattle (87.2%), followed by small ruminants (11.2%) and pigs (1.6%). Two types of networks representing animal shipments between districts were created for each species based on monthly (n = 30) and seasonal (n = 10) temporal windows. Measures of centrality and cohesiveness were computed for all the temporal windows and our analysis identified the most central districts in the networks. Results The median in-degree for monthly networks ranged from 0-3 for cattle, 0-1 for small ruminants and 0-1 for pigs. The highest median out-degrees for cattle, small ruminant and pig monthly networks were observed in Lira, Oyam and Butambala districts, respectively. Unlike the pig networks, the cattle and small ruminant networks were found to be of small-world and free-scale topologies. Discussion The cattle and small ruminant trade movement networks were also found to be highly connected, which could facilitate quick spread of infectious animal diseases across these networks. The findings from this study highlighted the significance of characterizing animal movement networks to inform surveillance, early detection, and subsequent control of infectious animal disease outbreaks.
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Affiliation(s)
- Emmanuel Hasahya
- International Livestock Research Institute (ILRI), Kampala, Uganda
| | - Krishna Thakur
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada,*Correspondence: Krishna Thakur ✉
| | - Michel M. Dione
- International Livestock Research Institute (ILRI), Dakar, Senegal
| | - Susan D. Kerfua
- National Livestock Resources Research Institute (NaLIRRI), Kampala, Uganda
| | - Israel Mugezi
- Department of Animal Health, Ministry of Agriculture, Animal Industry and Fisheries (MAAIF), Kampala, Uganda
| | - Hu Suk Lee
- International Livestock Research Institute (ILRI), Hanoi, Vietnam,College of Veterinary Medicine, Chungnam National University, Daejeon, Republic of Korea,Hu Suk Lee ✉ ; ✉
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Thanapongtharm W, Wongphruksasoong V, Sangrat W, Thongsrimoung K, Ratanavanichrojn N, Kasemsuwan S, Khamsiriwatchara A, Kaewkungwal J, Leelahapongsathon K. Application of Spatial Risk Assessment Integrated With a Mobile App in Fighting Against the Introduction of African Swine Fever in Pig Farms in Thailand: Development Study. JMIR Form Res 2022; 6:e34279. [PMID: 35639455 PMCID: PMC9198819 DOI: 10.2196/34279] [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: 10/14/2021] [Revised: 03/12/2022] [Accepted: 03/30/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND African swine fever (ASF), a highly contagious disease affecting both domestic and wild pigs, has been having a serious impact on the swine industry worldwide. This important transboundary animal disease can be spread by animals and ticks via direct transmission and by contaminated feed and fomites via indirect transmission because of the high environmental resistance of the ASF virus. Thus, the prevention of the introduction of ASF to areas free of ASF is essential. After an outbreak was reported in China, intensive import policies and biosecurity measures were implemented to prevent the introduction of ASF to pig farms in Thailand. OBJECTIVE Enhancing prevention and control, this study aims to identify the potential areas for ASF introduction and transmission in Thailand, develop a tool for farm assessment of ASF risk introduction focusing on smallholders, and develop a spatial analysis tool that is easily used by local officers for disease prevention and control planning. METHODS We applied a multi-criteria decision analysis approach with spatial and farm assessment and integrated the outputs with the necessary spatial layers to develop a spatial analysis on a web-based platform. RESULTS The map that referred to potential areas for ASF introduction and transmission was derived from 6 spatial risk factors; namely, the distance to the port, which had the highest relative importance, followed by the distance to the border, the number of pig farms using swill feeding, the density of small pig farms (<50 heads), the number of pigs moving in the area, and the distance to the slaughterhouse. The possible transmission areas were divided into 5 levels (very low, low, medium, high, and very high) at the subdistrict level, with 27 subdistricts in 10 provinces having very high suitability and 560 subdistricts in 34 provinces having high suitability. At the farm level, 17 biosecurity practices considered as useful and practical for smallholders were selected and developed on a mobile app platform. The outputs from the previous steps integrated with necessary geographic information system layers were added to a spatial analysis web-based platform. CONCLUSIONS The tools developed in this study have been complemented with other strategies to fight against the introduction of ASF to pig farms in the country. The areas showing high and very high risk for disease introduction and transmission were applied for spatial information planning, for example, intensive surveillance, strict animal movement, and public awareness. In addition, farms with low biosecurity were improved in these areas, and the risk assessment developed on a mobile app in this study helped enhance this matter. The spatial analysis on a web-based platform helped facilitate disease prevention planning for the authorities.
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Affiliation(s)
| | | | | | | | | | - Suwicha Kasemsuwan
- Faculty of Veterinary Medicine, Kasetsart University, Nakhon Pathom, Thailand
| | - Amnat Khamsiriwatchara
- Center of Excellence for Biomedical and Public Health Informatics (BIOPHICS), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Jaranit Kaewkungwal
- Center of Excellence for Biomedical and Public Health Informatics (BIOPHICS), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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Penrith ML, Kivaria FM. One hundred years of African swine fever in Africa: where have we been, where are we now, where are we going? Transbound Emerg Dis 2022; 69:e1179-e1200. [PMID: 35104041 DOI: 10.1111/tbed.14466] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/26/2022] [Accepted: 01/27/2022] [Indexed: 11/26/2022]
Abstract
One hundred years have passed since the first paper on African swine fever (ASF) was published by Montgomery in 1921. With no vaccine, ineffectiveness of prevention and control measures, and lack of common interest in eradicating the disease, ASF has proven to be one of the most devastating diseases because of its significant sanitary and socioeconomic consequences. The rapid spread of the disease on the European and Asian continents and its recent appearance in the Caribbean puts all countries at great risk because of global trade. The incidence of ASF has also increased on the African continent over the last few decades, extending its distribution far beyond the area in which the ancient sylvatic cycle is present with its complex epidemiological transmission pathways involving virus reservoirs in ticks and wild African Suidae. Both in that area and elsewhere, efficient transmission by infected domestic pigs and virus resistance in infected animal products and fomites mean that human driven factors along the pig value chain are the dominant impediments for its prevention, control, and eradication. Control efforts in Africa are furthermore hampered by the lack of information about the size and location of the fast-growing pig population, particularly in the dynamic smallholder sector that constitutes up to 90% of pig production in the region. A vaccine that will be both affordable and effective against multiple genotypes of the virus is not a short-term reality. Therefore, a strategy for management of ASF in sub-Saharan Africa is needed to provide a roadmap for the way forward for the continent. This review explores the progression of ASF and our knowledge of it through research over a century in Africa, our current understanding of ASF, and what must be done going forwards to improve the African situation and contribute to global prevention and control. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Mary Louise Penrith
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - Fredrick Mathias Kivaria
- Food and Agriculture Organization of the UN, Block P, Level 3, United Nations Complex, UN Avenue, Gigiri, Nairobi, PO Box: 30470, GPO, Nairobi, 00100, Kenya
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Lysholm S, Fischer K, Lindahl JF, Munyeme M, Wensman JJ. Seropositivity rates of zoonotic pathogens in small ruminants and associated public health risks at informal urban markets in Zambia. Acta Trop 2022; 225:106217. [PMID: 34751139 DOI: 10.1016/j.actatropica.2021.106217] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 09/29/2021] [Accepted: 10/25/2021] [Indexed: 02/05/2023]
Abstract
Informal livestock markets are an important source of animal-derived proteins for growing urban populations in countries such as Zambia. In parallel, they can also constitute pathways of zoonotic pathogen transmission to humans. This risk is aggravated by limited disease monitoring and poor control systems with regards to biosecurity and public health. The aim of this study was to investigate the risks for spread of zoonotic diseases in Zambia's two largest informal small ruminant markets, located in Lusaka and Kasumbalesa, through combining seroepidemiology with interviews and observations. In April, May and September 2018, serum samples (n = 237) were collected and analysed for antibodies for the zoonotic pathogens Brucella spp., Coxiella (C.) burnetii and Rift Valley fever virus (RVFV), using commercially available enzyme linked immunosorbent assays (ELISA). In addition, slaughterhouse activities were observed and semi-structured interviews and focus group discussions held with slaughterhouse workers and small ruminant traders, focusing on the handling of animals and meat, and the perceptions of zoonotic disease risks at slaughter and consumption. The study found seropositivity rates of 10.1% (95% confidence interval [CI] 6.60-14.7) for Brucella spp., 5.9% (95% CI 3.27-9.71) for C. burnetii, and 0.8% (95% CI 0.10-3.01) for RVFV. Interviews with value chain members and observations at the slaughterhouse revealed unsanitary procedures and multiple occupational hazards for slaughterhouse workers. This study showed that the Zambian informal small ruminant trade system poses risks to public health, and that these risks are exacerbated by a lack of information about food-borne diseases and how associated risks can be mitigated amongst value chain actors. The results of this study can be used to formulate preventive measures to improve informal meat markets and reduce the risks to public health.
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Mutua F, Dione M. The Context of Application of Biosecurity for Control of African Swine Fever in Smallholder Pig Systems: Current Gaps and Recommendations. Front Vet Sci 2021; 8:689811. [PMID: 34409087 PMCID: PMC8364973 DOI: 10.3389/fvets.2021.689811] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 06/15/2021] [Indexed: 11/28/2022] Open
Abstract
African swine fever (ASF) is a highly fatal disease of pigs. It is a threat to the pig industry as it lowers production and significantly impacts on livelihoods. ASF has no cure and a vaccine against it is yet to be developed. Outbreaks continue to be reported in Africa and Asia, where the setting of the pig value chain (farm, market, and slaughter practices) coupled with the risky behaviors of actors, contribute to persistence of the virus in pig populations. The role of these factors in the epidemiology of the disease is reviewed with a focus on smallholder pig systems in Africa. Biosecurity at the farm level is particularly emphasized, and factors influencing its adoption highlighted. Socio-cultural factors and weaknesses at the disease control policy level are critical and should not be ignored. Gender and equity are important aspects and ought to be considered in discussions to improve the sector. The findings are expected to define priorities for interventions to improve pig productivity (as these regions wait for the vaccine to be developed).
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Affiliation(s)
- Florence Mutua
- Animal and Human Health Program, International Livestock Research Institute, Nairobi, Kenya
| | - Michel Dione
- Animal and Human Health Program, International Livestock Research Institute, Dakar, Senegal
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11
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Li Z, Wei J, Di D, Wang X, Li C, Li B, Qiu Y, Liu K, Gu F, Tong M, Wang S, Wu X, Ma Z. Rapid and accurate detection of African swine fever virus by DNA endonuclease-targeted CRISPR trans reporter assay. Acta Biochim Biophys Sin (Shanghai) 2020; 52:1413-1419. [PMID: 33201182 DOI: 10.1093/abbs/gmaa135] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Indexed: 12/26/2022] Open
Abstract
The first case of African swine fever (ASF) outbreak in China was reported in a suburban pig farm in Shenyang in 2018. Since then, the rapid spread and extension of ASF has become the most serious threat for the swine industry. Therefore, rapid and accurate detection of African swine fever virus (ASFV) is essential to provide effective strategies to control the disease. In this study, we developed a rapid and accurate ASFV-detection method based on the DNA endonuclease-targeted CRISPR trans reporter (DETECTR) assay. By combining recombinase polymerase amplification with CRISPR-Cas12a proteins, the DETECTR assay demonstrated a minimum detection limit of eight copies with no cross reactivity with other swine viruses. Clinical blood samples were detected by DETECTR assay and showed 100% (30/30) agreement with real-time polymerase chain reaction assay. The rapid and accurate detection of ASFV may facilitate timely eradication measures and strict sanitary procedures to control and prevent the spread of ASF.
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Affiliation(s)
- Zongjie Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China
| | - Jianchao Wei
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China
| | - Di Di
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China
| | - Xin Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China
| | - Chenxi Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China
| | - Beibei Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China
| | - Yafeng Qiu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China
| | - Ke Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China
| | - Feng Gu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture, Shanghai 200241, China
| | - Minglong Tong
- Yixing Customs, General Administration of Customs of the People’s Republic of China, Yixing 214206, China
| | - Shuiming Wang
- Yixing Customs, General Administration of Customs of the People’s Republic of China, Yixing 214206, China
| | - Xiaodong Wu
- National Research Center for Exotic Animal Diseases, China Animal Health and Epidemiology Center, Qingdao 266032, China
| | - Zhiyong Ma
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China
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12
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Perceptions and practices among Zambian sheep and goat traders concerning small ruminant health and disease. PLoS One 2020; 15:e0233611. [PMID: 32569297 PMCID: PMC7307758 DOI: 10.1371/journal.pone.0233611] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 05/08/2020] [Indexed: 11/19/2022] Open
Abstract
Trade in animals and animal products is a key factor in the transmission of infectious diseases. Livestock traders play an important role in this process, yet there is little knowledge of traders’ perceptions of animal disease or their associated actions. The aim of this study was to investigate perceptions and practices of Zambian small ruminant traders with regard to sheep and goat health and disease. It also analysed how existing perceptions and practices might affect risks of disease transmission through trade. A case study was performed at the two largest small livestock markets in Zambia: the Lusaka market in the capital and the Kasumbalesa market near the border with the Democratic Republic of Congo. Semi-structured interviews with 47 traders performed in April-May and September 2018 represent the core material. Zambian small ruminant traders frequently trade animals that have clinical signs of disease, either because they appear unaware or indifferent to the associated risks, experience financial constraints or assign responsibility for disease prevention to other value chain actors. In their decision about whether or not to sell a visibly sick small ruminant, traders appear to consider whether the clinical sign is perceived as ‘natural’ or the result of an illness, whether the buyer is aware of the animal’s health condition, and whether the animal is sold for consumption or breeding purposes. Traders appear to regard the veterinary certificate required to transport small ruminants in Zambia as proof of health, placing the responsibility for potential disease in traded animals on the veterinary authorities. In their description of a model trader, taking good care of and being sensitive to customer needs was emphasized, indicating that an efficient way to encourage traders to change their behaviour is to influence customer demands. In contrast to the focus in previous studies on identifying and filling knowledge gaps, the present study show that lack of knowledge is not central to why traders engage in disease-transmitting behaviour. Greater awareness of other reasons for certain perceptions and practices could lead to the formulation of risk communication strategies and mitigation measures that are relevant for the local context, as well as alternative strategies for changing trader behaviour.
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13
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Mutua F, Lindahl J, Randolph D. Possibilities of establishing a smallholder pig identification and traceability system in Kenya. Trop Anim Health Prod 2019; 52:859-870. [PMID: 31529303 PMCID: PMC7039844 DOI: 10.1007/s11250-019-02077-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 09/06/2019] [Indexed: 11/07/2022]
Abstract
Consumers have a right to safer foods, and traceability is one approach to meeting their expectations. Kenya does not have an operational animal traceability system, and while a few initiatives have been piloted, these have only focused on the beef value chain. In this paper, we begin a discussion on traceability in the pig value chain, with an initial focus on smallholder systems of Western Kenya. First, a background to local pig production is given, and a description of animal identification and traceability options applicable to these systems is explained. Based on this, a “butcher-to-farm” traceability system, with health, production and food safety as objectives, is discussed. Requirements for establishing such a system (including actor incentives) are additionally discussed. The proposed approach can be piloted in the field and findings used to inform the design of a larger pilot and possibly pave way for implementation of a national traceability system, in line with the guidelines provided by the World Organization for Animal Health (OIE). Organized systems in the area (including commercial producer and trader groups) would offer a useful starting point.
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Affiliation(s)
- Florence Mutua
- International Livestock Research Institute, P. O. Box 30709, Nairobi, 00100, Kenya.
| | - Johanna Lindahl
- International Livestock Research Institute, P. O. Box 30709, Nairobi, 00100, Kenya.,Zoonoses Science Centre, Uppsala University, P. O. Box 70790, SE-750 07, Uppsala, Sweden.,Department of Clinical Sciences, Swedish University of Agricultural Sciences, P. O. Box 70790, SE-750 07, Uppsala, Sweden
| | - Delia Randolph
- International Livestock Research Institute, P. O. Box 30709, Nairobi, 00100, Kenya
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Penrith ML, Bastos AD, Etter EMC, Beltrán-Alcrudo D. Epidemiology of African swine fever in Africa today: Sylvatic cycle versus socio-economic imperatives. Transbound Emerg Dis 2019; 66:672-686. [PMID: 30633851 DOI: 10.1111/tbed.13117] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 12/04/2018] [Accepted: 12/14/2018] [Indexed: 11/29/2022]
Abstract
African swine fever (ASF) is believed to have evolved in eastern and southern Africa in a sylvatic cycle between common warthogs (Phacochoerus africanus) and argasid ticks of the Ornithodoros moubata complex that live in their burrows. The involvement of warthogs and possibly other wild suids in the maintenance of ASF virus means that the infection cannot be eradicated from Africa, but only prevented and controlled in domestic pig populations. Historically, outbreaks of ASF in domestic pigs in Africa were almost invariably linked to the presence of warthogs, but subsequent investigations of the disease in pigs revealed the presence of another cycle involving domestic pigs and ticks, with a third cycle becoming apparent when the disease expanded into West Africa where the sylvatic cycle is not present. The increase in ASF outbreaks that has accompanied the exponential growth of the African pig population over the last three decades has heralded a shift in the epidemiology of ASF in Africa, and the growing importance of the pig husbandry and trade in the maintenance and spread of ASF. This review, which focuses on the ASF situation between 1989 and 2017, suggests a minor role for wild suids compared with the domestic cycle, driven by socio-economic factors that determine the ability of producers to implement the control measures needed for better management of ASF in Africa.
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Affiliation(s)
- Mary-Louise Penrith
- Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa
| | - Armanda Duarte Bastos
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, South Africa
| | - Eric M C Etter
- Department of Production Animal Studies, University of Pretoria, Pretoria, South Africa.,CIRAD, UMR Animal Santé, Territoires, Risque et Ecosystèmes (ASTRE), Montpellier, France.,ASTRE, Univ. Montpellier, CIRAD, INRA, Montpellier, France
| | - Daniel Beltrán-Alcrudo
- Regional Office for Europe and Central Asia, Food and Agriculture Organization of the United Nations, Budapest, Hungary
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Genome Sequences of Five African Swine Fever Virus Genotype IX Isolates from Domestic Pigs in Uganda. Microbiol Resour Announc 2018; 7:MRA01018-18. [PMID: 30533685 PMCID: PMC6256554 DOI: 10.1128/mra.01018-18] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 09/12/2018] [Indexed: 11/20/2022] Open
Abstract
Complete genome sequences of five African swine fever virus isolates were determined directly from clinical material obtained from domestic pigs in Uganda. Four sequences were essentially identical to each other, and all were closely related to the only known genome sequence of p72 genotype IX. Complete genome sequences of five African swine fever virus isolates were determined directly from clinical material obtained from domestic pigs in Uganda. Four sequences were essentially identical to each other, and all were closely related to the only known genome sequence of p72 genotype IX.
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Beltrán-Alcrudo D, Kukielka EA, de Groot N, Dietze K, Sokhadze M, Martínez-López B. Descriptive and multivariate analysis of the pig sector in Georgia and its implications for disease transmission. PLoS One 2018; 13:e0202800. [PMID: 30142224 PMCID: PMC6108502 DOI: 10.1371/journal.pone.0202800] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 08/09/2018] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Georgia is a country in the Caucasus region with a traditional backyard and highly variable pig farming system. The practices of such sectors have seldom been described and analyzed to better understand their implication in the introduction and spread of infectious pig diseases. Moreover, the Georgian pig sector was badly hit by an epidemic of African swine fever in 2007 that quickly spread throughout the region. MATERIALS AND METHODS We interviewed 487 pig farmers and 116 butchers using closed questionnaires on socioeconomic issues related to pig production, husbandry practices, biosecurity, marketing and movements, and disease awareness. Surveys were conducted in four regions of Georgia and descriptive statistics were computed. Factorial analyses of mixed data and hierarchical clustering on principal components were applied to study the relationship among collected variables for both farmers and butchers. RESULTS Results show that pig farming in Georgia is a non-professional sector, highly heterogeneous by region, characterized by smallholdings of few animals, with low inputs, outdated technologies, and poor biosecurity, which all translates into low outputs and productivity. The hierarchical clustering on principal components confirmed that there are five major production and husbandry strategies, which match the four regions where the study was conducted. CONCLUSIONS Our results are the first step to quantify biosecurity gaps and risky behaviours, develop risk profiles, and identify critical control points across the market chain where to implement mitigation measures. This study provides the baseline information needed to design realistic and sustainable prevention, surveillance and control strategies.
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Affiliation(s)
- Daniel Beltrán-Alcrudo
- Regional Office for Europe and Central Asia, Food and Agriculture Organization, Budapest, Hungary
| | - Esther A. Kukielka
- Center for Animal Disease Modeling and Surveillance (CADMS), Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, CA, United States of America
| | | | - Klaas Dietze
- Institut für Epidemiologie, Friedrich-Loeffler-Institut (FLI), Greifswald—Insel Riems, Germany
| | - Mikheil Sokhadze
- National Food Agency, Tbilisi, Georgia
- FAO Representation in Georgia, Food and Agriculture Organization, Tbilisi, Georgia
| | - Beatriz Martínez-López
- Center for Animal Disease Modeling and Surveillance (CADMS), Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, CA, United States of America
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