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Balmoș OM, Ionică AM, Horvath C, Supeanu A, Moțiu M, Ancuceanu BC, Tamba P, Bărbuceanu F, Cotuțiu V, Coroian M, Dhollander S, Mihalca AD. African swine fever virus DNA is present in non-biting flies collected from outbreak farms in Romania. Parasit Vectors 2024; 17:278. [PMID: 38943218 PMCID: PMC11212390 DOI: 10.1186/s13071-024-06346-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 06/07/2024] [Indexed: 07/01/2024] Open
Abstract
BACKGROUND African swine fever (ASF) is a highly contagious and severe haemorrhagic disease of Suidae, with mortalities that approach 100 percent. Several studies suggested the potential implication of non-biting dipterans in the spread of ASFV in pig farms due to the identification of the ASFV DNA. However, to our knowledge, no study has evaluated the viral DNA load in non-biting dipterans collected in outbreak farms and no risk factors have been analysed. In this context, our study aimed to analyse the risk factors associated with the presence of non-biting dipterans collected from ASF outbreaks in relation to the presence and load of viral DNA. METHODS Backyard farms (BF), type A farms (TAF), and commercial farms (CF), were targeted for sampling in 2020. In 2021, no BF were sampled. Each farm was sampled only once. The identification of the collected flies to family, genus, or species level was performed based on morphological characteristics using specific keys and descriptions. Pools were made prior to DNA extraction. All extracted DNA was tested for the presence of the ASFV using a real-time PCR protocol. For this study, we considered every sample with a CT value of 40 as positive. The statistical analysis was performed using Epi Info 7 software (CDC, USA). RESULTS All collected non-biting flies belonged to five families: Calliphoridae, Sarcophagidae, Fanniidae, Drosophilidae, and Muscidae. Of the 361 pools, 201 were positive for the presence of ASFV DNA. The obtained CT values of the positive samples ranged from 21.54 to 39.63, with a median value of 33.59 and a mean value of 33.56. Significantly lower CT values (corresponding to higher viral DNA load) were obtained in Sarcophagidae, with a mean value of 32.56; a significantly higher number of positive pools were noticed in August, mean value = 33.12. CONCLUSIONS Our study brings compelling evidence of the presence of the most common synanthropic flies near domestic pig farms carrying ASFV DNA, highlighting the importance of strengthening the biosecurity measures and protocols for prevention of the insect life cycle and distribution.
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Affiliation(s)
- Oana Maria Balmoș
- Department of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, Calea Mănăștur 3-5, 400372, Cluj-Napoca-Napoca, Romania.
| | - Angela Monica Ionică
- Clinical Hospital of Infectious Diseases of Cluj-Napoca, Strada Iuliu Moldovan 23, 400348, Cluj-Napoca-Napoca, Romania
| | - Cintia Horvath
- Department of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, Calea Mănăștur 3-5, 400372, Cluj-Napoca-Napoca, Romania
| | - Alexandru Supeanu
- National Sanitary Veterinary and Food Safety Authority, Piața Presei Libere 1, Corp D1, Sector 1, 013701, Bucharest, Romania
| | - Monica Moțiu
- Institute for Diagnosis and Animal Health, Strada Dr. Staicovici 63, Sector 5, 050557, Bucharest, Romania
| | - Beatris Corina Ancuceanu
- Institute for Diagnosis and Animal Health, Strada Dr. Staicovici 63, Sector 5, 050557, Bucharest, Romania
| | - Paula Tamba
- Institute for Diagnosis and Animal Health, Strada Dr. Staicovici 63, Sector 5, 050557, Bucharest, Romania
- Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine, Splaiul Independentei 105, Bucharest, 050097, Romania
| | - Florica Bărbuceanu
- Institute for Diagnosis and Animal Health, Strada Dr. Staicovici 63, Sector 5, 050557, Bucharest, Romania
- Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine, Splaiul Independentei 105, Bucharest, 050097, Romania
| | - Vlad Cotuțiu
- Department of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, Calea Mănăștur 3-5, 400372, Cluj-Napoca-Napoca, Romania
| | - Mircea Coroian
- Department of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, Calea Mănăștur 3-5, 400372, Cluj-Napoca-Napoca, Romania
| | - Sofie Dhollander
- European Food Safety Authority, Via Carlo Magno 1A, 43126, Parma, Italy
| | - Andrei Daniel Mihalca
- Department of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, Calea Mănăștur 3-5, 400372, Cluj-Napoca-Napoca, Romania
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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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Robert E, Goonewardene K, El Kanoa I, Hochman O, Nfon C, Ambagala A. Oral Fluids for the Early Detection of Classical Swine Fever in Commercial Level Pig Pens. Viruses 2024; 16:318. [PMID: 38543685 PMCID: PMC10974009 DOI: 10.3390/v16030318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 02/15/2024] [Accepted: 02/17/2024] [Indexed: 05/23/2024] Open
Abstract
The early detection of classical swine fever (CSF) remains a key challenge, especially when outbreaks are caused by moderate and low-virulent CSF virus (CSFV) strains. Oral fluid is a reliable and cost-effective sample type that is regularly surveilled for endemic diseases in commercial pig herds in North America. Here, we explored the possibility of utilizing oral fluids for the early detection of CSFV incursions in commercial-size pig pens using two independent experiments. In the first experiment, a seeder pig infected with the moderately-virulent CSFV Pinillos strain was used, and in the second experiment, a seeder pig infected with the highly-virulent CSFV Koslov strain was used. Pen-based oral fluid samples were collected daily and individual samples (whole blood, swabs) every other day. All samples were tested by a CSFV-specific real-time RT-PCR assay. CSFV genomic material was detected in oral fluids on the seventh and fourth day post-introduction of the seeder pig into the pen, in the first and second experiments, respectively. In both experiments, oral fluids tested positive before the contact pigs developed viremia, and with no apparent sick pigs in the pen. These results indicate that pen-based oral fluids are a reliable and convenient sample type for the early detection of CSF, and therefore, can be used to supplement the ongoing CSF surveillance activities in North America.
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Affiliation(s)
- Erin Robert
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3M4, Canada; (E.R.); (K.G.); (I.E.K.); (O.H.); (C.N.)
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB R3E 0W2, Canada
| | - Kalhari Goonewardene
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3M4, Canada; (E.R.); (K.G.); (I.E.K.); (O.H.); (C.N.)
| | - Ian El Kanoa
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3M4, Canada; (E.R.); (K.G.); (I.E.K.); (O.H.); (C.N.)
| | - Orie Hochman
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3M4, Canada; (E.R.); (K.G.); (I.E.K.); (O.H.); (C.N.)
| | - Charles Nfon
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3M4, Canada; (E.R.); (K.G.); (I.E.K.); (O.H.); (C.N.)
| | - Aruna Ambagala
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB R3E 3M4, Canada; (E.R.); (K.G.); (I.E.K.); (O.H.); (C.N.)
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB R3E 0W2, Canada
- Department of Animal Science, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada
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Uzelac A, Betić N, Karabasil N, Ćirković V, Djurković-Djaković O, Klun I. A Pork Industry in the Backyard: An Analysis of Toxoplasma gondii Infection in Serbia's Pigs. Microorganisms 2023; 11:1857. [PMID: 37513029 PMCID: PMC10385063 DOI: 10.3390/microorganisms11071857] [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: 06/22/2023] [Revised: 07/14/2023] [Accepted: 07/20/2023] [Indexed: 07/30/2023] Open
Abstract
As pork is an important source for Toxoplasma gondii infection, we have analyzed T. gondii genotypes and toxoplasmosis prevalence in pigs in Serbia in the context of production statistics and economics to assess the specific risk to public health. Genotyping was performed using MnPCR-RFLP; T. gondii-specific IgG antibodies were detected using a modified agglutination test (MAT); and statistical data were extracted from official records and provided by government authorities. The results indicate that, from 2006 to 2021, the median number of annually slaughtered pigs was 5.6 million, yet only 36.1% were processed by abattoirs. The remainder were "backyard pigs" slaughtered on family farms and homesteads. Toxoplasmosis seroprevalence in market-weight (MW) pigs prior to 2006 was 15.2%, and was 15.1% in 2019. The seroprevalence in owned city cats, likely infected by livestock meat, was 33.2%. ToxoDB#1 was identified in pig tissues. The results indicate that backyard pigs are the backbone of the industry and provide as much as 60% of the pork in Serbia. The seroprevalence in pigs and city cats shows that farms are reservoirs for the parasite. Thus, innovative means of reducing T. gondii infection designed with backyard farmers in mind are needed to reduce the risk to public health.
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Affiliation(s)
- Aleksandra Uzelac
- Centre of Excellence for Food- and Vector-Borne Zoonoses, Institute for Medical Research, University of Belgrade, 11129 Belgrade, Serbia
| | - Nikola Betić
- Institute of Meat Hygiene and Technology, 11000 Belgrade, Serbia
| | - Nedjeljko Karabasil
- Department of Food Hygiene and Technology, Faculty of Veterinary Medicine, University of Belgrade, 11000 Belgrade, Serbia
| | - Vladimir Ćirković
- Centre of Excellence for Food- and Vector-Borne Zoonoses, Institute for Medical Research, University of Belgrade, 11129 Belgrade, Serbia
| | - Olgica Djurković-Djaković
- Centre of Excellence for Food- and Vector-Borne Zoonoses, Institute for Medical Research, University of Belgrade, 11129 Belgrade, Serbia
| | - Ivana Klun
- Centre of Excellence for Food- and Vector-Borne Zoonoses, Institute for Medical Research, University of Belgrade, 11129 Belgrade, Serbia
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Klein L, Hessling-Zeinen S, Adler F, Gerdes U, Blome S, Beilage EG, Campe A. Exploring pig farmers' decision-making concerning biosecurity measures against African Swine Fever. Prev Vet Med 2023; 217:105949. [PMID: 37285701 DOI: 10.1016/j.prevetmed.2023.105949] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 05/03/2023] [Accepted: 05/22/2023] [Indexed: 06/09/2023]
Abstract
African Swine Fever (ASF) is a growing threat to the German pig production sector. Rigorous biosecurity measures can prevent the introduction of ASF in domestic pig farms. Increased efforts have been made to inform pig farmers and other stakeholders in the industry regarding disease prevention measures for ASF. As part of quality management in animal disease prevention, we investigated the extent to which these efforts were successful and how knowledge transfer needs to be improved. Applying a qualitative study design with open, structured face-to-face interviews, this study aimed at assessing pig farmers' decision-making processes concerning the implementation of biosecurity measures against ASF and deducing the best-fitted pathways to improve the dissemination of information among pig farmers. We developed a modified theoretical model using the Health Belief Model, Protection Motivation Theory, and Theory of Planned Behaviour as the basis for our interview questionnaire and analysis. We showed that despite the steady spread of ASF into and within Germany, most pig farmers did not perceive an increased threat to their farms. However, many pig farmers communicated their uncertainty on how to correctly implement biosecurity measures according to the law. This study identified the importance of veterinary officials and farm veterinarians as referents on the topic of biosecurity and the need for clear standards concerning biosecurity regulations. Further, it suggests the need for closer cooperation between pig farmers and these referents, and a focus on joint decision-making, taking into account the individual circumstances of the farmers.
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Affiliation(s)
- Leonie Klein
- Department of Biometry, Epidemiology and Information Processing, WHO Collaborating Centre for Research and Training for Health in the Human-Animal-Environment Interface, University for Veterinary Medicine, Buenteweg 2, 30559 Hannover, Germany.
| | - Stefanie Hessling-Zeinen
- Department of Biometry, Epidemiology and Information Processing, WHO Collaborating Centre for Research and Training for Health in the Human-Animal-Environment Interface, University for Veterinary Medicine, Buenteweg 2, 30559 Hannover, Germany.
| | - Friedemann Adler
- Department of Biometry, Epidemiology and Information Processing, WHO Collaborating Centre for Research and Training for Health in the Human-Animal-Environment Interface, University for Veterinary Medicine, Buenteweg 2, 30559 Hannover, Germany.
| | - Ursula Gerdes
- Niedersaechsische Tierseuchenkasse (Animal Disease Fund), Bruehlstrasse 9, 30169 Hannover, Germany.
| | - Sandra Blome
- Department of Virology, Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Suedufer 10, 17493 Greifswald, Insel Riems, Germany.
| | - Elisabeth Grosse Beilage
- Field Station for Epidemiology, University for Veterinary Medicine, Buescheler Strasse 9, Bakum, 49456 Hannover, Germany.
| | - Amely Campe
- Department of Biometry, Epidemiology and Information Processing, WHO Collaborating Centre for Research and Training for Health in the Human-Animal-Environment Interface, University for Veterinary Medicine, Buenteweg 2, 30559 Hannover, Germany.
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Innovative Research Offers New Hope for Managing African Swine Fever Better in Resource-Limited Smallholder Farming Settings: A Timely Update. Pathogens 2023; 12:pathogens12020355. [PMID: 36839627 PMCID: PMC9963711 DOI: 10.3390/pathogens12020355] [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: 02/01/2023] [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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Cui H, Yang J, Yang B, Hao Y, Shi X, Zhang D, Yang X, Zhang T, Zhao D, Yuan X, Chen X, Liu X, Zheng H, Zhang K. Cyproheptadine hydrochloride inhibits African swine fever viral replication in vitro. Microb Pathog 2023; 175:105957. [PMID: 36572196 DOI: 10.1016/j.micpath.2022.105957] [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: 04/30/2022] [Revised: 09/16/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022]
Abstract
African swine fever (ASF) is an infectious disease caused by the African swine fever virus (ASFV), and has a high mortality rate. It has caused serious socioeconomic consequences worldwide. Currently, there are no available commercial vaccines or antiviral drug interventions. D1133L is one of the key genes for ASFV replication and antiviral drug screening. In this study, a virtual screening software program, PyRx, was used to screen libraries of compounds against the potential drug target D1133L. Twelve compounds with a high affinity for ASFV D1133L were screened, and cyproheptadine hydrochloride (periactin) was identified as a candidate drug. The periactin has little cytotoxicity, and which dose-dependently inhibited ASFV replication in vitro. Further research indicated that periactin could significantly down-regulate D1133L at the transcriptional and protein levels with RT-qPCR and western blot methods. This study has provided important candidate drugs for the prevention and treatment of ASF, as well as biological materials and new fields of view for the research and development of vaccines and drugs for ASFV.
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Affiliation(s)
- Huimei Cui
- State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, PR China
| | - Jinke Yang
- State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, PR China
| | - Bo Yang
- State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, PR China
| | - Yu Hao
- State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, PR China
| | - Xijuan Shi
- State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, PR China
| | - Dajun Zhang
- State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, PR China
| | - Xing Yang
- State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, PR China
| | - Ting Zhang
- State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, PR China
| | - DengShuai Zhao
- State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, PR China
| | - Xingguo Yuan
- State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, PR China
| | - Xuehui Chen
- State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, PR China
| | - Xiangtao Liu
- State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, PR China
| | - Haixue Zheng
- State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, PR China.
| | - Keshan Zhang
- State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, PR China.
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Scollo A, Valentini F, Franceschini G, Rusinà A, Calò S, Cappa V, Bellato A, Mannelli A, Alborali GL, Bellini S. Semi-quantitative risk assessment of African swine fever virus introduction in pig farms. Front Vet Sci 2023; 10:1017001. [PMID: 36777667 PMCID: PMC9911915 DOI: 10.3389/fvets.2023.1017001] [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: 08/11/2022] [Accepted: 01/11/2023] [Indexed: 01/28/2023] Open
Abstract
A semi-quantitative risk assessment was developed to classify pig farms in terms of the probability of introduction of African swine fever virus (ASFV). Following on-farm data collection via a specific checklist, we applied a modified failure mode and effect analysis (FMEA) to calculate the risk priority codes (RPC's), indicating increasing risk levels ranging from 1 to 5. The importance of biosecurity measures was attributed by experts. To consider geographic risk factors, we classified pig farms based on local density of farmed pigs, and on the estimated wild boar population density. The combination of RPC's with geographical risk factors resulted into a final ranking of pig farms in terms of the risk of ASFV introduction. Furthermore, the estimation of frequency and levels of non-compliance with biosecurity measures was used to identify weak points in risk prevention at farm level. The outcome of the risk assessment was affected by choices in assigning non-compliance scores and importance to specific components of biosecurity. The method was applied in 60 commercial farms in major pig production areas in Italy. Furthermore, we applied a reduced version of our checklist in 12 non-commercial/small commercial (≤20 pigs) farms in the northern Apennines. In commercial farms, highest RPC's were obtained for biosecurity measures associated with personnel practices and farm buildings/planimetry. Intervention should be addressed to training of personnel on biosecurity and ASF, to avoid contacts with other pig herds, and to improve practices in the entrance into the farm. Sharing trucks with other farms, and loading/unloading of pigs were other weak points. Fencing was classified as insufficient in 70% of the commercial farms. Among these farms, breeding units were characterised by the lowest risk of ASFV introduction (although differences among median ranks were not statistically significant: P-value = 0.07; Kruskal-Wallis test), and increasing herd size was not significantly correlated with a higher risk (Kendall's τ = -0.13; P-value = 0.14). Density of farmed pig was greatest in the main pig production area in northern Italy. Conversely, exposure to wild boars was greatest for non-commercial/small commercial farms on the Apennines, which were also characterised by non-compliance with critical biosecurity measures.
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Affiliation(s)
- Annalisa Scollo
- Department of Veterinary Sciences, University of Torino, Torino, Italy,*Correspondence: Annalisa Scollo ✉
| | | | | | - Alessia Rusinà
- Department of Veterinary Sciences, University of Torino, Torino, Italy
| | - Stefania Calò
- Istituto Zooprofilattico della Lombardia ed Emilia-Romagna, Sorveglianza Epidemiologica, Brescia, Italy
| | - Veronica Cappa
- Istituto Zooprofilattico della Lombardia ed Emilia-Romagna, Sorveglianza Epidemiologica, Brescia, Italy
| | | | | | - Giovanni Loris Alborali
- Istituto Zooprofilattico della Lombardia ed Emilia-Romagna, Sorveglianza Epidemiologica, Brescia, Italy
| | - Silvia Bellini
- Istituto Zooprofilattico della Lombardia ed Emilia-Romagna, Sorveglianza Epidemiologica, Brescia, Italy
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Gao Y, Nielsen LH, Boklund AE, de Jong MCM, Alban L. SWOT analysis of risk factors associated with introduction of African Swine Fever through vehicles returning after export of pigs. Front Vet Sci 2023; 9:1049940. [PMID: 36686159 PMCID: PMC9846816 DOI: 10.3389/fvets.2022.1049940] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 12/12/2022] [Indexed: 01/06/2023] Open
Abstract
Denmark is a major pig exporter and applies a high level of biosecurity, with washing and disinfecting stations for returning livestock vehicles. The introduction of African Swine Fever (ASF) would have significant economic consequences related to loss of export of live pigs and products thereof. In this study, we focused on the role of empty livestock vehicles returning after exports of pigs for the introduction of ASF. Initially, the current components and measures related to export of livestock were described. Next, analyses of strengths, weaknesses, opportunities, and threats (SWOT) were conducted, covering the components and measures identified. Then, export of pigs was described either through assembly centers or directly from farms. Washing and disinfection, as required and undertaken at the designated stations, constitutes the most important among all risk-reducing measures identified. Recommendations are to: (1) ensure the quality of washing and disinfection through staff training; (2) find new, safe, and more efficient disinfectants; (3) ensure the required temperature, and therefore effect, of the disinfectant and water. It was impossible to assess, the influence of export through assembly centers compared to direct transport. However, through SWOT analyses we identified the strengths and weaknesses of the two pathways. Moreover, components/measures with risks of unknown sizes are also discussed, such as vehicles undertaking cabotage and the current vehicle quarantine periods.
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Affiliation(s)
- Yuqi Gao
- Quantitative Veterinary Epidemiology, Department of Animal Sciences, Wageningen University and Research, Wageningen, Netherlands,*Correspondence: Yuqi Gao ✉
| | - Lisbeth Harm Nielsen
- Department for Food Safety and Veterinary Issues, Danish Agriculture and Food Council, Copenhagen, Denmark
| | - Anette Ella Boklund
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mart C. M. de Jong
- Quantitative Veterinary Epidemiology, Department of Animal Sciences, Wageningen University and Research, Wageningen, Netherlands
| | - Lis Alban
- Department for Food Safety and Veterinary Issues, Danish Agriculture and Food Council, Copenhagen, Denmark,Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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10
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Jiang W, Jiang D, Li L, Wang J, Wang P, Shi X, Zhao Q, Liu B, Ji P, Zhang G. Identification of Two Novel Linear B Cell Epitopes on the CD2v Protein of African Swine Fever Virus Using Monoclonal Antibodies. Viruses 2022; 15:131. [PMID: 36680174 PMCID: PMC9866794 DOI: 10.3390/v15010131] [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: 12/02/2022] [Revised: 12/28/2022] [Accepted: 12/29/2022] [Indexed: 01/03/2023] Open
Abstract
African swine fever virus (ASFV) is a highly infectious viral pathogen that endangers the global pig industry, and no effective vaccine is available thus far. The CD2v protein is a glycoprotein on the outer envelope of ASFV, which mediates the transmission of the virus in the blood and recognition of the virus serotype, playing an important role in ASFV vaccine development and disease prevention. Here, we generated two specific monoclonal antibodies (mAbs), 6C11 and 8F12 (subtype IgG1/kappa-type), against the ASFV CD2v extracellular domain (CD2v-ex, GenBank: MK128995.1, 1-588 bp) and characterized their specificity. Peptide scanning technology was used to identify the epitopes recognized by mAbs 6C11 and 8F12. As a result, two novel B cell epitopes, 38DINGVSWN45 and 134GTNTNIY140, were defined. Amino acid sequence alignment showed that the defined epitopes were conserved in all referenced ASFV strains from various regions of China including the highly pathogenic, epidemic strain, Georgia2007/1 (NC_044959.2), with the same noted substitutions compared to the four foreign ASFV wild-type strains. This study provides important reference values for the design and development of an ASFV vaccine and useful biological materials for the functional study of the CD2v protein by deletion analysis.
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Affiliation(s)
- Wenting Jiang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
- International Joint Research Center of National Animal Immunology, Zhengzhou 450046, China
| | - Dawei Jiang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
- International Joint Research Center of National Animal Immunology, Zhengzhou 450046, China
- Longhu Laboratory, Zhengzhou 450046, China
| | - Lu Li
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
- International Joint Research Center of National Animal Immunology, Zhengzhou 450046, China
| | - Jiabin Wang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
- International Joint Research Center of National Animal Immunology, Zhengzhou 450046, China
| | - Panpan Wang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
- International Joint Research Center of National Animal Immunology, Zhengzhou 450046, China
| | - Xuejian Shi
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
- International Joint Research Center of National Animal Immunology, Zhengzhou 450046, China
| | - Qi Zhao
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
- International Joint Research Center of National Animal Immunology, Zhengzhou 450046, China
| | - Boyuan Liu
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
- International Joint Research Center of National Animal Immunology, Zhengzhou 450046, China
| | - Pengchao Ji
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
- International Joint Research Center of National Animal Immunology, Zhengzhou 450046, China
- Henan Engineering Laboratory of Animal Biological Products, Zhengzhou 450046, China
| | - Gaiping Zhang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
- International Joint Research Center of National Animal Immunology, Zhengzhou 450046, China
- Longhu Laboratory, Zhengzhou 450046, China
- Henan Engineering Laboratory of Animal Biological Products, Zhengzhou 450046, China
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11
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Ruiz-Saenz J, Diaz A, Bonilla-Aldana DK, Rodríguez-Morales AJ, Martinez-Gutierrez M, Aguilar PV. African swine fever virus: A re-emerging threat to the swine industry and food security in the Americas. Front Microbiol 2022; 13:1011891. [PMID: 36274746 PMCID: PMC9581234 DOI: 10.3389/fmicb.2022.1011891] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 09/16/2022] [Indexed: 12/15/2022] Open
Affiliation(s)
- Julian Ruiz-Saenz
- Grupo de Investigación en Ciencias Animales—GRICA, Universidad Cooperativa de Colombia, Bucaramanga, Colombia,*Correspondence: Julian Ruiz-Saenz ;
| | - Andres Diaz
- PIC—Pig Improvement Company, Querétaro, Mexico
| | - D. Katterine Bonilla-Aldana
- Grupo de Investigación Biomedicina, Faculty of Medicine, Fundación Universitaria Autónoma de las Américas, Pereira, Colombia
| | - Alfonso J. Rodríguez-Morales
- Grupo de Investigación Biomedicina, Faculty of Medicine, Fundación Universitaria Autónoma de las Américas, Pereira, Colombia,Faculty of Health Sciences, Universidad Cientifica del Sur, Lima, Peru
| | - Marlen Martinez-Gutierrez
- Grupo de Investigación en Microbiología Veterinaria, Escuela de Microbiología, Universidad de Antioquia, Medellín, Colombia
| | - Patricia V. Aguilar
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States,Center for Tropical Diseases, Institute for Human Infection and Immunity, University of Texas Medical Branch, Galveston, TX, United States
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12
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Influence of African Swine Fever Virus on Host Gene Transcription within Peripheral Blood Mononuclear Cells from Infected Pigs. Viruses 2022; 14:v14102147. [PMID: 36298701 PMCID: PMC9610944 DOI: 10.3390/v14102147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 09/26/2022] [Accepted: 09/26/2022] [Indexed: 11/17/2022] Open
Abstract
African swine fever virus (ASFV) has become a global threat to the pig production industry and has caused enormous economic losses in many countries in recent years. Peripheral blood mononuclear cells (PBMCs) from pigs infected with ASFV not only express ASFV genes (almost 200 in number) but have altered patterns of host gene expression as well. Both up- and down-regulation of host cell gene expression can be followed using RNAseq on poly(A)+ mRNAs harvested from the PBMCs of pigs collected at different times post-infection. Consistent with the time course of changes in viral gene expression, only few and limited changes in host gene expression were detected at 3 days post-infection (dpi), but by 6 dpi, marked changes in the expression of over 1300 host genes were apparent. This was co-incident with the major increase in viral gene expression. The majority of the changes in host gene expression were up-regulation, but many down-regulated genes were also identified. The patterns of changes in gene expression within the PBMCs detected by RNAseq were similar in each of the four infected pigs. Furthermore, changes in the expression of about twenty selected host genes, known to be important in host defence and inflammatory responses, were confirmed using high-throughput microfluidic qPCR assays.
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13
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Lamberga K, Depner K, Zani L, Oļševskis E, Seržants M, Ansonska S, Šteingolde Ž, Bērziņš A, Viltrop A, Blome S, Globig A. A practical guide for strategic and efficient sampling in African swine fever-affected pig farms. Transbound Emerg Dis 2022; 69:e2408-e2417. [PMID: 35502726 PMCID: PMC9790576 DOI: 10.1111/tbed.14582] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 04/13/2022] [Accepted: 04/27/2022] [Indexed: 12/30/2022]
Abstract
In the case of African swine fever (ASF) outbreaks in pig farms, EU legislation requires a thorough epidemiological investigation to determine, among other tasks, the extent of infection in the affected farm. The main aim of this study was to implement a reliable sampling strategy to quickly obtain an overview of the extent of ASF virus spread in an affected pig farm. We developed and tested a three-step approach: (i) identification of sub-units within the affected farm, (ii) categorization of sub-units, and (iii) targeted selection of animals for testing. We used commercially available lateral flow devices (LFDs) to detect ASF antigen and antibodies under field conditions and compared them with routinely performed laboratory tests (qPCR, ELISA, IPT). The study was conducted in three commercial farms in Latvia that were affected by ASF in July 2020. One of the affected farms was relatively small with only 31 pigs, whereas the other two were large with 1800 and 9800 animals, respectively. The approach proved to be helpful and practical for efficient and reliably assess the ASF situation on the farm and to identify sub-units within a farm where infected animals are present and sub-units which might (still) be free of infection. This important epidemiological information helps to better estimate the high-risk period and to track the potential spread of infection outside the farm. It allows also to prioritize culling and, if appropriate, to pursue a partial culling strategy taking into account the absence of clinical signs, implemented biosecurity measures, quarantine and negative test results, among others. This might be of interest for large commercial farms where the infection was identified very early and has not yet spread widely. Due to its limited sensitivity, the antigen LFD test is useful for testing animals showing signs of disease.
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Affiliation(s)
- Kristīne Lamberga
- Food and Veterinary ServiceRigaLatvia,Faculty of Veterinary MedicineLatvia University of Life Sciences and TechnologiesJelgavaLatvia
| | - Klaus Depner
- Friedrich‐Loeffler‐InstituteGreifswald—Insel RiemsGermany
| | - Laura Zani
- Friedrich‐Loeffler‐InstituteGreifswald—Insel RiemsGermany
| | - Edvīns Oļševskis
- Food and Veterinary ServiceRigaLatvia,Institute of Food SafetyAnimal Health and Environment “BIOR”RigaLatvia
| | | | - Santa Ansonska
- Food and Veterinary ServiceRigaLatvia,Institute of Food SafetyAnimal Health and Environment “BIOR”RigaLatvia
| | - Žanete Šteingolde
- Institute of Food SafetyAnimal Health and Environment “BIOR”RigaLatvia
| | - Aivars Bērziņš
- Faculty of Veterinary MedicineLatvia University of Life Sciences and TechnologiesJelgavaLatvia,Institute of Food SafetyAnimal Health and Environment “BIOR”RigaLatvia
| | - Arvo Viltrop
- Institute of Veterinary Medicine and Animal SciencesEstonian University of Life SciencesTartuEstonia
| | - Sandra Blome
- Friedrich‐Loeffler‐InstituteGreifswald—Insel RiemsGermany
| | - Anja Globig
- Friedrich‐Loeffler‐InstituteGreifswald—Insel RiemsGermany
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14
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Chenais E, Depner K, Ebata A, Penrith M, Pfeiffer DU, Price C, Ståhl K, Fischer K. Exploring the hurdles that remain for control of African swine fever in smallholder farming settings. Transbound Emerg Dis 2022; 69:e3370-e3378. [PMID: 35737577 PMCID: PMC9796485 DOI: 10.1111/tbed.14642] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 06/22/2022] [Accepted: 06/22/2022] [Indexed: 01/01/2023]
Abstract
To honour the 100 years anniversary of the first publication about African swine fever (ASF) a webinar with a particular focus on disease control in the smallholder sector was organized. This article is based on the webinar, summarizing the early history of ASF research, reflecting on the current global disease situation and bringing forward some suggestions that could contribute towards achieving control of ASF. The first description of ASF by R. Eustace Montgomery in 1921 laid the foundations for what we know about the disease today. Subsequent research confirmed its association with warthogs and soft ticks of the Ornithodoros moubata complex. During the latter half of the 21st century, exponential growth of pig production in Africa has led to a change in the ASF-epidemiology pattern. It is now dominated by a cycle involving domestic pigs and pork with virus spread driven by people. In 2007, a global ASF epidemic started, reaching large parts of Europe, Asia and the Americas. In Europe, this epidemic has primarily affected wild boar. In Asia, wild boar, smallholders and industrialized pig farms have been affected with impact on local, national and international pig value chains. Globally and historically, domestic pigs in smallholder settings are most frequently affected and the main driver of ASF virus transmission. Awaiting a safe and efficacious vaccine, we need to continue focus on other measures, such as biosecurity, for controlling the disease. However, smallholders face specific challenges linked to poverty and other structural factors in implementing biosecurity measures that can prevent spread. Improving biosecurity in the smallholder sector thus remains an important tool for preventing and controlling ASF. In this regard, interdisciplinary research can help to find new ways to promote safe practices, facilitate understanding and embrace smallholders' perspectives, engage stakeholders and adjust prevention and control policies to improve implementation.
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Affiliation(s)
- Erika Chenais
- Department of Disease Control and EpidemiologyNational Veterinary InstituteUppsalaSweden
| | - Klaus Depner
- Institute for International Animal Health / One HealthFriedrich‐Loeffler‐InstitutGreifswald‐Insel RiemsGermany
| | - Ayako Ebata
- Institute of Development StudiesUniversity of SussexBrightonUK
| | - Mary‐Louise Penrith
- Department of Veterinary Tropical DiseasesUniversity of PretoriaPretoriaSouth Africa
| | - Dirk U. Pfeiffer
- Centre for Applied One Health Research and Policy AdviceCity University of Hong KongHong KongPR China,Pathobiology and Population SciencesRoyal Veterinary CollegeLondonUK
| | - Cortney Price
- Animal Production and Health DivisionFood and Agriculture Organization of the United NationsRomeItaly
| | - Karl Ståhl
- Department of Disease Control and EpidemiologyNational Veterinary InstituteUppsalaSweden
| | - Klara Fischer
- Department of Urban and Rural DevelopmentSwedish University of Agricultural SciencesUppsalaSweden
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15
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Machuka EM, Juma J, Muigai AWT, Amimo JO, Pelle R, Abworo EO. Transcriptome profile of spleen tissues from locally-adapted Kenyan pigs (Sus scrofa) experimentally infected with three varying doses of a highly virulent African swine fever virus genotype IX isolate: Ken12/busia.1 (ken-1033). BMC Genomics 2022; 23:522. [PMID: 35854219 PMCID: PMC9294756 DOI: 10.1186/s12864-022-08754-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 07/08/2022] [Indexed: 11/10/2022] Open
Abstract
Background African swine fever (ASF) is a lethal hemorrhagic disease affecting domestic pigs resulting in up to 100% mortality rates caused by the ASF virus (ASFV). The locally-adapted pigs in South-western Kenya have been reported to be resilient to disease and harsh climatic conditions and tolerate ASF; however, the mechanisms by which this tolerance is sustained remain largely unknown. We evaluated the gene expression patterns in spleen tissues of these locally-adapted pigs in response to varying infective doses of ASFV to elucidate the virus-host interaction dynamics. Methods Locally adapted pigs (n = 14) were experimentally infected with a high dose (1x106HAD50), medium dose (1x104HAD50), and low dose (1x102HAD50) of the highly virulent genotype IX ASFV Ken12/busia.1 (Ken-1033) isolate diluted in PBS and followed through the course of infection for 29 days. The in vivo pig host and ASFV pathogen gene expression in spleen tissues from 10 pigs (including three from each infective group and one uninfected control) were analyzed in a dual-RNASeq fashion. We compared gene expression between three varying doses in the host and pathogen by contrasting experiment groups against the naïve control. Results A total of 4954 differentially expressed genes (DEGs) were detected after ASFV Ken12/1 infection, including 3055, 1771, and 128 DEGs in the high, medium, and low doses, respectively. Gene ontology and KEGG pathway analysis showed that the DEGs were enriched for genes involved in the innate immune response, inflammatory response, autophagy, and apoptosis in lethal dose groups. The surviving low dose group suppressed genes in pathways of physiopathological importance. We found a strong association between severe ASF pathogenesis in the high and medium dose groups with upregulation of proinflammatory cytokines and immunomodulation of cytokine expression possibly induced by overproduction of prostaglandin E synthase (4-fold; p < 0.05) or through downregulation of expression of M1-activating receptors, signal transductors, and transcription factors. The host-pathogen interaction resulted in induction of expression of immune-suppressive cytokines (IL-27), inactivation of autophagy and apoptosis through up-regulation of NUPR1 [5.7-fold (high dose) and 5.1-fold (medium dose) [p < 0.05] and IL7R expression. We detected repression of genes involved in MHC class II antigen processing and presentation, such as cathepsins, SLA-DQB1, SLA-DOB, SLA-DMB, SLA-DRA, and SLA-DQA in the medium and high dose groups. Additionally, the host-pathogen interaction activated the CD8+ cytotoxicity and neutrophil machinery by increasing the expression of neutrophils/CD8+ T effector cell-recruiting chemokines (CCL2, CXCL2, CXCL10, CCL23, CCL4, CXCL8, and CXCL13) in the lethal high and medium dose groups. The recovered pigs infected with ASFV at a low dose significantly repressed the expression of CXCL10, averting induction of T lymphocyte apoptosis and FUNDC1 that suppressed neutrophilia. Conclusions We provide the first in vivo gene expression profile data from locally-adapted pigs from south-western Kenya following experimental infection with a highly virulent ASFV genotype IX isolate at varying doses that mimic acute and mild disease. Our study showed that the locally-adapted pigs induced the expression of genes associated with tolerance to infection and repression of genes involved in inflammation at varying levels depending upon the ASFV dose administered. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08754-8.
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Affiliation(s)
- Eunice Magoma Machuka
- Animal and Human Health Program, International Livestock Research Institute (ILRI), P.O. Box 30709-00100, Nairobi, Kenya. .,Pan African University Institute for Basic Sciences Technology and Innovation (PAUSTI), P.O Box 62000-00200, Nairobi, Kenya.
| | - John Juma
- Animal and Human Health Program, International Livestock Research Institute (ILRI), P.O. Box 30709-00100, Nairobi, Kenya
| | | | - Joshua Oluoch Amimo
- Center for Food Animal Health, Department of Animal Sciences, The Ohio State University, 1680 Madison Avenue, Wooster, OH, 44691, USA
| | - Roger Pelle
- Biosciences eastern and central Africa, International Livestock Research Institute (BecA-ILRI) Hub, P.O. Box 30709-00100, Nairobi, Kenya.
| | - Edward Okoth Abworo
- Animal and Human Health Program, International Livestock Research Institute (ILRI), P.O. Box 30709-00100, Nairobi, Kenya
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16
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Cell Lines for the Development of African Swine Fever Virus Vaccine Candidates: An Update. Vaccines (Basel) 2022; 10:vaccines10050707. [PMID: 35632463 PMCID: PMC9144233 DOI: 10.3390/vaccines10050707] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 04/27/2022] [Accepted: 04/27/2022] [Indexed: 01/27/2023] Open
Abstract
African swine fever virus (ASFV) is the etiological agent of a highly lethal disease in both domestic and wild pigs. The virus has rapidly spread worldwide and has no available licensed vaccine. An obstacle to the construction of a safe and efficient vaccine is the lack of a suitable cell line for ASFV isolation and propagation. Macrophages are the main targets for ASFV, and they have been widely used to study virus–host interactions; nevertheless, obtaining these cells is time-consuming and expensive, and they are not ethically suitable for the production of large-scale vaccines. To overcome these issues, different virulent field isolates have been adapted on monkey or human continuous cells lines; however, several culture passages often lead to significant genetic modifications and the loss of immunogenicity of the adapted strain. Thus, several groups have attempted to establish a porcine cell line able to sustain ASFV growth. Preliminary data suggested that some porcine continuous cell lines might be an alternative to primary macrophages for ASFV research and for large-scale vaccine production, although further studies are still needed. In this review, we summarize the research to investigate the most suitable cell line for ASFV isolation and propagation.
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17
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Lecis R, Dondina O, Orioli V, Biosa D, Canu A, Fabbri G, Iacolina L, Cossu A, Bani L, Apollonio M, Scandura M. Main roads and land cover shaped the genetic structure of a Mediterranean island wild boar population. Ecol Evol 2022; 12:e8804. [PMID: 35414901 PMCID: PMC8986547 DOI: 10.1002/ece3.8804] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 03/12/2022] [Accepted: 03/21/2022] [Indexed: 01/12/2023] Open
Abstract
Patterns of genetic differentiation within and among animal populations might vary due to the simple effect of distance or landscape features hindering gene flow. An assessment of how landscape connectivity affects gene flow can help guide management, especially in fragmented landscapes. Our objective was to analyze population genetic structure and landscape genetics of the native wild boar (Sus scrofa meridionalis) population inhabiting the island of Sardinia (Italy), and test for the existence of Isolation-by-Distance (IBD), Isolation-by-Barrier (IBB), and Isolation-by-Resistance (IBR). A total of 393 Sardinian wild boar samples were analyzed using a set of 16 microsatellite loci. Signals of genetic introgression from introduced non-native wild boars or from domestic pigs were revealed by a Bayesian cluster analysis including 250 reference individuals belonging to European wild populations and domestic breeds. After removal of introgressed individuals, genetic structure in the population was investigated by different statistical approaches, supporting a partition into five discrete subpopulations, corresponding to five geographic areas on the island: north-west (NW), central west (CW), south-west (SW), north-central east (NCE), and south-east (SE). To test the IBD, IBB, and IBR hypotheses, we optimized resistance surfaces using genetic algorithms and linear mixed-effects models with a maximum likelihood population effects parameterization. Landscape genetics analyses revealed that genetic discontinuities between subpopulations can be explained by landscape elements, suggesting that main roads, urban settings, and intensively cultivated areas are hampering gene flow (and thus individual movements) within the Sardinian wild boar population. Our results reveal how human-transformed landscapes can affect genetic connectivity even in a large-sized and highly mobile mammal such as the wild boar, and provide crucial information to manage the spread of pathogens, including the African Swine Fever virus, endemic in Sardinia.
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Affiliation(s)
- Roberta Lecis
- Department of Veterinary MedicineUniversity of SassariSassariItaly
| | - Olivia Dondina
- Department of Earth and Environmental SciencesUniversity of Milano BicoccaMilanoItaly
| | - Valerio Orioli
- Department of Earth and Environmental SciencesUniversity of Milano BicoccaMilanoItaly
| | - Daniela Biosa
- Department of Veterinary MedicineUniversity of SassariSassariItaly
| | - Antonio Canu
- Department of Veterinary MedicineUniversity of SassariSassariItaly
| | - Giulia Fabbri
- Department of Veterinary MedicineUniversity of SassariSassariItaly
| | - Laura Iacolina
- Faculty of Mathematics, Natural Sciences and Information TechnologiesUniversity of PrimorskaKoperSlovenia
- Department of Chemistry and BioscienceAalborg UniversityAalborgDenmark
| | - Antonio Cossu
- Department of Veterinary MedicineUniversity of SassariSassariItaly
| | - Luciano Bani
- Department of Earth and Environmental SciencesUniversity of Milano BicoccaMilanoItaly
| | - Marco Apollonio
- Department of Veterinary MedicineUniversity of SassariSassariItaly
| | - Massimo Scandura
- Department of Veterinary MedicineUniversity of SassariSassariItaly
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18
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Ito S, Bosch J, Martínez-Avilés M, Sánchez-Vizcaíno JM. The Evolution of African Swine Fever in China: A Global Threat? Front Vet Sci 2022; 9:828498. [PMID: 35425825 PMCID: PMC9001964 DOI: 10.3389/fvets.2022.828498] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 02/15/2022] [Indexed: 12/03/2022] Open
Abstract
African swine fever (ASF) is one of the most critical diseases in the pig industry. In Asia, 15 countries have already reported an outbreak as of November 22, 2021. In 2021, China reported the genotype II lower virulent ASF virus (ASFV) and the emergence of genotype I ASFV. ASF is generally known as a contagious and lethal disease, but if chronic infection spreads, then disease control would be more difficult. In the current study, we highlighted the possibility of lower virulent virus distribution throughout China and the subsequent general risk of the virus being released from the country. The kernel density estimation showed that the two highest kernel density areas of ASF notification were located in Northeast and Midwest China. Four of the five provinces where lower virulent ASFV was isolated overlapped with areas of relatively high ASF notification density. In terms of the risk of ASFV spreading from China, eight of the 10 largest airports and three of the 10 largest seaports are located in areas of relatively high ASF notification density. There were flight flow from China to 67 countries and ship flow to 81 countries. Asia had the highest flight flow, followed by Europe, North America, Africa, and Oceania. The highest number of ship flows was also concentrated in Asia, but about 10% of ships head to Africa and South America. Chinese overseas residents were distributed in each continent in proportion to these results. Here, we highlight the potential risk of ASFV spread from China to the world.
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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, Complutense University of Madrid, Madrid, Spain
- *Correspondence: Satoshi Ito
| | - 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
| | - Marta Martínez-Avilés
- VISAVET Health Surveillance Center, Complutense University of Madrid, Madrid, Spain
- Department of Animal Health, Faculty of Veterinary, Complutense University of Madrid, Madrid, Spain
- Infectious Diseases and Global Health Department, Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria-Consejo Superior de Investigaciones Científicas (INIA-CSIC), 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
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Costard S, Perez AM, Zagmutt FJ, Pouzou JG, Groenendaal H. Partitioning, a Novel Approach to Mitigate the Risk and Impact of African Swine Fever in Affected Areas. Front Vet Sci 2022; 8:812876. [PMID: 35274016 PMCID: PMC8902292 DOI: 10.3389/fvets.2021.812876] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 12/31/2021] [Indexed: 11/13/2022] Open
Abstract
As African swine fever (ASF) continues to expand geographically, supplementary control strategies are needed to reduce disease risk and impact in affected areas. Full depopulation is central to current ASF control efforts, and its efficacy depends on surveillance and timely disease reporting, while resulting in large losses regardless of the producers' efforts to promptly detect, report, and contain the disease. This disconnect between prompt detection and reporting, and subsequent farm losses, can deter producers to invest in ASF detection and control. Alternative approaches are needed to incentivize individual producers to invest in early detection and reporting. We postulate that commercial swine farms may be effectively partitioned in separate units, or subpopulations, to which biosecurity, surveillance and control can be applied. The suggested Partitioning framework relies on three main components: 1. external and internal biosecurity to reduce the risk of ASF introduction and maintain separate subpopulations; 2. cost-effective on-farm ASF surveillance to enhance early detection; 3. response plans at the unit level, including culling of affected subpopulations, and demonstration of freedom from disease on the remaining ones. With such Partitioning approach, individual producers may reduce ASF risk on a farm and in the region, while also reducing ASF outbreak losses via targeted depopulation of affected units. It requires relevant legislation to incorporate the notion of within-farm subpopulations and provide a regulatory framework for targeted depopulation and substantiation of disease freedom. Its design should be tailored to fit individual farms. Partitioning can be an effective public-private partnership approach for ASF risk reduction. It should be driven by industry, as its benefits are accrued mainly by individual producers, but regulatory oversight is key to ensure proper implementation and avoid further disease spread. Partitioning's value is greatest for producers in ASF-affected regions, but ASF-free areas could also benefit from it for preparedness and early detection. It could also be adapted to other transboundary animal diseases and can be implemented as a stand-alone program or in conjunction with other efforts such as zoning and compartmentalization. Partitioning would contribute to the improved resilience and sustainability of the global pork industry and will benefit consumers and society through improved food security and animal welfare.
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Affiliation(s)
- Solenne Costard
- EpiX Analytics, Fort Collins, CO, United States
- *Correspondence: Solenne Costard
| | - Andres M. Perez
- Center for Animal Health and Food Safety, College of Veterinary Medicine, University of Minnesota, Minneapolis, MN, United States
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Effects of the NF-κB Signaling Pathway Inhibitor BAY11-7082 in the Replication of ASFV. Viruses 2022; 14:v14020297. [PMID: 35215890 PMCID: PMC8877168 DOI: 10.3390/v14020297] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/20/2022] [Accepted: 01/28/2022] [Indexed: 02/01/2023] Open
Abstract
African swine fever virus (ASFV) mainly infects the monocyte/macrophage lineage of pigs and regulates the production of cytokines that influence host immune responses. Several studies have reported changes in cytokine production after infection with ASFV, but the regulatory mechanisms have not yet been elucidated. Therefore, the aim of this study was to examine the immune response mechanism of ASFV using transcriptomic and proteomic analyses. Through multi-omics joint analysis, it was found that ASFV infection regulates the expression of the host NF-B signal pathway and related cytokines. Additionally, changes in the NF-κB signaling pathway and IL-1β and IL-8 expression in porcine alveolar macrophages (PAMs) infected with ASFV were examined. Results show that ASFV infection activates the NF-κB signaling pathway and up-regulates the expression of IL-1β and IL-8. The NF-κB inhibitor BAY11-7082 inhibited the expression profiles of phospho-NF-κB p65, p-IκB, and MyD88 proteins, and inhibited ASFV-induced NF-κB signaling pathway activation. Additionally, the results show that the NF-κB inhibitor BAY11-7082 can inhibit the replication of ASFV and can inhibit IL-1β and, IL-8 expression. Overall, the findings of this study indicate that ASFV infection activates the NF-κB signaling pathway and up-regulates the expression of IL-1β and IL-8, and inhibits the replication of ASFV by inhibiting the NF-κB signaling pathway and interleukin-1 beta and interleukin-8 production. These findings not only provide new insights into the molecular mechanism of the association between the NF-κB signaling pathway and ASFV infection, but also indicate that the NF-κB signaling pathway is a potential immunomodulatory pathway that controls ASF.
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21
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Superficial Inguinal Lymph Nodes for Screening Dead Pigs for African Swine Fever. Viruses 2022; 14:v14010083. [PMID: 35062287 PMCID: PMC8780992 DOI: 10.3390/v14010083] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 12/23/2021] [Accepted: 12/30/2021] [Indexed: 02/04/2023] Open
Abstract
African swine fever (ASF) has spread across the globe and has reached closer to North America since being reported in the Dominican Republic and Haiti. As a result, surveillance measures have been heightened and the utility of alternative samples for herd-level monitoring and dead pig sampling have been investigated. Passive surveillance based on the investigation of dead pigs, both domestic and wild, plays a pivotal role in the early detection of an ASF incursion. The World Organization for Animal Health (OIE)-recommended samples for dead pigs are spleen, lymph nodes, bone marrow, lung, tonsil and kidney. However, obtaining these samples requires opening up the carcasses, which is time-consuming, requires skilled labour and often leads to contamination of the premises. As a result, we investigated the suitability of superficial inguinal lymph nodes (SILNs) for surveillance of dead animals. SILNs can be collected in minutes with no to minimum environmental contamination. Here, we demonstrate that the ASF virus (ASFV) genome copy numbers in SILNs highly correlate with those in the spleen and, by sampling SILN, we can detect all pigs that succumb to highly virulent and moderately virulent ASFV strains (100% sensitivity). ASFV was isolated from all positive SILN samples. Thus, sampling SILNs could be useful for routine surveillance of dead pigs on commercial and backyard farms, holding pens and dead on arrival at slaughter houses, as well as during massive die-offs of pigs due to unknown causes.
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22
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Tizzani M, Muñoz-Gómez V, De Nardi M, Paolotti D, Muñoz O, Ceschi P, Viltrop A, Capua I. Integrating digital and field surveillance as complementary efforts to manage epidemic diseases of livestock: African swine fever as a case study. PLoS One 2022; 16:e0252972. [PMID: 34972117 PMCID: PMC8719698 DOI: 10.1371/journal.pone.0252972] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 12/13/2021] [Indexed: 11/18/2022] Open
Abstract
SARS-CoV-2 has clearly shown that efficient management of infectious diseases requires a top-down approach which must be complemented with a bottom-up response to be effective. Here we investigate a novel approach to surveillance for transboundary animal diseases using African Swine (ASF) fever as a model. We collected data both at a population level and at the local level on information-seeking behavior respectively through digital data and targeted questionnaire-based surveys to relevant stakeholders such as pig farmers and veterinary authorities. Our study shows how information-seeking behavior and resulting public attention during an epidemic, can be identified through novel data streams from digital platforms such as Wikipedia. Leveraging attention in a critical moment can be key to providing the correct information at the right moment, especially to an interested cohort of people. We also bring evidence on how field surveys aimed at local workers and veterinary authorities remain a crucial tool to assess more in-depth preparedness and awareness among front-line actors. We conclude that these two tools should be used in combination to maximize the outcome of surveillance and prevention activities for selected transboundary animal diseases such as ASF.
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Affiliation(s)
- Michele Tizzani
- Institute for Scientific Interchange Foundation, Torino, Italy
| | - Violeta Muñoz-Gómez
- SAFOSO, Liebefeld, Switzerland.,Section of Epidemiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | | | | | - Olga Muñoz
- One Health Centre of Excellence, Gainesville, Florida, Unites States of America.,Department of Environmental and Global Health, College of Public Health and Health Professionals, Gainesville, Florida, United States of America
| | - Piera Ceschi
- Department of Environmental and Global Health, College of Public Health and Health Professionals, Gainesville, Florida, United States of America
| | - Arvo Viltrop
- Estonian University of Life Sciences, Tartu, Estonia
| | - Ilaria Capua
- Department of Environmental and Global Health, College of Public Health and Health Professionals, Gainesville, Florida, United States of America
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23
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Genotyping of African Swine Fever Virus (ASFV) Isolates in Romania with the First Report of Genotype II in Symptomatic Pigs. Vet Sci 2021; 8:vetsci8120290. [PMID: 34941817 PMCID: PMC8706303 DOI: 10.3390/vetsci8120290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 11/17/2022] Open
Abstract
The World Organisation for Animal Health has listed African swine fever as the most important deadly disease in domestic swine around the world. The virus was recently brought from South-East Africa to Georgia in 2007, and it has since expanded to Russia, Eastern Europe, China, and Southeast Asia, having a devastating impact on the global swine industry and economy. In this study, we report for the first time the molecular characterization of nine African swine fever virus (ASFV) isolates obtained from domestic pigs in Mureş County, Romania. All nine Romanian samples clustered within p72 genotype II and showed 100% identity with all compared isolates from Georgia, Armenia, Russia, Azerbaijan, Ukraine, Belarus, Lithuania, and Poland. This is the first report of ASFV genotype II in the country.
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Identification of African Swine Fever Virus Transcription within Peripheral Blood Mononuclear Cells of Acutely Infected Pigs. Viruses 2021; 13:v13112333. [PMID: 34835139 PMCID: PMC8623482 DOI: 10.3390/v13112333] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/16/2021] [Accepted: 11/18/2021] [Indexed: 12/30/2022] Open
Abstract
African swine fever virus (ASFV) has become widespread in Europe, Asia and elsewhere, thereby causing extensive economic losses. The viral genome includes nearly 200 genes, but their expression within infected pigs has not been well characterized previously. In this study, four pigs were infected with a genotype II strain (ASFV POL/2015/Podlaskie); blood samples were collected before inoculation and at both 3 and 6 days later. During this period, a range of clinical signs of infection became apparent in the pigs. From the blood, peripheral blood mononuclear cells (PBMCs) were isolated. The transcription of the ASFV genes was determined using RNAseq on poly(A)+ mRNAs isolated from these cells. Only very low levels of virus transcription were detected in the PBMCs at 3 days post-inoculation (dpi) but, at 6 dpi, extensive transcription was apparent. This was co-incident with a large increase in the level of ASFV DNA within these cells. The pattern of the virus gene expression was very reproducible between the individual pigs. Many highly expressed genes have undefined roles. Surprisingly, some genes with key roles in virus replication were expressed at only low levels. As the functions of individual genes are identified, information about their expression becomes important for understanding their contribution to virus biology.
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African Swine Fever in Wild Boar (Poland 2020): Passive and Active Surveillance Analysis and Further Perspectives. Pathogens 2021; 10:pathogens10091219. [PMID: 34578251 PMCID: PMC8465799 DOI: 10.3390/pathogens10091219] [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: 09/10/2021] [Revised: 09/16/2021] [Accepted: 09/17/2021] [Indexed: 11/17/2022] Open
Abstract
African swine fever (ASF) is a fatal hemorrhagic disease of wild boar and domestic pigs which has been present in Poland since 2014. By 2020, the ASF virus (ASFV) spread across Central, Eastern and Western Europe (including Germany), and Asian countries (including China, Vietnam, and South Korea). The national ASF eradication and prevention program includes continuous passive (wild boar found dead and road-killed wild boar) and active (hunted wild boar) surveillance. The main goal of this study was to analyze the dynamic of the spread of ASF in the wild boar population across the territory of Poland in 2020. In that year in Poland, in total 6191 ASF-positive wild boar were declared. Most of them were confirmed in a group of animals found dead. The conducted statistical analysis indicates that the highest chance of obtaining an ASF-positive result in wild boar was during the winter months, from January to March, and in December 2020. Despite the biosecurity measures implemented by holdings of domestic pigs, the disease also occurred in 109 pig farms. The role of ASF surveillance in the wild boar population is crucial to apply more effective and tailored measures of disease control and eradication. The most essential measures to maintain sustainable production of domestic pigs in Poland include effective management of the wild boar population, along with strict implementation of biosecurity measures by domestic pig producers.
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Rolesu S, Mandas D, Loi F, Oggiano A, Dei Giudici S, Franzoni G, Guberti V, Cappai S. African Swine Fever in Smallholder Sardinian Farms: Last 10 Years of Network Transmission Reconstruction and Analysis. Front Vet Sci 2021; 8:692448. [PMID: 34395576 PMCID: PMC8361751 DOI: 10.3389/fvets.2021.692448] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 06/30/2021] [Indexed: 12/20/2022] Open
Abstract
African swine fever (ASF) is a viral disease of suids that frequently leads to death. There are neither licensed vaccines nor treatments available, and even though humans are not susceptible to the disease, the serious socio-economic consequences associated with ASF have made it one of the most serious animal diseases of the last century. In this context, prevention and early detection play a key role in controlling the disease and avoiding losses in the pig value chain. Target biosecurity measures are a strong strategy against ASF virus (ASFV) incursions in farms nowadays, but to be efficient, these measures must be well-defined and easy to implement, both in commercial holdings and in the backyard sector. Furthermore, the backyard sector is of great importance in low-income settings, mainly for social and cultural practices that are highly specific to certain areas and communities. These contexts need to be addressed when authorities decide upon the provisions that should be applied in the case of infection or decide to combine them with strict preventive measures to mitigate the risk of virus spread. The need for a deeper understanding of the smallholder context is essential to prevent ASFV incursion and spread. Precise indications for pig breeding and risk estimation for ASFV introduction, spread and maintenance, taking into account the fact that these recommendations would be inapplicable in some contexts, are the keys for efficient target control measures. The aim of this work is to describe the 305 outbreaks that occurred in domestic pigs in Sardinia during the last epidemic season (2010-2018) in depth, providing essential features associated with intensive and backyard farms where the outbreaks occurred. In addition, the study estimates the average of secondary cases by kernel transmission network. Considering the current absence of ASF outbreaks in domestic pig farms in Sardinia since 2018, this work is a valid tool to specifically estimate the risk associated with different farm types and update our knowledge in this area.
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Affiliation(s)
- Sandro Rolesu
- Sardinian Regional Veterinary Epidemiological Observatory, Istituto Zooprofilattico Sperimentale della Sardegna “G. Pegreffi”, Cagliari, Italy
| | - Daniela Mandas
- Sardinian Regional Veterinary Epidemiological Observatory, Istituto Zooprofilattico Sperimentale della Sardegna “G. Pegreffi”, Cagliari, Italy
| | - Federica Loi
- Sardinian Regional Veterinary Epidemiological Observatory, Istituto Zooprofilattico Sperimentale della Sardegna “G. Pegreffi”, Cagliari, Italy
| | - Annalisa Oggiano
- Department of Animal Health, Istituto Zooprofilattico Sperimentale Della Sardegna, Sassari, Italy
| | - Silvia Dei Giudici
- Department of Animal Health, Istituto Zooprofilattico Sperimentale Della Sardegna, Sassari, Italy
| | - Giulia Franzoni
- Department of Animal Health, Istituto Zooprofilattico Sperimentale Della Sardegna, Sassari, Italy
| | - Vittorio Guberti
- ISPRA—Institute for Environmental Protection and Research, Rome, Italy
| | - Stefano Cappai
- Sardinian Regional Veterinary Epidemiological Observatory, Istituto Zooprofilattico Sperimentale della Sardegna “G. Pegreffi”, Cagliari, Italy
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Deutschmann P, Pikalo J, Beer M, Blome S. Lateral flow assays for the detection of African swine fever virus antigen are not fit for field diagnosis of wild boar carcasses. Transbound Emerg Dis 2021; 69:2344-2348. [PMID: 34312995 DOI: 10.1111/tbed.14248] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 07/03/2021] [Accepted: 07/18/2021] [Indexed: 11/28/2022]
Abstract
African swine fever (ASF) is one of the most important viral diseases of domestic pigs and wild boar. Apart from endemic cycles in Africa, ASF is now continuously spreading in Europe and Asia. As ASF leads to severe but unspecific clinical signs and high lethality, early pathogen detection is of utmost importance. Recently, 'point-of-care' (POC) tests, especially immunochromatographic assays, have been intensively discussed for the use in remote areas but also in the context of on-farm epidemiological investigations and wild boar carcass screening. The later topic was the starting point for our present study. In detail, we evaluated the performance of the commercially available INGEZIM ASFV CROM Ag lateral flow assay (Eurofins Technologies Ingenasa) with selected high-quality reference blood samples, and with blood samples from wild boar carcasses collected under field conditions in Germany. While we observed a sensitivity of roughly 77% in freeze-thawed matrices of close to ideal quality, our approach to simulate field conditions in direct testing of blood samples from carcasses without any modification, resulted in a drastically reduced sensitivity of only 12.5% with the given sample set. Freeze thawing increased the sensitivity to roughly 44% which mirrored the overall sensitivity of 49% in the total data set of wild boar carcass samples. A diagnostic specificity of 100% was observed. In summary, the antigen LFA should not be regarded as a substitute for any OIE listed diagnostic method and has very limited use for carcass testing at the point of care. For optimized LFA antigen tests, the sensitivity with field samples must be significantly increased. An improved sensitivity is seen with freeze-thawed samples, which may indicate problems in the accessibility of ASFV antigen that could be overcome, to a certain extent, with assay modifications.
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Affiliation(s)
- Paul Deutschmann
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Greifswald, Germany
| | - Jutta Pikalo
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Greifswald, Germany
| | - Martin Beer
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Greifswald, Germany
| | - Sandra Blome
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Greifswald, Germany
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African Swine Fever Virus as a Difficult Opponent in the Fight for a Vaccine-Current Data. Viruses 2021; 13:v13071212. [PMID: 34201761 PMCID: PMC8310326 DOI: 10.3390/v13071212] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/17/2021] [Accepted: 06/19/2021] [Indexed: 12/13/2022] Open
Abstract
Prevention and control of African swine fever virus (ASFV) in Europe, Asia, and Africa seem to be extremely difficult in view of the ease with which it spreads, its high resistance to environmental conditions, and the many obstacles related to the introduction of effective specific immunoprophylaxis. Biological properties of ASFV indicate that the African swine fever (ASF) pandemic will continue to develop and that only the implementation of an effective and safe vaccine will ensure a reduction in the spread of ASFV. At present, vaccines against ASF are not available. The latest approaches to the ASFV vaccine’s design concentrate on the development of either modified live vaccines by targeted gene deletion from different isolates or subunit vaccines. The construction of an effective vaccine is hindered by the complex structure of the virus, the lack of an effective continuous cell line for the isolation and propagation of ASFV, unpredictable and stain-specific phenotypes after the genetic modification of ASFV, a risk of reversion to virulence, and our current inability to differentiate infected animals from vaccinated ones. Moreover, the design of vaccines intended for wild boars and oral administration is desirable. Despite several obstacles, the design of a safe and effective vaccine against ASFV seems to be achievable.
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