1
|
Vlasov M, Sindryakova I, Kudryashov D, Morgunov S, Kolbasova O, Lyska V, Zhivoderov S, Pivova E, Balyshev V, Namsrayn S, Sevskikh T, Sereda A, Kolbasov D. Administration Routes and Doses of the Attenuated African Swine Fever Virus Strain PSA-1NH Influence Cross-Protection of Pigs against Heterologous Challenge. Animals (Basel) 2024; 14:1277. [PMID: 38731281 PMCID: PMC11083577 DOI: 10.3390/ani14091277] [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: 03/14/2024] [Revised: 04/19/2024] [Accepted: 04/22/2024] [Indexed: 05/13/2024] Open
Abstract
African swine fever (ASF) is a lethal hemorrhagic disease of Suidae, i.e., domestic pigs and wild boars, caused by African swine fever virus (ASFV). The development of cross-protective vaccines against ASF is imperative for effective disease control, particularly in regions where ASF is endemic, potentially featuring multiple circulating ASFV isolates. The investigation of non-hemadsorbing naturally attenuated isolates and laboratory recombinant strains with a deletion in the EP402R gene has attracted interest. Our study aimed to assess the impacts of various administration routes and doses of the naturally attenuated ASFV-PSA-1NH (immunotype IV, genotype I) isolate on the manifestation of clinical signs of ASF and the level of protection against the heterologous ASFV-Stavropol 01/08 strain (seroimmunotype VIII, genotype II). The results demonstrated that the intranasal administration of a low dose of ASFV-PSA-1NH to pigs minimized the clinical signs of ASF and established a high level of protection against the heterologous strain ASFV-Stavropol 01/08. Despite the challenges in standardizing the dosage for intranasal administration, this approach appears as a viable alternative in ASF vaccination.
Collapse
Affiliation(s)
| | - Irina Sindryakova
- Federal Research Center for Virology and Microbiology (FRCVM), Academician Bakoulov Street, Bldg. 1, 601125 Volginsky, Russia; (M.V.); (D.K.); (S.M.); (O.K.); (V.L.); (S.Z.); (E.P.); (V.B.); (S.N.); (T.S.); (D.K.)
| | | | | | | | | | | | | | | | | | | | - Alexey Sereda
- Federal Research Center for Virology and Microbiology (FRCVM), Academician Bakoulov Street, Bldg. 1, 601125 Volginsky, Russia; (M.V.); (D.K.); (S.M.); (O.K.); (V.L.); (S.Z.); (E.P.); (V.B.); (S.N.); (T.S.); (D.K.)
| | | |
Collapse
|
2
|
Giammarioli M, Alessandro D, Cammà C, Masoero L, Torresi C, Marcacci M, Zoppi S, Curini V, Rinaldi A, Rossi E, Casciari C, Pela M, Pellegrini C, Iscaro C, Feliziani F. Molecular Characterization of the First African Swine Fever Virus Genotype II Strains Identified from Mainland Italy, 2022. Pathogens 2023; 12:pathogens12030372. [PMID: 36986294 PMCID: PMC10055901 DOI: 10.3390/pathogens12030372] [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: 12/22/2022] [Revised: 02/20/2023] [Accepted: 02/21/2023] [Indexed: 03/30/2023] Open
Abstract
African swine fever (ASF) is responsible for important socio-economic effects in the global pig industry, especially for countries with large-scale piggery sectors. In January 2022, the African swine fever virus (ASFV) genotype II was identified in a wild boar population in mainland Italy (Piedmont region). This study describes the molecular characterization, by Sanger and next-generation sequencing (NGS), of the first index case 632/AL/2022 and of another isolate (2802/AL/2022) reported in the same month, in close proximity to the first, following multiple ASF outbreaks. Phylogenetic analysis based on the B646L gene and NGS clustered the isolates 632/AL/2022 and 2802/AL/2022 within the wide and most homogeneous p72 genotype II that includes viruses from European and Asian countries. The consensus sequence obtained from the ASFV 2802/AL/2022 isolate was 190,598 nucleotides in length and had a mean GC content of 38.38%. At the whole-genome level, ASF isolate 2802/AL/2022 showed a close genetic correlation with the other representative ASFV genotype II strains isolated between April 2007 and January 2022 from wild and domestic pigs in Eastern/Central European (EU) and Asian countries. CVR subtyping clustered the two Italian ASFV strains within the major CVR variant circulating since the first virus introduction in Georgia in 2007. Intergenic region I73R-I329L subtyping placed the Italian ASFV isolates within the variant identical to the strains frequently identified among wild boars and domestic pigs. Presently, given the high sequence similarity, it is impossible to trace the precise geographic origin of the virus at a country level. Moreover, the full-length sequences available in the NCBI are not completely representative of all affected territories.
Collapse
Affiliation(s)
- Monica Giammarioli
- Istituto Zooprofilattico Sperimentale Umbria e Marche "Togo Rosati", 06126 Perugia, Italy
| | - Dondo Alessandro
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, 10154 Torino, Italy
| | - Cesare Cammà
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise "G. Caporale", Campo Boario, 64100 Teramo, Italy
| | - Loretta Masoero
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, 10154 Torino, Italy
| | - Claudia Torresi
- Istituto Zooprofilattico Sperimentale Umbria e Marche "Togo Rosati", 06126 Perugia, Italy
| | - Maurilia Marcacci
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise "G. Caporale", Campo Boario, 64100 Teramo, Italy
| | - Simona Zoppi
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, 10154 Torino, Italy
| | - Valentina Curini
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise "G. Caporale", Campo Boario, 64100 Teramo, Italy
| | - Antonio Rinaldi
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise "G. Caporale", Campo Boario, 64100 Teramo, Italy
| | - Elisabetta Rossi
- Istituto Zooprofilattico Sperimentale Umbria e Marche "Togo Rosati", 06126 Perugia, Italy
| | - Cristina Casciari
- Istituto Zooprofilattico Sperimentale Umbria e Marche "Togo Rosati", 06126 Perugia, Italy
| | - Michela Pela
- Istituto Zooprofilattico Sperimentale Umbria e Marche "Togo Rosati", 06126 Perugia, Italy
| | - Claudia Pellegrini
- Istituto Zooprofilattico Sperimentale Umbria e Marche "Togo Rosati", 06126 Perugia, Italy
| | - Carmen Iscaro
- Istituto Zooprofilattico Sperimentale Umbria e Marche "Togo Rosati", 06126 Perugia, Italy
| | - Francesco Feliziani
- Istituto Zooprofilattico Sperimentale Umbria e Marche "Togo Rosati", 06126 Perugia, Italy
| |
Collapse
|
3
|
Lysholm S, Lindahl JF, Dautu G, Johansson E, Bergkvist PK, Munyeme M, Wensman JJ. Seroepidemiology of selected transboundary animal diseases in goats in Zambia. Prev Vet Med 2022; 206:105708. [PMID: 35835047 DOI: 10.1016/j.prevetmed.2022.105708] [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: 06/23/2021] [Revised: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 11/25/2022]
Abstract
Transboundary pathogens of goats present significant constraints to the livelihoods of millions of farmers in countries such as Zambia. Consequently, this study aimed to investigate the seroprevalence of Mycoplasma capricolum subsp. capripneumoniae (Mccp), foot and mouth disease virus (FMDV), Brucella spp., Crimean Congo haemorrhagic fever virus (CCHFV), and Rift Valley fever virus (RVFV) in Zambian goats. Another aim was to identify associations between seroprevalence and different predictor variables, such as trade and border proximity. From September to October 2019, 962 serum samples were collected from goats in seven Zambian districts, four of which have an international border while the remaining three do not. A questionnaire survey was conducted with each household, focusing on trade routines, management strategies and herd disease history. Animal-level seroprevalence adjusted for herd-level clustering was 8.2 % (95 % confidence interval [CI] 7.5-9.0) for Mccp, 12.9% (95% CI 12.0-13.7) for FMDV, 13.0 % (95% CI 12.1-13.9) for Brucella spp., 3.3 % (95% CI 2.8-3.7) for CCHFV, and 0.4 % (95 % CI 0.3-0.7) for RVFV. The association between herd-level seroprevalence and border proximity and trade appeared negligible, with the exception of selling goats at least twice a year which was identified as a potential risk factor for Brucella spp. (OR 4.1, 95 % CI 1.1-16.0, p = 0.040). In addition, a positive association between herd-level seroprevalence of FMDV and a herd size of 21 goats or more (OR 3.3, 95 % CI 1.0-11.1, p = 0.049) was detected. Also, positive associations between animal-level seroprevalence of Brucella spp. and increasing age (OR 7.7, 95 % CI 1.5-40.7, p = 0.016), and CCHFV and keeping pigs in the household (OR 2.7, 95 % CI 1.0-7.1, p = 0.044), were found. For FMDV (OR 3.8, 95 % CI 1.4-10.9, p = 0.011) and Brucella spp. (OR 4.5, 95 % CI 1.2-17.3, p = 0.031) on the other hand, animal-level seroprevalence was significantly higher in households without pigs. To the best of the authors' knowledge, this is the first study to describe the presence of antibodies for CCPP and CCHF in the Zambian goat population. While the association between seroprevalence and trade and border proximity generally appeared negligible, it is recommended that their influence is further evaluated in future studies, preferably through in-depth longitudinal studies incorporating impacts of different biosecurity measures and trade variations, linked to for example seasonality and trade peaks.
Collapse
Affiliation(s)
- Sara Lysholm
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden.
| | - Johanna F Lindahl
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden; Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden; Department of Biosciences, International Livestock Research Institute, Nairobi, Kenya
| | - George Dautu
- Department of Veterinary Services Ministry of Fisheries and Livestock, Central Veterinary Research Institute, Zambia
| | - Elin Johansson
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | | | - Musso Munyeme
- Department of Disease Control, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia; Africa Centre of Excellence for Infectious Diseases of Humans and Animals (ACEIDHA), Lusaka, Zambia
| | - Jonas Johansson Wensman
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden; Department of Disease Control and Epidemiology, National Veterinary Institute, Uppsala, Sweden
| |
Collapse
|
4
|
Molini U, Franzo G, Settypalli TBK, Hemberger MY, Khaiseb S, Cattoli G, Dundon WG, Lamien CE. Viral Co-Infections of Warthogs in Namibia with African Swine Fever Virus and Porcine Parvovirus 1. Animals (Basel) 2022; 12:ani12131697. [PMID: 35804594 PMCID: PMC9265065 DOI: 10.3390/ani12131697] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 06/28/2022] [Accepted: 06/29/2022] [Indexed: 11/25/2022] Open
Abstract
Simple Summary Wild animals can transmit diseases to domestic animals. In Africa, warthogs are known to be carriers of pathogens that can infect pigs; consequently, it is important to identify these pathogens in order to protect pigs from infection. In this study, two important swine pathogens i.e., African swine fever virus (ASFV) and porcine parvovirus 1 (PPV1) were identified in warthogs in Namibia and characterized genetically. The results will be of interest to those working in swine disease management and control in Namibia. Abstract Understanding virus circulation in wild animals, particularly those that have contact with domestic animals, is crucial for disease management and control. In Africa, warthogs are known to be asymptomatic carriers of porcine pathogens; a recent study in Namibia has shown them to be positive for Porcine circovirus-2 (PCV-2). In this study, the same samples used for the PCV-2 investigation in Namibia were further screened for the presence of African swine fever virus (ASFV) and porcine parvovirus 1 (PPV1) by PCR. Of the 42 animals tested, 2 (4.8%) and 13 (31%) were positive for AFSV and PPV1, respectively. The two AFSV were also co-infected with PPV1. Combing the results of this study with the results of the previous PCV-2 investigation, four warthogs were shown to be co-infected with both PPV1 and PCV-2. Sequence and phylogenetic analysis revealed that the AFSV belonged to genotype (Ib) but were from different serogroups. Unexpectedly, the ASFVs from the warthogs were genetically distinct to those observed in an outbreak in the same region of Namibia that occurred less than fifteen months prior to the sampling of the warthogs. In fact, a stronger genetic relationship was observed between the warthog viruses and historical Namibian and South African ASFVs identified in 1980, 2004 and 2008. For the PPV1s, the closest relative to the Namibian PPV1 were viruses identified in wild boar in Romania in 2011. This study confirms that warthogs are carriers of porcine pathogens and the data should encourage further studies on larger populations of wild and domestic swine to more fully understand the epidemiology and transmission of viral pathogens from these species.
Collapse
Affiliation(s)
- Umberto Molini
- School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, Neudamm Campus, Private Bag 13301, Windhoek 9000, Namibia; (U.M.); (M.Y.H.)
- Central Veterinary Laboratory (CVL), 24 Goethe Street, Private Bag 18137, Windhoek 9000, Namibia;
| | - Giovanni Franzo
- Department of Animal Medicine, Production and Health, University of Padova, Viale dell’Università 16, 35020 Legnaro, Italy;
| | - 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; (T.B.K.S.); (G.C.); (C.E.L.)
| | - Maria Y. Hemberger
- School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, Neudamm Campus, Private Bag 13301, Windhoek 9000, Namibia; (U.M.); (M.Y.H.)
| | - Siegfried Khaiseb
- Central Veterinary Laboratory (CVL), 24 Goethe Street, Private Bag 18137, Windhoek 9000, Namibia;
| | - 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; (T.B.K.S.); (G.C.); (C.E.L.)
| | - 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; (T.B.K.S.); (G.C.); (C.E.L.)
- Correspondence:
| | - 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; (T.B.K.S.); (G.C.); (C.E.L.)
| |
Collapse
|
5
|
Shi K, Liu H, Yin Y, Si H, Long F, Feng S. Molecular Characterization of African Swine Fever Virus From 2019-2020 Outbreaks in Guangxi Province, Southern China. Front Vet Sci 2022; 9:912224. [PMID: 35782548 PMCID: PMC9240437 DOI: 10.3389/fvets.2022.912224] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 05/23/2022] [Indexed: 11/13/2022] Open
Abstract
African swine fever virus (ASFV) causes contagious hemorrhagic disease of pigs with high morbidity and mortality. To identify the molecular characteristics of ASFV strains circulating in Guangxi province, southern China, a total of 336 tissue samples collected from 336 domestic pigs that died as a result of severe hemorrhagic disease during 2019–2020 were tested for ASFV. Furthermore, 66 ASFV strains were genetically characterized by sequence analysis of the C-terminal region of B646L (p72) gene, the complete E183L (p54) gene, the variable region of EP402R (CD2v) gene, the central variable region (CVR) of B602L gene, the full MGF505-2R gene, and the tandem repeat sequence (TRS) within intergenic region (IGR) between the I73R and I329L (I73R/I329L) genes. Phylogenetic analysis revealed that the ASFV strains from Guangxi province belonged to genotypes I and II based on the B646L (p72) and E183L (p54) genes, and there were eight different tetrameric TRS variants based on the CVR of B602L gene. Phylogenetic analysis of the EP402R (CD2v) gene revealed that these ASFV strains belonged to serogroups 4 and 8. Eight of the 66 strains belonged to genotype I and serogroup 4, and showed deletion of whole MGF505-2R gene. The sequence analysis of the IGR between the I73R/I329L genes showed that IGR II and III variants were co-circulating in Guangxi province. The results indicated that ASFV strains circulating in Guangxi province during 2019–2020 outbreaks showed high genetic diversity, of which genotypes I and II, as well as serogroups 4 and 8, were simultaneously circulating in Guangxi province, and there existed wild-type and naturally gene-deleted strains in the field. This is the first detailed report on the molecular characterization of the ASFV strains circulating in southern China, and serogroup 4 in China.
Collapse
Affiliation(s)
- Kaichuang Shi
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
- College of Animal Science and Technology, Guangxi University, Nanning, China
- *Correspondence: Kaichuang Shi
| | - Huixin Liu
- College of Animal Science and Technology, Guangxi University, Nanning, China
| | - Yanwen Yin
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
| | - Hongbin Si
- College of Animal Science and Technology, Guangxi University, Nanning, China
- Hongbin Si
| | - Feng Long
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
| | - Shuping Feng
- Guangxi Center for Animal Disease Control and Prevention, Nanning, China
| |
Collapse
|
6
|
Adedeji AJ, Atai RB, Gyang HE, Gambo P, Habib MA, Weka R, Muwanika VB, Masembe C, Luka PD. Live pig markets are hotspots for spread of African swine fever virus in Nigeria. Transbound Emerg Dis 2022; 69:e1526-e1540. [PMID: 35179830 DOI: 10.1111/tbed.14483] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/08/2022] [Accepted: 02/16/2022] [Indexed: 11/28/2022]
Abstract
Livestock trading through live animal markets are potential pathways for the introduction and spread of economically important pathogens like the African swine fever virus (ASFV) to new areas in several countries. Due to the high demand for live pigs in Nigeria both for restocking and slaughter, live pigs are sold at designated live pig markets (LPM) in the country. This involves movement of pigs over long distances. Despite, reports of ASF outbreaks following restocking of pigs bought from LPMs, there is paucity of information on the role of LPMs in the epidemiology of ASF. In this study, data and pig samples (whole blood, sera, tissue) were collected from 4 selected LPMs in Nigeria (Dawaki, Katsit, Numan & Pandam) between 2019 and 2020. Samples were analysed by polymerase chain reaction (PCR) and Enzyme-linked Immunosorbent Assay (ELISA). Four genes of ASFV positive samples were characterized to identify the circulating genotypes. Results revealed trade activities involving transportation of pigs from these selected markets to 42 major cities and towns in thirteen (13) States of Nigeria. PCR results revealed an overall ASF prevalence of 10.77% (66/613). ASFV was confirmed by PCR in all the selected LPMs with a prevalence rate of 3.13%-23.81%. The phylogeny revealed genotype I and serogroup 4 based on the p72 protein that encodes the B646L gene and the EP402R gene encoding the CD2V. While sequence analysis of CVR of B602L gene revealed 8 tetrameric repeats variants, six of which have never been reported in Nigeria. Analysis of sera samples recorded a seroprevalence of 6.9% (16/217) within the study period. Findings from this study show that LPM are hotspots and channels for transmission and continuous spread of ASFV in Nigeria. Therefore, for ASF to be controlled in Nigeria, disease surveillance and regulation at LPMs are critical. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Adeyinka J Adedeji
- National Veterinary Research Institute, Vom, Nigeria.,College of Natural Sciences, Makerere University, P.O. Box 7062, Kampala, Kampala, Uganda
| | | | - Helen E Gyang
- National Veterinary Research Institute, Vom, Nigeria
| | - Panzam Gambo
- Federal College of Animal Health and Production Technology, Vom, Nigeria
| | - Maimuna A Habib
- Animal Health and Clinical Services Division, Federal Ministry of Agriculture and Rural Development, Abuja, Nigeria
| | - Rebecca Weka
- National Veterinary Research Institute, Vom, Nigeria
| | - Vincent B Muwanika
- College of Agricultural & Environmental Sciences, Makerere University, Kampala, P.O. Box 7062, Uganda
| | - Charles Masembe
- College of Natural Sciences, Makerere University, P.O. Box 7062, Kampala, Kampala, Uganda
| | - Pam D Luka
- National Veterinary Research Institute, Vom, Nigeria
| |
Collapse
|
7
|
Penrith ML, Kivaria FM. One hundred years of African swine fever in Africa: where have we been, where are we now, where are we going? Transbound Emerg Dis 2022; 69:e1179-e1200. [PMID: 35104041 DOI: 10.1111/tbed.14466] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/26/2022] [Accepted: 01/27/2022] [Indexed: 11/26/2022]
Abstract
One hundred years have passed since the first paper on African swine fever (ASF) was published by Montgomery in 1921. With no vaccine, ineffectiveness of prevention and control measures, and lack of common interest in eradicating the disease, ASF has proven to be one of the most devastating diseases because of its significant sanitary and socioeconomic consequences. The rapid spread of the disease on the European and Asian continents and its recent appearance in the Caribbean puts all countries at great risk because of global trade. The incidence of ASF has also increased on the African continent over the last few decades, extending its distribution far beyond the area in which the ancient sylvatic cycle is present with its complex epidemiological transmission pathways involving virus reservoirs in ticks and wild African Suidae. Both in that area and elsewhere, efficient transmission by infected domestic pigs and virus resistance in infected animal products and fomites mean that human driven factors along the pig value chain are the dominant impediments for its prevention, control, and eradication. Control efforts in Africa are furthermore hampered by the lack of information about the size and location of the fast-growing pig population, particularly in the dynamic smallholder sector that constitutes up to 90% of pig production in the region. A vaccine that will be both affordable and effective against multiple genotypes of the virus is not a short-term reality. Therefore, a strategy for management of ASF in sub-Saharan Africa is needed to provide a roadmap for the way forward for the continent. This review explores the progression of ASF and our knowledge of it through research over a century in Africa, our current understanding of ASF, and what must be done going forwards to improve the African situation and contribute to global prevention and control. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Mary Louise Penrith
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - Fredrick Mathias Kivaria
- Food and Agriculture Organization of the UN, Block P, Level 3, United Nations Complex, UN Avenue, Gigiri, Nairobi, PO Box: 30470, GPO, Nairobi, 00100, Kenya
| |
Collapse
|
8
|
A systematic review of genotypes and serogroups of African swine fever virus. Virus Genes 2022; 58:77-87. [PMID: 35061204 PMCID: PMC8778497 DOI: 10.1007/s11262-021-01879-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Accepted: 11/20/2021] [Indexed: 11/04/2022]
Abstract
African swine fever virus (ASFV) is the causative agent of African swine fever (ASF). The virus causes an acute highly hemorrhagic disease in domestic pigs, with high mortality. Although the overall genome mutation rate of ASFV, a large DNA virus, is relatively low, ASFV exhibits genetic and antigenic diversity. ASFV can be classified into 24 genotypes on the basis of the B646L gene. Cross-protected ASFV strains can be divided into eight serogroups on the basis of antibody-mediated hemadsorption inhibition. Here, we review research progress on ASFV genotyping and serogrouping, and explain how this information assists in the rapid identification of virus origin during ASF outbreaks and will aid in the development of ASF vaccines.
Collapse
|
9
|
Seroprevalence and Risk Factors of Crimean-Congo Hemorrhagic Fever in Cattle of Smallholder Farmers in Central Malawi. Pathogens 2021; 10:pathogens10121613. [PMID: 34959568 PMCID: PMC8709441 DOI: 10.3390/pathogens10121613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 12/07/2021] [Accepted: 12/07/2021] [Indexed: 11/29/2022] Open
Abstract
Crimean-Congo hemorrhagic fever virus (CCHFV) is endemic in Africa, Asia, and Eastern Europe where it circulates among animals and ticks causing sporadic outbreaks in humans. Although CCHF is endemic in sub-Saharan Africa, epidemiological information is lacking in many countries, including Malawi. To assess the risk of CCHF in Malawi, we conducted an epidemiological study in cattle reared by smallholder livestock farmers in central Malawi. A cross-sectional study was conducted in April 2020 involving seven districts, four from Kasungu and three from Lilongwe Agriculture Development Divisions. A structured questionnaire was administered to farmers to obtain demographic, animal management, and ecological risk factors data. Sera were collected from randomly selected cattle and screened for CCHF virus (CCHFV) specific antibodies using a commercial ELISA kit. Ticks were collected from cattle and classified morphologically to species level. An overall CCHFV seropositivity rate of 46.9% (n = 416; 95% CI: 42.0–51.8%) was observed. The seropositivity was significantly associated with the age of cattle (p < 0.001), sex (p < 0.001), presence of ticks in herds (p = 0.01), district (p = 0.025), and type of grazing lands (p = 0.013). Five species of ticks were identified, including Hyalomma truncatum, a known vector of CCHFV. Ticks of the species Hyalomma truncatum were not detected in two districts with the highest seroprevalence for CCHF and vector competency must be further explored in the study area. To our knowledge, this is the first report of serologic evidence of the presence of CCHV among smallholder cattle in central Malawi. This study emphasizes the need for continued monitoring of CCHFV infection among livestock, ticks, and humans for the development of data-based risk mitigation strategies.
Collapse
|
10
|
Njau EP, Machuka EM, Cleaveland S, Shirima GM, Kusiluka LJ, Okoth EA, Pelle R. African Swine Fever Virus (ASFV): Biology, Genomics and Genotypes Circulating in Sub-Saharan Africa. Viruses 2021; 13:2285. [PMID: 34835091 PMCID: PMC8623397 DOI: 10.3390/v13112285] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 10/17/2021] [Accepted: 11/03/2021] [Indexed: 12/22/2022] Open
Abstract
African swine fever (ASF) is a highly infectious and fatal haemorrhagic disease of pigs that is caused by a complex DNA virus of the genus Asfivirus and Asfarviridae African suids family. The disease is among the most devastating pig diseases worldwide including Africa. Although the disease was first reported in the 19th century, it has continued to spread in Africa and other parts of the world. Globally, the rising demand for pork and concomitant increase in transboundary movements of pigs and pork products is likely to increase the risk of transmission and spread of ASF and pose a major challenge to the pig industry. Different genotypes of the ASF virus (ASFV) with varying virulence have been associated with different outbreaks in several countries in sub-Saharan Africa (SSA) and worldwide, and understanding genotype circulation will be important for ASF prevention and control strategies. ASFV genotypes unique to Africa have also been reported in SSA. This review briefly recounts the biology, genomics and genotyping of ASFV and provides an account of the different genotypes circulating in SSA. The review also highlights prevention, control and progress on vaccine development and identifies gaps in knowledge of ASFV genotype circulation in SSA that need to be addressed.
Collapse
Affiliation(s)
- Emma P. Njau
- Biosciences Eastern and Central Africa—International Livestock Research Institute Hub, P.O. Box 30709, Nairobi 00100, Kenya; (E.M.M.); (E.A.O.); (R.P.)
- Nelson Mandela African Institution of Science and Technology, Arusha P.O. Box 447, Tanzania; (S.C.); (G.M.S.); (L.J.K.)
- College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Chuo Kikuu, Morogoro P.O. Box 3015, Tanzania
| | - Eunice M. Machuka
- Biosciences Eastern and Central Africa—International Livestock Research Institute Hub, P.O. Box 30709, Nairobi 00100, Kenya; (E.M.M.); (E.A.O.); (R.P.)
| | - Sarah Cleaveland
- Nelson Mandela African Institution of Science and Technology, Arusha P.O. Box 447, Tanzania; (S.C.); (G.M.S.); (L.J.K.)
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Gabriel M. Shirima
- Nelson Mandela African Institution of Science and Technology, Arusha P.O. Box 447, Tanzania; (S.C.); (G.M.S.); (L.J.K.)
| | - Lughano J. Kusiluka
- Nelson Mandela African Institution of Science and Technology, Arusha P.O. Box 447, Tanzania; (S.C.); (G.M.S.); (L.J.K.)
- College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Chuo Kikuu, Morogoro P.O. Box 3015, Tanzania
- Mzumbe University, Morogoro P.O. Box 1, Tanzania
| | - Edward A. Okoth
- Biosciences Eastern and Central Africa—International Livestock Research Institute Hub, P.O. Box 30709, Nairobi 00100, Kenya; (E.M.M.); (E.A.O.); (R.P.)
| | - Roger Pelle
- Biosciences Eastern and Central Africa—International Livestock Research Institute Hub, P.O. Box 30709, Nairobi 00100, Kenya; (E.M.M.); (E.A.O.); (R.P.)
| |
Collapse
|
11
|
Harima H, Okuya K, Kajihara M, Ogawa H, Simulundu E, Bwalya E, Qiu Y, Mori-Kajihara A, Munyeme M, Sakoda Y, Saito T, Hang'ombe BM, Sawa H, Mweene AS, Takada A. Serological and molecular epidemiological study on swine influenza in Zambia. Transbound Emerg Dis 2021; 69:e931-e943. [PMID: 34724353 DOI: 10.1111/tbed.14373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 10/05/2021] [Accepted: 10/24/2021] [Indexed: 11/28/2022]
Abstract
Influenza A viruses (IAVs) cause highly contagious respiratory diseases in humans and animals. In 2009, a swine-origin pandemic H1N1 IAV, designated A(H1N1)pdm09 virus, spread worldwide, and has since frequently been introduced into pig populations. Since novel reassortant IAVs with pandemic potential may emerge in pigs, surveillance for IAV in pigs is therefore necessary not only for the pig industry but also for public health. However, epidemiological information on IAV infection of pigs in Africa remains sparse. In this study, we collected 246 serum and 605 nasal swab samples from pigs in Zambia during the years 2011-2018. Serological analyses revealed that 49% and 32% of the sera collected in 2011 were positive for hemagglutination-inhibition (HI) and neutralizing antibodies against A(H1N1)pdm09 virus, respectively, whereas less than 5.3% of sera collected during the following period (2012-2018) were positive in both serological tests. The positive rate and the neutralization titres to A(H1N1)pdm09 virus were higher than those to classical swine H1N1 and H1N2 IAVs. On the other hand, the positive rate for swine H3N2 IAV was very low in the pig population in Zambia in 2011-2018 (5.3% and 0% in HI and neutralization tests, respectively). From nasal swab samples, we isolated one H3N2 and eight H1N1 IAV strains with an isolation rate of 1.5%. Phylogenetic analyses of all eight gene segments revealed that the isolated IAVs were closely related to human IAV strains belonging to A(H1N1)pdm09 and seasonal H3N2 lineages. Our findings indicate that reverse zoonotic transmission from humans to pigs occurred during the study period in Zambia and highlight the need for continued surveillance to monitor the status of IAVs circulating in swine populations in Africa.
Collapse
Affiliation(s)
- Hayato Harima
- Hokudai Center for Zoonosis Control in Zambia, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Kosuke Okuya
- Division of Global Epidemiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Masahiro Kajihara
- Division of Global Epidemiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Hirohito Ogawa
- Department of Virology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Edgar Simulundu
- Department of Disease Control, School of Veterinary Medicine, the University of Zambia, Lusaka, Zambia.,Macha Research Trust, Choma, Zambia
| | - Eugene Bwalya
- Department of Clinical Studies, School of Veterinary Medicine, the University of Zambia, Lusaka, Zambia
| | - Yongjin Qiu
- Hokudai Center for Zoonosis Control in Zambia, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Akina Mori-Kajihara
- Division of Global Epidemiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Musso Munyeme
- Department of Disease Control, School of Veterinary Medicine, the University of Zambia, Lusaka, Zambia
| | - Yoshihiro Sakoda
- Laboratory of Microbiology, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.,International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Takehiko Saito
- Department of Animal Disease Control and Prevention, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
| | - Bernard M Hang'ombe
- Department of Para-clinical Studies, School of Veterinary Medicine, the University of Zambia, Lusaka, Zambia.,Africa Center of Excellence for Infectious Diseases of Humans and Animals, the University of Zambia, Lusaka, Zambia
| | - Hirofumi Sawa
- Department of Disease Control, School of Veterinary Medicine, the University of Zambia, Lusaka, Zambia.,International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan.,Africa Center of Excellence for Infectious Diseases of Humans and Animals, the University of Zambia, Lusaka, Zambia.,Division of Molecular Pathobiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan.,One Health Research Center, Hokkaido University, Sapporo, Japan.,Global Virus Network, Baltimore, Maryland, USA
| | - Aaron S Mweene
- Department of Disease Control, School of Veterinary Medicine, the University of Zambia, Lusaka, Zambia.,Africa Center of Excellence for Infectious Diseases of Humans and Animals, the University of Zambia, Lusaka, Zambia
| | - Ayato Takada
- Division of Global Epidemiology, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan.,Department of Disease Control, School of Veterinary Medicine, the University of Zambia, Lusaka, Zambia.,International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan.,Africa Center of Excellence for Infectious Diseases of Humans and Animals, the University of Zambia, Lusaka, Zambia
| |
Collapse
|
12
|
Njau EP, Domelevo Entfellner JB, Machuka EM, Bochere EN, Cleaveland S, Shirima GM, Kusiluka LJ, Upton C, Bishop RP, Pelle R, Okoth EA. The first genotype II African swine fever virus isolated in Africa provides insight into the current Eurasian pandemic. Sci Rep 2021; 11:13081. [PMID: 34158551 PMCID: PMC8219699 DOI: 10.1038/s41598-021-92593-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 05/24/2021] [Indexed: 02/05/2023] Open
Abstract
African swine fever (ASF) caused by the African swine fever virus (ASFV) is ranked by OIE as the most important source of mortality in domestic pigs globally and is indigenous to African wild suids and soft ticks. Despite two ASFV genotypes causing economically devastating epidemics outside the continent since 1961, there have been no genome-level analyses of virus evolution in Africa. The virus was recently transported from south-eastern Africa to Georgia in 2007 and has subsequently spread to Russia, eastern Europe, China, and south-east Asia with devastating socioeconomic consequences. To date, two of the 24 currently described ASFV genotypes defined by sequencing of the p72 gene, namely genotype I and II, have been reported outside Africa, with genotype II being responsible for the ongoing pig pandemic. Multiple complete genotype II genome sequences have been reported from European, Russian and Chinese virus isolates but no complete genome sequences have yet been reported from Africa. We report herein the complete genome of a Tanzanian genotype II isolate, Tanzania/Rukwa/2017/1, collected in 2017 and determined using an Illumina short read strategy. The Tanzania/Rukwa/2017/1 sequence is 183,186 bp in length (in a single contig) and contains 188 open reading frames. Considering only un-gapped sites in the pairwise alignments, the new sequence has 99.961% identity with the updated Georgia 2007/1 reference isolate (FR682468.2), 99.960% identity with Polish isolate Pol16_29413_o23 (MG939586) and 99.957% identity with Chinese isolate ASFV-wbBS01 (MK645909.1). This represents 73 single nucleotide polymorphisms (SNPs) relative to the Polish isolate and 78 SNPs with the Chinese genome. Phylogenetic analysis indicated that Tanzania/Rukwa/2017/1 clusters most closely with Georgia 2007/1. The majority of the differences between Tanzania/Rukwa/2017/1 and Georgia 2007/1 genotype II genomes are insertions/deletions (indels) as is typical for ASFV. The indels included differences in the length and copy number of the terminal multicopy gene families, MGF 360 and 110. The Rukwa2017/1 sequence is the first complete genotype II genome from a precisely mapped locality in Africa, since the exact origin of Georgia2007/1 is unknown. It therefore provides baseline information for future analyses of the diversity and phylogeography of this globally important genetic sub-group of ASF viruses.
Collapse
Affiliation(s)
- Emma P Njau
- Biosciences Eastern and Central Africa-International Livestock Research Institute Hub, Nairobi, Kenya.
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania.
- Sokoine University of Agriculture, P. O. Box 3019, Morogoro, Tanzania.
| | | | - Eunice M Machuka
- Biosciences Eastern and Central Africa-International Livestock Research Institute Hub, Nairobi, Kenya
| | - Edwina N Bochere
- Biosciences Eastern and Central Africa-International Livestock Research Institute Hub, Nairobi, Kenya
| | - Sarah Cleaveland
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Gabriel M Shirima
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Lughano J Kusiluka
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
- Mzumbe University, Morogoro, Tanzania
| | - Chris Upton
- Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8W 3P6, Canada
| | - Richard P Bishop
- Biosciences Eastern and Central Africa-International Livestock Research Institute Hub, Nairobi, Kenya
| | - Roger Pelle
- Biosciences Eastern and Central Africa-International Livestock Research Institute Hub, Nairobi, Kenya
| | - Edward A Okoth
- Biosciences Eastern and Central Africa-International Livestock Research Institute Hub, Nairobi, Kenya
| |
Collapse
|
13
|
Hakizimana JN, Yona C, Kamana O, Nauwynck H, Misinzo G. African Swine Fever Virus Circulation between Tanzania and Neighboring Countries: A Systematic Review and Meta-Analysis. Viruses 2021; 13:v13020306. [PMID: 33672090 PMCID: PMC7919636 DOI: 10.3390/v13020306] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/08/2021] [Accepted: 02/09/2021] [Indexed: 11/16/2022] Open
Abstract
For over 100 years after the description of the first case of African swine fever (ASF) in Kenya, ASF virus (ASFV) cross-border spread in eastern and southern Africa has not been fully investigated. In this manuscript, we reviewed systematically the available literature on molecular epidemiology of ASF in Tanzania and its eight neighboring countries in order to establish the transmission dynamics of ASFV between these countries. Data were retrieved from World Animal Health Information System (WAHIS), Google Scholar, PubMed, Scopus, and CrossRef databases, using the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and reviewed to document ASF outbreaks and ASFV genotypes distribution. Using phylogeographic approach applied to ASFV p72 sequence dataset, the evolutionary history and the dispersal pattern of the ASFV strains were assessed. From 2005 to 2019, a total of 1588 ASF outbreaks affecting 341,742 cases that led to 302,739 domestic pig deaths were reported. The case fatality rates (CFR) varied from 15.41% to 98.95% with an overall CFR of 88.58%. Fifteen different p72 ASFV genotypes were reported and the time to the most recent common ancestor (TMRCA) for ASFV strains dated back to 1652.233 (1626.473, 1667.735) with an evolutionary rate of 4.805 × 10−5 (2.5857 × 10−5, 9.7789 × 10−5). Phylogeographic dispersal analysis revealed several transboundary spread events of ASFV strains between these countries. These results suggest persistent circulation of ASFV in these countries and advocate for more research to improve our understanding of the transmission dynamics of the virus and for a regional approach to mitigate the spread of ASFV.
Collapse
Affiliation(s)
- Jean N. Hakizimana
- SACIDS Africa Centre of Excellence for Infectious Diseases, SACIDS Foundation for One Health, Sokoine University of Agriculture, P.O. Box 3019 Morogoro, Tanzania;
- Department of Veterinary Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, P.O. Box 3019 Morogoro, Tanzania
- Correspondence: (J.N.H.); (G.M.)
| | - Clara Yona
- SACIDS Africa Centre of Excellence for Infectious Diseases, SACIDS Foundation for One Health, Sokoine University of Agriculture, P.O. Box 3019 Morogoro, Tanzania;
- Department of Biosciences, Solomon Mahlangu College of Science and Education, Sokoine University of Agriculture, P.O. Box 3019 Morogoro, Tanzania
| | - Olivier Kamana
- Department of Applied Research and Development and Foresight Incubation, National Industrial Research and Development Agency, P.O. Box 273 Kigali, Rwanda;
| | - Hans Nauwynck
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium;
| | - Gerald Misinzo
- SACIDS Africa Centre of Excellence for Infectious Diseases, SACIDS Foundation for One Health, Sokoine University of Agriculture, P.O. Box 3019 Morogoro, Tanzania;
- Department of Veterinary Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, P.O. Box 3019 Morogoro, Tanzania
- Correspondence: (J.N.H.); (G.M.)
| |
Collapse
|
14
|
Bosch-Camós L, López E, Navas MJ, Pina-Pedrero S, Accensi F, Correa-Fiz F, Park C, Carrascal M, Domínguez J, Salas ML, Nikolin V, Collado J, Rodríguez F. Identification of Promiscuous African Swine Fever Virus T-Cell Determinants Using a Multiple Technical Approach. Vaccines (Basel) 2021; 9:29. [PMID: 33430316 PMCID: PMC7825812 DOI: 10.3390/vaccines9010029] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 01/02/2021] [Accepted: 01/04/2021] [Indexed: 11/23/2022] Open
Abstract
The development of subunit vaccines against African swine fever (ASF) is mainly hindered by the lack of knowledge regarding the specific ASF virus (ASFV) antigens involved in protection. As a good example, the identity of ASFV-specific CD8+ T-cell determinants remains largely unknown, despite their protective role being established a long time ago. Aiming to identify them, we implemented the IFNγ ELISpot as readout assay, using as effector cells peripheral blood mononuclear cells (PBMCs) from pigs surviving experimental challenge with Georgia2007/1. As stimuli for the ELISpot, ASFV-specific peptides or full-length proteins identified by three complementary strategies were used. In silico prediction of specific CD8+ T-cell epitopes allowed identifying a 19-mer peptide from MGF100-1L, as frequently recognized by surviving pigs. Complementarily, the repertoire of SLA I-bound peptides identified in ASFV-infected porcine alveolar macrophages (PAMs), allowed the characterization of five additional SLA I-restricted ASFV-specific epitopes. Finally, in vitro stimulation studies using fibroblasts transfected with plasmids encoding full-length ASFV proteins, led to the identification of MGF505-7R, A238L and MGF100-1L as promiscuously recognized antigens. Interestingly, each one of these proteins contain individual peptides recognized by surviving pigs. Identification of the same ASFV determinants by means of such different approaches reinforce the results presented here.
Collapse
Affiliation(s)
- Laia Bosch-Camós
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain; (L.B.-C.); (E.L.); (M.J.N.); (S.P.-P.); (F.C.-F.)
- OIE Collaborating Centre for the Research and Control of Emerging and Re-Emerging Swine Diseases in Europe (IRTA-CReSA), 08193 Bellaterra, Spain;
| | - Elisabet López
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain; (L.B.-C.); (E.L.); (M.J.N.); (S.P.-P.); (F.C.-F.)
- OIE Collaborating Centre for the Research and Control of Emerging and Re-Emerging Swine Diseases in Europe (IRTA-CReSA), 08193 Bellaterra, Spain;
| | - María Jesús Navas
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain; (L.B.-C.); (E.L.); (M.J.N.); (S.P.-P.); (F.C.-F.)
- OIE Collaborating Centre for the Research and Control of Emerging and Re-Emerging Swine Diseases in Europe (IRTA-CReSA), 08193 Bellaterra, Spain;
| | - Sonia Pina-Pedrero
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain; (L.B.-C.); (E.L.); (M.J.N.); (S.P.-P.); (F.C.-F.)
- OIE Collaborating Centre for the Research and Control of Emerging and Re-Emerging Swine Diseases in Europe (IRTA-CReSA), 08193 Bellaterra, Spain;
| | - Francesc Accensi
- OIE Collaborating Centre for the Research and Control of Emerging and Re-Emerging Swine Diseases in Europe (IRTA-CReSA), 08193 Bellaterra, Spain;
- UAB, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
- Departament de Sanitat i Anatomia Animals, Facultat de Veterinària, UAB, 08193 Bellaterra, Spain
| | - Florencia Correa-Fiz
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain; (L.B.-C.); (E.L.); (M.J.N.); (S.P.-P.); (F.C.-F.)
- OIE Collaborating Centre for the Research and Control of Emerging and Re-Emerging Swine Diseases in Europe (IRTA-CReSA), 08193 Bellaterra, Spain;
| | - Chankyu Park
- Department of Stem Cells and Regenerative Biology, Konkuk University, Seoul 05029, Korea;
| | - Montserrat Carrascal
- Instituto de Investigaciones Biomédicas de Barcelona-Unidad de Espectrometría de Masas Biológica y Proteómica, Consejo Superior de Investigaciones Científicas (CSIC), 08193 Bellaterra, Spain;
| | - Javier Domínguez
- Departamento de Biotecnología, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 28049 Madrid, Spain;
| | - Maria Luisa Salas
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autònoma de Madrid, 28049 Madrid, Spain;
| | - Veljko Nikolin
- Boehringer Ingelheim Veterinary Research Center (BIVRC) GmbH & Co. KG, 30559 Hannover, Germany;
| | - Javier Collado
- Departament de Biologia Cel·lular, Fisiologia i Immunologia, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain;
| | - Fernando Rodríguez
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain; (L.B.-C.); (E.L.); (M.J.N.); (S.P.-P.); (F.C.-F.)
- OIE Collaborating Centre for the Research and Control of Emerging and Re-Emerging Swine Diseases in Europe (IRTA-CReSA), 08193 Bellaterra, Spain;
| |
Collapse
|
15
|
Lopez E, van Heerden J, Bosch-Camós L, Accensi F, Navas MJ, López-Monteagudo P, Argilaguet J, Gallardo C, Pina-Pedrero S, Salas ML, Salt J, Rodriguez F. Live Attenuated African Swine Fever Viruses as Ideal Tools to Dissect the Mechanisms Involved in Cross-Protection. Viruses 2020; 12:v12121474. [PMID: 33371460 PMCID: PMC7767464 DOI: 10.3390/v12121474] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 12/03/2022] Open
Abstract
African swine fever (ASF) has become the major threat for the global swine industry. Furthermore, the epidemiological situation of African swine fever virus (ASFV) in some endemic regions of Sub-Saharan Africa is worse than ever, with multiple virus strains and genotypes currently circulating in a given area. Despite the recent advances on ASF vaccine development, there are no commercial vaccines yet, and most of the promising vaccine prototypes available today have been specifically designed to fight the genotype II strains currently circulating in Europe, Asia, and Oceania. Previous results from our laboratory have demonstrated the ability of BA71∆CD2, a recombinant LAV lacking CD2v, to confer protection against homologous (BA71) and heterologous genotype I (E75) and genotype II (Georgia2007/01) ASFV strains, both belonging to same clade (clade C). Here, we extend these results using BA71∆CD2 as a tool trying to understand ASFV cross-protection, using phylogenetically distant ASFV strains. We first observed that five out of six (83.3%) of the pigs immunized once with 106 PFU of BA71∆CD2 survived the tick-bite challenge using Ornithodoros sp. soft ticks naturally infected with RSA/11/2017 strain (genotype XIX, clade D). Second, only two out of six (33.3%) survived the challenge with Ken06.Bus (genotype IX, clade A), which is phylogenetically more distant to BA71∆CD2 than the RSA/11/2017 strain. On the other hand, homologous prime-boosting with BA71∆CD2 only improved the survival rate to 50% after Ken06.Bus challenge, all suffering mild ASF-compatible clinical signs, while 100% of the pigs immunized with BA71∆CD2 and boosted with the parental BA71 virulent strain survived the lethal challenge with Ken06.Bus, without almost no clinical signs of the disease. Our results confirm that cross-protection is a multifactorial phenomenon that not only depends on sequence similarity. We believe that understanding this complex phenomenon will be useful for designing future vaccines for ASF-endemic areas.
Collapse
Affiliation(s)
- Elisabeth Lopez
- IRTA, Centre de Recerca en Sanitat Animal (IRTA-CReSA), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain; (E.L.); (L.B.-C.); (F.A.); (M.J.N.); (P.L.-M.); (J.A.); (S.P.-P.)
| | - Juanita van Heerden
- Agricultural Research Council-Onderstepoort Veterinary Research, Pretoria 0110, South Africa;
| | - Laia Bosch-Camós
- IRTA, Centre de Recerca en Sanitat Animal (IRTA-CReSA), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain; (E.L.); (L.B.-C.); (F.A.); (M.J.N.); (P.L.-M.); (J.A.); (S.P.-P.)
| | - Francesc Accensi
- IRTA, Centre de Recerca en Sanitat Animal (IRTA-CReSA), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain; (E.L.); (L.B.-C.); (F.A.); (M.J.N.); (P.L.-M.); (J.A.); (S.P.-P.)
- Departament de Sanitat i d’Anatomia Animals, Facultat de Veterinària, UAB, 08193 Bellaterra, Spain
| | - Maria Jesus Navas
- IRTA, Centre de Recerca en Sanitat Animal (IRTA-CReSA), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain; (E.L.); (L.B.-C.); (F.A.); (M.J.N.); (P.L.-M.); (J.A.); (S.P.-P.)
| | - Paula López-Monteagudo
- IRTA, Centre de Recerca en Sanitat Animal (IRTA-CReSA), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain; (E.L.); (L.B.-C.); (F.A.); (M.J.N.); (P.L.-M.); (J.A.); (S.P.-P.)
| | - Jordi Argilaguet
- IRTA, Centre de Recerca en Sanitat Animal (IRTA-CReSA), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain; (E.L.); (L.B.-C.); (F.A.); (M.J.N.); (P.L.-M.); (J.A.); (S.P.-P.)
| | - Carmina Gallardo
- Centro de Investigación en Sanidad Animal (CISA-INIA), 28130 Madrid, Spain;
| | - Sonia Pina-Pedrero
- IRTA, Centre de Recerca en Sanitat Animal (IRTA-CReSA), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain; (E.L.); (L.B.-C.); (F.A.); (M.J.N.); (P.L.-M.); (J.A.); (S.P.-P.)
| | - Maria Luisa Salas
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autònoma de Madrid, 28049 Madrid, Spain;
| | - Jeremy Salt
- GALVmed, Doherty Building, Pentlands Science Park, Bush Loan, Penicuik Edinburgh EH26 0PZ, UK;
| | - Fernando Rodriguez
- IRTA, Centre de Recerca en Sanitat Animal (IRTA-CReSA), Campus de la Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain; (E.L.); (L.B.-C.); (F.A.); (M.J.N.); (P.L.-M.); (J.A.); (S.P.-P.)
- Correspondence:
| |
Collapse
|
16
|
Hakizimana JN, Nyabongo L, Ntirandekura JB, Yona C, Ntakirutimana D, Kamana O, Nauwynck H, Misinzo G. Genetic Analysis of African Swine Fever Virus From the 2018 Outbreak in South-Eastern Burundi. Front Vet Sci 2020; 7:578474. [PMID: 33251264 PMCID: PMC7674587 DOI: 10.3389/fvets.2020.578474] [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: 06/30/2020] [Accepted: 10/01/2020] [Indexed: 11/24/2022] Open
Abstract
African swine fever (ASF) is a contagious viral disease that causes high mortality, approaching 100%, in domestic pigs and wild boars. The disease has neither a cure nor a vaccine, and it is caused by an ASF virus (ASFV), the only member of the family Asfarviridae, genus Asfivirus, and the only known DNA arbovirus. Twenty-four genotypes of ASFV have been described to date, and all of them have been described in Africa. ASF is endemic in Burundi, and several outbreaks have been reported in the country; the disease continues to economically impact on small-scale farmers. This study aimed at genetic characterization of ASFV that caused an ASF outbreak in the Rutana region, Burundi, in the year 2018. Tissue samples from domestic pigs that died as a result of a severe hemorrhagic disease were collected in order to confirm the disease using polymerase chain reaction (PCR) and to conduct partial genome sequencing. Nucleotide sequences were obtained for the B646L (p72) gene, the intergenic fragment between the I73R and I329L genes, and the central variable region (CVR) of the B602L gene. Phylogenetic analysis of the Burundian 2018 ASFV grouped the virus within B646L (p72) genotype X and clustered together with those reported during the 1984 and 1990 outbreaks in Burundi with high nucleotide identity to some ASFV strains previously reported in neighboring East African countries, indicating a regional distribution of this ASFV genotype. Analysis of the intergenic fragment between I73R and I329L genes showed that the Burundian 2018 ASFV described in this study lacked a 32–base pair (bp) fragment present in the reference genotype X strain, Kenya 1950. In addition, the strain described in this study had the signature AAABNAABA at the CVR (B602L) gene and showed 100% amino acid sequence identity to viruses responsible for recent ASF outbreaks in the region. The virus described in this study showed high genetic similarities with ASFV strains previously described in domestic pigs, wild suids, and soft ticks in East African countries, indicating a possible common wild source and continuous circulation in domestic pigs in the region.
Collapse
Affiliation(s)
- Jean N Hakizimana
- SACIDS Africa Centre of Excellence for Infectious Diseases, SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania.,Department of Veterinary Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Lionel Nyabongo
- National Veterinary Laboratory of Burundi, Bujumbura, Burundi
| | - Jean B Ntirandekura
- Department of Animal Health and Productions, University of Burundi, Bujumbura, Burundi
| | - Clara Yona
- SACIDS Africa Centre of Excellence for Infectious Diseases, SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania.,Department of Biosciences, Solomon Mahlangu College of Science and Education, Sokoine University of Agriculture, Morogoro, Tanzania
| | | | - Olivier Kamana
- Department of Food Science and Technology, College of Agriculture, Animal Sciences and Veterinary Medicine, University of Rwanda, Busogo, Rwanda.,Department of Applied Research and Development and Foresight Incubation, National Industrial Research and Development Agency, Kigali, Rwanda
| | - Hans Nauwynck
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Gerald Misinzo
- SACIDS Africa Centre of Excellence for Infectious Diseases, SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania.,Department of Veterinary Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
| |
Collapse
|
17
|
Yona CM, Vanhee M, Simulundu E, Makange M, Nauwynck HJ, Misinzo G. Persistent domestic circulation of African swine fever virus in Tanzania, 2015-2017. BMC Vet Res 2020; 16:369. [PMID: 33004025 PMCID: PMC7528248 DOI: 10.1186/s12917-020-02588-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Accepted: 09/23/2020] [Indexed: 11/12/2022] Open
Abstract
Background African swine fever (ASF) is a highly fatal viral hemorrhagic disease of domestic pigs that threatens livelihoods and food security. In Africa, ASF virus (ASFV) circulates in sylvatic (transmission between warthogs and soft argasid ticks) and domestic (transmission between domestic pigs) cycles, with outbreaks resulting from ASFV spill-over from sylvatic cycle. A number of outbreaks were reported in different parts of Tanzania between 2015 and 2017. The present study investigated ASFV transmission patterns through viral DNA sequencing and phylogenetic analysis. A total of 3120 tissue samples were collected from 2396 domestic pigs during outbreaks at different locations in Tanzania between 2015 and 2017. Partial sequencing of the B646L (p72) gene was conducted for diagnostic confirmation and molecular characterization of ASFV. Phylogenetic analysis to study the relatedness of current ASFV with those that caused previous outbreaks in Tanzania and representatives of all known 24 ASFV was performed using the Maximum Composite Likelihood model with 1000 bootstrap replications in MEGA 6.0. Results ASFV was confirmed to cause disease in sampled domestic pigs. ASFV genotypes II, IX, and X were detected from reported outbreaks in 2015–2017. The current ASFV isolates were similar to those recently documented in the previous studies in Tanzania. The similarities of these isolates suggests for continuous circulation of ASFV with virus maintenance within the domestic pigs. Conclusions Genetic analysis confirmed the circulation of ASFV genotypes II, IX, and X by partial B646L (p72) gene sequencing. The similarities of current isolates to previously isolated Tanzanian isolates and pattern of disease spread suggest for continuous circulation of ASF with virus’ maintenance in the domestic pigs. Although certain viral genotypes seem to be geographically restricted into certain zones within Tanzania, genotype II seems to expand its geographical range northwards with the likelihood of spreading to other states of the East African Community. The spread of ASFV is due to breach of quarantine and transportation of infected pigs via major highways. Appropriate control measures including zoosanitary measures and quarantine enforcement are recommended to prevent ASF domestic circulation in Tanzania.
Collapse
Affiliation(s)
- Clara M Yona
- SACIDS Foundation for One Health, SACIDS Africa Centre of Excellence for Infectious Diseases, Sokoine University of Agriculture, Morogoro, Tanzania.,Department of Biosciences, Solomon Mahlangu College of Science and Education, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Merijn Vanhee
- Department of Biotechnology, VIVES University College, Roeselare, Belgium
| | - Edgar Simulundu
- Department of Disease Control, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Mariam Makange
- Department of Veterinary Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Hans J Nauwynck
- Laboratory of Virology, Faculty of Veterinary Medicine, University of Gent, Merelbeke, Belgium
| | - Gerald Misinzo
- SACIDS Foundation for One Health, SACIDS Africa Centre of Excellence for Infectious Diseases, Sokoine University of Agriculture, Morogoro, Tanzania. .,Department of Veterinary Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania.
| |
Collapse
|
18
|
Chambaro HM, Sasaki M, Simulundu E, Silwamba I, Sinkala Y, Gonzalez G, Squarre D, Fandamu P, Lubaba CH, Munyeme M, Maseko A, Chimvwele C, Mataa L, Mooya LE, Mukubesa AN, Harima H, Samui KL, Munang’andu HM, Simuunza M, Nalubamba KS, Qiu Y, Carr MJ, Hall WW, Eshita Y, Sawa H, Orba Y. Co-Circulation of Multiple Serotypes of Bluetongue Virus in Zambia. Viruses 2020; 12:v12090963. [PMID: 32878170 PMCID: PMC7552058 DOI: 10.3390/v12090963] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 08/25/2020] [Accepted: 08/28/2020] [Indexed: 11/16/2022] Open
Abstract
Bluetongue (BT) is an arthropod-borne viral disease of ruminants with serious trade and socio-economic implications. Although the disease has been reported in a number of countries in sub-Saharan Africa, there is currently no information on circulating serotypes and disease distribution in Zambia. Following surveillance for BT in domestic and wild ruminants in Zambia, BT virus (BTV) nucleic acid and antibodies were detected in eight of the 10 provinces of the country. About 40% (87/215) of pooled blood samples from cattle and goats were positive for BTV nucleic acid, while one hartebeest pool (1/43) was positive among wildlife samples. Sequence analysis of segment 2 revealed presence of serotypes 3, 5, 7, 12 and 15, with five nucleotypes (B, E, F, G and J) being identified. Segment 10 phylogeny showed Zambian BTV sequences clustering with Western topotype strains from South Africa, intimating likely transboundary spread of BTV in Southern Africa. Interestingly, two Zambian viruses and one isolate from Israel formed a novel clade, which we designated as Western topotype 4. The high seroprevalence (96.2%) in cattle from Lusaka and Central provinces and co-circulation of multiple serotypes showed that BT is widespread, underscoring the need for prevention and control strategies.
Collapse
Affiliation(s)
- Herman M. Chambaro
- Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan; (M.S.); (H.H.); (H.S.)
- Virology Unit, Central Veterinary Research Institute, Lusaka 10101, Zambia;
- Ministry of Fisheries and Livestock, Lusaka 10101, Zambia; (Y.S.); (P.F.); (C.H.L.); (A.M.); (C.C.); (L.M.)
- Correspondence: (H.M.C.); (E.S.); (Y.O.); Tel.: +81-80-1375-4174 (H.M.C.); +26-09-7746-9479 (E.S.); +81-11-706-5185 (Y.O.)
| | - Michihito Sasaki
- Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan; (M.S.); (H.H.); (H.S.)
| | - Edgar Simulundu
- School of Veterinary Medicine, The University of Zambia, Lusaka 10101, Zambia; (I.S.); (M.M.); (A.N.M.); (K.L.S.); (M.S.); (K.S.N.)
- Macha Research Trust, Choma 10101, Zambia
- Correspondence: (H.M.C.); (E.S.); (Y.O.); Tel.: +81-80-1375-4174 (H.M.C.); +26-09-7746-9479 (E.S.); +81-11-706-5185 (Y.O.)
| | - Isaac Silwamba
- School of Veterinary Medicine, The University of Zambia, Lusaka 10101, Zambia; (I.S.); (M.M.); (A.N.M.); (K.L.S.); (M.S.); (K.S.N.)
| | - Yona Sinkala
- Ministry of Fisheries and Livestock, Lusaka 10101, Zambia; (Y.S.); (P.F.); (C.H.L.); (A.M.); (C.C.); (L.M.)
| | - Gabriel Gonzalez
- National Virus Reference Laboratory, School of Medicine, Dublin DO4V1W8, Ireland; (G.G.); (M.J.C.); (W.W.H.)
| | - David Squarre
- The University of Edinburgh, Edinburgh EH25 9RG, Scotland, UK;
- Department of National Parks and Wildlife, Chilanga 10101, Zambia
| | - Paul Fandamu
- Ministry of Fisheries and Livestock, Lusaka 10101, Zambia; (Y.S.); (P.F.); (C.H.L.); (A.M.); (C.C.); (L.M.)
| | - Caesar H. Lubaba
- Ministry of Fisheries and Livestock, Lusaka 10101, Zambia; (Y.S.); (P.F.); (C.H.L.); (A.M.); (C.C.); (L.M.)
| | - Musso Munyeme
- School of Veterinary Medicine, The University of Zambia, Lusaka 10101, Zambia; (I.S.); (M.M.); (A.N.M.); (K.L.S.); (M.S.); (K.S.N.)
| | - Alikhadio Maseko
- Ministry of Fisheries and Livestock, Lusaka 10101, Zambia; (Y.S.); (P.F.); (C.H.L.); (A.M.); (C.C.); (L.M.)
| | - Choopa Chimvwele
- Ministry of Fisheries and Livestock, Lusaka 10101, Zambia; (Y.S.); (P.F.); (C.H.L.); (A.M.); (C.C.); (L.M.)
| | - Liywalii Mataa
- Ministry of Fisheries and Livestock, Lusaka 10101, Zambia; (Y.S.); (P.F.); (C.H.L.); (A.M.); (C.C.); (L.M.)
| | - Lynnfield E. Mooya
- Virology Unit, Central Veterinary Research Institute, Lusaka 10101, Zambia;
- Ministry of Fisheries and Livestock, Lusaka 10101, Zambia; (Y.S.); (P.F.); (C.H.L.); (A.M.); (C.C.); (L.M.)
| | - Andrew N. Mukubesa
- School of Veterinary Medicine, The University of Zambia, Lusaka 10101, Zambia; (I.S.); (M.M.); (A.N.M.); (K.L.S.); (M.S.); (K.S.N.)
| | - Hayato Harima
- Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan; (M.S.); (H.H.); (H.S.)
| | - Kenny L. Samui
- School of Veterinary Medicine, The University of Zambia, Lusaka 10101, Zambia; (I.S.); (M.M.); (A.N.M.); (K.L.S.); (M.S.); (K.S.N.)
| | - Hetron M. Munang’andu
- Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, 0454 Oslo, Norway;
| | - Martin Simuunza
- School of Veterinary Medicine, The University of Zambia, Lusaka 10101, Zambia; (I.S.); (M.M.); (A.N.M.); (K.L.S.); (M.S.); (K.S.N.)
| | - King S. Nalubamba
- School of Veterinary Medicine, The University of Zambia, Lusaka 10101, Zambia; (I.S.); (M.M.); (A.N.M.); (K.L.S.); (M.S.); (K.S.N.)
| | - Yongjin Qiu
- Hokudai Center for Zoonosis Control in Zambia, School of Veterinary Medicine, University of Zambia, Lusaka 10101, Zambia; (Y.Q.); (Y.E.)
| | - Michael J. Carr
- National Virus Reference Laboratory, School of Medicine, Dublin DO4V1W8, Ireland; (G.G.); (M.J.C.); (W.W.H.)
- International Collaboration Unit, Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan
| | - William W. Hall
- National Virus Reference Laboratory, School of Medicine, Dublin DO4V1W8, Ireland; (G.G.); (M.J.C.); (W.W.H.)
- International Collaboration Unit, Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan
- Global Virus Network, Baltimore, MD 21201, USA
| | - Yuki Eshita
- Hokudai Center for Zoonosis Control in Zambia, School of Veterinary Medicine, University of Zambia, Lusaka 10101, Zambia; (Y.Q.); (Y.E.)
| | - Hirofumi Sawa
- Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan; (M.S.); (H.H.); (H.S.)
- International Collaboration Unit, Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan
- Global Virus Network, Baltimore, MD 21201, USA
| | - Yasuko Orba
- Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan; (M.S.); (H.H.); (H.S.)
- International Collaboration Unit, Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan
- Correspondence: (H.M.C.); (E.S.); (Y.O.); Tel.: +81-80-1375-4174 (H.M.C.); +26-09-7746-9479 (E.S.); +81-11-706-5185 (Y.O.)
| |
Collapse
|
19
|
Hakizimana JN, Kamwendo G, Chulu JLC, Kamana O, Nauwynck HJ, Misinzo G. Genetic profile of African swine fever virus responsible for the 2019 outbreak in northern Malawi. BMC Vet Res 2020; 16:316. [PMID: 32859205 PMCID: PMC7455991 DOI: 10.1186/s12917-020-02536-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 08/23/2020] [Indexed: 11/10/2022] Open
Abstract
Background African swine fever (ASF) is an infectious transboundary animal disease which causes high mortality, approaching 100% in domestic pigs and it is currently considered as the most serious constraint to domestic pig industry and food security globally. Despite regular ASF outbreaks within Malawi, few studies have genetically characterized the causative ASF virus (ASFV). This study aimed at genetic characterization of ASFV responsible for the 2019 outbreak in northern Malawi. The disease confirmation was done by polymerase chain reaction (PCR) followed by molecular characterization of the causative ASFV by partial genome sequencing and phylogenetic reconstruction of the B646L (p72) gene, nucleotide alignment of the intergenic region (IGR) between I73R and I329L genes and translation of the central variable region (CVR) coded by B602L gene. Results All thirteen samples collected during this study in Karonga district in September 2019 were ASFV-positive and after partial genome sequencing and phylogenetic reconstruction of the B646L (p72) gene, the viruses clustered into ASFV p72 genotype II. The viruses characterized in this study lacked a GAATATATAG fragment between the I173R and the I329L genes and were classified as IGR I variants. Furthermore, the tetrameric amino acid repeats within the CVR of the B602L gene of the 2019 Malawian ASFV reported in this study had the signature BNDBNDBNAA, 100% similar to ASFV responsible for the 2013 and 2017 ASF outbreaks in Zambia and Tanzania, respectively. Conclusions The results of this study confirm an ASF outbreak in Karonga district in northern Malawi in September 2019. The virus was closely related to other p72 genotype II ASFV that caused outbreaks in neighboring eastern and southern African countries, emphasizing the possible regional transboundary transmission of this ASFV genotype. These findings call for a concerted regional and international effort to control the spread of ASF in order to improve nutritional and food security.
Collapse
Affiliation(s)
- J N Hakizimana
- SACIDS Africa Centre of Excellence for Infectious Diseases, SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania.,Department of Veterinary Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
| | - G Kamwendo
- Department of Animal Health and Livestock Development, Ministry of Agriculture, Irrigation and Water Development, Lilongwe, Malawi
| | - J L C Chulu
- Department of Animal Health and Livestock Development, Ministry of Agriculture, Irrigation and Water Development, Lilongwe, Malawi
| | - O Kamana
- Department of Food Science and Technology, College of Agriculture, Animal Sciences and Veterinary Medicine, University of Rwanda, Busogo, Rwanda.,Department of Applied Research and Development and Foresight Incubation, National Industrial Research and Development Agency, Kigali, Rwanda
| | - H J Nauwynck
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - G Misinzo
- SACIDS Africa Centre of Excellence for Infectious Diseases, SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania. .,Department of Veterinary Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania.
| |
Collapse
|
20
|
Chambaro HM, Sasaki M, Sinkala Y, Gonzalez G, Squarre D, Fandamu P, Lubaba C, Mataa L, Shawa M, Mwape KE, Gabriël S, Chembensofu M, Carr MJ, Hall WW, Qiu Y, Kajihara M, Takada A, Orba Y, Simulundu E, Sawa H. Evidence for exposure of asymptomatic domestic pigs to African swine fever virus during an inter-epidemic period in Zambia. Transbound Emerg Dis 2020; 67:2741-2752. [PMID: 32434281 DOI: 10.1111/tbed.13630] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 04/05/2020] [Accepted: 05/14/2020] [Indexed: 11/29/2022]
Abstract
African swine fever (ASF) causes persistent outbreaks in endemic and non-endemic regions in Zambia. However, the epidemiology of the disease is poorly understood, particularly during the inter-epidemic periods. We conducted surveillance for ASF in asymptomatic domestic pigs and soft ticks in selected Zambian provinces. While serum samples (n = 1,134) were collected from crossbred pigs from all study sites between 2014 and 2017, whole blood (n = 300) was collected from both crossbred and indigenous pigs in Eastern Province (EP) in 2017. Soft ticks were collected from Mosi-oa-Tunya National Park in Southern Province (SP) in 2019. Sera were screened for antibodies against ASF by ELISA while genome detection in whole blood and soft ticks was conducted by PCR. Ticks were identified morphologically and by phylogenetic analysis of the 16S rRNA gene. Seroprevalence was highest in EP (50.9%, 95% CI [47.0-54.9]) compared to significantly lower rates in SP (2.9%, 95% CI [1.6-5.1]). No antibodies to ASFV were detected in Lusaka Province. In EP, the prevalence of ASFV genome was 11.7% (35/300), significantly higher (OR = 6.2, 95% CI [2.4-16.6]) in indigenous pigs compared to crossbred pigs. The pooled prevalence of ASFV genome in ticks was 11.0%, 95% CI [8.5-13.9]. Free-range husbandry system was the only factor that was significantly associated with seropositive (p < .0001, OR = 39.3) and PCR-positive results (p < .001, OR = 5.7). Phylogenetically, based on the p72 gene, ASFV from Ornithodoros moubata ticks detected in this study belonged to genotype I, but they separated into two distinct clusters. Besides confirming ASF endemicity in EP and the presence of ASFV-infected ticks in SP, these results provide evidence for exposure of domestic pigs to ASFV in non-endemic regions during the inter-epidemic period.
Collapse
Affiliation(s)
- Herman M Chambaro
- Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan.,Ministry of Fisheries and Livestock, Lusaka, Zambia.,Virology Unit, Central Veterinary Research Institute, Lusaka, Zambia
| | - Michihito Sasaki
- Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Yona Sinkala
- Ministry of Fisheries and Livestock, Lusaka, Zambia
| | - Gabriel Gonzalez
- Division of Bioinformatics, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - David Squarre
- Wildlife Veterinary Unit, Department of National Parks and Wildlife, Lusaka, Zambia.,Division of Collaboration and Education, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan.,Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, Scotland
| | - Paul Fandamu
- Ministry of Fisheries and Livestock, Lusaka, Zambia
| | | | | | - Misheck Shawa
- Division of Infection and Immunity, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Kabemba E Mwape
- Department of Clinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Sarah Gabriël
- Department of Veterinary Public Health and Food Safety, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Mwelwa Chembensofu
- Department of Paraclinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Michael J Carr
- Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Japan.,National Virus Reference Laboratory, School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - William W Hall
- Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Japan.,National Virus Reference Laboratory, School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland.,Global Virus Network, Baltimore, MD, USA
| | - Yongjin Qiu
- Hokudai Center for Zoonosis Control in Zambia, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Masahiro Kajihara
- Hokudai Center for Zoonosis Control in Zambia, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Ayato Takada
- Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Japan.,Division of Global Epidemiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan.,Department of Disease Control, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Yasuko Orba
- Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Edgar Simulundu
- Department of Disease Control, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Hirofumi Sawa
- Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan.,Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Japan.,Global Virus Network, Baltimore, MD, USA
| |
Collapse
|
21
|
Xu R, Gong L, Wang H, Zhang G. Disinfection Effect of Short-wave Ultraviolet Radiation(UV-C) on ASFV in Water. J Infect 2020; 80:671-693. [DOI: 10.1016/j.jinf.2020.02.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 02/20/2020] [Indexed: 11/30/2022]
|
22
|
Systematic Review of Important Viral Diseases in Africa in Light of the 'One Health' Concept. Pathogens 2020; 9:pathogens9040301. [PMID: 32325980 PMCID: PMC7238228 DOI: 10.3390/pathogens9040301] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 04/03/2020] [Accepted: 04/07/2020] [Indexed: 12/19/2022] Open
Abstract
Emerging and re-emerging viral diseases are of great public health concern. The recent emergence of Severe Acute Respiratory Syndrome (SARS) related coronavirus (SARS-CoV-2) in December 2019 in China, which causes COVID-19 disease in humans, and its current spread to several countries, leading to the first pandemic in history to be caused by a coronavirus, highlights the significance of zoonotic viral diseases. Rift Valley fever, rabies, West Nile, chikungunya, dengue, yellow fever, Crimean-Congo hemorrhagic fever, Ebola, and influenza viruses among many other viruses have been reported from different African countries. The paucity of information, lack of knowledge, limited resources, and climate change, coupled with cultural traditions make the African continent a hotspot for vector-borne and zoonotic viral diseases, which may spread globally. Currently, there is no information available on the status of virus diseases in Africa. This systematic review highlights the available information about viral diseases, including zoonotic and vector-borne diseases, reported in Africa. The findings will help us understand the trend of emerging and re-emerging virus diseases within the African continent. The findings recommend active surveillance of viral diseases and strict implementation of One Health measures in Africa to improve human public health and reduce the possibility of potential pandemics due to zoonotic viruses.
Collapse
|
23
|
Prevalence and genotypic characterization of Giardia duodenalis isolates from asymptomatic school-going children in Lusaka, Zambia. Food Waterborne Parasitol 2020; 19:e00072. [PMID: 32258446 PMCID: PMC7125351 DOI: 10.1016/j.fawpar.2020.e00072] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 12/19/2019] [Accepted: 12/20/2019] [Indexed: 12/19/2022] Open
Abstract
Giardia duodenalis is one of the most common causes of diarrhea in humans with about 250–300 million cases per year. It is considered to be a species complex comprising of eight genetic assemblages (A to H), with assemblages A and B being the major causes of human infections. In this study we carried out genotypic characterization of G. duodenalis isolates detected in asymptomatic school-going children aged 3–16 years. Between May and September 2017, a total of 329 fecal samples were collected from school-going children from Chawama compound of Lusaka City and were screened for Giardia by microscopic examination. All microscopically positive fecal samples were analyzed by semi-nested polymerase chain reaction (PCR) targeting the glutamate dehydrogenase (gdh) gene. Genotyping of amplified PCR products was conducted by restriction fragment length polymorphism (RFLP) and DNA sequence analysis. Microscopically, Giardia was found in 10% (33/329) of fecal samples. The PCR-RFLP analysis of the gdh gene revealed assemblages A and B in 27.3% (9/33) and 72.7% (24/33), respectively. Furthermore, analysis with restriction enzymes identified sub-assemblages AII (27.3%, 9/33), BIII (12.1%, 4/33), BIV (51.5%, 17/33) and mixed infections of BIII and BIV (9.1%, 3/33). Phylogenetic analysis showed the clustering of 27.6% (8/29) and 72.4% (21/29) of Zambian Giardia gdh gene sequences into assemblages A and B, respectively. This study has revealed the presence of both assemblage A and B and that spread of G. duodenalis in school-going children appears to be mostly through anthroponotic transmission. To our knowledge, this is the first report of genotypic characterization of G. duodenalis identified in Zambia. Giardia duodenalis infection observed in asymptomatic children First report of genotypes circulating in Zambia Presence of sub-assemblages AII, BIII and BIV Co-infection with sub-assemblages BIII and BIV reported
Collapse
|
24
|
The recombination hot spots and genetic diversity of the genomes of African swine fever viruses. J Infect 2020; 80:121-142. [DOI: 10.1016/j.jinf.2019.08.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 08/06/2019] [Indexed: 11/20/2022]
|
25
|
Molini U, Mushonga B, Settypalli TBK, Dundon WG, Khaiseb S, Jago M, Cattoli G, Lamien CE. Molecular characterization of African swine fever virus from outbreaks in Namibia in 2018. Transbound Emerg Dis 2019; 67:1008-1014. [PMID: 31650681 DOI: 10.1111/tbed.13399] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 10/02/2019] [Accepted: 10/07/2019] [Indexed: 11/27/2022]
Abstract
Five samples were collected from four suspected outbreaks of African swine fever in Namibia in 2018. Sequencing of the C-terminus of the B646L gene (p72 protein), the central hypervariable region (CVR) of the B602L gene, the E183L gene (p54 protein) and the CD2v (used to determine the serogroup) was performed on DNA isolated from the samples. Phylogenetic analyses of the B646L (p72) revealed that one of the samples belonged to genotype I while the remaining samples could not be assigned to any currently known genotype. In contrast, by using the E183L gene three of the samples were shown to belong to genotype Id and only two were of unknown genotype. Based on the analysis of the partial CD2v amino acid sequences of four of the samples, one of the viruses clustered with serogroup 2 while the other three did not cluster within any of the eight known serogroups. Examination of the CVR identified three variants with 8, 18 and 24 tetrameric tandem repeat sequences. This study indicates that at least three different genetically distinct ASFV are currently present in Namibia.
Collapse
Affiliation(s)
- Umberto Molini
- Faculty of Agriculture and Natural Resources, School of Veterinary Medicine, University of Namibia, Windhoek, Namibia.,Central Veterinary Laboratory, Windhoek, Namibia
| | - Borden Mushonga
- Faculty of Agriculture and Natural Resources, School of Veterinary Medicine, University of Namibia, Windhoek, Namibia
| | - Tirumala B K Settypalli
- Animal Production and Health Laboratory, Department of Nuclear Sciences and Applications, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria
| | - William G Dundon
- Animal Production and Health Laboratory, Department of Nuclear Sciences and Applications, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria
| | | | - Mark Jago
- Faculty of Agriculture and Natural Resources, School of Veterinary Medicine, University of Namibia, Windhoek, Namibia
| | - Giovanni Cattoli
- Animal Production and Health Laboratory, Department of Nuclear Sciences and Applications, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria
| | - Charles E Lamien
- Animal Production and Health Laboratory, Department of Nuclear Sciences and Applications, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria
| |
Collapse
|
26
|
Teklue T, Sun Y, Abid M, Luo Y, Qiu HJ. Current status and evolving approaches to African swine fever vaccine development. Transbound Emerg Dis 2019; 67:529-542. [PMID: 31538406 DOI: 10.1111/tbed.13364] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 08/22/2019] [Accepted: 09/09/2019] [Indexed: 12/21/2022]
Abstract
African swine fever (ASF) is a highly lethal haemorrhagic disease of swine caused by African swine fever virus (ASFV), a unique and genetically complex virus. The disease continues to be a huge burden to the pig industry in Africa, Europe and recently in Asia, especially China. The purpose of this review was to recapitulate the current scenarios and evolving trends in ASF vaccine development. The unavailability of an applicable ASF vaccine is partly due to the complex nature of the virus, which encodes various proteins associated with immune evasion. Moreover, the incomplete understanding of immune protection determinants of ASFV hampers the rational vaccine design. Developing an effective ASF vaccine continues to be a challenging task due to many undefined features of ASFV immunobiology. Recent attempts on DNA and live attenuated ASF vaccines have been reported with promising efficacy, and especially live attenuated vaccines have been proved to provide complete homologous protection. Single-cycle viral vaccines have been developed for various diseases such as Rift Valley fever and bluetongue, and the rational extension of these strategies could be helpful for developing single-cycle ASF vaccines. Therefore, live attenuated vaccines in short term and single-cycle vaccines in long term would be the next generation of ASF vaccines.
Collapse
Affiliation(s)
- Teshale Teklue
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China.,Tigray Agricultural Research Institute, Mekelle, Ethiopia
| | - Yuan Sun
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Muhammad Abid
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Yuzi Luo
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Hua-Ji Qiu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| |
Collapse
|
27
|
Phiri MM, Kaimoyo E, Changula K, Silwamba I, Chambaro HM, Kapila P, Kajihara M, Simuunza M, Muma JB, Pandey GS, Takada A, Mweene AS, Chitanga S, Simulundu E. Molecular detection and characterization of genotype 1 bovine leukemia virus from beef cattle in the traditional sector in Zambia. Arch Virol 2019; 164:2531-2536. [PMID: 31300890 DOI: 10.1007/s00705-019-04350-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 03/29/2019] [Indexed: 11/28/2022]
Abstract
Whilst bovine leukemia virus (BLV) causes considerable economic losses to the dairy industry worldwide, information on its molecular epidemiology and economic impact in beef cattle is limited. Here, blood from 880 animals from Zambia's major cattle-rearing provinces was screened for BLV by nested PCR. Positive pools were sequenced and phylogenetically analyzed. The estimated pooled prevalence was 2.1%. All strains belonged to genotype 1 and formed a distinct phylogenetic cluster. The study suggests circulation of genotype 1 BLV in beef cattle in these regions. This is the first report on molecular detection and characterization of BLV from beef cattle in Africa.
Collapse
Affiliation(s)
- Mundia M Phiri
- School of Natural Sciences, The University of Zambia, PO Box 32379, Lusaka, 10101, Zambia
| | - Evans Kaimoyo
- School of Natural Sciences, The University of Zambia, PO Box 32379, Lusaka, 10101, Zambia
| | - Katendi Changula
- Department of Disease Control, School of Veterinary Medicine, The University of Zambia, PO Box 32379, Lusaka, 10101, Zambia
| | - Isaac Silwamba
- Department of Disease Control, School of Veterinary Medicine, The University of Zambia, PO Box 32379, Lusaka, 10101, Zambia
| | - Herman M Chambaro
- Division of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo, Japan
| | - Penjaninge Kapila
- Department of Disease Control, School of Veterinary Medicine, The University of Zambia, PO Box 32379, Lusaka, 10101, Zambia
| | - Masahiro Kajihara
- Division of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo, Japan
| | - Martin Simuunza
- Department of Disease Control, School of Veterinary Medicine, The University of Zambia, PO Box 32379, Lusaka, 10101, Zambia.,Africa Center of Excellence of Infectious Diseases of Humans and Animals, University of Zambia, Lusaka, Zambia
| | - John Bwalya Muma
- Department of Disease Control, School of Veterinary Medicine, The University of Zambia, PO Box 32379, Lusaka, 10101, Zambia
| | - Girja S Pandey
- Department of Disease Control, School of Veterinary Medicine, The University of Zambia, PO Box 32379, Lusaka, 10101, Zambia
| | - Ayato Takada
- Department of Disease Control, School of Veterinary Medicine, The University of Zambia, PO Box 32379, Lusaka, 10101, Zambia.,Division of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo, Japan
| | - Aaron S Mweene
- Department of Disease Control, School of Veterinary Medicine, The University of Zambia, PO Box 32379, Lusaka, 10101, Zambia.,Africa Center of Excellence of Infectious Diseases of Humans and Animals, University of Zambia, Lusaka, Zambia
| | - Simbarashe Chitanga
- School of Health Sciences, The University of Zambia, PO Box 50110, Lusaka, 10101, Zambia
| | - Edgar Simulundu
- Department of Disease Control, School of Veterinary Medicine, The University of Zambia, PO Box 32379, Lusaka, 10101, Zambia.
| |
Collapse
|
28
|
Mulumba-Mfumu LK, Saegerman C, Dixon LK, Madimba KC, Kazadi E, Mukalakata NT, Oura CAL, Chenais E, Masembe C, Ståhl K, Thiry E, Penrith ML. African swine fever: Update on Eastern, Central and Southern Africa. Transbound Emerg Dis 2019; 66:1462-1480. [PMID: 30920725 DOI: 10.1111/tbed.13187] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 03/21/2019] [Accepted: 03/24/2019] [Indexed: 11/28/2022]
Abstract
Control of African swine fever (ASF) in countries in Eastern, Central and Southern Africa (ECSA) is particularly complex owing to the presence of all three known epidemiological cycles of maintenance of the virus, namely an ancient sylvatic cycle involving the natural hosts and vectors of the disease as well as domestic cycles with and without involvement of natural vectors. While the situation is well documented in some of the countries, for others very little information is available. In spite of the unfavourable ASF situation, the pig population in the sub-region has grown exponentially in recent decades and is likely to continue to grow in response to rapid urban growth resulting in increasing demand for animal protein by populations that are no longer engaged in livestock production. Better management of ASF will be essential to permit the pig sector to reach its full potential as a supplier of high quality protein and a source of income to improve livelihoods and create wealth. No vaccine is currently available and it is likely that, in the near future, the sub-region will continue to rely on the implementation of preventive measures, based on the epidemiology of the disease, to avoid both the devastating losses that outbreaks can cause and the risk the sub-region poses to other parts of Africa and the world. The current situation in the ECSA sub-region is reviewed and gaps in knowledge are identified in order to support ongoing strategy development for managing ASF in endemic areas.
Collapse
Affiliation(s)
- Léopold K Mulumba-Mfumu
- Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Kinshasa, Kinshasa, Democratic Republic of the Congo.,Research Unit of Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR- ULiège), Fundamental and Applied Research for Animals & Health (FARAH) Center, Faculty of Veterinary Medicine, University of Liege, Liege, Belgium
| | - Claude Saegerman
- Research Unit of Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR- ULiège), Fundamental and Applied Research for Animals & Health (FARAH) Center, Faculty of Veterinary Medicine, University of Liege, Liege, Belgium
| | | | - Kapanga C Madimba
- Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Eric Kazadi
- Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Ndeji T Mukalakata
- Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Chris A L Oura
- School of Veterinary Medicine, Faculty of Medical Sciences, University of the West Indies, Champ Fleurs, Trinidad and Tobago
| | - Erika Chenais
- Department of Disease Control and Epidemiology, SVA, Uppsala, Sweden
| | - Charles Masembe
- College of Natural Sciences, Makerere University, Kampala, Uganda
| | - Karl Ståhl
- Department of Disease Control and Epidemiology, SVA, Uppsala, Sweden
| | - Etienne Thiry
- Veterinary Virology and Animal Viral Diseases, Fundamental and Applied Research for Animals & Health (FARAH) Center, Faculty of Veterinary Medicine, University of Liege, Liege, Belgium
| | - Mary Louise Penrith
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| |
Collapse
|
29
|
Bao J, Wang Q, Lin P, Liu C, Li L, Wu X, Chi T, Xu T, Ge S, Liu Y, Li J, Wang S, Qu H, Jin T, Wang Z. Genome comparison of African swine fever virus China/2018/Anhui
XCGQ
strain and related European p72 Genotype
II
strains. Transbound Emerg Dis 2019; 66:1167-1176. [DOI: 10.1111/tbed.13124] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 12/17/2018] [Accepted: 01/07/2019] [Indexed: 12/16/2022]
Affiliation(s)
- Jingyue Bao
- China Animal Health and Epidemiology Center Qingdao Shandong China
| | - Qinghua Wang
- China Animal Health and Epidemiology Center Qingdao Shandong China
| | - Peng Lin
- BGI‐Qingdao BGI‐Shenzhen Qingdao Shandong China
- BGI Education Center University of Chinese Academy of Sciences Shenzhen China
| | - Chunju Liu
- China Animal Health and Epidemiology Center Qingdao Shandong China
| | - Lin Li
- China Animal Health and Epidemiology Center Qingdao Shandong China
| | - Xiaodong Wu
- China Animal Health and Epidemiology Center Qingdao Shandong China
| | - Tianying Chi
- China Animal Health and Epidemiology Center Qingdao Shandong China
| | - Tiangang Xu
- China Animal Health and Epidemiology Center Qingdao Shandong China
| | - Shengqiang Ge
- China Animal Health and Epidemiology Center Qingdao Shandong China
| | - Yutian Liu
- China Animal Health and Epidemiology Center Qingdao Shandong China
| | - Jinming Li
- China Animal Health and Epidemiology Center Qingdao Shandong China
| | - Shujuan Wang
- China Animal Health and Epidemiology Center Qingdao Shandong China
| | - Hailong Qu
- China Animal Health and Epidemiology Center Qingdao Shandong China
| | - Tao Jin
- BGI‐Qingdao BGI‐Shenzhen Qingdao Shandong China
- BGI‐Shenzhen Shenzhen China
| | - Zhiliang Wang
- China Animal Health and Epidemiology Center Qingdao Shandong China
| |
Collapse
|
30
|
Penrith ML, Bastos AD, Etter EMC, Beltrán-Alcrudo D. Epidemiology of African swine fever in Africa today: Sylvatic cycle versus socio-economic imperatives. Transbound Emerg Dis 2019; 66:672-686. [PMID: 30633851 DOI: 10.1111/tbed.13117] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 12/04/2018] [Accepted: 12/14/2018] [Indexed: 11/29/2022]
Abstract
African swine fever (ASF) is believed to have evolved in eastern and southern Africa in a sylvatic cycle between common warthogs (Phacochoerus africanus) and argasid ticks of the Ornithodoros moubata complex that live in their burrows. The involvement of warthogs and possibly other wild suids in the maintenance of ASF virus means that the infection cannot be eradicated from Africa, but only prevented and controlled in domestic pig populations. Historically, outbreaks of ASF in domestic pigs in Africa were almost invariably linked to the presence of warthogs, but subsequent investigations of the disease in pigs revealed the presence of another cycle involving domestic pigs and ticks, with a third cycle becoming apparent when the disease expanded into West Africa where the sylvatic cycle is not present. The increase in ASF outbreaks that has accompanied the exponential growth of the African pig population over the last three decades has heralded a shift in the epidemiology of ASF in Africa, and the growing importance of the pig husbandry and trade in the maintenance and spread of ASF. This review, which focuses on the ASF situation between 1989 and 2017, suggests a minor role for wild suids compared with the domestic cycle, driven by socio-economic factors that determine the ability of producers to implement the control measures needed for better management of ASF in Africa.
Collapse
Affiliation(s)
- Mary-Louise Penrith
- Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa
| | - Armanda Duarte Bastos
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, South Africa
| | - Eric M C Etter
- Department of Production Animal Studies, University of Pretoria, Pretoria, South Africa.,CIRAD, UMR Animal Santé, Territoires, Risque et Ecosystèmes (ASTRE), Montpellier, France.,ASTRE, Univ. Montpellier, CIRAD, INRA, Montpellier, France
| | - Daniel Beltrán-Alcrudo
- Regional Office for Europe and Central Asia, Food and Agriculture Organization of the United Nations, Budapest, Hungary
| |
Collapse
|
31
|
Liu L, Atim S, LeBlanc N, Rauh R, Esau M, Chenais E, Mwebe R, Nelson WM, Masembe C, Nantima N, Ayebazibwe C, Ståhl K. Overcoming the challenges of pen-side molecular diagnosis of African swine fever to support outbreak investigations under field conditions. Transbound Emerg Dis 2018; 66:908-914. [PMID: 30554469 DOI: 10.1111/tbed.13103] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 12/03/2018] [Accepted: 12/06/2018] [Indexed: 11/30/2022]
Abstract
African swine fever (ASF) is a devastating disease of pigs. Without a vaccine, early detection and rapid diagnosis of ASF is a crucial step towards effective disease control. In many countries where ASF is endemic, laboratory infrastructure including sampling and sample shipment is inadequate, and a rapid laboratory confirmation would require that the diagnosis is performed at regional laboratories close to the pig farms of concern, or even at the farm-side. This study intended to evaluate measures including sample preparation methods, a dried-down assay, and a portable, battery-powered real-time PCR instrument, to improve molecular diagnosis under field conditions. A simple dilution of blood samples, either in Phosphate-buffered saline or a commercial buffer, worked similarly to beads-based nucleic acid extraction using a magnet as the core equipment; the latter method did work as well for those samples with low viral load or high Ct values. The real-time PCR assay using a Universal ProbeLibrary (UPL) probe tolerated suspected inhibitory substances present in the prepared samples better, whereas the dried-down assay had a higher diagnostic sensitivity. Additionally, an inhibition control assay proved to be helpful in avoiding false negative results when interpreting negative results of samples that might be of low quality or with inadequate reduction in inhibitory substances. When tested with synthetic DNA standards, the portable instrument performed at a level approaching stationary thermocyclers. In summary, the developments of suitable sample preparation methods, robust and thermal-stable real-time PCR assays with inhibition control, and battery-powered portable thermocyclers with middle-throughput offer one way forward to provide rapid, reliable molecular diagnosis under challenging field conditions.
Collapse
Affiliation(s)
- Lihong Liu
- National Veterinary Institute, Uppsala, Sweden
| | - Stella Atim
- National Animal Disease Diagnosis and Epidemiology Center, Entebbe, Uganda
| | - Neil LeBlanc
- Consultant molecular diagnostics, Uppsala, Sweden
| | | | - Martin Esau
- National Animal Disease Diagnosis and Epidemiology Center, Entebbe, Uganda
| | | | - Robert Mwebe
- National Animal Disease Diagnosis and Epidemiology Center, Entebbe, Uganda
| | | | | | - Noelina Nantima
- National Animal Disease Diagnosis and Epidemiology Center, Entebbe, Uganda
| | | | - Karl Ståhl
- National Veterinary Institute, Uppsala, Sweden
| |
Collapse
|
32
|
Simulundu E, Sinkala Y, Chambaro HM, Chinyemba A, Banda F, Mooya LE, Ndebe J, Chitanga S, Makungu C, Munthali G, Fandamu P, Takada A, Mweene AS. Genetic characterisation of African swine fever virus from 2017 outbreaks in Zambia: Identification of p72 genotype II variants in domestic pigs. ACTA ACUST UNITED AC 2018; 85:e1-e5. [PMID: 30035596 PMCID: PMC6238689 DOI: 10.4102/ojvr.v85i1.1562] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 05/15/2018] [Accepted: 05/16/2018] [Indexed: 11/01/2022]
Abstract
African swine fever (ASF) is a contagious haemorrhagic disease associated with causing heavy economic losses to the swine industry in many African countries. In 2017, Zambia experienced ASF outbreaks in Mbala District (Northern province) and for the first time in Isoka and Chinsali districts (Muchinga province). Meanwhile, another outbreak was observed in Chipata District (Eastern province). Genetic analysis of part of the B646L gene, E183L gene, CP204L gene and the central variable region of the B602L gene of ASF virus (ASFV) associated with the outbreaks in Mbala and Chipata districts was conducted. The results revealed that the ASFV detected in Mbala District was highly similar to that of the Georgia 2007/1 isolate across all the genome regions analysed. In contrast, while showing close relationship with the Georgia 2007/1 virus in the B646L gene, the ASFV detected in Chipata District showed remarkable genetic variation in the rest of the genes analysed. These results suggest that the Georgia 2007/1-like virus could be more diverse than what was previously thought, underscoring the need of continued surveillance and monitoring of ASFVs within the south-eastern African region to better understand their epidemiology and the relationships between outbreaks and their possible origin.
Collapse
|
33
|
Alkhamis MA, Gallardo C, Jurado C, Soler A, Arias M, Sánchez-Vizcaíno JM. Phylodynamics and evolutionary epidemiology of African swine fever p72-CVR genes in Eurasia and Africa. PLoS One 2018; 13:e0192565. [PMID: 29489860 PMCID: PMC5831051 DOI: 10.1371/journal.pone.0192565] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 01/25/2018] [Indexed: 12/11/2022] Open
Abstract
African swine fever (ASF) is a complex infectious disease of swine that constitutes devastating impacts on animal health and the world economy. Here, we investigated the evolutionary epidemiology of ASF virus (ASFV) in Eurasia and Africa using the concatenated gene sequences of the viral protein 72 and the central variable region of isolates collected between 1960 and 2015. We used Bayesian phylodynamic models to reconstruct the evolutionary history of the virus, to identify virus population demographics and to quantify dispersal patterns between host species. Results suggest that ASFV exhibited a significantly high evolutionary rate and population growth through time since its divergence in the 18th century from East Africa, with no signs of decline till recent years. This increase corresponds to the growing pig trade activities between continents during the 19th century, and may be attributed to an evolutionary drift that resulted from either continuous circulation or maintenance of the virus within Africa and Eurasia. Furthermore, results implicate wild suids as the ancestral host species (root state posterior probability = 0.87) for ASFV in the early 1700s in Africa. Moreover, results indicate the transmission cycle between wild suids and pigs is an important cycle for ASFV spread and maintenance in pig populations, while ticks are an important natural reservoir that can facilitate ASFV spread and maintenance in wild swine populations. We illustrated the prospects of phylodynamic methods in improving risk-based surveillance, support of effective animal health policies, and epidemic preparedness in countries at high risk of ASFV incursion.
Collapse
Affiliation(s)
- Moh A Alkhamis
- Faculty of Public Heath, Health Sciences Centre, Kuwait University, Kuwait City, Kuwait
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, United States of America
| | - Carmina Gallardo
- European Union Reference Laboratory for African swine fever. Centro de Investigación en Sanidad Animal (INIA-CISA), Madrid, Spain
| | - Cristina Jurado
- VISAVET Health Surveillance Centre and Animal Health Department, Veterinary School, Complutense University of Madrid, Madrid, Spain
| | - Alejandro Soler
- European Union Reference Laboratory for African swine fever. Centro de Investigación en Sanidad Animal (INIA-CISA), Madrid, Spain
| | - Marisa Arias
- European Union Reference Laboratory for African swine fever. Centro de Investigación en Sanidad Animal (INIA-CISA), Madrid, Spain
| | - José M Sánchez-Vizcaíno
- VISAVET Health Surveillance Centre and Animal Health Department, Veterinary School, Complutense University of Madrid, Madrid, Spain
| |
Collapse
|
34
|
BA71ΔCD2: a New Recombinant Live Attenuated African Swine Fever Virus with Cross-Protective Capabilities. J Virol 2017; 91:JVI.01058-17. [PMID: 28814514 PMCID: PMC5640839 DOI: 10.1128/jvi.01058-17] [Citation(s) in RCA: 177] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 08/07/2017] [Indexed: 12/04/2022] Open
Abstract
African swine fever is a highly contagious viral disease of mandatory declaration to the World Organization for Animal Health (OIE). The lack of available vaccines makes its control difficult; thus, African swine fever virus (ASFV) represents a major threat to the swine industry. Inactivated vaccines do not confer solid protection against ASFV. Conversely, live attenuated viruses (LAV), either naturally isolated or obtained by genetic manipulation, have demonstrated reliable protection against homologous ASFV strains, although little or no protection has been demonstrated against heterologous viruses. Safety concerns are a major issue for the use of ASFV attenuated vaccine candidates and have hampered their implementation in the field so far. While trying to develop safer and efficient ASFV vaccines, we found that the deletion of the viral CD2v (EP402R) gene highly attenuated the virulent BA71 strain in vivo. Inoculation of pigs with the deletion mutant virus BA71ΔCD2 conferred protection not only against lethal challenge with the parental BA71 but also against the heterologous E75 (both genotype I strains). The protection induced was dose dependent, and the cross-protection observed in vivo correlated with the ability of BA71ΔCD2 to induce specific CD8+ T cells capable of recognizing both BA71 and E75 viruses in vitro. Interestingly, 100% of the pigs immunized with BA71ΔCD2 also survived lethal challenge with Georgia 2007/1, the genotype II strain of ASFV currently circulating in continental Europe. These results open new avenues to design ASFV cross-protective vaccines, essential to fight ASFV in areas where the virus is endemic and where multiple viruses are circulating. IMPORTANCE African swine fever virus (ASFV) remains enzootic in most countries of Sub-Saharan Africa, today representing a major threat for the development of their swine industry. The uncontrolled presence of ASFV has favored its periodic exportation to other countries, the last event being in Georgia in 2007. Since then, ASFV has spread toward neighboring countries, reaching the European Union's east border in 2014. The lack of available vaccines against ASFV makes its control difficult; so far, only live attenuated viruses have demonstrated solid protection against homologous experimental challenges, but they have failed at inducing solid cross-protective immunity against heterologous viruses. Here we describe a new LAV candidate with unique cross-protective abilities: BA71ΔCD2. Inoculation of BA71ΔCD2 protected pigs not only against experimental challenge with BA71, the virulent parental strain, but also against heterologous viruses, including Georgia 2007/1, the genotype II strain of ASFV currently circulating in Eastern Europe.
Collapse
|
35
|
Siamupa C, Saasa N, Phiri AM. Contribution of market value chain to the control of African swine fever in Zambia. Trop Anim Health Prod 2017; 50:177-185. [PMID: 28986685 DOI: 10.1007/s11250-017-1419-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 09/19/2017] [Indexed: 11/25/2022]
Abstract
African swine fever (ASF) is a worldwide disease of pigs endemic in most sub-Saharan African countries. Zambia has been experiencing outbreaks of ASF for many years because the disease is endemic in the eastern part of the country, with incursion into the central part of Lusaka Province. The latest outbreaks of ASF in Lusaka occurred in 2013 with substantial pig mortalities, loss in trade, and cost of control measures and compensation of affected farmers. The aims of the study were to identify market value chain-related factors that were associated with ASF outbreaks and assess why these outbreaks are becoming frequent despite control measures being put in place. Using a mixed-method design, participants involved in the value chain were purposively sampled. Some pig farmers were included using a respondent-driven technique. Farmers came from Lusaka, Chilanga, Kafue, and Chongwe districts. Other participants included district veterinary officers, veterinary assistants, police officers, and veterinary staff manning veterinary checkpoints, abattoir and processing plant managers, meat inspectors, market chairpersons, and traders. Semi-structured questionnaires, in-depth interviews, and direct observations were used to collect data to come up with narrations, tables, and flow charts. In assessing the contribution of the value chain in ASF, aspects of ASF screening, market availability and procedures, knowledge on ASF transmission, occurrence of ASF outbreak, and regulation of pig movement were investigated. Despite government ASF control measures being applied, the following were noted: (1) low awareness levels of ASF transmission among pig farmers and traders; (2) only 50% of farmers had their animals screened for ASF before sale; (3) all the markets did not have the pork inspected; (4) laxity in enforcing livestock movement control because of inadequate police and veterinary staff manning checkpoints; (5) lack of enforcement of meat inspection and food safety regulations at pig markets; and (6) inadequate and bureaucratic ASF screening. Improving biosecurity; sensitizing farmers, traders, and all stakeholders in the pig value chain on ASF prevention and control; reinforcement of staff at checkpoints; and regulation of pig markets are some of the ways in which future outbreaks can be prevented.
Collapse
Affiliation(s)
- C Siamupa
- Department of Disease Control, School of Veterinary Medicine, University of Zambia, P.O. Box 32379, Lusaka, Zambia
| | - N Saasa
- Department of Disease Control, School of Veterinary Medicine, University of Zambia, P.O. Box 32379, Lusaka, Zambia
| | - A M Phiri
- Department of Clinical Studies, School of Veterinary Medicine, University of Zambia, P.O. Box 32379, Lusaka, Zambia.
| |
Collapse
|
36
|
The Epidemiology of African Swine Fever in "Nonendemic" Regions of Zambia (1989-2015): Implications for Disease Prevention and Control. Viruses 2017; 9:v9090236. [PMID: 28832525 PMCID: PMC5618003 DOI: 10.3390/v9090236] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 08/11/2017] [Accepted: 08/21/2017] [Indexed: 11/29/2022] Open
Abstract
African swine fever (ASF) is a highly contagious and deadly viral hemorrhagic disease of swine. In Zambia, ASF was first reported in 1912 in Eastern Province and is currently believed to be endemic in that province only. Strict quarantine measures implemented at the Luangwa River Bridge, the only surface outlet from Eastern Province, appeared to be successful in restricting the disease. However, in 1989, an outbreak occurred for the first time outside the endemic province. Sporadic outbreaks have since occurred almost throughout the country. These events have brought into acute focus our limited understanding of the epidemiology of ASF in Zambia. Here, we review the epidemiology of the disease in areas considered nonendemic from 1989 to 2015. Comprehensive sequence analysis conducted on genetic data of ASF viruses (ASFVs) detected in domestic pigs revealed that p72 genotypes I, II, VIII and XIV have been involved in causing ASF outbreaks in swine during the study period. With the exception of the 1989 outbreak, we found no concrete evidence of dissemination of ASFVs from Eastern Province to other parts of the country. Our analyses revealed a complex epidemiology of the disease with a possibility of sylvatic cycle involvement. Trade and/or movement of pigs and their products, both within and across international borders, appear to have been the major factor in ASFV dissemination. Since ASFVs with the potential to cause countrywide and possibly regional outbreaks, could emerge from “nonendemic regions”, the current ASF control policy in Zambia requires a dramatic shift to ensure a more sustainable pig industry.
Collapse
|