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Dundon WG, Molini U, Franzo G. Six underreported viral diseases of domesticated and wild swine in Africa: Implications and perspectives. Vet Microbiol 2024; 294:110120. [PMID: 38749211 DOI: 10.1016/j.vetmic.2024.110120] [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: 03/04/2024] [Revised: 05/08/2024] [Accepted: 05/10/2024] [Indexed: 06/11/2024]
Abstract
Pig production is increasing annually in Africa as it is recognized as a significant source of income, livelihood and food security, particularly in rural communities. Understanding the circulating swine pathogens is crucial for the success of this emerging industry. Although there is extensive data available on the African swine fever virus due to its devastating impact on pig production, knowledge about the presence of other viral swine pathogens on the continent is still extremely limited. This review discusses what is currently known about six swine pathogens in Africa: classical swine fever virus, porcine reproductive and respiratory syndrome virus, porcine circovirus-2, porcine circovirus-3, porcine parvovirus-1, and pseudorabies virus. Gaps in our knowledge are identified and topics of future focus discussed.
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Affiliation(s)
- William G Dundon
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Center, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, P.O. Box 100, Vienna 1400, Austria.
| | - Umberto Molini
- School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, Neudamm Campus, Private Bag 13301, Windhoek, Namibia; Central Veterinary Laboratory (CVL), 24 Goethe Street, Private Bag 18137, Windhoek, Namibia
| | - Giovanni Franzo
- Department of Animal Medicine, Production and Health, University of Padova, Legnaro, viale dell'Università 16, 35020, Italy
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Molini U, Coetzee LM, Hemberger MY, Chiwome B, Khaiseb S, Dundon WG, Franzo G. First detection and molecular characterization of porcine reproductive and respiratory syndrome virus in Namibia, Africa. Front Vet Sci 2024; 10:1323974. [PMID: 38288380 PMCID: PMC10822890 DOI: 10.3389/fvets.2023.1323974] [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: 10/18/2023] [Accepted: 12/08/2023] [Indexed: 01/31/2024] Open
Abstract
Introduction The swine sector in Africa plays an important role in local economies, contributing to poverty alleviation and community subsistence. In addition, intensive farming is progressively becoming more important in the region. Therefore, any disease affecting swine populations can have detrimental effects on local communities. Porcine Reproductive and Respiratory Syndrome (PRRS) is among the most important infectious diseases affecting swine worldwide, but information on its epidemiology in Africa is extremely limited. Material and methods In the present study, 147 healthy butchered pigs, originating from 15 Namibian intensive and rural farms were tested by RT-PCR and the ORF7 genes of positive samples were sequenced for further genetic characterization and phylogenetic analysis. Additionally, 55 warthogs were also evaluated using the same approach. Results Overall, 7 out of 147 pigs (4.76%) tested positive, all originating from 3 rural farms (with a within-herd detection frequency higher than 14%) characterized by strong epidemiological links. All industrial pig and warthog samples were negative. Sequence analysis revealed that all strains belonged to the Betaarterivirus suid1 species, previously known as PRRSV type I, and were likely imported from Europe at least 6 years ago, evolving independently thereafter. When and how the first introduction occurred could not be determined due to the absence of other African sequences for comparison. Discussion The present work provides the first detection and characterization of PRRSV molecular epidemiology in Namibia. Based on the present findings, the presence of the PPRSV appears marginal and limited to backyard farms. While biosecurity measures applied in industrial farms appear to be effective in preventing viral introduction, PRRSV circulation in rural settings still represents a potential threat, and considering the socio-economical implication of livestock diseases decreasing animal performances in rural areas, active monitoring should be encouraged to promptly act against emerging menaces and guarantee the welfare of local pig populations.
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Affiliation(s)
- Umberto Molini
- School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, Windhoek, Namibia
- Central Veterinary Laboratory (CVL), Windhoek, Namibia
| | - Lauren M. Coetzee
- Central Veterinary Laboratory (CVL), Windhoek, Namibia
- Faculty of Veterinary Medicine, University of Teramo, Teramo, Italy
| | - Maria Y. Hemberger
- School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, Windhoek, Namibia
| | - Bernard Chiwome
- School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, Windhoek, Namibia
| | | | - William G. Dundon
- Animal Production and Health Laboratory, Animal Production and Health Section, Department of Nuclear Sciences and Applications, Joint FAO/IAEA Division, International Atomic Energy Agency, Vienna, Austria
| | - Giovanni Franzo
- Department of Animal Medicine, Production and Health, University of Padova, Legnaro, Legnaro, Italy
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Molini U, Coetzee LM, Christians V, Hemberger MY, Chiwome B, Amukwaya M, Khaiseb S, Cattoli G, Dundon WG, Franzo G. High detection frequency and genetic diversity of porcine circovirus 3 (PCV-3) in Namibian backyard farms and warthogs. Acta Trop 2024; 249:107085. [PMID: 38016512 DOI: 10.1016/j.actatropica.2023.107085] [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: 08/01/2023] [Revised: 11/02/2023] [Accepted: 11/25/2023] [Indexed: 11/30/2023]
Abstract
Since its first identification in 2015, porcine circovirus 3 (PCV-3) has been reported worldwide with a high frequency and in the presence of several clinical conditions, although its impact on pig health and productivity is still debated. Data on the presence of PCV-3 in Africa are, however, limited. A previous study performed on commercial pigs in Namibia failed to identify the pathogen. In the present study, the viral circulation in backyard farms, characterised by lower biosecurity measures and frequent animal exchange between farms, was assessed. The susceptibility of warthogs to PCV-3 infection and their potential epidemiological role were also evaluated. Tonsils from 77 pigs from backyard piggeries and 55 warthogs were collected in different regions of Namibia and tested by PCR. Positive samples were sequenced and compared to PCV-3 strains circulating globally. Forty-two out of 77 pigs (54.54 %) and 12 out of 55 warthogs (21.82 %) tested positive, demonstrating the presence of PCV-3 in the country and suggesting that the high biosecurity measures implemented in the commercial farms that previously tested negative for PCV-3 probably prevented viral introduction. The partial ORF2 gene was successfully sequenced in samples from 27 pigs and 6 warthogs. Genetically, the identified strains were part of 3 distinct groups which included both backyard pigs and warthogs from different regions of Namibia. There is also evidence for the occurrence of multiple introduction events most likely from Asian countries, either directly into Namibia or through other African countries. Considering the strict Namibian regulations on live animal importation, understanding the source of viral introduction is challenging, although semen importation or the habit of feeding backyard pigs with human food waste might have played a role. Pig exchanges between farms for breeding purposes or wildlife movements could also have been involved in PCV-3 dispersal within Namibia. Despite the significant advances in the field, further studies should be undertaken to properly understand PCV-3 epidemiology in Namibia and its impact on pig productivity and wildlife health.
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Affiliation(s)
- Umberto Molini
- Faculty of Health Sciences and Veterinary Medicine, School of Veterinary Medicine, Neudamm Campus, University of Namibia, Private Bag 13301, Windhoek 9000, Namibia
| | - Lauren M Coetzee
- Central Veterinary Laboratory (CVL), 24 Goethe Street, Private Bag 18137, Windhoek 9000, Namibia; Faculty of Veterinary Medicine, University of Teramo, Teramo 64100, Italy
| | - Vernon Christians
- Faculty of Health Sciences and Veterinary Medicine, School of Veterinary Medicine, Neudamm Campus, University of Namibia, Private Bag 13301, Windhoek 9000, Namibia
| | - Maria Y Hemberger
- Faculty of Health Sciences and Veterinary Medicine, School of Veterinary Medicine, Neudamm Campus, University of Namibia, Private Bag 13301, Windhoek 9000, Namibia
| | - Bernard Chiwome
- Faculty of Health Sciences and Veterinary Medicine, School of Veterinary Medicine, Neudamm Campus, University of Namibia, Private Bag 13301, Windhoek 9000, Namibia
| | - Maria Amukwaya
- Faculty of Health Sciences and Veterinary Medicine, School of Veterinary Medicine, Neudamm Campus, University of Namibia, Private Bag 13301, Windhoek 9000, Namibia
| | - Siegfried Khaiseb
- Central Veterinary Laboratory (CVL), 24 Goethe Street, Private Bag 18137, Windhoek 9000, Namibia
| | - Giovanni Cattoli
- Department of Nuclear Sciences and Applications, Joint FAO/IAEA Division, Animal Production and Health Laboratory, Animal Production and Health Section, International Atomic Energy Agency, P.O. Box 100, Vienna 1400, Austria
| | - William G Dundon
- Department of Nuclear Sciences and Applications, Joint FAO/IAEA Division, Animal Production and Health Laboratory, Animal Production and Health Section, International Atomic Energy Agency, P.O. Box 100, Vienna 1400, Austria
| | - Giovanni Franzo
- Department. of Animal Medicine, Production and Health, University of Padova, viale dell'Università 16, Legnaro 35020, Italy.
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An Updated Review of Ornithodoros Ticks as Reservoirs of African Swine Fever in Sub-Saharan Africa and Madagascar. Pathogens 2023; 12:pathogens12030469. [PMID: 36986391 PMCID: PMC10059854 DOI: 10.3390/pathogens12030469] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/13/2023] [Accepted: 03/14/2023] [Indexed: 03/19/2023] Open
Abstract
This updated review provides an overview of the available information on Ornithodoros ticks as reservoirs and biological vectors of the ASF virus in Africa and Indian Ocean islands in order to update the current knowledge in this field, inclusive of an overview of available methods to investigate the presence of ticks in the natural environment and in domestic pig premises. In addition, it highlights the major areas of research that require attention in order to guide future investigations and fill knowledge gaps. The available information suggests that current knowledge is clearly insufficient to develop risk-based control and prevention strategies, which should be based on a sound understanding of genotype distribution and the potential for spillover from the source population. Studies on tick biology in the natural and domestic cycle, including genetics and systematics, represent another important knowledge gap. Considering the rapidly changing dynamics affecting the African continent (demographic growth, agricultural expansion, habitat transformation), anthropogenic factors influencing tick population distribution and ASF virus (ASFV) evolution in Africa are anticipated and have been recorded in southern Africa. This dynamic context, together with the current global trends of ASFV dissemination, highlights the need to prioritize further investigation on the acarological aspects linked with ASF ecology and evolution.
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Franzo G, Zerbo HL, Ouoba BL, Dji-Tombo AD, Kindo MG, Sawadogo R, Chang’a J, Bitanyi S, Kamigwe A, Mayenga C, Lo MM, Ndiaye M, Ba A, Diop GL, Anahory IV, Mapaco LP, Achá SJ, Kouakou VK, Couacy-Hymann E, Gacheru SG, Lichoti JK, Kasivalu JK, Njagi ON, Settypalli TBK, Cattoli G, Lamien CE, Molini U, Dundon WG. A Phylogeographic Analysis of Porcine Parvovirus 1 in Africa. Viruses 2023; 15:207. [PMID: 36680247 PMCID: PMC9864576 DOI: 10.3390/v15010207] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 01/05/2023] [Accepted: 01/08/2023] [Indexed: 01/13/2023] Open
Abstract
Porcine parvovirus 1 (PPV1) is recognized as a major cause of reproductive failure in pigs, leading to several clinical outcomes globally known as SMEDI. Despite being known since the late 1960s its circulation is still of relevance to swine producers. Additionally, the emergence of variants such as the virulent 27a strain, for which lower protection induced by vaccines has been demonstrated, is of increasing concern. Even though constant monitoring of PPV1 using molecular epidemiological approaches is of pivotal importance, viral sequence data are scarce especially in low-income countries. To fill this gap, a collection of 71 partial VP2 sequences originating from eight African countries (Burkina Faso, Côte d'Ivoire, Kenya, Mozambique, Namibia, Nigeria, Senegal, and Tanzania) during the period 2011-2021 were analyzed within the context of global PPV1 variability. The observed pattern largely reflected what has been observed in high-income regions, i.e., 27a-like strains were more frequently detected than less virulent NADL-8-like strains. A phylogeographic analysis supported this observation, highlighting that the African scenario has been largely shaped by multiple PPV1 importation events from other continents, especially Europe and Asia. The existence of such an international movement coupled with the circulation of potential vaccine-escape variants requires the careful evaluation of the control strategies to prevent new strain introduction and persistence.
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Affiliation(s)
- Giovanni Franzo
- Department of Animal Medicine, Production and Health, University of Padova, viale dell’Università 16, 35020 Legnaro, Italy
| | | | | | | | | | - Rasablaga Sawadogo
- Laboratoire National d’Elevage (LNE), Ouagadougou 03 BP 907, Burkina Faso
| | - Jelly Chang’a
- Centre for Infectious Diseases and Biotechnology, Tanzania Veterinary Laboratory Agency, Dar es Salaam P.O. Box 9254, Tanzania
| | - Stella Bitanyi
- Centre for Infectious Diseases and Biotechnology, Tanzania Veterinary Laboratory Agency, Dar es Salaam P.O. Box 9254, Tanzania
| | - Aloyce Kamigwe
- Centre for Infectious Diseases and Biotechnology, Tanzania Veterinary Laboratory Agency, Dar es Salaam P.O. Box 9254, Tanzania
| | - Charles Mayenga
- Centre for Infectious Diseases and Biotechnology, Tanzania Veterinary Laboratory Agency, Dar es Salaam P.O. Box 9254, Tanzania
| | - Modou Moustapha Lo
- Laboratoire National de l’Elevage et de Recherches Vétérinaires, Institut Sénégalais de Recherches Agricoles (ISRA), Dakar BP 3120, Senegal
| | - Mbengué Ndiaye
- Laboratoire National de l’Elevage et de Recherches Vétérinaires, Institut Sénégalais de Recherches Agricoles (ISRA), Dakar BP 3120, Senegal
| | - Aminata Ba
- Laboratoire National de l’Elevage et de Recherches Vétérinaires, Institut Sénégalais de Recherches Agricoles (ISRA), Dakar BP 3120, Senegal
| | - Gaye Laye Diop
- Laboratoire National de l’Elevage et de Recherches Vétérinaires, Institut Sénégalais de Recherches Agricoles (ISRA), Dakar BP 3120, Senegal
| | - Iolanda Vieira Anahory
- Central Veterinary Laboratory, Agricultural Research Institute of Mozambique, Directorate of Animal Science, Maputo 1922, Mozambique
| | - Lourenço P. Mapaco
- Central Veterinary Laboratory, Agricultural Research Institute of Mozambique, Directorate of Animal Science, Maputo 1922, Mozambique
| | - Sara J. Achá
- Central Veterinary Laboratory, Agricultural Research Institute of Mozambique, Directorate of Animal Science, Maputo 1922, Mozambique
| | | | | | - Stephen G. Gacheru
- Central Veterinary Laboratory, Directorate of Veterinary Services, Kabete P.O. Box 00100-34188, Kenya
| | - Jacqueline K. Lichoti
- Central Veterinary Laboratory, Directorate of Veterinary Services, Kabete P.O. Box 00100-34188, Kenya
| | - Justus K. Kasivalu
- Central Veterinary Laboratory, Directorate of Veterinary Services, Kabete P.O. Box 00100-34188, Kenya
| | - Obadiah N. Njagi
- Central Veterinary Laboratory, Directorate of Veterinary Services, Kabete P.O. Box 00100-34188, Kenya
| | - Tirumala B. K. Settypalli
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Division, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, P.O. Box 100, 1400 Vienna, Austria
| | - Giovanni Cattoli
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Division, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, P.O. Box 100, 1400 Vienna, Austria
| | - Charles E. Lamien
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Division, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, P.O. Box 100, 1400 Vienna, Austria
| | - Umberto Molini
- School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, Neudamm Campus, Windhoek Private Bag 13301, Namibia
- Central Veterinary Laboratory (CVL), 24 Goethe Street, Windhoek Private Bag 18137, Namibia
| | - William G. Dundon
- Animal Production and Health Laboratory, Animal Production and Health Section, Joint FAO/IAEA Division, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, P.O. Box 100, 1400 Vienna, Austria
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