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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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Zhu JJ, Wang HJ. Semiochemicals and natural repellents in biting fly management. CURRENT OPINION IN INSECT SCIENCE 2024; 64:101223. [PMID: 38908821 DOI: 10.1016/j.cois.2024.101223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 06/06/2024] [Accepted: 06/14/2024] [Indexed: 06/24/2024]
Abstract
Biting flies, including stable flies and horn flies, are considered important pests of livestock, companion animals, and humans by inflicting painful bites and interrupting normal animal behavior and human recreational/outdoor activities. It is estimated that they cause an annual loss of over 3 billion dollars in the US livestock industry. Both groups of pest flies further transmit various infectious diseases to animals and humans. The present review summarizes recent research advancements in stable and horn fly chemical and sensory ecology, especially in the discovery of novel attractants and repellents, as well as their controls for these blood-sucking flies and beyond.
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Affiliation(s)
- Junwei J Zhu
- USDA-ARS Agroecosystem Management Research Unit, Lincoln, NE 68583, USA.
| | - Haichuan J Wang
- USDA-ARS Agroecosystem Management Research Unit, Lincoln, NE 68583, USA
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Teo EJM, Apanaskevich DA, Barker SC, Nakao R. Dermacentor (Indocentor) auratus Supino 1897: Potential geographic range, and medical and veterinary significance. Acta Trop 2024; 254:107197. [PMID: 38554993 DOI: 10.1016/j.actatropica.2024.107197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 03/05/2024] [Accepted: 03/21/2024] [Indexed: 04/02/2024]
Abstract
Dermacentor (Indocentor) auratus Supino, 1897 occurs in many regions of Southeast Asia and South Asia. In many regions of Southeast Asia and South Asia, targeted tick sampling and subsequent screening of collected D. auratus ticks have detected pathogenic bacteria and viruses in D. auratus. These disease-causing pathogens that have been detected in D. auratus include Anaplasma, Bartonella, Borrelia, Rickettsia (including spotted fever group rickettsiae), African swine fever virus, Lanjan virus, and Kyasanur forest disease virus. Although D. auratus predominantly infests wild pigs, this tick is also an occasional parasite of humans and other animals. Indeed, some 91 % of human otoacariasis cases in Sri Lanka were due to infestation by D. auratus. With the propensity of this tick to feed on multiple species of hosts, including humans, and the detection of pathogenic bacteria and viruses from this tick, D. auratus is a tick of medical, veterinary, and indeed zoonotic concern. The geographic range of this tick, however, is not well known. Therefore, in the present paper, we used the species distribution model, BIOCLIM, to project the potential geographic range of D. auratus, which may aid pathogen and tick-vector surveillance. We showed that the potential geographic range of D. auratus is far wider than the current geographic distribution of this tick, and that regions in Africa, and in North and South America seem to have suitable climates for D. auratus. Interestingly, in Southeast Asia, Borneo and Philippines also have suitable climates for D. auratus, but D. auratus has not been found in these regions yet despite the apparent close proximity of these regions to Mainland Southeast Asia, where D. auratus occurs. We thus hypothesize that the geographic distribution of D. auratus is largely dependent on the movement of wild pigs and whether or not these wild pigs are able to overcome dispersal barriers. We also review the potential pathogens and the diseases that may be associated with D. auratus and provide an updated host index for this tick.
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Affiliation(s)
- Ernest J M Teo
- Laboratory of Parasitology, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido 060-0818, Japan.
| | - Dmitry A Apanaskevich
- United States National Tick Collection, The James H. Oliver, Jr. Institute for Coastal Plain Science, Georgia Southern University, Statesboro, GA 30460, USA; Department of Biology, Georgia Southern University, Statesboro, GA 30460, USA
| | - Stephen C Barker
- Department of Parasitology, School of Chemistry & Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia
| | - Ryo Nakao
- Laboratory of Parasitology, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido 060-0818, Japan
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YAO Z, ZHAI Y, WANG X, WANG H. Estimating the spatial distribution of African swine fever outbreak in China
by combining four regional-level spatial models. J Vet Med Sci 2023; 85:1330-1340. [PMID: 37899237 PMCID: PMC10788172 DOI: 10.1292/jvms.23-0146] [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: 04/03/2023] [Accepted: 10/09/2023] [Indexed: 10/31/2023] Open
Abstract
The outbreaks of African Swine Fever (ASF) in China are ongoing, and the inadequate management of the pig supply chain is criticized. In the past four years, a series of preventive and control measures have been supplied national wide, while the outbreaks have not been terminated. This suggests the existing animal disease management at the district level may not be appropriate to control ASF under the current situation of the ASF outbreak in China. It is urgent to further describe real distribution areas of ASF in China. In this study, we combined four regional-scale models to predict the risk distribution of ASF in mainland China and identify risk factors related to ASF outbreaks. The results showed that the four regional-scale models were more accurate in predicting the ASF outbreaks than the nationwide scale model. The four regional-scale models identified the potential risk factors associated with ASF outbreaks, such as population density, pig density, land cover, temperature, and elevation factors. Moreover, seven clusters with high potential risk of ASF outbreaks were identified. Then, based on the results, we proposed more suitable prevention and control plans for ASF, which can assist the implementation of transport management policies within and between risk clusters.
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Affiliation(s)
- ZhenFei YAO
- Center of Conservation Medicine and Ecological Safety,
Northeast Forestry University, Heilongjiang, P.R. China
- College of Wildlife and Protected Area, Northeast
Forestry University, Heilongjiang, P.R. China
| | - YuJia ZHAI
- Center of Conservation Medicine and Ecological Safety,
Northeast Forestry University, Heilongjiang, P.R. China
- College of Wildlife and Protected Area, Northeast
Forestry University, Heilongjiang, P.R. China
| | - XiaoLong WANG
- Center of Conservation Medicine and Ecological Safety,
Northeast Forestry University, Heilongjiang, P.R. China
- College of Wildlife and Protected Area, Northeast
Forestry University, Heilongjiang, P.R. China
| | - HaoNing WANG
- School of Geography and Tourism, Harbin University,
Heilongjiang, P.R. China
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Schwarz L, Hamar F, Bernreiter-Hofer T, Loncaric I, Arnold M, Voglmayr T, Ladinig A. Bleeding skin lesions in gestating sows of a piglet producing farm in Austria. Porcine Health Manag 2023; 9:52. [PMID: 37964382 PMCID: PMC10647148 DOI: 10.1186/s40813-023-00348-4] [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: 10/19/2023] [Accepted: 11/04/2023] [Indexed: 11/16/2023] Open
Abstract
BACKGROUND Stomoxys calcitrans, the stable fly, occurs in pig producing countries worldwide. While in cattle the impact of this blood sucking insect is quite well described, its role in pig production is poorly investigated. Here we describe a case of a massive stable fly overpopulation in the gestation unit of a piglet producing farm in Austria that resulted in bleeding skin lesions in bitten sows. CASE PRESENTATION In October 2021, the responsible herd veterinarian of the case farm reported of sows in the gestation area presenting with bloody crusts on the whole skin surface of the body and of bleeding skin lesions. 33/55 sows were affected by moderate to severe skin lesions. Reproductive performance decreased during the time of massive stable fly overpopulation. Sows in the gestation unit showed defensive behaviour and at a certain time point resigned and accepted being bitten by stable flies. After controlling the fly population, reproductive performance improved and even exceeded the performance before the massive overgrowth of the stable fly population. CONCLUSIONS Stable flies are a serious harm to pigs and should be kept in mind for improved animal health and welfare. Knowledge about the determination of Stomoxys calcitrans and early recognition of an increasing stable fly population in pig farming systems followed by proper insect control measures have to be performed to reduce losses caused by this harming insect.
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Affiliation(s)
- Lukas Schwarz
- University Clinic for Swine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria.
| | - Flora Hamar
- University Clinic for Swine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Tanja Bernreiter-Hofer
- University Clinic for Swine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
- Tierarztpraxis an der Nordbahn, Strasshof, Austria
| | - Igor Loncaric
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Mirjam Arnold
- Clinic for Swine, Department for Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- Institute for Animal Health I, Bavarian Health and Food Safety Authority, Oberschleißheim, Germany
| | | | - Andrea Ladinig
- University Clinic for Swine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
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Rogoll L, Güttner AK, Schulz K, Bergmann H, Staubach C, Conraths FJ, Sauter-Louis C. Seasonal Occurrence of African Swine Fever in Wild Boar and Domestic Pigs in EU Member States. Viruses 2023; 15:1955. [PMID: 37766361 PMCID: PMC10536336 DOI: 10.3390/v15091955] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 09/14/2023] [Accepted: 09/19/2023] [Indexed: 09/29/2023] Open
Abstract
Since 2007, African swine fever (ASF) has spread widely within Europe and beyond. Most affected countries recorded outbreaks in domestic pigs and cases in wild boar. Outbreak data from 2014 to 2021 were used to investigate the seasonal pattern of ASF in domestic pigs and wild boar across affected member states of the European Union, since knowledge of seasonal patterns may provide the potential to adapt prevention, surveillance and control during times of increased risk. In domestic pigs, a yearly peak was observed in many European countries in summer (predominantly in July and August). In wild boar, the patterns showed more variability. In many countries, there was a seasonal peak of ASF occurrence in winter (predominantly in January and December), with an additional summer peak in the Baltic States (predominantly in July) and a further spring peak in Poland (predominantly in March). The observed seasonal effects may be related to the abundance and population dynamics of wild boar and to seasonality in pig farming. Moreover, ASF occurrence may also be influenced by human activities in both domestic pigs and wild boar.
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Affiliation(s)
- Lisa Rogoll
- Institute of Epidemiology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (A.-K.G.); (K.S.); (H.B.); (C.S.); (F.J.C.); (C.S.-L.)
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7
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Olesen AS, Stelder JJ, Tjørnehøj K, Johnston CM, Lohse L, Kjær LJ, Boklund AE, Bøtner A, Belsham GJ, Bødker R, Rasmussen TB. Detection of African Swine Fever Virus and Blood Meals of Porcine Origin in Hematophagous Insects Collected Adjacent to a High-Biosecurity Pig Farm in Lithuania; A Smoking Gun? Viruses 2023; 15:1255. [PMID: 37376554 DOI: 10.3390/v15061255] [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: 04/24/2023] [Revised: 05/16/2023] [Accepted: 05/24/2023] [Indexed: 06/29/2023] Open
Abstract
A seasonal trend of African swine fever (ASF) outbreaks in domestic pig farms has been observed in affected regions of Eastern Europe. Most outbreaks have been observed during the warmer summer months, coinciding with the seasonal activity pattern of blood-feeding insects. These insects may offer a route for introduction of the ASF virus (ASFV) into domestic pig herds. In this study, insects (hematophagous flies) collected outside the buildings of a domestic pig farm, without ASFV-infected pigs, were analyzed for the presence of the virus. Using qPCR, ASFV DNA was detected in six insect pools; in four of these pools, DNA from suid blood was also identified. This detection coincided with ASFV being reported in the wild boar population within a 10 km radius of the pig farm. These findings show that blood from ASFV-infected suids was present within hematophagous flies on the premises of a pig farm without infected animals and support the hypothesis that blood-feeding insects can potentially transport the virus from wild boars into domestic pig farms.
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Affiliation(s)
- Ann Sofie Olesen
- Section for Veterinary Virology, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen, Denmark
| | - Jonno Jorn Stelder
- Section for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 8, DK-1870 Frederiksberg C, Denmark
| | - Kirsten Tjørnehøj
- Section for Veterinary Virology, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen, Denmark
| | - Camille Melissa Johnston
- Section for Veterinary Virology, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen, Denmark
| | - Louise Lohse
- Section for Veterinary Virology, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen, Denmark
| | - Lene Jung Kjær
- Section for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 8, DK-1870 Frederiksberg C, Denmark
| | - Anette Ella Boklund
- Section for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 8, DK-1870 Frederiksberg C, Denmark
| | - Anette Bøtner
- Section for Veterinary Clinical Microbiology, Department of Veterinary and Animal Sciences, University of Copenhagen, Stigbøjlen 4, DK-1870 Frederiksberg C, Denmark
| | - Graham J Belsham
- Section for Veterinary Clinical Microbiology, Department of Veterinary and Animal Sciences, University of Copenhagen, Stigbøjlen 4, DK-1870 Frederiksberg C, Denmark
| | - René Bødker
- Section for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 8, DK-1870 Frederiksberg C, Denmark
| | - Thomas Bruun Rasmussen
- Section for Veterinary Virology, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen, Denmark
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Hannat S, La Scola B, Andreani J, Aherfi S. Asfarviruses and Closely Related Giant Viruses. Viruses 2023; 15:v15041015. [PMID: 37112995 PMCID: PMC10146109 DOI: 10.3390/v15041015] [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: 03/17/2023] [Revised: 04/14/2023] [Accepted: 04/16/2023] [Indexed: 04/29/2023] Open
Abstract
Acanthamoeba polyphaga mimivirus, so called because of its "mimicking microbe", was discovered in 2003 and was the founding member of the first family of giant viruses isolated from amoeba. These giant viruses, present in various environments, have opened up a previously unexplored field of virology. Since 2003, many other giant viruses have been isolated, founding new families and taxonomical groups. These include a new giant virus which was isolated in 2015, the result of the first co-culture on Vermamoeba vermiformis. This new giant virus was named "Faustovirus". Its closest known relative at that time was African Swine Fever Virus. Pacmanvirus and Kaumoebavirus were subsequently discovered, exhibiting phylogenetic clustering with the two previous viruses and forming a new group with a putative common ancestor. In this study, we aimed to summarise the main features of the members of this group of giant viruses, including Abalone Asfarvirus, African Swine Fever Virus, Faustovirus, Pacmanvirus, and Kaumoebavirus.
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Affiliation(s)
- Sihem Hannat
- Institut Hospitalo-Universitaire Méditerranée Infection, 13005 Marseille, France
- MEPHI, Institut de Recherche pour le Développement (IRD), Aix-Marseille Université, 13005 Marseille, France
| | - Bernard La Scola
- Institut Hospitalo-Universitaire Méditerranée Infection, 13005 Marseille, France
- MEPHI, Institut de Recherche pour le Développement (IRD), Aix-Marseille Université, 13005 Marseille, France
- Assistance Publique des Hôpitaux de Marseille (AP-HM), 13005 Marseille, France
| | - Julien Andreani
- CHU Grenoble Alpes, 27 Boulevard de la Chantourne, 38700 La Tronche, France
| | - Sarah Aherfi
- Institut Hospitalo-Universitaire Méditerranée Infection, 13005 Marseille, France
- MEPHI, Institut de Recherche pour le Développement (IRD), Aix-Marseille Université, 13005 Marseille, France
- Assistance Publique des Hôpitaux de Marseille (AP-HM), 13005 Marseille, France
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Wolff J, Beer M, Hoffmann B. Cross-Protection of an Inactivated and a Live-Attenuated Lumpy Skin Disease Virus Vaccine against Sheeppox Virus Infections in Sheep. Vaccines (Basel) 2023; 11:vaccines11040763. [PMID: 37112675 PMCID: PMC10143431 DOI: 10.3390/vaccines11040763] [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: 02/13/2023] [Revised: 03/23/2023] [Accepted: 03/28/2023] [Indexed: 04/29/2023] Open
Abstract
Sheeppox virus (SPPV) (genus Capripoxvirus, family Poxviridae) infections are a highly virulent and contagious disease of sheep with a high morbidity and mortality, especially in naïve populations and young animals. For the control of SPPV, homologous and heterologous live-attenuated vaccines are commercially available. In our study, we compared a commercially available live-attenuated lumpy skin disease virus (LSDV) vaccine strain (Lumpyvax) with our recently developed inactivated LSDV vaccine candidate regarding their protective efficacy against SPPV in sheep. Both vaccines were proven to be safe in sheep, and neither clinical signs nor viremia could be detected after vaccination and challenge infection. However, the local replication of the challenge virus in the nasal mucosa of previously vaccinated animals was observed. Because of the advantages of an inactivated vaccine and its heterologous protection efficacy against SPPV in sheep, our inactivated LSDV vaccine candidate is a promising additional tool for the prevention and control of SPPV outbreaks in the future.
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Affiliation(s)
- Janika Wolff
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, D-17493 Greifswald-Insel Riems, Germany
| | - Martin Beer
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, D-17493 Greifswald-Insel Riems, Germany
| | - Bernd Hoffmann
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, D-17493 Greifswald-Insel Riems, Germany
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10
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African Swine Fever Virus Load in Hematophagous Dipterans Collected in an Outbreak from Romania: Risk Factors and Implications. Transbound Emerg Dis 2023. [DOI: 10.1155/2023/3548109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
African swine fever (ASF) is a contagious viral disease of swine that causes significant economic damage. The summer peaks and river courses have triggered the hypothesis that vectors may be involved in the transmission of the virus. In temperate climates, insect numbers increase in the late summer. Low temperatures and frosts decrease the number of active insects. Their presence is strongly associated with the nearby wetlands or swamps around the farms. The aim of our study was to evaluate the risk factors associated with the presence of ASFV DNA in hematophagous dipterans and to analyze the relevance of Ct values obtained following RT-PCR analysis of the positive samples in ASF outbreaks in Romania, as an indication for the viral load. The current study included 99 pools of stable flies (Stomoxys calcitrans) and 296 pools of biting midges (Culicoides spp.), collected in June-September 2020, from 30 outbreaks of ASF in domestic swine from backyard farms (BF), type A farms (TAF), and commercial farms (CF). All extracted DNA was tested for the presence of the ASFV genome using a real-time PCR protocol. Ct values of 39.53 and below were considered as positive (min: 18.19; median: 31.41; max: 39.53). The blood meal source was identified in the hematophagous insects by using a PCR protocol targeting the mitochondrial gene cytochrome c oxidase subunit 1. Data were analyzed using R software v. 4.0.5. In total, 3,158 insects (S. calcitrans n = 198 and Culicoides n = 2960) were collected in 23 farms of the 30 outbreak farms. Ten species of biting midges were identified. The total number of insect pools showed significant differences according to the month of sampling, with a higher number of pools collected in August and September. Overall, 137 pools out of the 395 examined were positive for the presence of ASFV DNA. There was a higher viral DNA load in farms where pigs were present at the moment of sampling compared to farms where pigs were already culled, in S. calcitrans compared to Culicoides spp. and in CF and TAF compared to BF.
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11
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Stelder JJ, Mihalca AD, Olesen AS, Kjær LJ, Boklund AE, Rasmussen TB, Marinov M, Alexe V, Balmoş OM, Bødker R. Potential mosquito vector attraction to- and feeding preferences for pigs in Romanian backyard farms. Front Vet Sci 2023; 9:1046263. [PMID: 36686172 PMCID: PMC9846066 DOI: 10.3389/fvets.2022.1046263] [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: 09/16/2022] [Accepted: 12/08/2022] [Indexed: 01/05/2023] Open
Abstract
Introduction Mosquitoes either biologically or mechanically transmit various vector-borne pathogens affecting pigs. Mosquito species display a wide variety of host preference, as well as host attraction and behaviours. Mosquito species attraction rates to- and feeding rates on pigs or other potential hosts, as well as the seasonal abundance of the mosquito species affects their pathogen transmission potential. Methods We caught mosquitoes in experimental cages containing pigs situated in Romanian backyard farms. The host species of blood meals were identified with PCR and sequencing. Results High feeding preferences for pigs were observed in Aedes vexans (90%), Anopheles maculipennis (80%) and Culiseta annulata (72.7%). However, due to a high abundance in the traps, Culex pipiens/torrentium were responsible for 37.9% of all mosquito bites on pigs in the Romanian backyards, despite low feeding rates on pigs in the cages (18.6%). We also found that other predominantly ornithophilic mosquito species, as well as mosquitoes that are already carrying a blood meal from a different (mammalian) host, were attracted to backyard pigs or their enclosure. Discussion These results indicate that viraemic blood carrying, for instance, African swine fever virus, West-Nile virus or Japanese encephalitis virus could be introduced to these backyard pig farms and therefore cause an infection, either through subsequent feeding, via ingestion by the pig or by environmental contamination.
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Affiliation(s)
- Jonno Jorn Stelder
- Section for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, Copenhagen University, Copenhagen, Denmark,*Correspondence: Jonno Jorn Stelder ✉
| | - Andrei Daniel Mihalca
- Department of Parasitology and Parasitic Diseases, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, Cluj-Napoca, Romania
| | - Ann Sofie Olesen
- Department of Virus and Microbiological Special Diagnostics, Statens Serum Institut, Copenhagen, Denmark
| | - Lene Jung Kjær
- Section for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, Copenhagen University, Copenhagen, Denmark
| | - Anette Ella Boklund
- Section for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, Copenhagen University, Copenhagen, Denmark
| | - Thomas Bruun Rasmussen
- Department of Virus and Microbiological Special Diagnostics, Statens Serum Institut, Copenhagen, Denmark
| | - Mihai Marinov
- Department of Biodiversity Conservation and Sustainable Use of Natural Resources, Danube Delta National Institute for Research and Development, Tulcea, Romania
| | - Vasile Alexe
- Department of Biodiversity Conservation and Sustainable Use of Natural Resources, Danube Delta National Institute for Research and Development, Tulcea, Romania
| | - Oana Maria Balmoş
- Department of Parasitology and Parasitic Diseases, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, Cluj-Napoca, Romania
| | - René Bødker
- Section for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, Copenhagen University, Copenhagen, Denmark
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12
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Krutko KS, Kinareikina AG, Serkova MI, Silivanova EA, Fedorova OA. Detection of genetic material of causative agents of animal viral diseases in blood-sucking dipterans from the Tyumen Region. RUSSIAN JOURNAL OF PARASITOLOGY 2023. [DOI: 10.31016/1998-8435-2022-16-4-389-402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The purpose of the research is to test blood-sucking dipterans collected in the Tyumen Region for genetic material of viruses that cause dangerous diseases in live-stock animals.Materials and methods. From May to October 2021, blood-sucking insects of the Diptera order whose species membership was established by tabular keys were collected on pastures and farms in ten Tyumen Region districts. In 60 samples formed from the captured insects according to the taxonomic affiliation and the period and place of collection, the presence of genetic material of the leukemia provirus and the dermatitis nodularis virus of cattle (bovine) and the African swine fever virus was evaluated by polymerase chain reaction (PCR) in real time.Results and discussion. Adult insects collected for the PCR analysis were blood-sucking flies (family Muscidae, genus Stomoxys), mosquitoes (family Culicidae, genus Aedes), midges (family Simuliidae, genera Byssodon and Schoenbaueria), horseflies (family Tabanidae, genera Hybomitra, Tabanus and Haematopota), and biting midges (family Ceratopogonidae, genus Culicoides). As a result of the PCR testing of the samples for the bovine leukemia provirus DNA, 1 out of 13 samples of Stomoxys spp. (7.7%) and 1 of 13 samples of Hybomitra spp. (7.7%) were positive. The bovine leukemia provirus DNA detected in blood-sucking insects indicates the presence of this pathogen in the insect collection area as well as their possible involvement in its spread. Further research is needed on the Stomoxys spp. and Hybomitra spp. vector competence in vivo, considering natural and climatic features of the Tyumen Region.
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Affiliation(s)
- K. S. Krutko
- All-Russian Scientific Research Institute of Veterinary Entomology and Arachnology – Branch of Federal State Institution Federal Research Centre Tyumen Scientific Centre of Siberian Branch of the Russian Academy of Sciences (ASRIVEA – Branch of Tyumen Scientific Centre SB RAS)
| | - A. G. Kinareikina
- All-Russian Scientific Research Institute of Veterinary Entomology and Arachnology – Branch of Federal State Institution Federal Research Centre Tyumen Scientific Centre of Siberian Branch of the Russian Academy of Sciences (ASRIVEA – Branch of Tyumen Scientific Centre SB RAS)
| | - M. I. Serkova
- All-Russian Scientific Research Institute of Veterinary Entomology and Arachnology – Branch of Federal State Institution Federal Research Centre Tyumen Scientific Centre of Siberian Branch of the Russian Academy of Sciences (ASRIVEA – Branch of Tyumen Scientific Centre SB RAS)
| | - E. A. Silivanova
- All-Russian Scientific Research Institute of Veterinary Entomology and Arachnology – Branch of Federal State Institution Federal Research Centre Tyumen Scientific Centre of Siberian Branch of the Russian Academy of Sciences (ASRIVEA – Branch of Tyumen Scientific Centre SB RAS)
| | - O. A. Fedorova
- All-Russian Scientific Research Institute of Veterinary Entomology and Arachnology – Branch of Federal State Institution Federal Research Centre Tyumen Scientific Centre of Siberian Branch of the Russian Academy of Sciences (ASRIVEA – Branch of Tyumen Scientific Centre SB RAS)
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13
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First molecular detection of SARS-CoV-2 virus in cockroaches. Biologia (Bratisl) 2023; 78:1153-1160. [PMID: 36741802 PMCID: PMC9890436 DOI: 10.1007/s11756-023-01332-7] [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: 10/16/2022] [Accepted: 01/20/2023] [Indexed: 02/04/2023]
Abstract
Coronavirus is one of the main pathogens that primarily targets the human respiratory system. There are several ways to transmit this virus, such as direct contact or droplets spread by coughing or sneezing, and direct contact with fomites and surfaces is another way. This cross-sectional study was conducted in Shiraz, southern Iran, in 2021. 5 locations, including 3 hospitals and 2 dormitories, were selected for the survey. The cockroaches were collected from selected locations and transferred to the Laboratory of Medical Entomology at Shiraz University of Medical Sciences. All specimens were identified morphologically. The external and gastrointestinal washouts of collected samples with sterile phosphate-buffered saline separately were used for molecular analysis. An RT-qPCR assay, which suggests the possible insect‑borne transmission, was used. External and gastrointestinal washout of B. germanica from Dastgheyb Dormitory and P. americana from Ali-Asghar Hospital were positive for contamination with the SARS-CoV-2. Cockroaches spread the virus in the environment and contaminate human food and various surfaces of buildings. Their role will be more important in crowded places such as hotels, lodging houses, restaurants, and hospitals; vector control programs should be carried out with more accuracy in such places.
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14
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Olesen AS, Lazov CM, Lecocq A, Accensi F, Jensen AB, Lohse L, Rasmussen TB, Belsham GJ, Bøtner A. Uptake and Survival of African Swine Fever Virus in Mealworm ( Tenebrio molitor) and Black Soldier Fly ( Hermetia illucens) Larvae. Pathogens 2022; 12:pathogens12010047. [PMID: 36678395 PMCID: PMC9864530 DOI: 10.3390/pathogens12010047] [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: 12/02/2022] [Revised: 12/20/2022] [Accepted: 12/23/2022] [Indexed: 12/29/2022] Open
Abstract
Insect production offers a sustainable source of nutrients for livestock. This comes with a risk for transmission of pathogens from the insects into the livestock sector, including viruses causing serious diseases, such as African swine fever virus (ASFV), classical swine fever virus and foot-and-mouth disease virus. ASFV is known to survive for a long time within animal meat and byproducts. Therefore, we conducted experimental exposure studies of insects to ASFV using larvae of two key insect species produced for food and feed, the mealworm; Tenebrio molitor, and the black soldier fly, Hermetia illucens. The larvae were exposed to ASFV POL/2015/Podlaskie, via oral uptake of serum or spleen material from ASFV-infected pigs. Using qPCR, the amounts of viral DNA present immediately after exposure varied from ~104.7 to 107.2 genome copies per insect. ASFV DNA was detectable in the larvae of H. illucens for up to 3 days post exposure and in T. molitor larvae for up to 9 days post exposure. To assess the presence of infectious virus within the larvae and with this, the risk of virus transmission via oral consumption, pigs were fed cakes containing larvae exposed to ASFV. Pigs that consumed 50 T. molitor or 50 H. illucens virus-exposed larvae did not become infected with ASFV. Thus, it appears, that in our experimental setting, the risk of ASFV transmission via consumption of unprocessed insect larvae, used as feed, is low.
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Affiliation(s)
- Ann Sofie Olesen
- Department of Virus & Microbiological Special Diagnostics, Statens Serum Institut, DK-2300 Copenhagen, Denmark
- Correspondence:
| | - Christina Marie Lazov
- Department of Veterinary and Animal Sciences, University of Copenhagen, DK-1870 Frederiksberg, Denmark
| | - Antoine Lecocq
- Department of Plant and Environmental Sciences, University of Copenhagen, DK-1870 Frederiksberg, Denmark
| | - Francesc Accensi
- Unitat Mixta d’Investigació IRTA-UAB en Sanitat Animal, Centre de Recerca en Sanitat Animal (CReSA), Campus de la Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain
- Departament de Sanitat i d’Anatomia Animals, Facultat de Veterinària, Campus de la Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain
| | - Annette Bruun Jensen
- Department of Plant and Environmental Sciences, University of Copenhagen, DK-1870 Frederiksberg, Denmark
| | - Louise Lohse
- Department of Virus & Microbiological Special Diagnostics, Statens Serum Institut, DK-2300 Copenhagen, Denmark
| | - Thomas Bruun Rasmussen
- Department of Virus & Microbiological Special Diagnostics, Statens Serum Institut, DK-2300 Copenhagen, Denmark
| | - Graham J. Belsham
- Department of Veterinary and Animal Sciences, University of Copenhagen, DK-1870 Frederiksberg, Denmark
| | - Anette Bøtner
- Department of Veterinary and Animal Sciences, University of Copenhagen, DK-1870 Frederiksberg, Denmark
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15
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Dankwa EA, Lambert S, Hayes S, Thompson RN, Donnelly CA. Stochastic modelling of African swine fever in wild boar and domestic pigs: Epidemic forecasting and comparison of disease management strategies. Epidemics 2022; 40:100622. [PMID: 36041286 DOI: 10.1016/j.epidem.2022.100622] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 07/21/2022] [Accepted: 08/10/2022] [Indexed: 11/25/2022] Open
Abstract
African swine fever (ASF), caused by the African swine fever virus (ASFV), is highly virulent in domestic pigs and wild boar (Sus scrofa), causing up to 100% mortality. The recent epidemic of ASF in Europe has had a serious economic impact and poses a threat to global food security. Unfortunately, there is no effective treatment or vaccine against ASFV, limiting the available disease management strategies. Mathematical models allow us to further our understanding of infectious disease dynamics and evaluate the efficacy of disease management strategies. The ASF Challenge, organised by the French National Research Institute for Agriculture, Food, and the Environment, aimed to expand the development of ASF transmission models to inform policy makers in a timely manner. Here, we present the model and associated projections produced by our team during the challenge. We developed a stochastic model combining transmission between wild boar and domestic pigs, which was calibrated to synthetic data corresponding to different phases describing the epidemic progression. The model was then used to produce forward projections describing the likely temporal evolution of the epidemic under various disease management scenarios. Despite the interventions implemented, long-term projections forecasted persistence of ASFV in wild boar, and hence repeated outbreaks in domestic pigs. A key finding was that it is important to consider the timescale over which different measures are evaluated: interventions that have only limited effectiveness in the short term may yield substantial long-term benefits. Our model has several limitations, partly because it was developed in real-time. Nonetheless, it can inform understanding of the likely development of ASF epidemics and the efficacy of disease management strategies, should the virus continue its spread in Europe.
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Affiliation(s)
| | - Sébastien Lambert
- Centre for Emerging, Endemic and Exotic Diseases, Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, United Kingdom
| | - Sarah Hayes
- Department of Infectious Disease Epidemiology, Faculty of Medicine, School of Public Health, Imperial College London, United Kingdom
| | - Robin N Thompson
- Mathematics Institute, University of Warwick, Coventry, United Kingdom; Zeeman Institute for Systems Biology and Infectious Disease Epidemiology Research, University of Warwick, Coventry, United Kingdom
| | - Christl A Donnelly
- Department of Statistics, University of Oxford, Oxford, United Kingdom; Department of Infectious Disease Epidemiology, Faculty of Medicine, School of Public Health, Imperial College London, United Kingdom.
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16
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Temporal and Spatial Evolution of the African Swine Fever Epidemic in Vietnam. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19138001. [PMID: 35805660 PMCID: PMC9265385 DOI: 10.3390/ijerph19138001] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/21/2022] [Accepted: 06/28/2022] [Indexed: 11/17/2022]
Abstract
African swine fever (ASF) is a severe infectious disease affecting domestic and wild suids. Spatiotemporal dynamics analysis of the ASF is crucial to understanding its transmission. The ASF broke out in Vietnam in February 2019. The research on the spatiotemporal evolution characteristics of ASF in Vietnam is lacking. Spatiotemporal statistical methods, including direction analysis, spatial autocorrelation analysis, and spatiotemporal scan statistics were used to reveal the dynamics of the spatial diffusion direction and spatiotemporal aggregation characteristics of ASF in Vietnam. According to the cessation of the epidemic, it was divided into three phases: February to August 2019 (phase 1), April to December 2020 (phase 2), and January 2021 to March 2022 (phase 3). The ASF showed a significant spread trend from north to south in phase 1. The occurrence rate of the ASF aggregated spatially in phase 1 and became random in phases 2 and 3. The high−high ASF clusters (the province was a high cluster and both it and its neighbors had a high ASF occurrence rate) were concentrated in the north in phases 1 and 2. Four spatiotemporal high-risk ASF clusters were identified with a mean radius of 121.88 km. In general, there were significant concentrated outbreak areas and directional spread in the early stage and small-scale, high-frequency, and randomly scattered outbreaks in the later stage. The findings could contribute to a deeper understanding of the spatiotemporal spread of the ASF in Vietnam.
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17
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High Efficiency of Low Dose Preparations of an Inactivated Lumpy Skin Disease Virus Vaccine Candidate. Vaccines (Basel) 2022; 10:vaccines10071029. [PMID: 35891195 PMCID: PMC9319008 DOI: 10.3390/vaccines10071029] [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: 03/17/2022] [Revised: 06/17/2022] [Accepted: 06/24/2022] [Indexed: 12/04/2022] Open
Abstract
Capripox virus-induced diseases are commonly described as the most serious poxvirus diseases of production animals, as they have a significant impact on national and global economies. Therefore, they are classified as notifiable diseases under the guidelines of the World Organization for Animal Health (OIE). Controlling lumpy skin disease viral infections is based on early detection, slaughter of affected herds, and ring vaccinations. Until now, only live attenuated vaccines have been commercially available, which often induce adverse effects in vaccinated animals. Furthermore, their application leads to the loss of the “disease-free” status of the respective country. For these reasons, inactivated vaccines have increasingly generated interest. Since 2016, experimental studies have been published showing the high efficacy of inactivated capripox virus vaccines. In the present study, we examined the minimum protective dose of a BEI-inactivated LSDV-Serbia field strain adjuvanted with a low-molecular-weight copolymer adjuvant. Unexpectedly, even the lowest dose tested, with a virus titer of 104 CCID50 before inactivation, was able to provide complete clinical protection in all vaccinated cattle. Moreover, none of the vaccinated cattle showed viremia or viral shedding, indicating the high efficacy of the prototype vaccine even with a relatively low antigen amount.
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18
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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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19
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African swine fever virus: A raised global upsurge and a continuous threaten to pig husbandry. Microb Pathog 2022; 167:105561. [DOI: 10.1016/j.micpath.2022.105561] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 04/01/2022] [Accepted: 04/27/2022] [Indexed: 11/21/2022]
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20
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Hakobyan S, Ross P, Bayramyan N, Poghosyan A, Avetisyan A, Avagyan H, Hakobyan L, Abroyan L, Harutyunova L, Karalyan Z. Experimental models of ecological niches for african swine fever virus. Vet Microbiol 2022; 266:109365. [DOI: 10.1016/j.vetmic.2022.109365] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 01/21/2022] [Accepted: 02/05/2022] [Indexed: 10/19/2022]
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21
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Liu Y, Zhang X, Qi W, Yang Y, Liu Z, An T, Wu X, Chen J. Prevention and Control Strategies of African Swine Fever and Progress on Pig Farm Repopulation in China. Viruses 2021; 13:2552. [PMID: 34960821 PMCID: PMC8704102 DOI: 10.3390/v13122552] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 12/15/2021] [Accepted: 12/15/2021] [Indexed: 01/26/2023] Open
Abstract
African swine fever (ASF) is a devastating disease in domestic and wild pigs. Since the first outbreak of ASF in August 2018 in China, the disease has spread throughout the country with an unprecedented speed, causing heavy losses to the pig and related industries. As a result, strategies for managing the disease are urgently needed. This paper summarizes the important aspects of three key elements about African swine fever virus (ASFV) transmission, including the sources of infection, transmission routes, and susceptible animals. It overviews the relevant prevention and control strategies, focusing on the research progress of ASFV vaccines, anti-ASFV drugs, ASFV-resistant pigs, efficient disinfection, and pig farm biosecurity. We then reviewed the key technical points concerning pig farm repopulation, which is critical to the pork industry. We hope to not only provide a theoretical basis but also practical strategies for effective dealing with the ASF epidemic and restoration of pig production.
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Affiliation(s)
- Yuanjia Liu
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (Y.L.); (Z.L.)
| | - Xinheng Zhang
- College of Animal Science, South China Agricultural University, Guangzhou 510642, China; (X.Z.); (X.W.)
| | - Wenbao Qi
- Research Center for African Swine Fever Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China;
| | - Yaozhi Yang
- Heilongjiang Dabeinong Agriculture and Animal Husbandry Food Company Limited, Harbin 150028, China;
| | - Zexin Liu
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (Y.L.); (Z.L.)
| | - Tongqing An
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China;
| | - Xiuhong Wu
- College of Animal Science, South China Agricultural University, Guangzhou 510642, China; (X.Z.); (X.W.)
| | - Jianxin Chen
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (Y.L.); (Z.L.)
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22
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Juszkiewicz M, Walczak M, Woźniakowski G, Szczotka-Bochniarz A. Virucidal Activity of Plant Extracts against African Swine Fever Virus. Pathogens 2021; 10:1357. [PMID: 34832513 PMCID: PMC8624909 DOI: 10.3390/pathogens10111357] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/14/2021] [Accepted: 10/18/2021] [Indexed: 11/16/2022] Open
Abstract
African swine fever is one of the most dangerous and fatal swine diseases, described for the first time roughly a hundred years ago. Even now, there is neither a commercially approved vaccine nor treatment available. The only way to hinder further spread of the disease is by culling the affected herds and applying prevention based mainly on proper biosecurity. Due to growing awareness of the potential ASF threat among pig producers, disinfection processes are considered as one of the most important preventive measures. Currently, a variety of chemical compounds are applied for the disinfection of pig farms. Meanwhile, these chemicals may pose a potential risk, due to their toxic, irritant or corrosive effect. The aim of this study was to determine whether any plant-based natural compounds may show a virucidal effect against ASFV, and simultaneously be depleted of some of the side-effects typical for chemical compounds. Ideally, natural virucidal compounds should be safe for both humans and animals, biodegradable, easily available and inexpensive. Fourteen plant extracts were selected and screened for their virucidal effect against ASFV, using the suspension test inspired by the PN-EN 14675:2015 European Standard procedure. The results of our study showed that most of the tested plant extracts were ineffective against ASFV. Some extracts suspended in a hydroglycolic medium exhibited high virus titre reduction, but it was confirmed that the effect resulted from medium composition. However, a 1.05% peppermint extract showed high effectiveness against ASFV, reducing the virus titre by ≥4 log10, thus demonstrating that natural compounds used as virucidal agents could potentially be used in disinfection procedures, being both effective and harmless to humans and animals.
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Affiliation(s)
- Małgorzata Juszkiewicz
- Department of Swine Diseases, National Veterinary Research Institute, Partyzantów 57 Avenue, 24-100 Puławy, Poland; (M.W.); (G.W.); (A.S.-B.)
| | - Marek Walczak
- Department of Swine Diseases, National Veterinary Research Institute, Partyzantów 57 Avenue, 24-100 Puławy, Poland; (M.W.); (G.W.); (A.S.-B.)
| | - Grzegorz Woźniakowski
- Department of Swine Diseases, National Veterinary Research Institute, Partyzantów 57 Avenue, 24-100 Puławy, Poland; (M.W.); (G.W.); (A.S.-B.)
- Department of Diagnostics and Clinical Sciences, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1 Street, 87-100 Toruń, Poland
| | - Anna Szczotka-Bochniarz
- Department of Swine Diseases, National Veterinary Research Institute, Partyzantów 57 Avenue, 24-100 Puławy, Poland; (M.W.); (G.W.); (A.S.-B.)
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Sauter-Louis C, Conraths FJ, Probst C, Blohm U, Schulz K, Sehl J, Fischer M, Forth JH, Zani L, Depner K, Mettenleiter TC, Beer M, Blome S. African Swine Fever in Wild Boar in Europe-A Review. Viruses 2021; 13:1717. [PMID: 34578300 PMCID: PMC8472013 DOI: 10.3390/v13091717] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 08/19/2021] [Accepted: 08/23/2021] [Indexed: 12/20/2022] Open
Abstract
The introduction of genotype II African swine fever (ASF) virus, presumably from Africa into Georgia in 2007, and its continuous spread through Europe and Asia as a panzootic disease of suids, continues to have a huge socio-economic impact. ASF is characterized by hemorrhagic fever leading to a high case/fatality ratio in pigs. In Europe, wild boar are especially affected. This review summarizes the currently available knowledge on ASF in wild boar in Europe. The current ASF panzootic is characterized by self-sustaining cycles of infection in the wild boar population. Spill-over and spill-back events occur from wild boar to domestic pigs and vice versa. The social structure of wild boar populations and the spatial behavior of the animals, a variety of ASF virus (ASFV) transmission mechanisms and persistence in the environment complicate the modeling of the disease. Control measures focus on the detection and removal of wild boar carcasses, in which ASFV can remain infectious for months. Further measures include the reduction in wild boar density and the limitation of wild boar movements through fences. Using these measures, the Czech Republic and Belgium succeeded in eliminating ASF in their territories, while the disease spread in others. So far, no vaccine is available to protect wild boar or domestic pigs reliably against ASF.
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Affiliation(s)
- Carola Sauter-Louis
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Epidemiology, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (F.J.C.); (C.P.); (K.S.)
| | - Franz J. Conraths
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Epidemiology, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (F.J.C.); (C.P.); (K.S.)
| | - Carolina Probst
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Epidemiology, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (F.J.C.); (C.P.); (K.S.)
| | - Ulrike Blohm
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Immunology, Südufer 10, 17493 Greifswald-Insel Riems, Germany;
| | - Katja Schulz
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Epidemiology, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (F.J.C.); (C.P.); (K.S.)
| | - Julia Sehl
- Department of Experimental Animal Facilities and Biorisk Management, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald-Insel Riems, Germany;
| | - Melina Fischer
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Diagnostic Virology, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (M.F.); (J.H.F.); (M.B.); (S.B.)
| | - Jan Hendrik Forth
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Diagnostic Virology, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (M.F.); (J.H.F.); (M.B.); (S.B.)
| | - Laura Zani
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of International Animal Health/One Health, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (L.Z.); (K.D.)
| | - Klaus Depner
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of International Animal Health/One Health, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (L.Z.); (K.D.)
| | - Thomas C. Mettenleiter
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald-Insel Riems, Germany;
| | - Martin Beer
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Diagnostic Virology, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (M.F.); (J.H.F.); (M.B.); (S.B.)
| | - Sandra Blome
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Diagnostic Virology, Südufer 10, 17493 Greifswald-Insel Riems, Germany; (M.F.); (J.H.F.); (M.B.); (S.B.)
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Abstract
African swine fever (ASF) is a highly contagious viral infection of domestic and wild pigs with high mortality. First reported in East Africa in the early 1900s, ASF was largely controlled in domestic pigs in many countries. However, in recent years ASF outbreaks have been reported in several countries in Europe and Asia. The occurrence of ASF in China, the largest pork producer in the world, in 2018 and in India, the country that surrounds and shares open borders with Nepal, has increased the risk of ASF transmission to Nepal. Lately, the pork industry has been growing in Nepal, overcoming traditional religious and cultural biases against it. However, the emergence of viral infections such as ASF could severely affect the industry’s growth and sustainability. Because there are no effective vaccines available to prevent ASF, the government should focus on preventing entry of the virus through strict quarantine measures at the borders, controls on illegal trade, and effective management practices, including biosecurity measures.
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Soltan-Alinejad P, Soltani A. Vector-borne diseases and tourism in Iran: Current issues and recommendations. Travel Med Infect Dis 2021; 43:102108. [PMID: 34111565 DOI: 10.1016/j.tmaid.2021.102108] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 04/14/2021] [Accepted: 06/04/2021] [Indexed: 12/24/2022]
Abstract
Iran is one of the largest countries in the Middle East with lots of historical and natural attractions. This country has always been considered to be one of the most important tourist destinations in the world. Several important vector-borne diseases have been reported from different parts of the country. Thus, having comprehensive and adequate knowledge about the main vector-borne diseases in Iran and their high-risk areas are really important. In this review, different provinces of Iran have been studied in terms of arthropod-borne diseases reported in the last decades. Reports indicated that some vector-borne diseases such as Leishmaniasis and CCHF had the highest incidence rate and they need serious attention. However, some diseases reported from Iran are not endemic, and all cases were imported such as Dengue fever. A group of arthropod-borne diseases was reported only from animals, and the health of travelers is not threatened such as Eyeworm infection.
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Affiliation(s)
- Parisa Soltan-Alinejad
- Department of Medical Entomology and Vector Control, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Aboozar Soltani
- Research Center for Health Sciences, Institute of Health, Department of Medical Entomology and Vector Control, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran.
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Yoon H, Hong SK, Lee I, Choi DS, Lee JH, Lee E, Wee SH. Arthropods as potential vectors of African swine fever virus outbreaks in pig farms in the Republic of Korea. Vet Med Sci 2021; 7:1841-1844. [PMID: 34085400 PMCID: PMC8464277 DOI: 10.1002/vms3.545] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 03/30/2021] [Accepted: 05/03/2021] [Indexed: 11/25/2022] Open
Abstract
The seasonality of African swine fever (ASF) in the summers and outbreaks in farms with high biosecurity levels suggest that the ASF virus (ASFV) may be transmitted by arthropod vectors. Arthropods were collected in this study from 14 pig farms with ASF outbreaks in Korea in 2019 to explore the role of arthropods as potential ASFV vectors. A total of 28,729 arthropods, including 28,508 (99.2%) Diptera, were collected using blacklight traps, insect nets and yellow sticky strips. All arthropod samples were negative for ASFV genomic DNA according to laboratory tests using real‐time polymerase chain reaction. This result may reflect the effects of immediate control measures following the detection of farms with ASF outbreaks in the early phase of infection in Korea. We collected 28,729 arthropods in 14 outbreaks pig farms in Korea to know the possibility that ASF may be transmitted by arthropod vector.
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Affiliation(s)
- Hachung Yoon
- Veterinary Epidemiology Division, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
| | - Seong-Keun Hong
- Veterinary Epidemiology Division, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
| | - Ilseob Lee
- Veterinary Epidemiology Division, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
| | - Deuk-Soo Choi
- Plant Quarantine Technology Center, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
| | - Jong-Ho Lee
- Plant Pest Control Division, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
| | - Eunesub Lee
- Veterinary Epidemiology Division, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
| | - Sung-Hwan Wee
- Department of Animal Disease Control and Quarantine, Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
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27
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Nielsen SS, Alvarez J, Bicout DJ, Calistri P, Depner K, Drewe JA, Garin‐Bastuji B, Gonzales Rojas JL, Schmidt C, Herskin M, Michel V, Pasquali P, Roberts HC, Sihvonen LH, Spoolder H, Stahl K, Velarde A, Winckler C, Blome S, Boklund A, Bøtner A, Dhollander S, Rapagnà C, Van der Stede Y, Miranda Chueca MA. Research priorities to fill knowledge gaps in the control of African swine fever: possible transmission of African swine fever virus by vectors. EFSA J 2021; 19:e06676. [PMID: 34188718 PMCID: PMC8215588 DOI: 10.2903/j.efsa.2021.6676] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The European Commission requested that EFSA provide study designs for the investigation of four research domains according to major gaps in knowledge identified by EFSA in a report published in 2019: (i) the patterns of seasonality of African Swine Fever (ASF) in wild boar and domestic pigs in the EU; (ii) the epidemiology of ASF in wild boar; (iii) survival of ASF virus (ASFV) in the environment and (iv) transmission of ASFV by vectors. In this Scientific Opinion, the fourth research domain on ASFV transmission by vectors is addressed. Eleven research objectives were proposed by the EFSA working group and broader ASF expert networks, such as ASF stop, ENETWILD, VectorNet, AHAW network and the AHAW Panel Experts. Of the 11 research objectives, six were prioritised based on the following set of criteria: (1) the impact on ASF management; (2) the feasibility or practicality to carry out the study; (3) the potential implementation of study results in practice; (4) a possible short time-frame study (< 1 year); (5) the novelty of the study and (6) if it was a priority for risk managers. The prioritised research objectives were: (I) Studies on the potential vector fauna at the pig-wild boar interface and the feeding preference of blood-feeding potential vectors in ASF-affected areas; (II) Assessment of the efficacy of insect screens on indoor/outdoor pig holdings to prevent the entry of blood-sucking vectors (i.e. Stomoxys) in ASF endemic areas; (III) Assess the role of mechanical vectors in the virus transmission in ASF-affected areas; (IV) Distribution of the potential mechanical transmission vectors in ASF-affected areas of the EU; (V) ASFV transmission by synanthropic birds; and (VI) Assessment on the presence/absence of the soft tick Ornithodoros erraticus in ASF-affected areas in Europe. For each of the selected research objectives, a research protocol has been proposed considering the potential impact on ASF management and the period of 1 year for the research activities.
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Quantifying and Modeling the Acquisition and Retention of Lumpy Skin Disease Virus by Hematophagus Insects Reveals Clinically but Not Subclinically Affected Cattle Are Promoters of Viral Transmission and Key Targets for Control of Disease Outbreaks. J Virol 2021; 95:JVI.02239-20. [PMID: 33568514 PMCID: PMC8104101 DOI: 10.1128/jvi.02239-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 02/02/2021] [Indexed: 12/21/2022] Open
Abstract
Lumpy skin disease virus (LSDV) causes a severe systemic disease characterized by cutaneous nodules in cattle. LSDV is a rapidly emerging pathogen, having spread since 2012 into Europe and Russia and across Asia. Lumpy skin disease virus (LSDV) is a vector-transmitted poxvirus that causes disease in cattle. Vector species involved in LSDV transmission and their ability to acquire and transmit the virus are poorly characterized. Using a highly representative bovine experimental model of lumpy skin disease, we fed four model vector species (Aedes aegypti, Culex quinquefasciatus, Stomoxys calcitrans, and Culicoides nubeculosus) on LSDV-inoculated cattle in order to examine their acquisition and retention of LSDV. Subclinical disease was a more common outcome than clinical disease in the inoculated cattle. Importantly, the probability of vectors acquiring LSDV from a subclinical animal (0.006) was very low compared with that from a clinical animal (0.23), meaning an insect feeding on a subclinical animal was 97% less likely to acquire LSDV than one feeding on a clinical animal. All four potential vector species studied acquired LSDV from the host at a similar rate, but Aedes aegypti and Stomoxys calcitrans retained the virus for a longer time, up to 8 days. There was no evidence of virus replication in the vector, consistent with mechanical rather than biological transmission. The parameters obtained in this study were combined with data from studies of LSDV transmission and vector life history parameters to determine the basic reproduction number of LSDV in cattle mediated by each of the model species. This reproduction number was highest for Stomoxys calcitrans (19.1), followed by C. nubeculosus (7.1) and Ae. aegypti (2.4), indicating that these three species are potentially efficient transmitters of LSDV; this information can be used to inform LSD control programs. IMPORTANCE Lumpy skin disease virus (LSDV) causes a severe systemic disease characterized by cutaneous nodules in cattle. LSDV is a rapidly emerging pathogen, having spread since 2012 into Europe and Russia and across Asia. The vector-borne nature of LSDV transmission is believed to have promoted this rapid geographic spread of the virus; however, a lack of quantitative evidence about LSDV transmission has hampered effective control of the disease during the current epidemic. Our research shows subclinical cattle play little part in virus transmission relative to clinical cattle and reveals a low probability of virus acquisition by insects at the preclinical stage. We have also calculated the reproductive number of different insect species, therefore identifying efficient transmitters of LSDV. This information is of utmost importance, as it will help to define epidemiological control measures during LSDV epidemics and of particular consequence in resource-poor regions where LSD vaccination may be less than adequate.
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Qin W, Gao Z, Wu S, Bao W. Preliminary analysis of whether mosquitoes can carry and transmit African swine fever. BMC Vet Res 2021; 17:152. [PMID: 33836768 PMCID: PMC8034110 DOI: 10.1186/s12917-021-02865-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 03/26/2021] [Indexed: 11/24/2022] Open
Abstract
Background Mosquitoes are important insect vectors, but whether they can carry and transmit African swine fever virus (ASFV) in large-scale pig farms in China is unknown. Results In this study, probe-based qPCR analysis was performed on mosquitoes from five pig farms with ASF virus (ASFV). Analysis of ASFV in 463 mosquitoes yielded negative cycle threshold (CT) value), and detection remained negative after mixing samples from all five pig farms. Conclusions Therefore, mosquitoes appear unlikely to transmit ASFV, and pose little threat to large-scale pig farms. Thus, farms should continue to follow normal mosquito control procedures when formulating strategies for the prevention and control of ASF.
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Affiliation(s)
- Weiyun Qin
- College of Animal Science and Technology, Yangzhou University, 225009, Yangzhou, China
| | - Zhongcheng Gao
- College of Animal Science and Technology, Yangzhou University, 225009, Yangzhou, China
| | - Shenglong Wu
- College of Animal Science and Technology, Yangzhou University, 225009, Yangzhou, China.,Joint International Research Laboratory of Agriculture & Agri-Product Safety, Yangzhou University, 225009, Yangzhou, China
| | - Wenbin Bao
- College of Animal Science and Technology, Yangzhou University, 225009, Yangzhou, China. .,Joint International Research Laboratory of Agriculture & Agri-Product Safety, Yangzhou University, 225009, Yangzhou, China.
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Herm R, Kirik H, Vilem A, Zani L, Forth JH, Müller A, Michelitsch A, Wernike K, Werner D, Tummeleht L, Kampen H, Viltrop A. No evidence for African swine fever virus DNA in haematophagous arthropods collected at wild boar baiting sites in Estonia. Transbound Emerg Dis 2021; 68:2696-2702. [PMID: 33527715 DOI: 10.1111/tbed.14013] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/25/2021] [Accepted: 01/27/2021] [Indexed: 11/29/2022]
Abstract
African swine fever (ASF) is a highly pathogenic viral disease affecting all Suidae, with Ornithodoros moubata complex soft ticks acting as the biological arthropod vectors of the causative agent, African swine fever virus (ASFV). While ASFV is also transmissible via direct contact, pig products and fomites, other arthropods may be involved in virus transmission and persistence. Therefore, we checked various groups of blood-feeding arthropods collected during summer 2017 in wild boar habitats on the Estonian Island of Saaremaa for the presence of ASFV. Saaremaa had the highest ASF infection prevalences in Estonia in 2017, with an incidence of 9% among hunted wild boar. In addition to ASFV, we tested for other selected pathogens. In total, 784 ticks, 6,274 culicoid biting midges, 77 tabanids and 757 mosquitoes were tested as individuals or pools. No ASFV-DNA was found in any of them although about 20% of the tick samples tested positive for swine DNA. By contrast, tick-borne encephalitis virus-RNA was detected in one out of 37 tick pools (2.7%) and Borrelia burgdorferi s.l.-DNA in 20 individual ticks and 17 tick pools (25.2% of all samples). No Schmallenberg virus was detected in the Culicoides specimens. In conclusion, we found no evidence for Ixodes ricinus ticks, Culicoides punctatus and Obsoletus complex biting midges, Aedes spp., Anopheles spp. and Culiseta annulata mosquitoes, and Haematopota pluvialis tabanids playing a role in ASFV transmission in the wild boar population in Estonia.
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Affiliation(s)
- Reet Herm
- Chair of Veterinary Bio- and Population Medicine, Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Tartu, Estonia
| | - Heli Kirik
- Chair of Biodiversity and Nature Tourism, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Tartu, Estonia
| | | | - Laura Zani
- Federal Research Institute for Animal Health, Friedrich-Loeffler-Institute, Greifswald, Germany
| | - Jan Hendrik Forth
- Federal Research Institute for Animal Health, Friedrich-Loeffler-Institute, Greifswald, Germany
| | - Alexandra Müller
- Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Porto, Portugal
| | - Anna Michelitsch
- Federal Research Institute for Animal Health, Friedrich-Loeffler-Institute, Greifswald, Germany
| | - Kerstin Wernike
- Federal Research Institute for Animal Health, Friedrich-Loeffler-Institute, Greifswald, Germany
| | - Doreen Werner
- Leibniz Centre for Agricultural Landscape Research, Müncheberg, Germany
| | - Lea Tummeleht
- Chair of Veterinary Bio- and Population Medicine, Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Tartu, Estonia
| | - Helge Kampen
- Federal Research Institute for Animal Health, Friedrich-Loeffler-Institute, Greifswald, Germany
| | - Arvo Viltrop
- Chair of Veterinary Bio- and Population Medicine, Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Tartu, Estonia
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Hamdi J, Bamouh Z, Jazouli M, Alhyane M, Safini N, Omari Tadlaoui K, Fassi Fihri O, El Harrak M. Experimental infection of indigenous North African goats with goatpox virus. Acta Vet Scand 2021; 63:9. [PMID: 33663573 PMCID: PMC7931584 DOI: 10.1186/s13028-021-00574-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 02/15/2021] [Indexed: 12/30/2022] Open
Abstract
Background Goatpox is a viral disease caused by infection with goatpox virus (GTPV) of the genus Capripoxvirus, Poxviridae family. Capripoxviruses cause serious disease to livestock and contribute to huge economic losses. Goatpox and sheeppox are endemic to Africa, particularly north of the Equator, the Middle East and many parts of Asia. GTPV and sheeppox virus are considered host-specific; however, both strains can cause clinical disease in either goats or sheep with more severe disease in the homologous species and mild or sub-clinical infection in the other. Goatpox has never been reported in Morocco, Algeria or Tunisia despite the huge population of goats living in proximity with sheep in those countries. To evaluate the susceptibility and pathogenicity of indigenous North African goats to GTPV infection, we experimentally inoculated eight locally bred goats with a virulent Vietnamese isolate of GTPV. Two uninfected goats were kept as controls. Clinical examination was carried out daily and blood was sampled for virology and for investigating the antibody response. After necropsy, tissues were collected and assessed for viral DNA using real-time PCR. Results Following the experimental infection, all inoculated goats displayed clinical signs characteristic of goatpox including varying degrees of hyperthermia, loss of appetite, inactivity and cutaneous lesions. The infection severely affected three of the infected animals while moderate to mild disease was noticed in the remaining goats. A high antibody response was developed. High viral DNA loads were detected in skin crusts and nodules, and subcutaneous tissue at the injection site with cycle threshold (Ct) values ranging from 14.6 to 22.9, while lower viral loads were found in liver and lung (Ct = 35.7 and 35.1). The results confirmed subcutaneous tropism of the virus. Conclusion Clinical signs of goatpox were reproduced in indigenous North African goats and confirmed a high susceptibility of the North African goat breed to GTPV infection. A clinical scoring system is proposed that can be applied in GTPV vaccine efficacy studies.
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Nielsen SS, Alvarez J, Bicout DJ, Calistri P, Depner K, Drewe JA, Garin‐Bastuji B, Gonzales Rojas JL, Gortazar Schmidt C, Herskin M, Michel V, Miranda Chueca MÁ, Pasquali P, Roberts HC, Sihvonen LH, Spoolder H, Stahl K, Velarde A, Winckler C, Abrahantes JC, Dhollander S, Ivanciu C, Papanikolaou A, Van der Stede Y, Blome S, Guberti V, Loi F, More S, Olsevskis E, Thulke HH, Viltrop A. ASF Exit Strategy: Providing cumulative evidence of the absence of African swine fever virus circulation in wild boar populations using standard surveillance measures. EFSA J 2021; 19:e06419. [PMID: 33717352 PMCID: PMC7926520 DOI: 10.2903/j.efsa.2021.6419] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
EFSA assessed the role of seropositive wild boar in African swine fever (ASF) persistence. Surveillance data from Estonia and Latvia investigated with a generalised equation method demonstrated a significantly slower decline in seroprevalence in adult animals compared with subadults. The seroprevalence in adults, taking more than 24 months to approach zero after the last detection of ASFV circulation, would be a poor indicator to demonstrate the absence of virus circulation. A narrative literature review updated the knowledge on the mortality rate, the duration of protective immunity and maternal antibodies and transmission parameters. In addition, parameters potentially leading to prolonged virus circulation (persistence) in wild boar populations were reviewed. A stochastic explicit model was used to evaluate the dynamics of virus prevalence, seroprevalence and the number of carcasses attributed to ASF. Secondly, the impact of four scenarios on the duration of ASF virus (ASFV) persistence was evaluated with the model, namely a: (1) prolonged, lifelong infectious period, (2) reduction in the case-fatality rate and prolonged transient infectiousness; (3) change in duration of protective immunity and (4) change in the duration of protection from maternal antibodies. Only the lifelong infectious period scenario had an important prolonging effect on the persistence of ASF. Finally, the model tested the performance of different proposed surveillance strategies to provide evidence of the absence of virus circulation (Exit Strategy). A two-phase approach (Screening Phase, Confirmation Phase) was suggested for the Exit Strategy. The accuracy of the Exit Strategy increases with increasing numbers of carcasses collected and tested. The inclusion of active surveillance based on hunting has limited impact on the performance of the Exit Strategy compared with lengthening of the monitoring period. This performance improvement should be reasonably balanced against an unnecessary prolonged 'time free' with only a marginal gain in performance. Recommendations are provided for minimum monitoring periods leading to minimal failure rates of the Exit Strategy. The proposed Exit Strategy would fail with the presence of lifelong infectious wild boar. That said, it should be emphasised that the existence of such animals is speculative, based on current knowledge.
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Stelder JJ, Kjær LJ, Jensen LB, Boklund AE, Denwood M, Carlsen M, Bødker R. Livestock-associated MRSA survival on house flies (Musca domestica) and stable flies (Stomoxys calcitrans) after removal from a Danish pig farm. Sci Rep 2021; 11:3527. [PMID: 33574465 PMCID: PMC7878913 DOI: 10.1038/s41598-021-83228-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 02/01/2021] [Indexed: 01/30/2023] Open
Abstract
We caught stable- and house flies on a Danish LA-MRSA positive pig farm. Stable- and house flies were housed together and culled over time to test for the presence of live LA-MRSA bacteria at 24 h intervals to establish the length of time for which LA-MRSA can persist on flies. On average, 7% of stable flies and 27% of house flies tested positive for LA-MRSA immediately upon removal from the farm. LA-MRSA prevalence decreased over time and estimates based on a Kaplan-Meier time-to-event analysis indicated that the probability of a stable- or house fly testing positive for LA-MRSA was 5.4% and 7.8% after 24 h, 3.5% and 4.3% after 48 h, 3.1% and 2.2% after 72 h and 0.4% and 0% after 96 h of removal from the pig farm, respectively. Simultaneously, we found that caged cultivated house flies became carriers of LA-MRSA, without direct contact with pigs, in the same proportions as wild flies inside the farm. We provide distance distributions of Danish pig farms and residential addresses as well as the calculated maximum dispersal potentials of stable- and house flies, which suggest that there is a potential for stable- and house flies dispersing live LA-MRSA bacteria into the surrounding environment of a pig farm. This potential should therefore be considered when modelling the spread between farms or the risk posed to humans living in close proximity to LA-MRSA pig farm sources.
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Affiliation(s)
- Jonno Jorn Stelder
- grid.5254.60000 0001 0674 042XSection for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, Copenhagen University, Grønnegårdsvej 8, 1870 Frederiksberg C, Denmark
| | - Lene Jung Kjær
- grid.5254.60000 0001 0674 042XSection for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, Copenhagen University, Grønnegårdsvej 8, 1870 Frederiksberg C, Denmark
| | - Lars Bogø Jensen
- grid.5170.30000 0001 2181 8870National Food Institute, DTU Technical University of Denmark, Kemitorvet Building 204, 2800 Lyngby, Denmark
| | - Anette Ella Boklund
- grid.5254.60000 0001 0674 042XSection for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, Copenhagen University, Grønnegårdsvej 8, 1870 Frederiksberg C, Denmark
| | - Matt Denwood
- grid.5254.60000 0001 0674 042XSection for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, Copenhagen University, Grønnegårdsvej 8, 1870 Frederiksberg C, Denmark
| | - Margrethe Carlsen
- grid.5170.30000 0001 2181 8870National Food Institute, DTU Technical University of Denmark, Kemitorvet Building 204, 2800 Lyngby, Denmark
| | - René Bødker
- grid.5254.60000 0001 0674 042XSection for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, Copenhagen University, Grønnegårdsvej 8, 1870 Frederiksberg C, Denmark
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Kurian A, Hall WF, Neumann EJ. African swine fever: a New Zealand perspective on epidemiological risk factors for its occurrence. N Z Vet J 2021; 69:135-146. [PMID: 33570468 DOI: 10.1080/00480169.2021.1875934] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
This article reviews key epidemiological and clinical features of African swine fever (ASF). We identify particular aspects of New Zealand's pig populations (commercial, non-commercial, and wild) that may affect the risk of disease entry or spread. Review of published literature is supplemented by analysis of demographic and spatial aspects of the New Zealand commercial, non-commercial, and feral pig populations to provide context around risk factors for the disease that are most relevant to New Zealand. The current Eurasian outbreak of ASF, including recent spread into Oceania, has increased the risk of an incursion of the disease into New Zealand. Large volumes of fresh pork importation (including from countries affected by ASF), large non-commercial pig populations with substantial spatial overlap with the country's commercial industry, limited monitoring of compliance with waste food feeding regulations, and lack of mandatory premises identification for non-commercial pig holdings would likely contribute to the risk of spread of ASF in the event of an incursion. Awareness amongst veterinarians of these risk factors will contribute to national biosecurity and disease preparedness efforts in New Zealand.
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Affiliation(s)
- A Kurian
- Epi-Insight Limited, East Taieri, New Zealand
| | - W F Hall
- William Hall and Associates, Googong, NSW, Australia
| | - E J Neumann
- Epi-Insight Limited, East Taieri, New Zealand
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35
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Brookes VJ, Barrett TE, Ward MP, Roby JA, Hernandez-Jover M, Cross EM, Donnelly CM, Barnes TS, Wilson CS, Khalfan S. A scoping review of African swine fever virus spread between domestic and free-living pigs. Transbound Emerg Dis 2021; 68:2643-2656. [PMID: 33455062 DOI: 10.1111/tbed.13993] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 01/12/2021] [Accepted: 01/13/2021] [Indexed: 12/31/2022]
Abstract
Since 2007, African swine fever virus (ASFV) has spread to countries in Europe, Asia and Oceania and has caused devastating impacts on pigs and the pork industry. Transmission can be direct or indirect, and epidemiologic scenarios have been described in which spread occurs between free-living and domestic pigs. The purpose of this scoping review was to identify primary research in which authors made statements to support ASFV transmission between free-living and domestic pigs and assess the circumstances in which transmission events occurred. A search was conducted in five bibliographic databases and the grey literature. Two reviewers (from a team of ten) independently screened each record and charted data (demographics of the pig populations, their husbandry [domestic pigs] and habitat [free-living pigs], the spatial and temporal distribution of ASF, the occurrence or burden of ASF in the populations, and whether ticks were present in the geographic range of the pig populations). Data synthesis included statistics and a narrative summary. From 1,349 records screened, data were charted from 46 individual studies published from 1985 to 2020. Outbreak investigations revealed that whilst poor biosecurity of domestic pig operations was often reported, direct contact resulting in transmission between free-living and domestic pigs was rarely reported. Studies in which quantitative associations were made generally found that spread within populations was more important than spread between populations, although this was not always the case, particularly when domestic pigs were free-ranging. We conclude that there is limited evidence that transmission of ASFV between free-living and domestic pigs is an important feature of ASF epidemiology, especially in the current ASF epidemic in Europe and the Russian Federation. If ASFV elimination cannot be achieved in free-living pigs, compartmentalization of domestic pig populations from free-living populations via biosecurity strategies could be used to support trade of domestic pigs.
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Affiliation(s)
- Victoria J Brookes
- School of Animal and Veterinary Sciences, Faculty of Science, Charles Sturt University, Wagga Wagga, NSW, Australia.,Graham Centre for Agricultural Innovation (NSW Department of Primary Industries and Charles Sturt University), Wagga Wagga, NSW, Australia
| | - Tamille E Barrett
- School of Animal and Veterinary Sciences, Faculty of Science, Charles Sturt University, Wagga Wagga, NSW, Australia.,Graham Centre for Agricultural Innovation (NSW Department of Primary Industries and Charles Sturt University), Wagga Wagga, NSW, Australia
| | - Michael P Ward
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Camden, NSW, Australia
| | - Justin A Roby
- Graham Centre for Agricultural Innovation (NSW Department of Primary Industries and Charles Sturt University), Wagga Wagga, NSW, Australia.,School of Biomedical Sciences, Faculty of Science, Charles Sturt University, Wagga Wagga, NSW, Australia
| | - Marta Hernandez-Jover
- School of Animal and Veterinary Sciences, Faculty of Science, Charles Sturt University, Wagga Wagga, NSW, Australia.,Graham Centre for Agricultural Innovation (NSW Department of Primary Industries and Charles Sturt University), Wagga Wagga, NSW, Australia
| | - Emily M Cross
- School of Biomedical Sciences, Faculty of Science, Charles Sturt University, Wagga Wagga, NSW, Australia
| | - Camilla M Donnelly
- School of Biomedical Sciences, Faculty of Science, Charles Sturt University, Wagga Wagga, NSW, Australia
| | - Tamsin S Barnes
- The University of Queensland, School of Veterinary Science, Gatton, Qld, Australia.,The University of Queensland, Queensland Alliance for Agriculture and Food Innovation, Gatton, Qld, Australia
| | - Cara S Wilson
- School of Animal and Veterinary Sciences, Faculty of Science, Charles Sturt University, Wagga Wagga, NSW, Australia.,Graham Centre for Agricultural Innovation (NSW Department of Primary Industries and Charles Sturt University), Wagga Wagga, NSW, Australia
| | - Shahid Khalfan
- School of Animal and Veterinary Sciences, Faculty of Science, Charles Sturt University, Wagga Wagga, NSW, Australia.,Graham Centre for Agricultural Innovation (NSW Department of Primary Industries and Charles Sturt University), Wagga Wagga, NSW, Australia
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Penrith ML, Bastos A, Chenais E. With or without a Vaccine-A Review of Complementary and Alternative Approaches to Managing African Swine Fever in Resource-Constrained Smallholder Settings. Vaccines (Basel) 2021; 9:vaccines9020116. [PMID: 33540948 PMCID: PMC7913123 DOI: 10.3390/vaccines9020116] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/28/2021] [Accepted: 01/28/2021] [Indexed: 02/07/2023] Open
Abstract
The spectacular recent spread of African swine fever (ASF) in Eastern Europe and Asia has been strongly associated, as it is in the endemic areas in Africa, with free-ranging pig populations and low-biosecurity backyard pig farming. Managing the disease in wild boar populations and in circumstances where the disease in domestic pigs is largely driven by poverty is particularly challenging and may remain so even in the presence of effective vaccines. The only option currently available to prevent ASF is strict biosecurity. Among small-scale pig farmers biosecurity measures are often considered unaffordable or impossible to implement. However, as outbreaks of ASF are also unaffordable, the adoption of basic biosecurity measures is imperative to achieve control and prevent losses. Biosecurity measures can be adapted to fit smallholder contexts, culture and costs. A longer-term approach that could prove valuable particularly for free-ranging pig populations would be exploitation of innate resistance to the virus, which is fully effective in wild African suids and has been observed in some domestic pig populations in areas of prolonged endemicity. We explore available options for preventing ASF in terms of feasibility, practicality and affordability among domestic pig populations that are at greatest risk of exposure to ASF.
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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
- Correspondence: ; Tel.: +27-12-342-1514
| | - Armanda Bastos
- Department of Zoology and Entomology, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0028, South Africa;
| | - Erika Chenais
- Department of Disease Control and Epidemiology, National Veterinary Institute, S-751 89 Uppsala, Sweden;
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A Review of Risk Factors of African Swine Fever Incursion in Pig Farming within the European Union Scenario. Pathogens 2021; 10:pathogens10010084. [PMID: 33478169 PMCID: PMC7835761 DOI: 10.3390/pathogens10010084] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/15/2021] [Accepted: 01/18/2021] [Indexed: 12/21/2022] Open
Abstract
African swine fever (ASF) is a notifiable viral disease of pigs and wild boars that could lead to serious economic losses for the entire European pork industry. As no effective treatment or vaccination is available, disease prevention and control rely on strictly enforced biosecurity measures tailored to the specific risk factors of ASF introduction within domestic pig populations. Here, we present a review addressing the risk factors associated with different European pig farming systems in the context of the actual epidemiological scenario. A list of keywords was combined into a Boolean query, “African swine fever” AND (“Risk factors” OR “Transmission” OR “Spread” OR “Pig farming” OR “Pigs” OR “Wild boars”); was run on 4 databases; and resulted in 52 documents of interest being reviewed. Based on our review, each farming system has its own peculiar risk factors: commercial farms, where best practices are already in place, may suffer from unintentional breaches in biosecurity, while backyard and outdoor farms may suffer from poor ASF awareness, sociocultural factors, and contact with wild boars. In the literature selected for our review, human-related activities and behaviours are presented as the main risks, but we also stress the need to implement biosecurity measures also tailored to risks factors that are specific for the different pig farming practices in the European Union (EU).
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Wolff J, Moritz T, Schlottau K, Hoffmann D, Beer M, Hoffmann B. Development of a Safe and Highly Efficient Inactivated Vaccine Candidate against Lumpy Skin Disease Virus. Vaccines (Basel) 2020; 9:vaccines9010004. [PMID: 33374808 PMCID: PMC7823700 DOI: 10.3390/vaccines9010004] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/16/2020] [Accepted: 12/22/2020] [Indexed: 11/16/2022] Open
Abstract
Capripox virus (CaPV)-induced diseases (lumpy skin disease, sheeppox, goatpox) are described as the most serious pox diseases of livestock animals, and therefore are listed as notifiable diseases under guidelines of the World Organisation for Animal Health (OIE). Until now, only live-attenuated vaccines are commercially available for the control of CaPV. Due to numerous potential problems after vaccination (e.g., loss of the disease-free status of the respective country, the possibility of vaccine virus shedding and transmission as well as the risk of recombination with field strains during natural outbreaks), the use of these vaccines must be considered carefully and is not recommended in CaPV-free countries. Therefore, innocuous and efficacious inactivated vaccines against CaPV would provide a great tool for control of these diseases. Unfortunately, most inactivated Capripox vaccines were reported as insufficient and protection seemed to be only short-lived. Nevertheless, a few studies dealing with inactivated vaccines against CaPV are published, giving evidence for good clinical protection against CaPV-infections. In our studies, a low molecular weight copolymer-adjuvanted vaccine formulation was able to induce sterile immunity in the respective animals after severe challenge infection. Our findings strongly support the possibility of useful inactivated vaccines against CaPV-infections, and indicate a marked impact of the chosen adjuvant for the level of protection.
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Issimov A, Taylor DB, Zhugunissov K, Kutumbetov L, Zhanabayev A, Kazhgaliyev N, Akhmetaliyeva A, Nurgaliyev B, Shalmenov M, Absatirov G, Dushayeva L, White PJ. The combined effects of temperature and relative humidity parameters on the reproduction of Stomoxys species in a laboratory setting. PLoS One 2020; 15:e0242794. [PMID: 33347453 PMCID: PMC7751869 DOI: 10.1371/journal.pone.0242794] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 11/09/2020] [Indexed: 11/29/2022] Open
Abstract
In this study, Stomoxys species (S. calcitrans, S. sitiens and S. indica) were examined to improve on the current technique for mass rearing using a method of combined incubation parameters. Moreover, the reproductive potential of immature forms at various stages of development was defined. Immature forms of stable flies were incubated according to species. There was no significant difference in the number of immature forms obtained among species incubated under the same conditions. Six incubation parameters were used in combination, at temperatures (T) of 32°C, 27°C and 22°C and relative humidity (RH) of 90% and 70% RH. The combined method resulted in a higher number of eggs hatching at 32°C and 90% humidity as well as an increase in the number of larva pupated and emergence of imago at 27°C and 70% humidity.
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Affiliation(s)
- Arman Issimov
- Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Sydney, Australia
- * E-mail: ,
| | - David B. Taylor
- Agroecosystems Management Research Unit, USDA-ARS, Lincoln, NE, United States of America
| | - Kuandyk Zhugunissov
- RGE “Research Institute for Biological Safety Problems” Committee of Science, The Ministry of Education and Science of the Republic of Kazakhstan, Nur-Sultan, Kazakhstan
| | - Lespek Kutumbetov
- RGE “Research Institute for Biological Safety Problems” Committee of Science, The Ministry of Education and Science of the Republic of Kazakhstan, Nur-Sultan, Kazakhstan
| | - Assylbek Zhanabayev
- Department of Veterinary Medicine, Saken Seifullin Kazakh Agrotechnical University, Nur-Sultan, Kazakhstan
| | - Nurlybay Kazhgaliyev
- Department of Veterinary Medicine, Saken Seifullin Kazakh Agrotechnical University, Nur-Sultan, Kazakhstan
| | - Aliya Akhmetaliyeva
- Department of Veterinary Medicine, Zhangir Khan West Kazakhstan Agrarian–Technical University, Uralsk, Kazakhstan
| | - Birzhan Nurgaliyev
- Department of Veterinary Medicine, Zhangir Khan West Kazakhstan Agrarian–Technical University, Uralsk, Kazakhstan
| | - Malik Shalmenov
- Department of Veterinary Medicine, Zhangir Khan West Kazakhstan Agrarian–Technical University, Uralsk, Kazakhstan
| | - Gaisa Absatirov
- Department of Veterinary Medicine, Zhangir Khan West Kazakhstan Agrarian–Technical University, Uralsk, Kazakhstan
| | - Laura Dushayeva
- Department of Veterinary Medicine, Zhangir Khan West Kazakhstan Agrarian–Technical University, Uralsk, Kazakhstan
| | - Peter J. White
- Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Sydney, Australia
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Wolff J, Abd El Rahman S, King J, El-Beskawy M, Pohlmann A, Beer M, Hoffmann B. Establishment of a Challenge Model for Sheeppox Virus Infection. Microorganisms 2020; 8:microorganisms8122001. [PMID: 33333872 PMCID: PMC7765277 DOI: 10.3390/microorganisms8122001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 12/08/2020] [Accepted: 12/12/2020] [Indexed: 12/25/2022] Open
Abstract
Sheeppox virus (SPPV) together with goatpox virus and lumpy skin disease virus form the genus Capripoxvirus of the Poxviridae family. Due to their great economic importance and major impact on livelihood of small-scale farmers, OIE guidelines classify capripox viruses as notifiable diseases. In the present study, we examined pathogenesis of an Indian SPPV isolate and an Egyptian SPPV isolate in sheep. Three different infection routes were tested: (i) intravenous infection, (ii) intranasal infection and (iii) contact transmission between infected and naïve sheep. Clinical course, viremia and viral shedding as well as seroconversion were analyzed in order to establish a challenge model for SPPV infections that can be used in future vaccine studies. Next to in vivo characterization, both SPPV strains underwent next- and third-generation sequencing to obtain high quality full-length genomes for genetic characterization and comparison to already published SPPV sequences.
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Affiliation(s)
- Janika Wolff
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, Insel Riems, D-17493 Greifswald, Germany; (J.W.); (J.K.); (A.P.); (M.B.)
| | - Sahar Abd El Rahman
- Department of Virology, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt;
| | - Jacqueline King
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, Insel Riems, D-17493 Greifswald, Germany; (J.W.); (J.K.); (A.P.); (M.B.)
| | - Mohamed El-Beskawy
- Department of Animal Medicine, Faculty of Veterinary Medicine, Matrouh University, Matrouh 51744, Egypt;
| | - Anne Pohlmann
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, Insel Riems, D-17493 Greifswald, Germany; (J.W.); (J.K.); (A.P.); (M.B.)
| | - Martin Beer
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, Insel Riems, D-17493 Greifswald, Germany; (J.W.); (J.K.); (A.P.); (M.B.)
| | - Bernd Hoffmann
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, Insel Riems, D-17493 Greifswald, Germany; (J.W.); (J.K.); (A.P.); (M.B.)
- Correspondence: ; Tel.: +49-3835-17-1506
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41
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Mee PT, Wong S, O’Riley KJ, da Conceição F, Bendita da Costa Jong J, Phillips DE, Rodoni BC, Rawlin GT, Lynch SE. Field Verification of an African Swine Fever Virus Loop-Mediated Isothermal Amplification (LAMP) Assay During an Outbreak in Timor-Leste. Viruses 2020; 12:v12121444. [PMID: 33334037 PMCID: PMC7765541 DOI: 10.3390/v12121444] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 12/11/2020] [Indexed: 02/07/2023] Open
Abstract
Recent outbreaks of African swine fever virus (ASFV) have seen the movement of this virus into multiple new regions with devastating impact. Many of these outbreaks are occurring in remote, or resource-limited areas, that do not have access to molecular laboratories. Loop-mediated isothermal amplification (LAMP) is a rapid point of care test that can overcome a range of inhibitors. We outline further development of a real-time ASFV LAMP, including field verification during an outbreak in Timor-Leste. To increase field applicability, the extraction step was removed and an internal amplification control (IAC) was implemented. Assay performance was assessed in six different sample matrices and verified for a range of clinical samples. A LAMP detection limit of 400 copies/rxn was determined based on synthetic positive control spikes. A colourmetric LAMP assay was also assessed on serum samples. Comparison of the LAMP assay to a quantitative polymerase chain reaction (qPCR) was performed on clinical ASFV samples, using both serum and oral/rectal swabs, with a substantial level of agreement observed. The further verification of the ASFV LAMP assay, removal of extraction step, implementation of an IAC and the assessment of a range of sample matrix, further support the use of this assay for rapid in-field detection of ASFV.
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Affiliation(s)
- Peter T. Mee
- Agriculture Victoria Research, AgriBio Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (S.W.); (K.J.O.); (B.C.R.); (G.T.R.); (S.E.L.)
- Correspondence: ; Tel.: +61-390-327-143
| | - Shani Wong
- Agriculture Victoria Research, AgriBio Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (S.W.); (K.J.O.); (B.C.R.); (G.T.R.); (S.E.L.)
| | - Kim J. O’Riley
- Agriculture Victoria Research, AgriBio Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (S.W.); (K.J.O.); (B.C.R.); (G.T.R.); (S.E.L.)
| | - Felisiano da Conceição
- Ministry of Agriculture and Fisheries, Government of Timor-Leste, Av. Nicolao Lobato, Comoro, Dili 0332, Timor-Leste; (F.d.C.); (J.B.d.C.J.)
| | - Joanita Bendita da Costa Jong
- Ministry of Agriculture and Fisheries, Government of Timor-Leste, Av. Nicolao Lobato, Comoro, Dili 0332, Timor-Leste; (F.d.C.); (J.B.d.C.J.)
| | - Dianne E. Phillips
- Agriculture Victoria, Biosecurity and Agriculture Services, Bairnsdale, VIC 3857, Australia;
| | - Brendan C. Rodoni
- Agriculture Victoria Research, AgriBio Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (S.W.); (K.J.O.); (B.C.R.); (G.T.R.); (S.E.L.)
| | - Grant T. Rawlin
- Agriculture Victoria Research, AgriBio Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (S.W.); (K.J.O.); (B.C.R.); (G.T.R.); (S.E.L.)
| | - Stacey E. Lynch
- Agriculture Victoria Research, AgriBio Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (S.W.); (K.J.O.); (B.C.R.); (G.T.R.); (S.E.L.)
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42
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Blome S, Franzke K, Beer M. African swine fever – A review of current knowledge. Virus Res 2020; 287:198099. [DOI: 10.1016/j.virusres.2020.198099] [Citation(s) in RCA: 105] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 07/15/2020] [Accepted: 07/16/2020] [Indexed: 12/22/2022]
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Experimental Infection and Genetic Characterization of Two Different Capripox Virus Isolates in Small Ruminants. Viruses 2020; 12:v12101098. [PMID: 32998423 PMCID: PMC7600078 DOI: 10.3390/v12101098] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 09/24/2020] [Accepted: 09/26/2020] [Indexed: 02/06/2023] Open
Abstract
Capripox viruses, with their members “lumpy skin disease virus (LSDV)”, “goatpox virus (GTPV)” and “sheeppox virus (SPPV)”, are described as the most serious pox diseases of production animals. A GTPV isolate and a SPPV isolate were sequenced in a combined approach using nanopore MinION sequencing to obtain long reads and Illumina high throughput sequencing for short precise reads to gain full-length high-quality genome sequences. Concomitantly, sheep and goats were inoculated with SPPV and GTPV strains, respectively. During the animal trial, varying infection routes were compared: a combined intravenous and subcutaneous infection, an only intranasal infection, and the contact infection between naïve and inoculated animals. Sheep inoculated with SPPV showed no clinical signs, only a very small number of genome-positive samples and a low-level antibody reaction. In contrast, all GTPV inoculated or in-contact goats developed severe clinical signs with high viral genome loads observed in all tested matrices. Furthermore, seroconversion was detected in nearly all goats and no differences concerning the severity of the disease depending on the inoculation route were observed. Conclusively, the employed SPPV strain has the properties of an attenuated vaccine strain, consistent with the genetic data, whereas the GTPV strain represents a highly virulent field strain.
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44
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The Stable Fly ( Stomoxys calcitrans) as a Possible Vector Transmitting Pathogens in Austrian Pig Farms. Microorganisms 2020; 8:microorganisms8101476. [PMID: 32993009 PMCID: PMC7601539 DOI: 10.3390/microorganisms8101476] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/17/2020] [Accepted: 09/24/2020] [Indexed: 12/19/2022] Open
Abstract
This pilot study aimed to investigate stable flies from Austrian pig farms for the presence of defined swine pathogens, such as porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus 2 (PCV2), hemotrophic mycoplasmas in ingested blood and/or body parts and bacteria on the surface of the flies. Furthermore, the use of stable flies as a diagnostic matrix for the detection of pathogens in the ingested pig blood should be investigated. In total, 69 different microorganisms could be found on the surface of tested S. calcitrans from 20 different pig farms. Escherichia coli was the most common bacterium and could be found on flies from seven farms. In seven farms, hemotrophic mycoplasmas were detected in stable flies. PRRSV could not be found in any of the samples of these 20 farms but PCV2 was detected in six farms. Whether the stable fly can be used as a matrix to monitor the health status cannot be accurately determined through this study, especially in regard to PRRSV. Nevertheless, it might be possible to use the stable fly as diagnostic material for defined pathogens like Mycoplasma suis and PCV2.
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45
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Vergne T, Andraud M, Bonnet S, De Regge N, Desquesnes M, Fite J, Etore F, Garigliany MM, Jori F, Lempereur L, Le Potier MF, Quillery E, Saegerman C, Vial L, Bouhsira E. Mechanical transmission of African swine fever virus by Stomoxys calcitrans: Insights from a mechanistic model. Transbound Emerg Dis 2020; 68:1541-1549. [PMID: 32910533 DOI: 10.1111/tbed.13824] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/18/2020] [Accepted: 09/03/2020] [Indexed: 11/30/2022]
Abstract
African swine fever (ASF) represents a global threat with huge economic consequences for the swine industry. Even though direct contact is likely to be the main transmission route from infected to susceptible hosts, recent epidemiological investigations have raised questions regarding the role of haematophagous arthropods, in particular the stable fly (Stomoxys calcitrans). In this study, we developed a mechanistic vector-borne transmission model for ASF virus (ASFV) within an outdoor domestic pig farm in order to assess the relative contribution of stable flies to the spread of the virus. The model was fitted to the ecology of the vector, its blood-feeding behaviour and pig-to-pig transmission dynamic. Model outputs suggested that in a context of low abundance (<5 flies per pig), stable flies would play a minor role in the spread of ASFV, as they are expected to be responsible for around 10% of transmission events. However, with abundances of 20 and 50 stable flies per pig, the vector-borne transmission would likely be responsible for almost 30% and 50% of transmission events, respectively. In these situations, time to reach a pig mortality of 10% would be reduced by around 26% and 40%, respectively. The sensitivity analysis emphasized that the expected relative contribution of stable flies was strongly dependent on the volume of blood they regurgitated and the infectious dose for pigs. This study identified crucial knowledge gaps that need to be filled in order to assess more precisely the potential contribution of stable flies to the spread of ASFV, including a quantitative description of the populations of haematophagous arthropods that could be found in pig farms, a better understanding of blood-feeding behaviours of stable flies and the quantification of the probability that stable flies partially fed with infectious blood transmit the virus to a susceptible pig during a subsequent blood-feeding attempt.
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Affiliation(s)
- Timothée Vergne
- UMR ENVT-INRAE IHAP, National Veterinary School of Toulouse, France
| | - Mathieu Andraud
- Unité d'Epidémiologie et de Bien-être Animal, Laboratoire de Ploufragan/Plouzané/Niort, Anses, France
| | - Sarah Bonnet
- UMR BIPAR, Animal Health Laboratory, INRAE, ANSES, Ecole Nationale Vétérinaire d'Alfort, Université Paris-Est, Maisons-Alfort Cedex, France
| | - Nick De Regge
- Sciensano, Scientific Direction Infectious Diseases in Animals, Brussels, Belgium
| | - Marc Desquesnes
- InterTryp, University of Montpellier, CIRAD, IRD, Montpellier, France
| | - Johanna Fite
- French Agency for Food, Environmental and Occupational Health & Safety, Maisons-Alfort Cedex, France
| | - Florence Etore
- French Agency for Food, Environmental and Occupational Health & Safety, Maisons-Alfort Cedex, France
| | - Mutien-Marie Garigliany
- Fundamental and Applied Research for Animal and Health (FARAH) Center, University of Liège, Liège
| | - Ferran Jori
- UMR Animal, Santé, Territoires, Risque et Ecosystèmes (ASTRE), CIRAD-INRAE Montpellier, Montpellier, France
| | | | | | - Elsa Quillery
- UMR Animal, Santé, Territoires, Risque et Ecosystèmes (ASTRE), CIRAD-INRAE Montpellier, Montpellier, France
| | - Claude Saegerman
- Fundamental and Applied Research for Animal and Health (FARAH) Center, University of Liège, Liège
| | - Laurence Vial
- UMR Animal, Santé, Territoires, Risque et Ecosystèmes (ASTRE), CIRAD-INRAE Montpellier, Montpellier, France
| | - Emilie Bouhsira
- UMR ENVT-INRAE InTheRes, National Veterinary School of Toulouse, Toulouse, France
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46
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Saegerman C, Bonnet S, Bouhsira E, De Regge N, Fite J, Etoré F, Garigliany MM, Jori F, Lempereur L, Le Potier MF, Quillery E, Vergne T, Vial L. An expert opinion assessment of blood-feeding arthropods based on their capacity to transmit African swine fever virus in Metropolitan France. Transbound Emerg Dis 2020; 68:1190-1204. [PMID: 32750188 DOI: 10.1111/tbed.13769] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 07/29/2020] [Accepted: 07/29/2020] [Indexed: 11/29/2022]
Abstract
To deal with the limited literature data on the vectorial capacity of blood-feeding arthropods (BFAs) and their role in the transmission of African swine fever virus (ASFV) in Metropolitan France, a dedicated working group of the French Agency for Food, Environmental and Occupational Health & Safety performed an expert knowledge elicitation. In total, 15 different BFAs were selected as potential vectors by the ad hoc working group involved. Ten criteria were considered to define the vectorial capacity: vectorial competence, current abundance, expected temporal abundance, spatial distribution, longevity, biting rate, active dispersal capacity, trophic preferences for Suidae, probability of contact with domestic pigs and probability of contact with wild boar. Fourteen experts participated to the elicitation. For each BFA, experts proposed a score (between 0 and 3) for each of the above criteria with an index of uncertainty (between 1 and 4). Overall, all experts gave a weight for all criteria (by distributing 100 marbles). A global weighted sum of score per BFA was calculated permitting to rank the different BFAs in decreasing order. Finally, a regression tree analysis was used to group those BFAs with comparable likelihood to play a role in ASF transmission. Out of the ten considered criteria, the experts indicated vectorial competence, abundance and biting rate as the most important criteria. In the context of Metropolitan France, the stable fly (Stomoxys calcitrans) was ranked as the most probable BFA to be a vector of ASFV, followed by lice (Haematopinus suis), mosquitoes (Aedes, Culex and Anopheles), Culicoides and Tabanidea. Since scientific knowledge on their vectorial competence for ASF is scarce and associated uncertainty on expert elicitation moderate to high, more studies are however requested to investigate the potential vector role of these BFAs could have in ASFV spread, starting with Stomoxys calcitrans.
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Affiliation(s)
- Claude Saegerman
- Fundamental and Applied Research for Animal and Health (FARAH) Center, University of Liège, Liège, Belgium
| | - Sarah Bonnet
- UMR BIPAR, Animal Health Laboratory, INRAE, ANSES, Ecole Nationale Vétérinaire d'Alfort, Université Paris-Est, Maisons-Alfort Cedex, France
| | - Emilie Bouhsira
- UMR ENVT-INRA IHAP, National Veterinary School of Toulouse, Toulouse, France
| | - Nick De Regge
- Sciensano, Scientific Direction Infectious Diseases in Animals, Bruxelles, Belgium
| | - Johanna Fite
- French Agency for Food, Environmental and Occupational Health & Safety, Maisons-Alfort Cedex, France
| | - Florence Etoré
- French Agency for Food, Environmental and Occupational Health & Safety, Maisons-Alfort Cedex, France
| | - Mutien-Marie Garigliany
- Fundamental and Applied Research for Animal and Health (FARAH) Center, University of Liège, Liège, Belgium
| | - Ferran Jori
- UMR Animal, Santé, Risque et Ecosystèmes (ASTRE), CIRAD-INRAE-Université de Montpellier, Montpellier, France
| | - Laetitia Lempereur
- Fundamental and Applied Research for Animal and Health (FARAH) Center, University of Liège, Liège, Belgium
| | - Marie-Frédérique Le Potier
- Unité de Virologie Immunologie Porcines, Laboratoire de Ploufragan/Plouzané/Niort, Anses, Ploufragan, France
| | - Elsa Quillery
- French Agency for Food, Environmental and Occupational Health & Safety, Maisons-Alfort Cedex, France
| | - Timothée Vergne
- UMR ENVT-INRA IHAP, National Veterinary School of Toulouse, Toulouse, France
| | - Laurence Vial
- UMR Animal, Santé, Risque et Ecosystèmes (ASTRE), CIRAD-INRAE-Université de Montpellier, Montpellier, France
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Gubbins S, Stegeman A, Klement E, Pite L, Broglia A, Cortiñas Abrahantes J. Inferences about the transmission of lumpy skin disease virus between herds from outbreaks in Albania in 2016. Prev Vet Med 2020; 181:104602. [PMID: 30581093 PMCID: PMC7456782 DOI: 10.1016/j.prevetmed.2018.12.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 12/13/2018] [Indexed: 11/25/2022]
Abstract
Lumpy skin disease has recently emerged as a major threat to cattle populations outside of Africa, where it is endemic. In 2015 the first ever European outbreaks occurred in Greece, which were followed by spread across much of the Balkans in 2016. Here we use a simple mathematical model for the transmission of lumpy skin disease virus (LSDV) between herds to explore factors influencing its spread by fitting it to data on outbreaks in Albania in 2016. We show that most transmission occurs over short distances (<5 km), but with an appreciable probability of transmission at longer distances. We also show that there is evidence for seasonal variation in the force of infection associated with temperature, possibly through its influence on the relative abundance of the stable fly, Stomoxys calcitrans. These two results together are consistent with LSDV being transmitted by the bites of blood-feeding insects, though further work is required to incriminate specific species as vectors. Finally, we show that vaccination has a significant impact on spread and estimate the vaccine effectiveness to be 76%.
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Affiliation(s)
- Simon Gubbins
- The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK.
| | - Arjan Stegeman
- Utrecht University, Department of Farm Animal Health, Utrecht, the Netherlands
| | - Eyal Klement
- Koret School of Veterinary Medicine, The Hebrew University, Jerusalem, Israel
| | - Ledi Pite
- Ministry of Agriculture and Rural Development, Sector of Epidemiology and Identification and Registration, Tirana, Albania
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Putative Role of Arthropod Vectors in African Swine Fever Virus Transmission in Relation to Their Bio-Ecological Properties. Viruses 2020; 12:v12070778. [PMID: 32698448 PMCID: PMC7412232 DOI: 10.3390/v12070778] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/17/2020] [Accepted: 07/18/2020] [Indexed: 12/18/2022] Open
Abstract
African swine fever (ASF) is one of the most important diseases in Suidae due to its significant health and socioeconomic consequences and represents a major threat to the European pig industry, especially in the absence of any available treatment or vaccine. In fact, with its high mortality rate and the subsequent trade restrictions imposed on affected countries, ASF can dramatically disrupt the pig industry in afflicted countries. In September 2018, ASF was unexpectedly identified in wild boars from southern Belgium in the province of Luxembourg, not far from the Franco-Belgian border. The French authorities rapidly commissioned an expert opinion on the risk of ASF introduction and dissemination into metropolitan France. In Europe, the main transmission routes of the virus comprise direct contact between infected and susceptible animals and indirect transmission through contaminated material or feed. However, the seasonality of the disease in some pig farms in Baltic countries, including outbreaks in farms with high biosecurity levels, have led to questions on the possible involvement of arthropods in the transmission of the virus. This review explores the current body of knowledge on the most common arthropod families present in metropolitan France. We examine their potential role in spreading ASF-by active biological or mechanical transmission or by passive transport or ingestion-in relation to their bio-ecological properties. It also highlights the existence of significant gaps in our knowledge on vector ecology in domestic and wild boar environments and in vector competence for ASFV transmission. Filling these gaps is essential to further understanding ASF transmission in order to thus implement appropriate management measures.
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Minimum Infective Dose of a Lumpy Skin Disease Virus Field Strain from North Macedonia. Viruses 2020; 12:v12070768. [PMID: 32708708 PMCID: PMC7411612 DOI: 10.3390/v12070768] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/06/2020] [Accepted: 07/13/2020] [Indexed: 11/28/2022] Open
Abstract
Infection with Lumpy Skin Disease virus (LSDV), as well as infections with other Capripox virus species, are described as the most severe pox diseases of production animals and are therefore listed as notifiable diseases under the guidelines of the World Organization for Animal Health (OIE). To our knowledge there is only a single study examining dose dependency, clinical course, viremia, virus shedding, as well as serological response following experimental LSDV “Neethling” inoculation. Here, we inoculated cattle with four different doses of LSDV strain “Macedonia2016”, a recently characterized virulent LSDV field strain, and examined clinical symptoms, viremia, viral shedding, and seroconversion. Interestingly, around 400 cell culture infectious dose50 (CCID50) of LSDV-“Macedonia2016” were sufficient to induce generalized Lumpy Skin Disease (LSD) in two out of six cattle but with a different incubation time, whereas the other animals of this group showed only a mild course of LSD. However, differences in incubation time, viral loads, serology, and in the clinical scoring could not be observed in the other three groups. In summary, we concluded that experimental LSDV infection of cattle with an infectious virus titer of 105 to 106 CCID50/mL of “Macedonia2016” provides a robust and sufficient challenge model for future studies.
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Boklund A, Dhollander S, Chesnoiu Vasile T, Abrahantes JC, Bøtner A, Gogin A, Gonzalez Villeta LC, Gortázar C, More SJ, Papanikolaou A, Roberts H, Stegeman A, Ståhl K, Thulke HH, Viltrop A, Van der Stede Y, Mortensen S. Risk factors for African swine fever incursion in Romanian domestic farms during 2019. Sci Rep 2020; 10:10215. [PMID: 32576841 PMCID: PMC7311386 DOI: 10.1038/s41598-020-66381-3] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 05/18/2020] [Indexed: 01/06/2023] Open
Abstract
African swine fever (ASF) entered Georgia in 2007 and the EU in 2014. In the EU, the virus primarily spread in wild boar (Sus scrofa) in the period from 2014-2018. However, from the summer 2018, numerous domestic pig farms in Romania were affected by ASF. In contrast to the existing knowledge on ASF transmission routes, the understanding of risk factors and the importance of different transmission routes is still limited. In the period from May to September 2019, 655 Romanian pig farms were included in a matched case-control study investigating possible risk factors for ASF incursion in commercial and backyard pig farms. The results showed that close proximity to outbreaks in domestic farms was a risk factor in commercial as well as backyard farms. Furthermore, in backyard farms, herd size, wild boar abundance around the farm, number of domestic outbreaks within 2 km around farms, short distance to wild boar cases and visits of professionals working on farms were statistically significant risk factors. Additionally, growing crops around the farm, which could potentially attract wild boar, and feeding forage from ASF affected areas to the pigs were risk factors for ASF incursion in backyard farms.
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Affiliation(s)
- A Boklund
- University of Copenhagen, Faculty of Health and Medical Sciences, Section for Animal Welfare and Disease Control, Grønnegårdsvej 8, 1870, Frederiksberg C, Denmark.
| | - S Dhollander
- European Food Safety Authority, Via Carlo Magno 1A, 43126, Parma, Italy
| | - T Chesnoiu Vasile
- The National Sanitary Veterinary and Food Safety Authority, Bucharest, Piata Free Press no. 1 Body D1, District 1, Post Code 013 701, Bucharest, Romania
| | - J C Abrahantes
- European Food Safety Authority, Via Carlo Magno 1A, 43126, Parma, Italy
| | - A Bøtner
- University of Copenhagen, Faculty of Health and Medical Sciences, Section for Veterinary Clinical Microbiology, Stigbøjlen 4, 1870, Frederiksberg C, Denmark
- Statens Serum Institut, Department of Virus and Microbiological Special Diagnostics, Artillerivej 5, 2300, Copenhagen S, Denmark
| | - A Gogin
- Federal Research Center for Virology and Microbiology, 601125, Volginsky, Russia
| | | | - C Gortázar
- SaBio research group at IREC (Universidad de Castilla-La Mancha & CSIC), Ronda de Toledo 12, 13003, Ciudad Real, Spain
| | - S J More
- Centre for Veterinary Epidemiology and Risk Analysis, UCD School of Veterinary Medicine, University College Dublin, Belfield, Dublin, D04 W6F6, Ireland
| | - A Papanikolaou
- European Food Safety Authority, Via Carlo Magno 1A, 43126, Parma, Italy
| | - H Roberts
- Department for Environment Food and Rural Affairs (DEFRA), Exotic Disease Control team, Area 2D, Nobel House, 17 Smith Square, London, SW1P 3JR, England
| | - A Stegeman
- Utrecht University, Faculty of Veterinary Medicine, Yalelaan 7, Utrecht, The Netherlands
| | - K Ståhl
- National Veterinary Institute, 751 89, Uppsala, Sweden
| | - H H Thulke
- Helmholtz Centre for Environmental Research GmbH - UFZ, Department of Ecological Modelling, PG EcoEpi, Permoserstr. 15, Leipzig, Germany
| | - A Viltrop
- Estonian University of Life Sciences, Institute of Veterinary Medicine and Animal Sciences, Kreutzwaldi 62, Tartu, 51006, Estonia
| | - Y Van der Stede
- European Food Safety Authority, Via Carlo Magno 1A, 43126, Parma, Italy
| | - S Mortensen
- Danish Veterinary and Food Administration, Stationsparken 31-33, 2600, Glostrup, Denmark
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