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Tinto B, Quellec J, Cêtre-Sossah C, Dicko A, Salinas S, Simonin Y. Rift Valley fever in West Africa: A zoonotic disease with multiple socio-economic consequences. One Health 2023; 17:100583. [PMID: 37664171 PMCID: PMC10474305 DOI: 10.1016/j.onehlt.2023.100583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 06/12/2023] [Accepted: 06/12/2023] [Indexed: 09/05/2023] Open
Abstract
Rift Valley fever virus (RVFV) is an arbovirus that causes Rift Valley fever (RVF), a zoonotic disease that mainly affects domestic and wildlife ruminants and humans. The first epidemic in North-Western and West Africa occurred in Senegal and Mauritania in 1987, two countries where RVF is now endemic. Slaughterhouse workers, farmers, herders and veterinarians are at high risk of exposure to RVF. Beyond the health threat, RVF is considered to cause major socio-economic problems, specifically in developing countries where livestock farming and trade are important economic activities. Indeed, the mortality rate linked to RVF infection can reach 95-100% in newborns and young animals. In West Africa, livestock production is a key factor for food production and for national economics. Epizootics caused by RVF can therefore have serious socio-economic consequences by impacting multisectoral economics, the psycho-social health of pastoral communities, and food security. Improving prevention strategies against RVF, including vaccination, enhancing knowledge of RVF and correcting any inappropriate behaviors by populations of endemics areas, as well as better monitoring of RVF ecological factors are effective ways to better foresee and control outbreaks of RVF and its socio-economical side-effects in countries at high risk of occurrence of the disease.
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Affiliation(s)
- Bachirou Tinto
- Pathogenesis and Control of Chronic and Emerging Infections, University of Montpellier, INSERM, Etablissement Français du Sang, Montpellier, France
- Laboratoire National de Référence des Fièvres Hémorragiques Virale, Centre MURAZ, Institut National de Santé Publique (INSP), Bobo-Dioulasso, Burkina Faso
| | - Jordan Quellec
- Pathogenesis and Control of Chronic and Emerging Infections, University of Montpellier, INSERM, Etablissement Français du Sang, Montpellier, France
- ASTRE, University of Montpellier, CIRAD, INRAe, Montpellier, France
| | | | - Amadou Dicko
- Laboratoire central de référence, Institut National de Santé Publique (INSP), Ouagadougou, Burkina Faso
- Ministère de l'Agriculture, des ressources animales et halieutiques du Burkina Faso, Ouagadougou, Burkina Faso
| | - Sara Salinas
- Pathogenesis and Control of Chronic and Emerging Infections, University of Montpellier, INSERM, Etablissement Français du Sang, Montpellier, France
| | - Yannick Simonin
- Pathogenesis and Control of Chronic and Emerging Infections, University of Montpellier, INSERM, Etablissement Français du Sang, Montpellier, France
- ASTRE, University of Montpellier, CIRAD, INRAe, Montpellier, France
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Johnson SAM, Asmah R, Awuni JA, Tasiame W, Mensah GI, Paweska JT, Weyer J, Hellferscee O, Thompson PN. Evidence of Rift Valley Fever Virus Circulation in Livestock and Herders in Southern Ghana. Viruses 2023; 15:1346. [PMID: 37376647 DOI: 10.3390/v15061346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 06/05/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
Rift Valley fever (RVF) is a re-emerging zoonotic disease of domestic ruminants and humans. While neighbouring countries have reported outbreaks of RVF, Ghana has not yet identified any cases. The aim of this study was to determine whether RVF virus (RVFV) was circulating in livestock and herders in the southern part of Ghana, to estimate its seroprevalence, and to identify associated risk factors. The study surveyed 165 livestock farms randomly selected from two districts in southern Ghana. Serum samples of 253 goats, 246 sheep, 220 cattle, and 157 herdsmen were tested to detect IgG and IgM antibodies against RVFV. The overall seroprevalence of anti-RVF antibodies in livestock was 13.1% and 30.9% of farms had RVFV seropositive animals. The species-specific prevalence was 24.1% in cattle, 8.5% in sheep, and 7.9% in goats. A RVFV IgG seroprevalence of 17.8% was found among the ruminant herders, with 8.3% of all herders being IgM positive. RVFV was shown, for the first time, to have been circulating in southern Ghana, with evidence of a recent outbreak in Kwahu East; however, it was clinically undetected despite significant recent human exposure. A One Health approach is recommended to better understand RVF epidemiology and socio-economic impact in Ghana.
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Affiliation(s)
- Sherry Ama Mawuko Johnson
- Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa
- School of Veterinary Medicine, University of Ghana, Legon, Accra 00233, Ghana
| | - Richard Asmah
- School of Biomedical & Allied Health Sciences, University of Ghana, Accra 00233, Ghana
| | - Joseph Adongo Awuni
- Accra Veterinary Laboratory, Ministry of Food and Agriculture, Accra P.O. Box M161, Ghana
| | - William Tasiame
- School of Veterinary Medicine, Kwame Nkrumah University of Science and Technology, Kumasi 00233, Ghana
| | - Gloria Ivy Mensah
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra 00233, Ghana
| | - Janusz T Paweska
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Sandringham, Johannesburg 2192, South Africa
- Department of Medical Virology, Faculty of Health Sciences, University of Pretoria, Pretoria 0002, South Africa
| | - Jacqueline Weyer
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Sandringham, Johannesburg 2192, South Africa
- Department of Medical Virology, Faculty of Health Sciences, University of Pretoria, Pretoria 0002, South Africa
| | - Orienka Hellferscee
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Sandringham, Johannesburg 2192, South Africa
- Department of Medical Virology, Faculty of Health Sciences, University of Witwatersrand, Johannesburg 2050, South Africa
| | - Peter N Thompson
- Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa
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Agboli E, Zahouli JBZ, Badolo A, Jöst H. Mosquito-Associated Viruses and Their Related Mosquitoes in West Africa. Viruses 2021; 13:v13050891. [PMID: 34065928 PMCID: PMC8151702 DOI: 10.3390/v13050891] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/05/2021] [Accepted: 05/06/2021] [Indexed: 12/13/2022] Open
Abstract
Mosquito-associated viruses (MAVs), including mosquito-specific viruses (MSVs) and mosquito-borne (arbo)viruses (MBVs), are an increasing public, veterinary, and global health concern, and West Africa is projected to be the next front for arboviral diseases. As in-depth knowledge of the ecologies of both western African MAVs and related mosquitoes is still limited, we review available and comprehensive data on their diversity, abundance, and distribution. Data on MAVs’ occurrence and related mosquitoes were extracted from peer-reviewed publications. Data on MSVs, and mosquito and vertebrate host ranges are sparse. However, more data are available on MBVs (i.e., dengue, yellow fever, chikungunya, Zika, and Rift Valley fever viruses), detected in wild and domestic animals, and humans, with infections more concentrated in urban areas and areas affected by strong anthropogenic changes. Aedes aegypti, Culex quinquefasciatus, and Aedes albopictus are incriminated as key arbovirus vectors. These findings outline MAV, related mosquitoes, key knowledge gaps, and future research areas. Additionally, these data highlight the need to increase our understanding of MAVs and their impact on host mosquito ecology, to improve our knowledge of arbovirus transmission, and to develop specific strategies and capacities for arboviral disease surveillance, diagnostic, prevention, control, and outbreak responses in West Africa.
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Affiliation(s)
- Eric Agboli
- Molecular Biology and Immunology Department, Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany;
- Department of Epidemiology and Biostatistics, School of Public Health, University of Health and Allied Sciences, Ho PMB 31, Ghana
| | - Julien B. Z. Zahouli
- Centre d’Entomologie Médicale et Vétérinaire, Université Alassane Ouattara, Bouake, 27 BP 529 Abidjan 27, Cote D’Ivoire;
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Département de Recherche et Développement, 01 BP 1303 Abidjan 01, Cote D’Ivoire
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, 4051 Basel, Switzerland
| | - Athanase Badolo
- Laboratory of Fundamental and Applied Entomology, Universitée Joseph Ki-Zerbo, Ouagadougou 03 BP 7021, Burkina Faso;
| | - Hanna Jöst
- Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Hemorrhagic Fever Reference and Research, 20359 Hamburg, Germany
- Correspondence:
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Campbell Z, Coleman P, Guest A, Kushwaha P, Ramuthivheli T, Osebe T, Perry B, Salt J. Prioritizing smallholder animal health needs in East Africa, West Africa, and South Asia using three approaches: Literature review, expert workshops, and practitioner surveys. Prev Vet Med 2021; 189:105279. [PMID: 33581421 PMCID: PMC8024747 DOI: 10.1016/j.prevetmed.2021.105279] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 12/18/2020] [Accepted: 01/18/2021] [Indexed: 12/15/2022]
Abstract
Managing the health needs of livestock contributes to reducing poverty and improving the livelihoods of smallholder and pastoralist livestock keepers globally. Animal health practitioners, producers, policymakers, and researchers all must prioritize how to mobilize limited resources. This study employed three approaches to prioritize animal health needs in East and West Africa and South Asia to identify diseases and syndromes that impact livestock keepers. The approaches were a) systematic literature review, b) a series of expert workshops, and c) a practitioner survey of veterinarians and para-veterinary professionals. The top constraints that emerged from all three approaches include endo/ ectoparasites, foot and mouth disease, brucellosis, peste des petits ruminants, Newcastle disease, and avian influenza. Expert workshops additionally identified contagious caprine pleuropneumonia, contagious bovine pleuropneumonia, mastitis, and reproductive disorders as constraints not emphasized in the literature review. Practitioner survey results additionally identified nutrition as a constraint for smallholder dairy and pastoralist small ruminant production. Experts attending the workshops agreed most constraints can be managed using existing veterinary technologies and best husbandry practices, which supports a shift away from focusing on individual diseases and new technologies towards addressing systemic challenges that limit access to veterinary services and inputs. Few research studies focused on incidence/ prevalence of disease and impact, suggesting better incorporation of socio-economic impact measures in future research would better represent the interests of livestock keepers.
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Affiliation(s)
- Zoë Campbell
- International Livestock Research Institute (ILRI), P.O. Box 30709, Nairobi, 00100, Kenya.
| | - Paul Coleman
- H20 Venture Partners, 33-35 George Street, Oxford, OX1 2AY, United Kingdom
| | - Andrea Guest
- H20 Venture Partners, 33-35 George Street, Oxford, OX1 2AY, United Kingdom
| | - Peetambar Kushwaha
- GALVmed Asia Office, Unit 118 & 120 B, Splendor Forum, Plot No 3, Jasola District Centre, Jasola, New Delhi, 110025, India
| | - Thembinkosi Ramuthivheli
- GALVmed Africa Office, International Livestock Research Institute (ILRI), Swing One, Naivasha Road, Nairobi, Kenya
| | - Tom Osebe
- GALVmed Africa Office, International Livestock Research Institute (ILRI), Swing One, Naivasha Road, Nairobi, Kenya
| | - Brian Perry
- Nuffield College of Clinical Medicine, University of Oxford, United Kingdom; College of Medicine and Veterinary Medicine, University of Edinburgh, Arthurstone House, Meigle, Blairgowrie, PH12 8QW, Scotland, United Kingdom
| | - Jeremy Salt
- GALVmed UK Office, Doherty Building, Pentlands Science Park, Bush Loan, Penicuik Edinburgh, EH26 0PZ, Scotland, United Kingdom
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Detection of Two Species of the Genus Parapoxvirus (Bovine Papular Stomatitis Virus and Pseudocowpox Virus) in Ticks Infesting Cattle in Burkina Faso. Microorganisms 2020; 8:microorganisms8050644. [PMID: 32354102 PMCID: PMC7284340 DOI: 10.3390/microorganisms8050644] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/17/2020] [Accepted: 04/20/2020] [Indexed: 11/17/2022] Open
Abstract
The molecular identification of arboviruses in West Africa is of particular interest, due to their zoonotic potential in a population living in close contact with livestock, and in a region where the livestock migration across borders raises the risk of diseases infection and dissemination. The aim of the study was the screening of potential circulating arboviruses and the assessment of their zoonotic implications. Therefore, ticks were collected on cattle located in three provinces of eastern Burkina Faso. Tick pools were tested using a panel of genus-specific real-time assays targeting conserved regions of parapoxvirus, orthopoxvirus, flavivirus and phlebovirus. On the 26 farms visited, a total of 663 ticks were collected. Four genera and six tick species were morphologically identified, with Amblyomma variegatum and Hyalomma spp. being the most represented species. No arboviruses were found. However, this study highlights the presence of pseudocowpox virus (8.2%) and bovine papular stomatitis virus (5.8%) among the positive tick pools. BPSV positive ticks were found in herds sharing water and pastures resources and with a history of seasonal transhumance. Therefore, common grazing and the seasonal transhumance are likely to support the transmission of the virus. This could have important health and economic impacts, especially regarding transboundary cattle movements.
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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.
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Ngoshe YB, Avenant A, Rostal MK, Karesh WB, Paweska JT, Bagge W, Jansen van Vuren P, Kemp A, Cordel C, Msimang V, Thompson PN. Patterns of Rift Valley fever virus seropositivity in domestic ruminants in central South Africa four years after a large outbreak. Sci Rep 2020; 10:5489. [PMID: 32218486 PMCID: PMC7099094 DOI: 10.1038/s41598-020-62453-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 03/09/2020] [Indexed: 11/16/2022] Open
Abstract
Rift Valley fever (RVF) is a mosquito-borne viral zoonosis showing complex epidemiological patterns that are poorly understood in South Africa. Large outbreaks occur in the central interior at long, irregular intervals, most recently in 2010–2011; however, the level of herd immunity of ruminant livestock, a key determinant of outbreaks, is unknown. During 2015–2016 a cross-sectional study on 234 randomly-selected farms investigated the prevalence, patterns of, and factors associated with, antibodies to RVF virus (RVFV) in livestock in an area heavily affected by that outbreak. A RVFV inhibition ELISA was used to screen 977 cattle, 1,549 sheep and 523 goats and information on potential risk factors was collected using a comprehensive questionnaire. The estimated RVFV seroprevalence, adjusted for survey design, was 42.9% in cattle, 28.0% in sheep and 9.3% in goats, showing a high degree of farm-level clustering. Seroprevalence increased with age and was higher on private vs. communal land, on farms with seasonal pans (temporary, shallow wetlands) and perennial rivers and in recently vaccinated animals. Seropositivity amongst unvaccinated animals born after the last outbreak indicates likely viral circulation during the post-epidemic period. The current level of herd immunity in livestock may be insufficient to prevent another large outbreak, should suitable conditions recur.
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Affiliation(s)
- Yusuf B Ngoshe
- Epidemiology Section, Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, South Africa
| | - Alida Avenant
- Epidemiology Section, Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, South Africa
| | - Melinda K Rostal
- EcoHealth Alliance, 460 West 34th Street - 17th Floor, New York, NY, 10001, USA
| | - William B Karesh
- EcoHealth Alliance, 460 West 34th Street - 17th Floor, New York, NY, 10001, USA
| | - Janusz T Paweska
- Centre for Emerging Zoonotic & Parasitic Diseases, National Institute for Communicable Diseases, National Health Laboratory Service, Sandringham, Johannesburg, South Africa
| | - Whitney Bagge
- EcoHealth Alliance, 460 West 34th Street - 17th Floor, New York, NY, 10001, USA
| | - Petrus Jansen van Vuren
- Centre for Emerging Zoonotic & Parasitic Diseases, National Institute for Communicable Diseases, National Health Laboratory Service, Sandringham, Johannesburg, South Africa
| | - Alan Kemp
- Centre for Emerging Zoonotic & Parasitic Diseases, National Institute for Communicable Diseases, National Health Laboratory Service, Sandringham, Johannesburg, South Africa
| | | | - Veerle Msimang
- Epidemiology Section, Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, South Africa.,Centre for Emerging Zoonotic & Parasitic Diseases, National Institute for Communicable Diseases, National Health Laboratory Service, Sandringham, Johannesburg, South Africa
| | - Peter N Thompson
- Epidemiology Section, Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, South Africa.
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Rissmann M, Stoek F, Pickin MJ, Groschup MH. Mechanisms of inter-epidemic maintenance of Rift Valley fever phlebovirus. Antiviral Res 2019; 174:104692. [PMID: 31870761 DOI: 10.1016/j.antiviral.2019.104692] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 09/26/2019] [Accepted: 12/11/2019] [Indexed: 12/31/2022]
Abstract
Rift Valley fever phlebovirus (RVFV) is an arthropod-borne virus that has caused substantial epidemics throughout Africa and in the Arabian Peninsula. The virus can cause severe disease in livestock and humans and therefore the control and prevention of viral outbreaks is of utmost importance. The epidemiology of RVFV has some particular characteristics. Unexpected and significant epidemics have been observed in spatially and temporally divergent patterns across the African continent. Sudden epidemics in previously unaffected areas are followed by periods of long-term apparent absence of virus and sudden, unpredictable reoccurrence in disparate regions. Therefore, the elucidation of underlying mechanisms of viral maintenance is one of the largest gaps in the knowledge of RVFV ecology. It remains unknown whether the virus needs to be reintroduced before RVF outbreaks can occur, or if unperceived viral circulation in local vertebrates or mosquitoes is sufficient for maintenance of the virus. To gain insight into these knowledge gaps, we here review existing data that describe potential mechanisms of RVFV maintenance, as well as molecular and serological studies in endemic and non-endemic areas that provide evidence of an inter- or pre-epidemic virus presence. Basic and country-specific mechanisms of RVFV introduction into non-endemic countries are summarized and an overview of studies using mathematical modeling of RVFV persistence is given.
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Affiliation(s)
- Melanie Rissmann
- Friedrich-Loeffler-Institut, Institute of Novel and Emerging Infectious Diseases, Suedufer 10, 17489, Greifswald-Insel Riems, Germany
| | - Franziska Stoek
- Friedrich-Loeffler-Institut, Institute of Novel and Emerging Infectious Diseases, Suedufer 10, 17489, Greifswald-Insel Riems, Germany
| | - Matthew J Pickin
- Friedrich-Loeffler-Institut, Institute of Novel and Emerging Infectious Diseases, Suedufer 10, 17489, Greifswald-Insel Riems, Germany
| | - Martin H Groschup
- Friedrich-Loeffler-Institut, Institute of Novel and Emerging Infectious Diseases, Suedufer 10, 17489, Greifswald-Insel Riems, Germany.
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Tshilenge GM, Mulumba MLK, Misinzo G, Noad R, Dundon WG. Rift Valley fever virus in small ruminants in the Democratic Republic of the Congo. ACTA ACUST UNITED AC 2019; 86:e1-e5. [PMID: 31714136 PMCID: PMC6852419 DOI: 10.4102/ojvr.v86i1.1737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 05/02/2019] [Accepted: 05/07/2019] [Indexed: 11/01/2022]
Abstract
Rift Valley fever (RVF) is a zoonotic viral disease caused by the RVF phlebovirus (RVFV) that infects a variety of animal species including sheep and goats. Sera (n = 893) collected between 2013 and 2015 from randomly selected indigenous sheep and goats in seven provinces of the Democratic Republic of the Congo (DRC) were tested for the presence of specific immunoglobulin G (IgG) and M (IgM) against RVFV, using two commercially available enzyme-linked immunosorbent assays. The reverse transcription polymerase chain reaction (RT-PCR) was also used to detect RVFV nucleic acid. There was significant variation in true seroprevalence of RVFV for both sheep and goats between the seven provinces investigated. Values ranged from 0.0 (95% confidence interval [CI] 0.0-6.55) to 23.81 (95% CI 12.03-41.76) for goat and 0.0 (95% CI 0.0-7.56) to 37.11 (95% CI 15.48-65.94) for sheep, respectively. One serum (1.85%) out of 54 that tested positive for IgG was found to be IgM-positive. This same sample was also positive by RT-PCR indicating an active or recent infection. These findings report the presence of RVFV in small ruminants in the DRC for the first time and indicate variations in exposure to the virus in different parts of the country.
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Affiliation(s)
- Georges M Tshilenge
- Department of Preclinical Medicine, Faculty of Veterinary Medicine, University of Kinshasa, Kinshasa XI.
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van den Bergh C, Venter EH, Swanepoel R, Thompson PN. High seroconversion rate to Rift Valley fever virus in cattle and goats in far northern KwaZulu-Natal, South Africa, in the absence of reported outbreaks. PLoS Negl Trop Dis 2019; 13:e0007296. [PMID: 31050673 PMCID: PMC6519843 DOI: 10.1371/journal.pntd.0007296] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 05/15/2019] [Accepted: 03/12/2019] [Indexed: 11/19/2022] Open
Abstract
Background Rift Valley fever (RVF) is a mosquito-borne zoonotic disease characterized in South Africa by large epidemics amongst ruminant livestock at very long, irregular intervals, mainly in the central interior. However, the presence and patterns of occurrence of the virus in the eastern parts of the country are poorly known. This study aimed to detect the presence of RVF virus (RVFV) in cattle and goats in far northern KwaZulu-Natal province and to estimate the prevalence of antibodies to the virus and the incidence rate of seroconversion. Methodology Cross-sectional studies were performed in communally farmed cattle (n = 423) and goats (n = 104), followed by longitudinal follow-up of seronegative livestock (n = 253) 14 times over 24 months, representing 160.3 animal-years at risk. Exposure to RVFV was assessed using an IgG sandwich ELISA and a serum neutralization test (SNT) and seroconversion was assessed using SNT. Incidence density was estimated and compared using multivariable Poisson models and hazard of seroconversion was estimated over time. Principal findings Initial overall seroprevalence was 34.0% (95%CI: 29.5–38.8%) in cattle and 31.7% (95%CI: 22.9–41.6%) in goats, varying by locality from 18–54%. Seroconversions to RVFV based on SNT were detected throughout the year, with the incidence rate peaking during the high rainfall months of January to March, and differed considerably between years. Overall seroconversion rate in cattle was 0.59 per animal-year (95% CI: 0.46–0.75) and in goats it was 0.41 per animal-year (95% CI: 0.25–0.64), varying significantly over short distances. Conclusions/Significance The high seroprevalence in all age groups and evidence of year-round viral circulation provide evidence for a hyperendemic situation in the study area. This is the first study to directly estimate infection rate of RVFV in livestock in an endemic area in the absence of reported outbreaks and provides the basis for further investigation of factors affecting viral circulation and mechanisms for virus survival during interepidemic periods. Rift Valley fever (RVF) is a mosquito-transmitted viral disease that may cause large epidemics in domestic livestock and in humans. Although currently largely confined to Africa, it is of international concern due to its ability to spread and become established in areas where suitable mosquito vectors occur. Outbreaks occur sporadically, associated with conditions favourable for proliferation of mosquito populations, such as high rainfall and flooding, yet their location and timing remain difficult to predict. In other areas there is evidence that RVF virus is endemic and may circulate without causing outbreaks. However, the location and extent of such areas is poorly known, as is the transmission dynamics of the virus in those areas. In this paper, we report the existence of such an area of endemic RVF virus transmission on the tropical coastal plain of South Africa bordering Mozambique, where we found a high rate of exposure of domestic cattle and goats to the naturally circulating virus over a two-year period, with no outbreaks being reported. Research in such areas will help us to assess the potential for spread of the virus to other areas and also to better understand the behaviour of the virus during periods between epidemics.
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Affiliation(s)
- Carien van den Bergh
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Gauteng, South Africa
| | - Estelle H. Venter
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Gauteng, South Africa
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia
| | - Robert Swanepoel
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Gauteng, South Africa
| | - Peter N. Thompson
- Epidemiology Section, Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Gauteng, South Africa
- * E-mail:
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Kariuki Njenga M, Bett B. Rift Valley Fever Virus—How and Where Virus Is Maintained During Inter-epidemic Periods. CURRENT CLINICAL MICROBIOLOGY REPORTS 2018. [DOI: 10.1007/s40588-018-0110-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Clark MHA, Warimwe GM, Di Nardo A, Lyons NA, Gubbins S. Systematic literature review of Rift Valley fever virus seroprevalence in livestock, wildlife and humans in Africa from 1968 to 2016. PLoS Negl Trop Dis 2018; 12:e0006627. [PMID: 30036382 PMCID: PMC6072204 DOI: 10.1371/journal.pntd.0006627] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 08/02/2018] [Accepted: 06/22/2018] [Indexed: 02/03/2023] Open
Abstract
Background Rift Valley fever virus (RVFV) is a zoonotic arbovirus that causes severe disease in livestock and humans. The virus has caused recurrent outbreaks in Africa and the Arabian Peninsula since its discovery in 1931. This review sought to evaluate RVFV seroprevalence across the African continent in livestock, wildlife and humans in order to understand the spatio-temporal distribution of RVFV seroprevalence and to identify knowledge gaps and areas requiring further research. Risk factors associated with seropositivity were identified and study designs evaluated to understand the validity of their results. Methodology The Preferred Reporting of Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to produce a protocol to systematically search for RVFV seroprevalence studies in PubMed and Web of Science databases. The Strengthening the Reporting of Observational studies in Epidemiology (STROBE) statement guided the evaluation of study design and analyses. Principal findings A total of 174 RVFV seroprevalence studies in 126 articles fulfilled the inclusion criteria. RVFV seroprevalence was recorded in 31 African countries from 1968 to 2016 and varied by time, species and country. RVFV seroprevalence articles including either livestock and humans or livestock and wildlife seroprevalence records were limited in number (8/126). No articles considered wildlife, livestock and human seroprevalence concurrently, nor wildlife and humans alone. Many studies did not account for study design bias or the sensitivity and specificity of diagnostic tests. Conclusions Future research should focus on conducting seroprevalence studies at the wildlife, livestock and human interface to better understand the nature of cross-species transmission of RVFV. Reporting should be more transparent and biases accounted for in future seroprevalence research to understand the true burden of disease on the African continent. Rift Valley fever virus (RVFV) is a vector-borne virus that infects wildlife and livestock, and can subsequently spread to humans. Due to the nature of the disease it has the potential to cause substantial economic and public health impacts. Rift Valley Fever (RVF) has been identified in Africa and the Arabian Peninsula, but has the potential to spread more widely. This systematic review assessed the distribution of RVF in livestock and humans in Africa by collating all the relevant studies we could find, extracting the data and critically evaluating them. Understanding when and where RVF has occurred in Africa and why some animals and humans get disease helps target control strategies and, in particular, those that reduce spread from livestock to humans. Furthermore, by evaluating past studies we can ensure that future ones are more robust and reproducible, so they can help us better understand the disease.
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Affiliation(s)
- Madeleine H. A. Clark
- Transmission Biology Group, The Pirbright Institute, Pirbright, Woking, United Kingdom
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- * E-mail:
| | - George M. Warimwe
- Biosciences Department, Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Antonello Di Nardo
- Vesicular Disease Reference Laboratories, The Pirbright Institute, Pirbright, Woking, United Kingdom
| | - Nicholas A. Lyons
- Vesicular Disease Reference Laboratories, The Pirbright Institute, Pirbright, Woking, United Kingdom
| | - Simon Gubbins
- Transmission Biology Group, The Pirbright Institute, Pirbright, Woking, United Kingdom
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Rissmann M, Eiden M, Wade A, Poueme R, Abdoulkadiri S, Unger H, Ziegler U, Homeier T, Groschup M. Evidence for enzootic circulation of Rift Valley fever virus among livestock in Cameroon. Acta Trop 2017; 172:7-13. [PMID: 28427961 DOI: 10.1016/j.actatropica.2017.04.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 02/22/2017] [Accepted: 04/07/2017] [Indexed: 10/19/2022]
Abstract
Rift Valley fever virus (RVFV) is an arthropod-borne pathogen, causing serious epidemics in Africa and the Arabian Peninsula. In Cameroon serological data indicate the presence of RVFV, but active circulation of RVFV, causing clinical infections has not been proven yet. For this purpose we carried out a serological and molecular study on a total of 1953 randomly selected serum samples of small ruminants and cattle, which were collected in years 2013 and 2014 in Cameroon. In a first step, sera were screened serologically using a variety of assay formats to reveal RVFV specific antibodies. At the second stage, seropositive specimen were assessed for acute RVFV infections via IgM-specific ELISA and quantitative real-time RT-PCR. Our data show a significant difference in the antibody prevalence in cattle (13.5% [95% confidence interval: 11.4-15.7]) and small ruminants (3.4% [95% confidence interval: 2.3-4.7]), with indications for annual fluctuations and significant regional differences of seropositivity. One small ruminant and three bovines were eventually found to be positive in IgM ELISA and indications for viremia were found in one bovine by RVFV genome detection using quantitative real-time RT-PCR. The results of this study therefore corroborate the presence of acute RVFV-infection and its circulation in Cameroon.
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Tambo E, Olalubi OA, Sacko M. Rift valley fever epidemic in Niger near border with Mali. THE LANCET. INFECTIOUS DISEASES 2016; 16:1319-1320. [PMID: 27998581 DOI: 10.1016/s1473-3099(16)30477-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 10/25/2016] [Accepted: 10/26/2016] [Indexed: 11/18/2022]
Affiliation(s)
- Ernest Tambo
- Africa Disease Intelligence and Surveillance, Communication and Response (Africa DISCoR) Institute, Yaoundé, Cameroon; Department Biochemistry and Pharmaceutical Sciences, Higher Institute of Health Sciences, Université des Montagnes, Bangangté, Cameroon.
| | - Oluwasogo A Olalubi
- Department of Public Health, Kwara State University (KWASU), Malete, Nigeria
| | - Moussa Sacko
- Institut National de Recherche en Santé Publique (INRSP), Bamako, Mali
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Jori F, Alexander KA, Mokopasetso M, Munstermann S, Moagabo K, Paweska JT. Serological Evidence of Rift Valley Fever Virus Circulation in Domestic Cattle and African Buffalo in Northern Botswana (2010-2011). Front Vet Sci 2015; 2:63. [PMID: 26664990 PMCID: PMC4672236 DOI: 10.3389/fvets.2015.00063] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 11/09/2015] [Indexed: 11/24/2022] Open
Abstract
Rift Valley fever (RVF) is endemic in many countries in Sub-Saharan Africa and is responsible for severe outbreaks in livestock characterized by a sudden onset of abortions and high neonatal mortality. During the last decade, several outbreaks have occurred in Southern Africa, with a very limited number of cases reported in Botswana. To date, published information on the occurrence of RVF in wild and domestic animals from Botswana is very scarce and outdated, despite being critical to national and regional disease control. To address this gap, 863 cattle and 150 buffalo sampled at the interface between livestock areas and the Chobe National Park (CNP) and the Okavango Delta (OD) were screened for the presence of RVF virus (RVFV) neutralizing antibodies. Antibodies were detected in 5.7% (n = 863), 95% confidence intervals (CI) (4.3–7.5%) of cattle and 12.7% (n = 150), 95% CI (7.8–19.5%) of buffalo samples. The overall prevalence was significantly higher (p = 0.0016) for buffalo [12.7%] than for cattle [5.7%]. Equally, when comparing RVF seroprevalence in both wildlife areas for all pooled bovid species, it was significantly higher in CNP than in OD (9.5 vs. 4%, respectively; p = 0.0004). Our data provide the first evidence of wide circulation of RVFV in both buffalo and cattle populations in Northern Botswana and highlight the need for further epidemiological and ecological investigations on RVF at the wildlife–livestock–human interface in this region.
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Affiliation(s)
- Ferran Jori
- Integrated Animal Risk Management Unit, CIRAD, Campus International de Baillarguet , Montpellier , France ; Department of Animal Science and Production, Botswana College of Agriculture , Gaborone , Botswana
| | - Kathleen A Alexander
- Department of Fish and Wildlife Conservation, Virginia Tech , Blacksburg, VA , USA ; CARACAL, Center for African Resources: Communities, Animals, and Land Use , Kasane , Botswana
| | - Mokganedi Mokopasetso
- FAO-ECTAD Regional Office , Gaborone , Botswana ; Botswana Vaccine Institute , Gaborone , Botswana
| | - Suzanne Munstermann
- FAO-ECTAD Regional Office , Gaborone , Botswana ; World Organization for Animal Health (OIE) , Paris , France
| | | | - Janusz T Paweska
- Center for Emerging and Zoonotic Diseases, National Institute of Communicable Diseases of the National Health Laboratory Service , Johannesburg , South Africa ; Faculty of Health Sciences, University of the Witwatersrand , Johannesburg , South Africa
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