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Sadeghi B, Groschup MH, Eiden M. In silico identification of novel pre-microRNA genes in Rift valley fever virus suggest new pathomechanisms for embryo-fetal dysgenesis. Virulence 2024; 15:2329447. [PMID: 38548679 PMCID: PMC10984114 DOI: 10.1080/21505594.2024.2329447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 03/06/2024] [Indexed: 04/02/2024] Open
Abstract
MicroRNAs (miRNAs) are small non-coding RNAs that regulate the post-transcriptional expression of target genes. Virus-encoded miRNAs play an important role in the replication of viruses, modulate gene expression in both the virus and host, and affect their persistence and immune evasion in hosts. This renders viral miRNAs as potential targets for therapeutic applications, especially against pathogenic viruses that infect humans and animals. Rift Valley fever virus (RVFV) is a mosquito-borne zoonotic RNA virus that causes severe disease in both humans and livestock. High mortality among newborn lambs and abortion storms are key characteristics of an RVF outbreak. To date, limited information is available on RVFV-derived miRNAs. In this study, computational methods were used to analyse the RVFV genome for putative pre-miRNA genes, which were then analysed for the presence of mature miRNAs. We detected 19 RVFV-encoded miRNAs and identified their potential mRNAs targets in sheep (Ovis aries), the most susceptible host. The identification of significantly enriched O. aries genes in association with RVFV miRNAs will help elucidate the molecular mechanisms underlying RVFV pathogenesis and potentially uncover novel drug targets for RVFV.
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Affiliation(s)
- Balal Sadeghi
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Martin H. Groschup
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Martin Eiden
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
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2
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Wang Z, Pei S, Ye R, Chen J, Cheng N, Zhao M, Cao W, Jia Z. Increasing evolution, prevalence, and outbreaks for rift valley fever virus in the process of breaking geographical barriers. Sci Total Environ 2024; 917:170302. [PMID: 38272089 DOI: 10.1016/j.scitotenv.2024.170302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 01/27/2024]
Abstract
BACKGROUND Rift valley fever (RVF) is listed as one of prioritized diseases by WHO. This study aims to describe RVF virus' landscape distribution globally, and to insight dynamics change of its evolution, prevalence, and outbreaks in the process of breaking geographical barriers. METHODS A systematic literature review and meta-analyses was conducted to estimate RVF prevalence by hosts using a random-effect model. Molecular clock-based phylogenetic analyses were performed to estimate RVF virus nucleotide substitution rates using nucleotide sequences in NCBI database. RVF virus prevalence, nucleotide substitution rates, and outbreaks were compared before and after breaking geographical barriers twice, respectively. RESULTS RVF virus was reported from 26 kinds of hosts covering 48 countries from 1930 to 2022. Since RVF broke geographical barriers, (1) nucleotide substitution rates significantly increased after firstly spreading out of Africa in 2000, (2) prevalence in humans significantly increased from 1.92 % (95 % CI: 0.86-3.25 %) to 3.03 % (95 % CI: 2.09-4.12 %) after it broke Sahara Desert geographical barriers in 1977, and to 5.24 % (95 % CI: 3.81-6.82 %) after 2000, (3) RVF outbreaks in humans and the number of wildlife hosts presented increasing trends. RVF virus spillover may exist between bats and humans, and accelerate viral substitution rates in humans. During outbreaks, the RVF virus substitution rates accelerated in humans. 60.00 % RVF outbreaks occurred 0-2 months after floods and (or) heavy rainfall. CONCLUSION RVF has the increasing risk to cause pandemics, and global collaboration on "One Health" is needed to prevent potential pandemics.
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Affiliation(s)
- Zekun Wang
- School of Public Health, Peking University, Beijing, China
| | - Shaojun Pei
- School of Public Health, Peking University, Beijing, China
| | - Runze Ye
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Jingyuan Chen
- School of Public Health, Peking University, Beijing, China
| | - Nuo Cheng
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Mingchen Zhao
- School of Public Health, Peking University, Beijing, China
| | - Wuchun Cao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Zhongwei Jia
- School of Public Health, Peking University, Beijing, China; Center for Intelligent Public Health, Institute for Artificial Intelligence, Peking University, Beijing, China; Center for Drug Abuse Control and Prevention, National Institute of Health Data Science, Peking University, Beijing, China; Peking University Clinical Research Institute, Beijing, China.
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3
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Chemison A, Ramstein G, Jones A, Morse A, Caminade C. Ability of a dynamical climate sensitive disease model to reproduce historical Rift Valley Fever outbreaks over Africa. Sci Rep 2024; 14:3904. [PMID: 38365824 PMCID: PMC10873308 DOI: 10.1038/s41598-024-53774-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 02/05/2024] [Indexed: 02/18/2024] Open
Abstract
Rift Valley Fever (RVF) is a zoonosis transmitted by Aedes and Culex mosquitoes, and is considered a priority pathogen by the WHO. RVF epidemics mostly occur in Africa and can decimate livestock herds, causing significant economic losses and posing health risks for humans. RVF transmission is associated with the occurrence of El Niño events that cause floods in eastern Africa and favour the emergence of mosquitoes in wetlands. Different risk models have been developed to forecast RVF transmission risk but very few studies have validated models at pan-African scale. This study aims to validate the skill of the Liverpool Rift Valley Fever model (LRVF) in reproducing RVF epidemics over Africa and to explore the relationship between simulated climatic suitability for RVF transmission and large-scale climate modes of variability such as the El Niño Southern Oscillation (ENSO) and the Dipole Mode Index (DMI). Our results show that the LRVF model correctly simulates RVF transmission hotspots and reproduces large epidemics that affected African countries. LRVF was able to correctly reproduce major RVF epidemics in Somalia, Kenya, Zambia and to a lesser extent for Mauritania and Senegal. The positive phases of ENSO and DMI are associated with an increased risk of RVF over the Horn of Africa, with important time lags. Following research activities should focus on the development of predictive modelling systems at different time scales.
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Affiliation(s)
- Alizée Chemison
- Laboratoire des Sciences du Climat et de l'Environnement (LSCE), CEA, CNRS, UVSQ, 91190, Gif-sur-Yvette, France
| | - Gilles Ramstein
- Laboratoire des Sciences du Climat et de l'Environnement (LSCE), CEA, CNRS, UVSQ, 91190, Gif-sur-Yvette, France
| | - Anne Jones
- IBM Research Laboratory, Daresbury, WA4 4AD, UK
| | - Andy Morse
- Department of Geography and Planning, School of Environmental Sciences, University of Liverpool, Liverpool, L69 7ZT, UK
| | - Cyril Caminade
- Earth System Physics, Abdus Salam International Centre for Theoretical Physics, 34151, Trieste, Italy.
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Bron GM, Wichgers Schreur PJ, de Jong MCM, van Keulen L, Vloet RPM, Koenraadt CJM, Kortekaas J, ten Bosch QA. Quantifying Rift Valley fever virus transmission efficiency in a lamb-mosquito-lamb model. Front Cell Infect Microbiol 2023; 13:1206089. [PMID: 38170150 PMCID: PMC10759236 DOI: 10.3389/fcimb.2023.1206089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 10/30/2023] [Indexed: 01/05/2024] Open
Abstract
Rift Valley fever virus (RVFV) is a (re)emerging mosquito-borne pathogen impacting human and animal health. How RVFV spreads through a population depends on population-level and individual-level interactions between vector, host and pathogen. Here, we estimated the probability for RVFV to transmit to naive animals by experimentally exposing lambs to a bite of an infectious mosquito, and assessed if and how RVFV infection subsequently developed in the exposed animal. Aedes aegypti mosquitoes, previously infected via feeding on a viremic lamb, were used to expose naive lambs to the virus. Aedes aegypti colony mosquitoes were used as they are easy to maintain and readily feed in captivity. Other mosquito spp. could be examined with similar methodology. Lambs were exposed to either 1-3 (low exposure) or 7-9 (high exposure) infectious mosquitoes. All lambs in the high exposure group became viremic and showed characteristic signs of Rift Valley fever within 2-4 days post exposure. In contrast, 3 out of 12 lambs in the low exposure group developed viremia and disease, with similar peak-levels of viremia as the high exposure group but with some heterogeneity in the onset of viremia. These results suggest that the likelihood for successful infection of a ruminant host is affected by the number of infectious mosquitoes biting, but also highlights that a single bite of an infectious mosquito can result in disease. The per bite mosquito-to-host transmission efficiency was estimated at 28% (95% confidence interval: 15 - 47%). We subsequently combined this transmission efficiency with estimates for life traits of Aedes aegypti or related mosquitoes into a Ross-McDonald mathematical model to illustrate scenarios under which major RVFV outbreaks could occur in naïve populations (i.e., R0 >1). The model revealed that relatively high vector-to-host ratios as well as mosquitoes feeding preferably on competent hosts are required for R0 to exceed 1. Altogether, this study highlights the importance of experiments that mimic natural exposure to RVFV. The experiments facilitate a better understanding of the natural progression of disease and a direct way to obtain epidemiological parameters for mathematical models.
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Affiliation(s)
- Gebbiena M. Bron
- Quantitative Veterinary Epidemiology, Wageningen University and Research, Wageningen, Netherlands
| | | | - Mart C. M. de Jong
- Quantitative Veterinary Epidemiology, Wageningen University and Research, Wageningen, Netherlands
| | - Lucien van Keulen
- Wageningen Bioveterinary Research, Wageningen University and Research, Lelystad, Netherlands
| | - Rianka P. M. Vloet
- Wageningen Bioveterinary Research, Wageningen University and Research, Lelystad, Netherlands
| | | | - Jeroen Kortekaas
- Wageningen Bioveterinary Research, Wageningen University and Research, Lelystad, Netherlands
| | - Quirine A. ten Bosch
- Quantitative Veterinary Epidemiology, Wageningen University and Research, Wageningen, Netherlands
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5
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Tumusiime D, Nijhof AM, Groschup MH, Lutwama J, Roesel K, Bett B. Participatory survey of risk factors and pathways for Rift Valley fever in pastoral and agropastoral communities of Uganda. Prev Vet Med 2023; 221:106071. [PMID: 37984160 DOI: 10.1016/j.prevetmed.2023.106071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 11/01/2023] [Accepted: 11/03/2023] [Indexed: 11/22/2023]
Abstract
To assess pastoralists' and agropastoralists' knowledge on Rift Valley fever (RVF), participatory epidemiological studies were conducted with 215 livestock keepers and 27 key informants in Napak, Butebo, Isingiro and Lyantonde districts, Uganda, between January and February 2022. Livestock keepers in all four districts had knowledge of RVF and even had local names or descriptions for it. Pastoralists and agropastoralists possessed valuable knowledge of RVF clinical descriptions and epidemiological risk factors such as the presence of infected mosquitoes, living in flood-prone areas, and excessive rainfall. RVF was ranked among the top ten most important cattle diseases. Pastoralists called RVF Lonyang, symbolizing a disease associated with jaundice, high fever, abortions in pregnant cows, and sudden death in calves. Key informants identified infected domestic animals, the presence of infected mosquitoes, livestock movement and trade, and infected wild animals as risk pathways for the introduction of RVF into an area. Drinking raw blood and milk was perceived as the most likely pathway for human exposure to RVF virus; while the highest consequence was high treatment costs. The results indicate that pastoralists provided key epidemiological information that could be essential for designing an effective national RVF surveillance and early warning system.
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Affiliation(s)
- Dan Tumusiime
- Freie Universität Berlin, Institute of Parasitology and Tropical Veterinary Medicine, Robert-von-Ostertag-Str. 7-13, 14163 Berlin, Germany; International Livestock Research Institute, P.O. Box 24384, Kampala, Uganda; Ministry of Agriculture, Animal Industry and Fisheries, P.O. Box 103, Entebbe, Uganda.
| | - Ard M Nijhof
- Freie Universität Berlin, Institute of Parasitology and Tropical Veterinary Medicine, Robert-von-Ostertag-Str. 7-13, 14163 Berlin, Germany; Freie Universität Berlin, Veterinary Centre for Resistance Research, Robert-von-Ostertag-Str. 8, 14163 Berlin, Germany
| | - Martin H Groschup
- Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Südufer 10, 17493 Greifswald-Insel Riems, Germany
| | - Julius Lutwama
- Uganda Virus Research Institute, P.O. Box 49, Entebbe, Uganda
| | - Kristina Roesel
- International Livestock Research Institute, P. O. Box 30709, 00100 Nairobi, Kenya
| | - Bernard Bett
- International Livestock Research Institute, P. O. Box 30709, 00100 Nairobi, Kenya
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6
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Wandera N, Olds P, Muhindo R, Ivers L. Rift Valley Fever - The Need for an Integrated Response. N Engl J Med 2023; 389:1829-1832. [PMID: 37861216 DOI: 10.1056/nejmp2308666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2023]
Affiliation(s)
- Nelson Wandera
- From Mbarara University of Science and Technology and the Mbarara Regional Referral Hospital - both in Mbarara, Uganda (N.W., R.M.); and the Center for Global Health, Massachusetts General Hospital, Boston (P.O., L.I.), and the Harvard University Global Health Institute, Cambridge (L.I.) - both in Massachusetts
| | - Peter Olds
- From Mbarara University of Science and Technology and the Mbarara Regional Referral Hospital - both in Mbarara, Uganda (N.W., R.M.); and the Center for Global Health, Massachusetts General Hospital, Boston (P.O., L.I.), and the Harvard University Global Health Institute, Cambridge (L.I.) - both in Massachusetts
| | - Rose Muhindo
- From Mbarara University of Science and Technology and the Mbarara Regional Referral Hospital - both in Mbarara, Uganda (N.W., R.M.); and the Center for Global Health, Massachusetts General Hospital, Boston (P.O., L.I.), and the Harvard University Global Health Institute, Cambridge (L.I.) - both in Massachusetts
| | - Louise Ivers
- From Mbarara University of Science and Technology and the Mbarara Regional Referral Hospital - both in Mbarara, Uganda (N.W., R.M.); and the Center for Global Health, Massachusetts General Hospital, Boston (P.O., L.I.), and the Harvard University Global Health Institute, Cambridge (L.I.) - both in Massachusetts
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7
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Gibson S, Noronha LE, Tubbs H, Cohnstaedt LW, Wilson WC, Mire C, Mitzel D, Anyamba A, Rostal M, Linthicum KJ. The increasing threat of Rift Valley fever virus globalization: strategic guidance for protection and preparation. J Med Entomol 2023; 60:1197-1213. [PMID: 37862067 DOI: 10.1093/jme/tjad113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/25/2023] [Accepted: 08/07/2023] [Indexed: 10/21/2023]
Abstract
Rift Valley fever virus (RVFV) (Bunyavirales: Phlebovirus) is a prominent vector-borne zoonotic disease threat to global agriculture and public health. Risks of introduction into nonendemic regions are tied to changing climate regimes and other dynamic environmental factors that are becoming more prevalent, as well as virus evolutionary factors and human/animal movement. Endemic to the African continent, RVFV has caused large epizootics at the decadal scale since the early 20th century but has spread to the Arabian Peninsula and shows increasing patterns of interepizootic transmission on the annual scale. This virus can be transmitted by mosquitoes as well as through direct contact with infected tissues and can cause sporadic to widespread morbidity and mortality in domestic ungulate livestock as well as humans. High viremias in infected livestock moved for legal and illegal trade as well as in infected mosquitoes or human travelers can spread this virus worldwide. With increasing global commerce, it is likely RVFV will be introduced to new areas with suitable hosts, mosquito vector species, and environments. However, the strong mosquito component of RVFV epidemiology combined with advancements in vaccines, diagnostics, and virus evolutionary factors create opportunities for strategies to leverage models of connectivity among potential source and emerging regions to target surveillance and mitigation activities to reduce the risk of RVFV introduction, or contain the virus should it be introduced, into new regions.
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Affiliation(s)
- Seth Gibson
- USDA Agricultural Research Service Center for Medical, Agricultural, and Veterinary Entomology - Mosquito and Fly Research Unit, Gainesville, FL, USA
| | - Leela E Noronha
- The National Bio- and Agro-Defense Facility, USDA Agricultural Research Service, Foreign Arthropod Borne Animal Diseases Research Unit, Manhattan, KS, USA
| | - Heidi Tubbs
- Geospatial Science and Human Security Division, National Security Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Lee W Cohnstaedt
- The National Bio- and Agro-Defense Facility, USDA Agricultural Research Service, Foreign Arthropod Borne Animal Diseases Research Unit, Manhattan, KS, USA
| | - William C Wilson
- The National Bio- and Agro-Defense Facility, USDA Agricultural Research Service, Foreign Arthropod Borne Animal Diseases Research Unit, Manhattan, KS, USA
| | - Chad Mire
- The National Bio- and Agro-Defense Facility, USDA Agricultural Research Service, Foreign Arthropod Borne Animal Diseases Research Unit, Manhattan, KS, USA
| | - Dana Mitzel
- The National Bio- and Agro-Defense Facility, USDA Agricultural Research Service, Foreign Arthropod Borne Animal Diseases Research Unit, Manhattan, KS, USA
| | - Assaf Anyamba
- Geospatial Science and Human Security Division, National Security Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | | | - Kenneth J Linthicum
- USDA Agricultural Research Service Center for Medical, Agricultural, and Veterinary Entomology - Mosquito and Fly Research Unit, Gainesville, FL, USA
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Marzok M, Alkashif K, Kandeel M, Salem M, Sayed-Ahmed MZ, Selim A. Seroprevalence of Rift Valley Fever virus in one-humped camels (Camelus dromedaries) in Egypt. Trop Anim Health Prod 2023; 55:345. [PMID: 37789189 DOI: 10.1007/s11250-023-03765-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 09/12/2023] [Indexed: 10/05/2023]
Abstract
Rift Valley fever (RVF) is a mosquito-borne viral disease that affects a variety of domestic animals, including cattle, sheep, goats, and camels, and has zoonotic potential. Although the rift valley fever virus (RVFV) is usually asymptomatic in camels, it can induce abortion in some pregnant animals. In the current study, a serosurvey was carried out to investigate the prevalence of RVFV antibodies and related risk factors in camels from four Egyptian governorates. A total of 400 serum samples were examined for anti-RVFV antibodies using a competitive enzyme-linked immunosorbent assay (c-ELISA). The results revealed that the overall prevalence of RVF among examined camels was 21.5% and the disease was more prevalent in Kafr ElSheikh governorate in Nile Delta of Egypt. In addition, the age group of camels with more than 5 years (OR=4.49, 95%CI: 1.39-14.49), the female sex (OR=3.38, 95%CI: 1.51-7.58), the emaciated animals (OR=1.52, 95%CI: 0.86-2.66), the summer season's infection (OR=5.98, 95%CI: 1.79-19.93), the presence of mosquitoes (OR= 2.88, 95%CI: 1.39-5.95), and the absence of mosquitoes control (OR=3.97, 95%CI: 2.09-7.57) were identified as risk factors for RVFV infection. The results of this study support knowledge on the risk factors for RVFV infection and demonstrate that camels raising in Egypt have RVFV antibodies. Quarantine measures or vaccination program should be implemented to reduce the likelihood of RVFV introduction, dissemination among susceptible animals, and ultimately transmission to humans.
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Affiliation(s)
- Mohamed Marzok
- Department of Clinical Sciences, College of Veterinary Medicine, King Faisal University, Al-Ahsa, 31982, Saudi Arabia.
- Department of Surgery, Faculty of Veterinary Medicine, Kafr El Sheikh University, Kafr El Sheikh, Egypt.
| | - Khalid Alkashif
- Department of Pharmacology and Toxicology, College of Pharmacy, Jazan University, Jazan, 82722, Saudi Arabia
| | - Mahmoud Kandeel
- Department of Pharmacology, Faculty of Veterinary Medicine, Kafr elsheikh University, Kafrelsheikh, Egypt
- Department of Biomedical Sciences, College of Veterinary Medicine, King Faisal University, Al-Ahsa, Saudi Arabia
| | - Mohamed Salem
- Department of Clinical Pharmacy, College of Pharmacy, Jazan University, Jazan, 45142, Saudi Arabia
- Department of Medicine and Infectious Diseases, Faculty of Veterinary Medicine, Cairo University, Cairo, 12613, Egypt
| | - Mohamed Z Sayed-Ahmed
- Department of Internal Medicine and Infectious Diseases, Faculty of Veterinary Medicine, Mansoura University, Mansoura, 35516, Egypt
- Department of Animal Medicine (Infectious Diseases), Faculty of Veterinary Medicine, Benha University, Toukh, 13736, Egypt
| | - Abdelfattah Selim
- Department of Animal Medicine (Infectious Diseases), Faculty of Veterinary Medicine, Benha University, Toukh, 13736, Egypt.
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Muturi M, Mwatondo A, Nijhof AM, Akoko J, Nyamota R, Makori A, Nyamai M, Nthiwa D, Wambua L, Roesel K, Thumbi SM, Bett B. Ecological and subject-level drivers of interepidemic Rift Valley fever virus exposure in humans and livestock in Northern Kenya. Sci Rep 2023; 13:15342. [PMID: 37714941 PMCID: PMC10504342 DOI: 10.1038/s41598-023-42596-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 09/12/2023] [Indexed: 09/17/2023] Open
Abstract
Nearly a century after the first reports of Rift Valley fever (RVF) were documented in Kenya, questions on the transmission dynamics of the disease remain. Specifically, data on viral maintenance in the quiescent years between epidemics is limited. We implemented a cross-sectional study in northern Kenya to determine the seroprevalence, risk factors, and ecological predictors of RVF in humans and livestock during an interepidemic period. Six hundred seventy-six human and 1,864 livestock samples were screened for anti-RVF Immunoglobulin G (IgG). Out of the 1,864 livestock samples tested for IgG, a subset of 1,103 samples was randomly selected for additional testing to detect the presence of anti-RVFV Immunoglobulin M (IgM). The anti-RVF virus (RVFV) IgG seropositivity in livestock and humans was 21.7% and 28.4%, respectively. RVFV IgM was detected in 0.4% of the livestock samples. Participation in the slaughter of livestock and age were positively associated with RVFV exposure in humans, while age was a significant factor in livestock. We detected significant interaction between rainfall and elevation's influence on livestock seropositivity, while in humans, elevation was negatively associated with RVF virus exposure. The linear increase of human and livestock exposure with age suggests an endemic transmission cycle, further corroborated by the detection of IgM antibodies in livestock.
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Affiliation(s)
- Mathew Muturi
- Department of Veterinary Medicine, Dahlem Research School of Biomedical Sciences (DRS), Freie Universität Berlin, Berlin, Germany.
- International Livestock Research Institute, Nairobi, Kenya.
- Kenya Zoonotic Disease Unit, Ministry of Health and Ministry of Agriculture, Nairobi, Kenya.
- Center for Epidemiological Modelling and Analysis-University of Nairobi, Nairobi, Kenya.
| | - Athman Mwatondo
- International Livestock Research Institute, Nairobi, Kenya
- Kenya Zoonotic Disease Unit, Ministry of Health and Ministry of Agriculture, Nairobi, Kenya
- Department of Medical Microbiology and Immunology, University of Nairobi, Nairobi, Kenya
| | - Ard M Nijhof
- Veterinary Centre for Resistance Research, Freie Universität Berlin, Berlin, Germany
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Univesität Berlin, Berlin, Germany
| | - James Akoko
- International Livestock Research Institute, Nairobi, Kenya
| | | | - Anita Makori
- Center for Epidemiological Modelling and Analysis-University of Nairobi, Nairobi, Kenya
- Paul G Allen School for Global Health, Washington State University, Pullman, WA, USA
| | - Mutono Nyamai
- Center for Epidemiological Modelling and Analysis-University of Nairobi, Nairobi, Kenya
- Paul G Allen School for Global Health, Washington State University, Pullman, WA, USA
| | - Daniel Nthiwa
- Department of Biological Sciences, University of Embu, Embu, Kenya
| | - Lilian Wambua
- International Livestock Research Institute, Nairobi, Kenya
| | | | - S M Thumbi
- Center for Epidemiological Modelling and Analysis-University of Nairobi, Nairobi, Kenya
- Paul G Allen School for Global Health, Washington State University, Pullman, WA, USA
- Institute for Immunology and Infection Research, University of Edinburgh, Edinburgh, Scotland, UK
| | - Bernard Bett
- International Livestock Research Institute, Nairobi, Kenya
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Ebogo‐Belobo JT, Kenmoe S, Abanda NN, Bowo‐Ngandji A, Mbaga DS, Magoudjou‐Pekam JN, Kame‐Ngasse GI, Tchatchouang S, Menkem EZ, Okobalemba EA, Noura EA, Meta‐Djomsi D, Maïdadi‐Foudi M, Kenfack‐Zanguim J, Kenfack‐Momo R, Kengne‐Nde C, Esemu SN, Mbacham WF, Sadeuh‐Mba SA, Ndip L, Njouom R. Contemporary epidemiological data of Rift Valley fever virus in humans, mosquitoes and other animal species in Africa: A systematic review and meta-analysis. Vet Med Sci 2023; 9:2309-2328. [PMID: 37548116 PMCID: PMC10508527 DOI: 10.1002/vms3.1238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 03/29/2023] [Accepted: 07/21/2023] [Indexed: 08/08/2023] Open
Abstract
Rift Valley fever (RVF) is a severe zoonotic mosquito-borne disease that represents an important threat to human and animal health, with major public health and socioeconomic impacts. This disease is endemic throughout many African countries and the Arabian Peninsula. This systematic review with meta-analysis was conducted to determine the RVF prevalence in humans, mosquitoes and other animal species in Africa. The review also provides contemporary data on RVF case fatality rate (CFR) in humans. In this systematic review with meta-analysis, a comprehensive literature search was conducted on the PubMed, Embase, Web of Science and Global Index Medicus databases from January 2000 to June 2022 to identify relevant studies. Pooled CFR and prevalence estimates were calculated using the random-effects model. Subgroup analysis and sensitivity analysis were performed, and the I2 -statistic was used to investigate a potential source of heterogeneity. A total of 205 articles were included in the final analysis. The overall RVF CFR in humans was found to be 27.5% [95% CI = 8.0-52.5]. The overall pooled prevalence was 7.8% [95% CI = 6.2-9.6] in humans and 9.3% [95% CI = 8.1-10.6] in animals, respectively. The RVF prevalence in individual mosquitoes ranged from 0.0% to 25%. Subgroup analysis showed substantial heterogeneity with respect to geographical regions and human categories. The study shows that there is a correspondingly similar prevalence of RVF in human and animals; however, human CFR is much higher than the observed prevalence. The lack of a surveillance programme and the fact that this virus has subclinical circulation in animals and humans could explain these observations. The implementation of a One Health approach for RVF surveillance and control would be of great interest for human and animal health.
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Affiliation(s)
- Jean Thierry Ebogo‐Belobo
- Centre for Research on Health and Priority PathologiesInstitute of Medical Research and Medicinal Plants StudiesYaoundeCameroon
- Department of BiochemistryFaculty of SciencesThe University of Yaounde IYaoundéCameroon
| | - Sebastien Kenmoe
- Department of Microbiology and ParasitologyUniversity of BueaBueaCameroon
| | - Ngu Njei Abanda
- Virology DepartmentCentre Pasteur of CameroonYaoundéCameroon
| | - Arnol Bowo‐Ngandji
- Department of MicrobiologyFaculty of SciencesThe University of Yaounde IYaoundéCameroon
| | - Donatien Serge Mbaga
- Department of MicrobiologyFaculty of SciencesThe University of Yaounde IYaoundéCameroon
| | | | - Ginette Irma Kame‐Ngasse
- Centre for Research on Health and Priority PathologiesInstitute of Medical Research and Medicinal Plants StudiesYaoundeCameroon
| | | | | | | | - Efietngab Atembeh Noura
- Centre for Research on Health and Priority PathologiesInstitute of Medical Research and Medicinal Plants StudiesYaoundeCameroon
| | - Dowbiss Meta‐Djomsi
- Research Centre on Emerging and Re‐Emerging DiseasesInstitute of Medical Research and Medicinal Plants StudiesYaoundeCameroon
| | - Martin Maïdadi‐Foudi
- Research Centre on Emerging and Re‐Emerging DiseasesInstitute of Medical Research and Medicinal Plants StudiesYaoundeCameroon
| | | | - Raoul Kenfack‐Momo
- Department of BiochemistryFaculty of SciencesThe University of Yaounde IYaoundéCameroon
| | - Cyprien Kengne‐Nde
- Epidemiological Surveillance, Evaluation and Research UnitNational AIDS Control CommitteeYaoundéCameroon
| | | | - Wilfred Fon Mbacham
- Department of BiochemistryFaculty of SciencesThe University of Yaounde IYaoundéCameroon
| | - Serge Alain Sadeuh‐Mba
- Virology DepartmentCentre Pasteur of CameroonYaoundéCameroon
- Maryland Department of AgricultureSalisbury Animal Health LaboratorySalisburyMarylandUSA
| | - Lucy Ndip
- Department of Microbiology and ParasitologyUniversity of BueaBueaCameroon
| | - Richard Njouom
- Virology DepartmentCentre Pasteur of CameroonYaoundéCameroon
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11
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Issae AR, Katakweba AAS, Kicheleri RP, Chengula AA, Kasanga CJ. Knowledge, attitudes and practices on rift valley fever among pastoral and agropastoral communities of Ngorongoro in the rift valley ecosystem, Tanzania, conducted in 2021/2022. PLoS Negl Trop Dis 2023; 17:e0011560. [PMID: 37611063 PMCID: PMC10479901 DOI: 10.1371/journal.pntd.0011560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 09/05/2023] [Accepted: 07/27/2023] [Indexed: 08/25/2023] Open
Abstract
Epidemics of Rift Valley fever (RVF), a mosquito-borne zoonotic disease caused by RVF virus, have been linked to exceptionally heavy rainfall and widespread flooding. The disease is endemic in most African countries and pose a major global health risk. Given that the disease was reported in various districts of Tanzania, we hypothesized a lack of knowledge about RVF epidemiology among agropastoral and pastoral communities. The research took place in a period of 7 months, from July, 2021 to January, 2022. The aim of this study was to assess the knowledge, attitudes, and practices (KAP) among the agropastoral and pastoral communities of Ngorongoro district towards RVF. The survey employed a mixed method system, which included 3 focus groups (each comprised 12 individuals), 20 key informant interviews and administration of questionnaire (N = 352) in agropastoral and pastoral community members of Ngorongoro district. The relationship between demographic characteristics and communities' knowledge, attitudes, and practices regarding RVF was observed using a multiple logistic regression model. A total of 352 participants were interviewed, with the majority (67.61%) being male and 32.39% being female, majority (39.5%) attending primary school, and majority (58.2%) being pastoralists. The findings showed that only 36.1%, 38.64% and 16.19% of participants had good knowledge, positive attitude and good practices regarding RVF respectively. Significant demographic factors related with knowledge included: gender (OR = 1.9, CI = 1.03-3.56, P = 0.041), education levels (primary: OR = 3.97, CI = 2-8.16, P = 0.000; secondary: OR = 15.27, CI = 5.5-46.23, P = 0.000 and college: OR = 34. 23, CI = 5.4-67.22, P = 0.000), and locality (Pinyinyi: OR = 0.14, CI = 0.05-0.38, P = 0.000 and Sale: OR = 0.14, CI = 0.04-0.44, P = 0.001). Male participants showed significant positive attitude towards RVF compared to female (OR = 2.37, CI = 1.35-4.17, P = 0.003). Individuals with formal education showed a significant positive attitude toward RVF compared to informal (OR>1, P<0.05). Agropastoral members showed a significant negative attitude toward RVF compared to pastoralists (OR = 0.51, CI = 0.26-0.99, P = 0.048). The calculated RVF prevention practices values were insignificantly (P = 0.853) correlated with knowledge values. The significant correlation between knowledge and attitude, as well as attitude and practice were found (P<0.05). In general, the study revealed poor knowledge, negative attitude and poor practices of communities towards RVF. The lack of regular education programs to make the communities aware of the disease was implicated for these findings. This recommends that provision of health education should be a long-term practice among agropastoral and pastoral communities in order to prevent further RVF outbreaks in Tanzania.
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Affiliation(s)
- Amina Ramadhani Issae
- African Centre of Excellence for Innovative Rodent Pest Management and Biosensor Technology Development, Sokoine University of Agriculture, Morogoro, Tanzania
- Department of Wildlife Management, Sokoine University of Agriculture, Morogoro, Tanzania
- Institute of Pest Management, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Abdul Ahmed Selemani Katakweba
- African Centre of Excellence for Innovative Rodent Pest Management and Biosensor Technology Development, Sokoine University of Agriculture, Morogoro, Tanzania
- Institute of Pest Management, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Rose Peter Kicheleri
- Department of Wildlife Management, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Augustino Alfred Chengula
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Christopher Jacob Kasanga
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro, Tanzania
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12
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McMillen CM, Chapman NS, Hoehl RM, Skvarca LB, Schwarz MM, Handal LS, Crowe JE, Hartman AL. A highly potent human neutralizing antibody prevents vertical transmission of Rift Valley fever virus in a rat model. Nat Commun 2023; 14:4507. [PMID: 37495594 PMCID: PMC10372071 DOI: 10.1038/s41467-023-40187-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Accepted: 07/17/2023] [Indexed: 07/28/2023] Open
Abstract
Rift Valley fever virus (RVFV) is an emerging mosquito-transmitted virus that circulates in livestock and humans in Africa and the Middle East. Outbreaks lead to high rates of miscarriages in domesticated livestock. Women are also at risk of vertical virus transmission and late-term miscarriages. MAb RVFV-268 is a highly potent recombinant neutralizing human monoclonal antibody that targets RVFV. Here we show that mAb RVFV-268 reduces viral replication in rat placenta explant cultures and prevents vertical transmission in a rat model of congenital RVF. Passive transfer of mAb RVFV-268 from mother to fetus occurs as early as 6 h after administration and persists through 24 h. Administering mAb RVFV-268 2 h prior to RVFV challenge or 24 h post-challenge protects the dams and offspring from RVFV infection. These findings support mAb RVFV-268 as a pre- and post-infection treatment to subvert RVFV infection and vertical transmission, thus protecting the mother and offspring.
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Affiliation(s)
- Cynthia M McMillen
- University of Pittsburgh, Center for Vaccine Research, Pittsburgh, PA, USA
- University of Pittsburgh, Department of Infectious Diseases and Microbiology, School of Public Health, Pittsburgh, PA, USA
| | - Nathaniel S Chapman
- Vanderbilt University Medical Center, Department of Pathology, Microbiology and Immunology, Nashville, TN, USA
| | - Ryan M Hoehl
- University of Pittsburgh, Center for Vaccine Research, Pittsburgh, PA, USA
| | - Lauren B Skvarca
- University of Pittsburgh Medical Center, Magee-Womens Hospital, Department of Pathology, Pittsburgh, PA, USA
| | - Madeline M Schwarz
- University of Pittsburgh, Center for Vaccine Research, Pittsburgh, PA, USA
- University of Pittsburgh, Department of Infectious Diseases and Microbiology, School of Public Health, Pittsburgh, PA, USA
| | - Laura S Handal
- Vanderbilt University Medical Center, Vanderbilt Vaccine Center, Nashville, TN, USA
| | - James E Crowe
- Vanderbilt University Medical Center, Department of Pathology, Microbiology and Immunology, Nashville, TN, USA.
- Vanderbilt University Medical Center, Vanderbilt Vaccine Center, Nashville, TN, USA.
- Vanderbilt University Medical Center, Department of Pediatrics, Nashville, TN, USA.
| | - Amy L Hartman
- University of Pittsburgh, Center for Vaccine Research, Pittsburgh, PA, USA.
- University of Pittsburgh, Department of Infectious Diseases and Microbiology, School of Public Health, Pittsburgh, PA, USA.
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13
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Kabami Z, Ario AR, Migisha R, Naiga HN, Nankya AM, Ssebutinde P, Nahabwe C, Omia S, Mugabi F, Muwanguzi D, Muruta A, Kayiwa J, Gidudu S, Kadobera D, Nyakarahuka L, Baluku J, Balinandi S, Cossaboom CM, Harris JR. Notes from the Field: Rift Valley Fever Outbreak - Mbarara District, Western Uganda, January-March 2023. MMWR Morb Mortal Wkly Rep 2023; 72:639-640. [PMID: 37289672 PMCID: PMC10328460 DOI: 10.15585/mmwr.mm7223a6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
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14
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Nyakarahuka L, Whitmer S, Klena J, Balinandi S, Talundzic E, Tumusiime A, Kyondo J, Mulei S, Patel K, Baluku J, Akurut G, Namanya D, Kamugisha K, Cossaboom C, Whitesell A, Telford C, Graziano J, Montgomery J, Nichol S, Lutwama J, Shoemaker T. Detection of Sporadic Outbreaks of Rift Valley Fever in Uganda through the National Viral Hemorrhagic Fever Surveillance System, 2017-2020. Am J Trop Med Hyg 2023; 108:995-1002. [PMID: 36913925 PMCID: PMC10160879 DOI: 10.4269/ajtmh.22-0410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 11/22/2022] [Indexed: 03/15/2023] Open
Abstract
Rift Valley fever (RVF) is a zoonotic disease of public health and economic importance. Uganda has reported sporadic outbreaks of RVF in both humans and animals across the country, especially in the southwestern part of the "cattle corridor" through an established viral hemorrhagic fever surveillance system. We report 52 human cases of laboratory-confirmed RVF from 2017 to 2020. The case fatality rate was 42%. Among those infected, 92% were males and 90% were adults (≥ 18 years). Clinical symptoms were characterized by fever (69%), unexplained bleeding (69%), headache (51%), abdominal pain (49%), and nausea and vomiting (46%). Most of the cases (95%) originated from central and western districts that are part of the cattle corridor of Uganda, where the main risk factor was direct contact with livestock (P = 0.009). Other predictors of RVF positivity were determined to be male gender (P = 0.001) and being a butcher (P = 0.04). Next-generation sequencing identified the predominant Ugandan clade as Kenya-2, observed previously across East Africa. There is need for further investigation and research into the effect and spread of this neglected tropical disease in Uganda and the rest of Africa. Control measures such as promoting vaccination and limiting animal-human transmission could be explored to reduce the impact of RVF in Uganda and globally.
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Affiliation(s)
- Luke Nyakarahuka
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
- Department of Biosecurity, Ecosystems and Veterinary Public Health, Makerere University, Kampala, Uganda
| | - Shannon Whitmer
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - John Klena
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Stephen Balinandi
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | - Emir Talundzic
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Alex Tumusiime
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | - Jackson Kyondo
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | - Sophia Mulei
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | - Ketan Patel
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Jimmy Baluku
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | | | | | | | - Caitlin Cossaboom
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Amy Whitesell
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Carson Telford
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - James Graziano
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Joel Montgomery
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Stuart Nichol
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Julius Lutwama
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | - Trevor Shoemaker
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
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15
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Telford C, Nyakarahuka L, Waller L, Kitron U, Shoemaker T. Geostatistical Modeling and Prediction of Rift Valley Fever Seroprevalence among Livestock in Uganda. Am J Trop Med Hyg 2023; 108:712-721. [PMID: 36878208 PMCID: PMC10076992 DOI: 10.4269/ajtmh.22-0555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 12/19/2022] [Indexed: 03/08/2023] Open
Abstract
Uganda reported cases of Rift Valley fever virus (RVFV) for the first time in almost 50 years in 2016, following an outbreak of Rift Valley fever (RVF) that caused four human infections, two of which resulted in death. Subsequent outbreak investigation serosurveys found high seroprevalence of IgG antibodies without evidence of acute infection or IgM antibodies, suggesting the possibility of undetected RVFV circulation prior to the outbreak. After the 2016 outbreak investigation, a serosurvey was conducted in 2017 among domesticated livestock herds across Uganda. Sampling data were incorporated into a geostatistical model to estimate RVF seroprevalence among cattle, sheep, and goats. Variables resulting in the best fit to RVF seroprevalence sampling data included annual variability in monthly precipitation and enhanced vegetation index, topographic wetness index, log human population density percent increase, and livestock species. Individual species RVF seroprevalence prediction maps were created for cattle, sheep, and goats, and a composite livestock prediction was created based on the estimated density of each species across the country. Seroprevalence was greater in cattle compared with sheep and goats. Predicted seroprevalence was greatest in the central and northwestern quadrant of the country, surrounding Lake Victoria, and along the Southern Cattle Corridor. We identified areas that experienced conditions conducive to potential increased RVFV circulation in 2021 in central Uganda. An improved understanding of the determinants of RVFV circulation and locations with high probability of elevated RVF seroprevalence can guide prioritization of disease surveillance and risk mitigation efforts.
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Affiliation(s)
- Carson Telford
- Viral Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
- Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina
| | - Luke Nyakarahuka
- Uganda Virus Research Institute
- Department of Biosecurity, Ecosystems and Veterinary Public Health, Makerere University, Kampala, Uganda
| | - Lance Waller
- Rollins School of Public Health, Emory University, Atlanta, Georgia
| | - Uriel Kitron
- Rollins School of Public Health, Emory University, Atlanta, Georgia
| | - Trevor Shoemaker
- Viral Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
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16
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Rahman MM, Islam MR, Dhar PS. Recent re-emergence of Rift Valley fever: epidemiology, clinical characteristics, transmission, symptoms, diagnosis, prevention, and treatment. Int J Surg 2023; 109:117-119. [PMID: 36799821 PMCID: PMC10389314 DOI: 10.1097/js9.0000000000000043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 11/20/2022] [Indexed: 02/18/2023]
Affiliation(s)
- Md. Mominur Rahman
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, Dhaka, Bangladesh
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Abstract
BACKGROUND Epidemic retinitis occurs seasonally following febrile infections in endemic regions. Rift valley fever (RVF) is endemic to Sudan, with a recent outbreak starting in 2019. METHODS Retrospective case series of 3 patients travelling from Sudan with post-febrile retinitis, and with a history and clinical picture suggestive of RVF retinitis. RESULTS The three patients were adult males with underlying medical conditions and underwent fundus fluorescein angiography that confirmed bilateral retinitis and occlusive vasculitis involving the posterior pole. Optical coherence tomography showed distortion of the macular layers. Case 2 presented 1 month following febrile illness and had retinal thinning, with optical coherence tomography angiography showing marked reduction in vessel density. CONCLUSION We present multimodal imaging data of three cases with presumed RVF retinitis from a recent outbreak in Sudan. The unavailability of standardized methods of testing for RVF, as is the case for most epidemic retinitis-causing pathogens, makes the diagnosis challenging.
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Affiliation(s)
- Yousef A Fouad
- Al Mashreq Eye Center, Cairo, Egypt
- Department of Ophthalmology, 68792Ain Shams University Hospitals, Cairo, Egypt
| | | | - Ahmed B Sallam
- Jones Eye Institute, 12215University of Arkansas for Medical Sciences, Little Rock, AR, USA
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18
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Cossaboom CM, Nyakarahuka L, Mulei S, Kyondo J, Tumusiime A, Baluku J, Akurut GG, Namanya D, Kamugisha K, Nansikombi HT, Nyabakira A, Mutesasira S, Whitmer S, Telford C, Lutwama J, Balinandi S, Montgomery J, Klena JD, Shoemaker T. Rift Valley Fever Outbreak during COVID-19 Surge, Uganda, 2021. Emerg Infect Dis 2022; 28:2290-2293. [PMID: 36150455 PMCID: PMC9622231 DOI: 10.3201/eid2811.220364] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Rift Valley fever, endemic or emerging throughout most of Africa, causes considerable risk to human and animal health. We report 7 confirmed Rift Valley fever cases, 1 fatal, in Kiruhura District, Uganda, during 2021. Our findings highlight the importance of continued viral hemorrhagic fever surveillance, despite challenges associated with the COVID-19 pandemic.
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Ronchi GF, Testa L, Iorio M, Pinoni C, Bortone G, Dondona AC, Rossi E, Capista S, Mercante MT, Morelli D, Di Ventura M, Monaco F. Immunogenicity and safety studies of an inactivated vaccine against Rift Valley fever. Acta Trop 2022; 232:106498. [PMID: 35513072 DOI: 10.1016/j.actatropica.2022.106498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 04/20/2022] [Accepted: 04/30/2022] [Indexed: 11/29/2022]
Abstract
Rift Valley fever (RVF) is an emerging transboundary, mosquito-borne, zoonotic viral disease caused by a single serotype of a virus belonging to the Phenuiviridae family (genus Phlebovirus). It is considered an important threat to both agriculture and public health in endemic areas, because the virus, transmitted by different mosquito genera, leads to abortions in susceptible animal hosts especially sheep, goat, cattle, and buffaloes, resulting in severe economic losses. Humans can also acquire the infection, and the major sources are represented by the direct contact with infected animal blood, aerosol, consumption of unpasteurized contaminated milk and the bite of infected mosquitoes. Actually, the EU territory does not seem to be exposed to an imminent risk of RVFV introduction, however, the recent outbreaks in a French overseas department and some cases detected in Turkey, Tunisia and Libya, raised the attention of the EU for a possible risk of introduction of infected vectors. Thus, there is an urgent need to develop new therapeutic and/or preventive drugs, such as vaccines. In our work, we studied the immunogenicity of an inactivated and adjuvanted vaccine produced using a Namibian field strain of RVF virus (RVFV). The vaccine object of this study was formulated with Montanide Pet Gel A, a polymer-based adjuvant that has been previously reported for its promising safety profile and for the capacity to elicit a strong immune response. The produced inactivated vaccine was tested on six sheep and the level of IgM and IgG after the immunization of animals was evaluated by a commercial competitive ELISA, in order to assess the immunogenicity profile of our vaccine and to evaluate its potential use, as an alternative to the attenuated vaccines commercially available, in case of Rift Valley fever epidemic disease on EU territory. Following the administration of the second dose, 35 days after the first one, all animals seroconverted.
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Affiliation(s)
| | - Lilia Testa
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale, Teramo, Italy
| | - Mariangela Iorio
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale, Teramo, Italy.
| | - Chiara Pinoni
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale, Teramo, Italy
| | - Grazia Bortone
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale, Teramo, Italy
| | | | - Emanuela Rossi
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale, Teramo, Italy
| | - Sara Capista
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale, Teramo, Italy
| | - Maria Teresa Mercante
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale, Teramo, Italy
| | - Daniela Morelli
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale, Teramo, Italy
| | - Mauro Di Ventura
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale, Teramo, Italy
| | - Federica Monaco
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale, Teramo, Italy
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20
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Sindato C, Karimuribo ED, Vairo F, Misinzo G, Rweyemamu MM, Hamid MMA, Haider N, Tungu PK, Kock R, Rumisha SF, Mbilu T, Ntoumi F, Zumla A, Mboera LEG. Rift Valley fever seropositivity in humans and domestic ruminants and associated risk factors in Sengerema, Ilala, and Rufiji districts, Tanzania. Int J Infect Dis 2022; 122:559-565. [PMID: 35811085 DOI: 10.1016/j.ijid.2022.07.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/09/2022] [Accepted: 07/03/2022] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES Data on Rift Valley fever virus (RVFV) prevalence in urban settings and pastoral areas of Tanzania are scarce. We performed a cross-sectional study of RVFV seroprevalence and determinants in humans and animals from Ilala, Rufiji, and Sengerema districts of Tanzania. METHODS Blood samples from the study participants were tested for anti-RVFV immunoglobulin G (IgG) antibodies using an enzyme-linked immunosorbent assay. Logistic regression was used to determine association between exposure risk practices and RVFV seropositivity. RESULTS The study involved 664 humans, 361 cattle, 394 goats, and 242 sheep. The overall anti-RVFV IgG seroprevalence in humans and animals was 2.1% (95% confidence interval [CI] 0.01-0.04) and 9.5% (n = 95, 95% CI 0.08-0.12), respectively. Seroprevalence in humans in Rufiji, Ilala, and Sengerema was 3.0% (n = 225, 95% CI 0.01-0.06), 1.8% (n = 230, 95% CI-0.005- 0.04), and 1.4% (n = 209, 95% CI 0.01-0.04), respectively (P >0.05). Seroprevalence in animals in Sengerema, Rufiji, and Ilala was 12.1% (n = 40, 95% CI 0.09-0.16), 11.1% (n = 37, 95% CI 0.08-0.15), and 5.4% (n = 18, 95% CI 0.03-0.08), respectively (P = 0.006). Handling of carcasses increased the odds of RVFV seropositivity 12-fold (odds ratio 11.84, 95% CI 1.97-71.16). CONCLUSION The study confirms previous occurrence of RVFV in multiple species in the study districts. Animal handling practices appear to be essential determinants of seropositivity.
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Affiliation(s)
- Calvin Sindato
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania; National Institute for Medical Research, Tabora Research Centre, Tabora, Tanzania.
| | - Esron D Karimuribo
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania; Department of Veterinary Medicine and Public Health, Sokoine University of Agriculture, Morogoro, Tanzania.
| | - Francesco Vairo
- National Institute for Infectious Diseases Lazzaro Spallanzani, Rome, Italy.
| | - Gerald Misinzo
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania; Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro, Tanzania.
| | - Mark M Rweyemamu
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania.
| | | | - Najmul Haider
- The Royal Veterinary College, University of London, Hatfield, United Kingdom.
| | - Patrick K Tungu
- National Institute for Medical Research, Amani Research Centre, Muheza, Tanzania.
| | - Richard Kock
- The Royal Veterinary College, University of London, Hatfield, United Kingdom.
| | - Susan F Rumisha
- National Institute for Medical Research, The Headquarters, Dar es Salaam, Tanzania; Malaria Atlas Project, Geospatial Health and Development, Telethon Kids Institute, West Perth, Australia.
| | - Togolai Mbilu
- National Institute for Medical Research, Tabora Research Centre, Tabora, Tanzania.
| | - Francine Ntoumi
- Fondation Congolaise pour la Recherche Médicale, Brazzaville, Republic of Congo; Faculty of Sciences and Technology, University Marien Ngouabi, Brazzaville, Republic of Congo; University of Tübingen, Tübingen, Germany.
| | - Alimuddin Zumla
- Division of Infection and Immunity, Centre for Clinical Microbiology, University College London, United Kingdom; NIHR Biomedical Research Centre, UCL Hospitals NHS Foundation Trust, London, United Kingdom.
| | - Leonard E G Mboera
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania.
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21
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Borrego B, Moreno S, López-Valiñas Á, de la Losa N, Weber F, Núñez JI, Brun A. Identification of Single Amino Acid Changes in the Rift Valley Fever Virus Polymerase Core Domain Contributing to Virus Attenuation In Vivo. Front Cell Infect Microbiol 2022; 12:875539. [PMID: 35573791 PMCID: PMC9096444 DOI: 10.3389/fcimb.2022.875539] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 03/31/2022] [Indexed: 11/18/2022] Open
Abstract
Rift Valley fever (RVF) is an arboviral zoonotic disease affecting many African countries with the potential to spread to other geographical areas. RVF affects sheep, goats, cattle and camels, causing a high rate of abortions and death of newborn lambs. Also, humans can be infected, developing a usually self-limiting disease that can turn into a more severe illness in a low percentage of cases. Although different veterinary vaccines are available in endemic areas in Africa, to date no human vaccine has been licensed. In previous works, we described the selection and characterization of a favipiravir-mutagenized RVFV variant, termed 40Fp8, with potential as a RVF vaccine candidate due to the strong attenuation shown in immunocompromised animal models. Compared to the parental South African 56/74 viral strain, 40Fp8 displayed 7 amino acid substitutions in the L-protein, three of them located in the central region corresponding to the catalytic core of the RNA-dependent RNA polymerase (RdRp). In this work, by means of a reverse genetics system, we have analyzed the effect on virulence of these amino acid changes, alone or combined, both in vitro and in vivo. We found that the simultaneous introduction of two changes (G924S and A1303T) in the heterologous ZH548-RVFV Egyptian strain conferred attenuated phenotypes to the rescued viruses as shown in infected mice without affecting virus immunogenicity. Our results suggest that both changes induce resistance to favipiravir likely associated to some fitness cost that could be the basis for the observed attenuation in vivo. Conversely, the third change, I1050V, appears to be a compensatory mutation increasing viral fitness. Altogether, these results provide relevant information for the safety improvement of novel live attenuated RVFV vaccines.
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Affiliation(s)
- Belén Borrego
- Centro de Investigación en Sanidad Animal, CISA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria/Consejo Superior de Investigaciones Científicas (INIA/CSIC)), Madrid, Spain
- *Correspondence: Belén Borrego, ; Alejandro Brun,
| | - Sandra Moreno
- Centro de Investigación en Sanidad Animal, CISA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria/Consejo Superior de Investigaciones Científicas (INIA/CSIC)), Madrid, Spain
| | - Álvaro López-Valiñas
- Centre de Recerca en Sanitat Animal, Centre de Recerca en Sanitat Animal (CReSA) Institut de Recerca en Tecnologies Agroalimentàries (IRTA), Barcelona, Spain
| | - Nuria de la Losa
- Centro de Investigación en Sanidad Animal, CISA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria/Consejo Superior de Investigaciones Científicas (INIA/CSIC)), Madrid, Spain
| | - Friedemann Weber
- Institut für Virologie, FB10-Veterinary Medicine, Justus-Liebig-Universität Giessen, Giessen, Germany
| | - José Ignacio Núñez
- Centre de Recerca en Sanitat Animal, Centre de Recerca en Sanitat Animal (CReSA) Institut de Recerca en Tecnologies Agroalimentàries (IRTA), Barcelona, Spain
| | - Alejandro Brun
- Centro de Investigación en Sanidad Animal, CISA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria/Consejo Superior de Investigaciones Científicas (INIA/CSIC)), Madrid, Spain
- *Correspondence: Belén Borrego, ; Alejandro Brun,
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22
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Anywaine Z, Lule SA, Hansen C, Warimwe G, Elliott A. Clinical manifestations of Rift Valley fever in humans: Systematic review and meta-analysis. PLoS Negl Trop Dis 2022; 16:e0010233. [PMID: 35333856 PMCID: PMC8986116 DOI: 10.1371/journal.pntd.0010233] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 04/06/2022] [Accepted: 02/03/2022] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Rift Valley fever (RVF) is an emerging, neglected, mosquito-borne viral zoonosis associated with significant morbidity, mortality and expanding geographical scope. The clinical signs and symptoms in humans are non-specific and case definitions vary. We reviewed and analysed the clinical manifestations of RVF in humans. METHODS In this systematic review and meta-analysis we searched on different dates, the Embase (from 1947 to 13th October 2019), Medline (1946 to 14th October 2019), Global Health (1910 to 15th October 2019), and Web of Science (1970 to 15th October 2019) databases. Studies published in English, reporting frequency of symptoms in humans, and laboratory confirmed RVF were included. Animal studies, studies among asymptomatic volunteers, and single case reports for which a proportion could not be estimated, were excluded. Quality assessment was done using a modified Hoy and Brooks et al tool, data was extracted, and pooled frequency estimates calculated using random effects meta-analysis. RESULTS Of the 3765 articles retrieved, less than 1% (32 articles) were included in the systematic review and meta-analysis. Nine RVF clinical syndromes were reported including the general febrile, renal, gastrointestinal, hepatic, haemorrhagic, visual, neurological, cardio-pulmonary, and obstetric syndromes. The most common clinical manifestations included fever (81%; 95% Confidence Interval (CI) 69-91; [26 studies, 1286 patients]), renal failure (41%; 23-59; [4, 327]), nausea (38%; 12-67; [6, 325]), jaundice (26%; 16-36; [15, 393]), haemorrhagic disease (26%; 17-36; [16, 277]), partial blindness (24%; 7-45; [11, 225]), encephalitis (21%; 11-33; [4, 327]), cough (4%; 0-17; [4, 11]), and miscarriage (54%) respectively. Death occurred in 21% (95% CI 14-29; [16 studies, 328 patients]) of cases, most of whom were hospitalised. DISCUSSION This study delineates the complex symptomatology of human RVF disease into syndromes. This approach is likely to improve case definitions and detection rates, impact outbreak control, increase public awareness about RVF, and subsequently inform 'one-health' policies. This study provides a pooled estimate of the proportion of RVF clinical manifestations alongside a narrative description of clinical syndromes. However, most studies reviewed were case series with small sample sizes and enrolled mostly in-patients and out-patients, and captured symptoms either sparsely or using broad category terms.
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Affiliation(s)
- Zacchaeus Anywaine
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe, Uganda
- * E-mail:
| | - Swaib Abubaker Lule
- Institute for Global Health, University College London, London, United Kingdom
| | - Christian Hansen
- Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe, Uganda
- MRC International Statistics & Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - George Warimwe
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
- KEMRI WellcomeTrust Research Programme, Kilifi, Kenya
| | - Alison Elliott
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe, Uganda
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23
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Seck I, Lo MM, Fall AG, Diop M, Ciss M, Cêtre-Sossah CB, Faye C, Lo M, Gaye AM, Coste C, Squarzoni-Diaw C, Alambedji RB, Sall B, Apolloni A, Lancelot R. Identification of drivers of Rift Valley fever after the 2013–14 outbreak in Senegal using serological data in small ruminants. PLoS Negl Trop Dis 2022; 16:e0010024. [PMID: 35108284 PMCID: PMC8843136 DOI: 10.1371/journal.pntd.0010024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 02/14/2022] [Accepted: 11/24/2021] [Indexed: 11/18/2022] Open
Abstract
Rift Valley fever (RVF) is a mosquito-borne disease mostly affecting wild and domestic ruminants. It is widespread in Africa, with spillovers in the Arab Peninsula and the southwestern Indian Ocean. Although RVF has been circulating in West Africa for more than 30 years, its epidemiology is still not clearly understood. In 2013, an RVF outbreak hit Senegal in new areas that weren’t ever affected before. To assess the extent of the spread of RVF virus, a national serological survey was implemented in young small ruminants (6–18 months old), between November 2014 and January 2015 (after the rainy season) in 139 villages. Additionally, the drivers of this spread were identified. For this purpose, we used a beta-binomial ( BB) logistic regression model. An Integrated Nested Laplace Approximation (INLA) approach was used to fit the spatial model. Lower cumulative rainfall, and higher accessibility were both associated with a higher RVFV seroprevalence. The spatial patterns of fitted RVFV seroprevalence pointed densely populated areas of western Senegal as being at higher risk of RVFV infection in small ruminants than rural or southeastern areas. Thus, because slaughtering infected animals and processing their fresh meat is an important RVFV transmission route for humans, more human populations might have been exposed to RVFV during the 2013–2014 outbreak than in previous outbreaks in Senegal. An outbreak of Rift Valley fever (RVF)–a zoonotic mosquito-borne viral infection widespread in Africa, was reported in 2013–14 in Senegal. After its end in late 2014, its spatial distribution and drivers were assessed using a national serological survey in small ruminants, thus highlighting the high exposition of humans to RVF virus in urban areas.
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Affiliation(s)
- Ismaila Seck
- Food and Agriculture Organization of the United Nations (FAO), Regional Office for Africa (RAF), Accra, Ghana
- Direction des Services vétérinaires (DSV), Dakar, Sénégal
- * E-mail:
| | - Modou Moustapha Lo
- Institut Sénégalais de Recherches Agricoles (ISRA), Laboratoire National de l’Élevage et de Recherches Vétérinaires (LNERV), Dakar-Hann, Sénégal
| | - Assane Gueye Fall
- Institut Sénégalais de Recherches Agricoles (ISRA), Laboratoire National de l’Élevage et de Recherches Vétérinaires (LNERV), Dakar-Hann, Sénégal
| | - Mariane Diop
- Institut Sénégalais de Recherches Agricoles (ISRA), Laboratoire National de l’Élevage et de Recherches Vétérinaires (LNERV), Dakar-Hann, Sénégal
| | - Mamadou Ciss
- Institut Sénégalais de Recherches Agricoles (ISRA), Laboratoire National de l’Élevage et de Recherches Vétérinaires (LNERV), Dakar-Hann, Sénégal
| | - Catherine Béatrice Cêtre-Sossah
- ASTRE, Univ. Montpellier, CIRAD, INRAE, Montpellier, France
- Centre de cooperation internationale en recherche agronomique pour le développement (CIRAD), UMR ASTRESainte Clotilde, la Réunion, France
| | - Coumba Faye
- Direction des Services vétérinaires (DSV), Dakar, Sénégal
| | - Mbargou Lo
- Direction des Services vétérinaires (DSV), Dakar, Sénégal
| | | | - Caroline Coste
- ASTRE, Univ. Montpellier, CIRAD, INRAE, Montpellier, France
- Centre de cooperation internationale en recherche agronomique pour le développement (CIRAD), UMR ASTRE, Montpellier, France
| | - Cécile Squarzoni-Diaw
- ASTRE, Univ. Montpellier, CIRAD, INRAE, Montpellier, France
- Centre de cooperation internationale en recherche agronomique pour le développement (CIRAD), UMR ASTRESainte Clotilde, la Réunion, France
| | | | - Baba Sall
- Direction des Services vétérinaires (DSV), Dakar, Sénégal
| | - Andrea Apolloni
- Institut Sénégalais de Recherches Agricoles (ISRA), Laboratoire National de l’Élevage et de Recherches Vétérinaires (LNERV), Dakar-Hann, Sénégal
- ASTRE, Univ. Montpellier, CIRAD, INRAE, Montpellier, France
- Centre de cooperation internationale en recherche agronomique pour le développement (CIRAD), UMR ASTRE, Montpellier, France
| | - Renaud Lancelot
- Centre de cooperation internationale en recherche agronomique pour le développement (CIRAD), UMR ASTRESainte Clotilde, la Réunion, France
- Centre de cooperation internationale en recherche agronomique pour le développement (CIRAD), UMR ASTRE, Montpellier, France
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24
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Gerken KN, LaBeaud AD, Mandi H, L’Azou Jackson M, Breugelmans JG, King CH. Paving the way for human vaccination against Rift Valley fever virus: A systematic literature review of RVFV epidemiology from 1999 to 2021. PLoS Negl Trop Dis 2022; 16:e0009852. [PMID: 35073355 PMCID: PMC8812886 DOI: 10.1371/journal.pntd.0009852] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 02/03/2022] [Accepted: 12/22/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Rift Valley fever virus (RVFV) is a lethal threat to humans and livestock in many parts of Africa, the Arabian Peninsula, and the Indian Ocean. This systematic review's objective was to consolidate understanding of RVFV epidemiology during 1999-2021 and highlight knowledge gaps relevant to plans for human vaccine trials. METHODOLOGY/PRINCIPAL FINDINGS The review is registered with PROSPERO (CRD42020221622). Reports of RVFV infection or exposure among humans, animals, and/or vectors in Africa, the Arabian Peninsula, and the Indian Ocean during the period January 1999 to June 2021 were eligible for inclusion. Online databases were searched for publications, and supplemental materials were recovered from official reports and research colleagues. Exposures were classified into five groups: 1) acute human RVF cases, 2) acute animal cases, 3) human RVFV sero-surveys, 4) animal sero-surveys, and 5) arthropod infections. Human risk factors, circulating RVFV lineages, and surveillance methods were also tabulated. In meta-analysis of risks, summary odds ratios were computed using random-effects modeling. 1104 unique human or animal RVFV transmission events were reported in 39 countries during 1999-2021. Outbreaks among humans or animals occurred at rates of 5.8/year and 12.4/year, respectively, with Mauritania, Madagascar, Kenya, South Africa, and Sudan having the most human outbreak years. Men had greater odds of RVFV infection than women, and animal contact, butchering, milking, and handling aborted material were significantly associated with greater odds of exposure. Animal infection risk was linked to location, proximity to water, and exposure to other herds or wildlife. RVFV was detected in a variety of mosquito vectors during interepidemic periods, confirming ongoing transmission. CONCLUSIONS/SIGNIFICANCE With broad variability in surveillance, case finding, survey design, and RVFV case confirmation, combined with uncertainty about populations-at-risk, there were inconsistent results from location to location. However, it was evident that RVFV transmission is expanding its range and frequency. Gaps assessment indicated the need to harmonize human and animal surveillance and improve diagnostics and genotyping. Given the frequency of RVFV outbreaks, human vaccination has strong potential to mitigate the impact of this now widely endemic disease.
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Affiliation(s)
- Keli N. Gerken
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America
| | - A. Desirée LaBeaud
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Henshaw Mandi
- Coalition for Epidemic Preparedness Innovations (CEPI), Oslo, Norway
| | | | | | - Charles H. King
- Center for Global Health and Diseases, Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
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25
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Pawęska JT, Msimang V, Kgaladi J, Hellferscee O, Weyer J, Jansen van Vuren P. Rift Valley Fever Virus Seroprevalence among Humans, Northern KwaZulu-Natal Province, South Africa, 2018-2019. Emerg Infect Dis 2021; 27:3159-3162. [PMID: 34808090 PMCID: PMC8632195 DOI: 10.3201/eid2712.210643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
We detected Rift Valley fever virus (RVFV) IgM and IgG in human serum samples collected during 2018–2019 in northern KwaZulu-Natal Province, South Africa. Our results show recent RVFV circulation and likely RVFV endemicity in this tropical coastal plain region of South Africa in the absence of apparent clinical disease.
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26
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Tennant WSD, Cardinale E, Cêtre-Sossah C, Moutroifi Y, Le Godais G, Colombi D, Spencer SEF, Tildesley MJ, Keeling MJ, Charafouddine O, Colizza V, Edmunds WJ, Métras R. Modelling the persistence and control of Rift Valley fever virus in a spatially heterogeneous landscape. Nat Commun 2021; 12:5593. [PMID: 34552082 PMCID: PMC8458460 DOI: 10.1038/s41467-021-25833-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 09/02/2021] [Indexed: 02/08/2023] Open
Abstract
The persistence mechanisms of Rift Valley fever (RVF), a zoonotic arboviral haemorrhagic fever, at both local and broader geographical scales have yet to be fully understood and rigorously quantified. We developed a mathematical metapopulation model describing RVF virus transmission in livestock across the four islands of the Comoros archipelago, accounting for island-specific environments and inter-island animal movements. By fitting our model in a Bayesian framework to 2004-2015 surveillance data, we estimated the importance of environmental drivers and animal movements on disease persistence, and tested the impact of different control scenarios on reducing disease burden throughout the archipelago. Here we report that (i) the archipelago network was able to sustain viral transmission in the absence of explicit disease introduction events after early 2007, (ii) repeated outbreaks during 2004-2020 may have gone under-detected by local surveillance, and (iii) co-ordinated within-island control measures are more effective than between-island animal movement restrictions.
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Affiliation(s)
- Warren S D Tennant
- The Zeeman Institute: SBIDER, University of Warwick, Coventry, CV4 7AL, UK.
- Mathematics Institute, University of Warwick, Coventry, CV4 7AL, UK.
| | - Eric Cardinale
- Centre de Coopération Internationale en Recherche Agronomique pour le Développement, UMR Animal, Santé, Territoires, Risques, et Écosystèmes, F-97490, Sainte Clotilde, La Réunion, France
- Animal, Santé, Territoires, Risques, et Écosystèmes, Université de Montpellier, Centre de Coopération Internationale en Recherche Agronomique pour le Développement, INRAE, Montpellier, France
| | - Catherine Cêtre-Sossah
- Centre de Coopération Internationale en Recherche Agronomique pour le Développement, UMR Animal, Santé, Territoires, Risques, et Écosystèmes, F-97490, Sainte Clotilde, La Réunion, France
- Animal, Santé, Territoires, Risques, et Écosystèmes, Université de Montpellier, Centre de Coopération Internationale en Recherche Agronomique pour le Développement, INRAE, Montpellier, France
| | - Youssouf Moutroifi
- Vice-Présidence en charge de l'Agriculture, l'Elevage, la Pêche, l'Industrie, l'Energie et l'Artisanat, B.P. 41 Mdé, Moroni, Union of the Comoros
| | - Gilles Le Godais
- Direction de l'Alimentation, de l'Agriculture et de la Forêt de Mayotte, Service de l'Alimentation, 97600, Mamoudzou, France
| | - Davide Colombi
- Aizoon Technology Consulting, Str. del Lionetto 6, Torino, Italy
| | - Simon E F Spencer
- The Zeeman Institute: SBIDER, University of Warwick, Coventry, CV4 7AL, UK
- Department of Statistics, University of Warwick, Coventry, CV4, 7AL, UK
| | - Mike J Tildesley
- The Zeeman Institute: SBIDER, University of Warwick, Coventry, CV4 7AL, UK
- Mathematics Institute, University of Warwick, Coventry, CV4 7AL, UK
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Matt J Keeling
- The Zeeman Institute: SBIDER, University of Warwick, Coventry, CV4 7AL, UK
- Mathematics Institute, University of Warwick, Coventry, CV4 7AL, UK
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Onzade Charafouddine
- Vice-Présidence en charge de l'Agriculture, l'Elevage, la Pêche, l'Industrie, l'Energie et l'Artisanat, B.P. 41 Mdé, Moroni, Union of the Comoros
| | - Vittoria Colizza
- INSERM, Sorbonne Université, Institut Pierre Louis d'Épidémiologie et de Santé Publique (Unité Mixte de Recherche en Santé 1136), 75012, Paris, France
| | - W John Edmunds
- Centre for the Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Raphaëlle Métras
- INSERM, Sorbonne Université, Institut Pierre Louis d'Épidémiologie et de Santé Publique (Unité Mixte de Recherche en Santé 1136), 75012, Paris, France
- Centre for the Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
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27
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Youssouf H, Subiros M, Dennetiere G, Collet L, Dommergues L, Pauvert A, Rabarison P, Vauloup-Fellous C, Le Godais G, Jaffar-Bandjee MC, Jean M, Paty MC, Noel H, Oliver S, Filleul L, Larsen C. Rift Valley Fever Outbreak, Mayotte, France, 2018-2019. Emerg Infect Dis 2021; 26:769-772. [PMID: 32186500 PMCID: PMC7101114 DOI: 10.3201/eid2604.191147] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
From November 2018 through July 2019, an outbreak of Rift Valley fever in humans occurred in Mayotte, France; 142 cases were confirmed. Exposure to animals or their biological fluid was reported by 73% of patients. Health authorities have been implementing control measures, including veterinary surveys, vector control interventions, and prevention measures.
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Abstract
We evaluated the prevalence of Rift Valley fever virus IgG and IgM in human serum samples (n = 1,276) collected in 2013–2014 in northern Botswana. Our findings provide evidence of active circulation of this virus in humans in the absence of clinical disease in this region.
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Ahmed A, Ali Y, Elduma A, Eldigail MH, Mhmoud RA, Mohamed NS, Ksiazek TG, Dietrich I, Weaver SC. Unique Outbreak of Rift Valley Fever in Sudan, 2019. Emerg Infect Dis 2021; 26:3030-3033. [PMID: 33219787 PMCID: PMC7706939 DOI: 10.3201/eid2612.201599] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
We report a unique outbreak of Rift Valley fever in the Eldamar area, Sudan, May–July 2019, that resulted in 1,129 case-patients and 19 (1.7%) deaths. Patients exhibited clinical signs including fever (100%), headache (79%), and bleeding (4%). Most (98%) patients also reported death and abortions among their livestock.
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Obaidat MM, Graziano JC, Morales-Betoulle M, Brown SM, Chiang CF, Klena JD. Rift Valley Fever and Crimean-Congo Hemorrhagic Fever Viruses in Ruminants, Jordan. Emerg Infect Dis 2021; 27:653-655. [PMID: 33496248 PMCID: PMC7853544 DOI: 10.3201/eid2702.203713] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The epidemiology of Rift Valley fever virus (RVFV) and Crimean-Congo hemorrhagic fever virus (CCHFV) in Jordan is unknown. Our investigation showed 3% of 989 tested dairy cattle, sheep, and goats were RVFV seropositive and 14% were CCHFV seropositive. Ongoing surveillance is needed to assess risk to humans and protect public health.
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Pedarrieu A, El Mellouli F, Khallouki H, Zro K, Sebbar G, Sghaier S, Madani H, Bouayed N, Lo MM, Diop M, Ould El Mamy AB, Barry Y, Dakouo M, Traore A, Gagara H, Souley MM, Acha S, Mapaco L, Chang’a J, Nyakilinga D, Lubisi BA, Tshabalala T, Filippone C, Heraud JM, Chamassy SB, Achiraffi A, Keck N, Grard G, Mohammed KAA, Alrizqi AM, Cetre-Sossah C. External quality assessment of Rift Valley fever diagnosis in countries at risk of the disease: African, Indian Ocean and Middle-East regions. PLoS One 2021; 16:e0251263. [PMID: 34010292 PMCID: PMC8133482 DOI: 10.1371/journal.pone.0251263] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/23/2021] [Indexed: 12/14/2022] Open
Abstract
Rift Valley fever virus (RVFV), an arbovirus belonging to the Phlebovirus genus of the Phenuiviridae family, causes the zoonotic and mosquito-borne RVF. The virus, which primarily affects livestock (ruminants and camels) and humans, is at the origin of recent major outbreaks across the African continent (Mauritania, Libya, Sudan), and in the South-Western Indian Ocean (SWIO) islands (Mayotte). In order to be better prepared for upcoming outbreaks, to predict its introduction in RVFV unscathed countries, and to run efficient surveillance programmes, the priority is harmonising and improving the diagnostic capacity of endemic countries and/or countries considered to be at risk of RVF. A serological inter-laboratory proficiency test (PT) was implemented to assess the capacity of veterinary laboratories to detect antibodies against RVFV. A total of 18 laboratories in 13 countries in the Middle East, North Africa, South Africa, and the Indian Ocean participated in the initiative. Two commercial kits and two in-house serological assays for the detection of RVFV specific IgG antibodies were tested. Sixteen of the 18 participating laboratories (88.9%) used commercial kits, the analytical performance of test sensitivity and specificity based on the seroneutralisation test considered as the reference was 100%. The results obtained by the laboratories which used the in-house assay were correct in only one of the two criteria (either sensitivity or specificity). In conclusion, most of the laboratories performed well in detecting RVFV specific IgG antibodies and can therefore be considered to be prepared. Three laboratories in three countries need to improve their detection capacities. Our study demonstrates the importance of conducting regular proficiency tests to evaluate the level of preparedness of countries and of building a network of competent laboratories in terms of laboratory diagnosis to better face future emerging diseases in emergency conditions.
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Affiliation(s)
- Aurélie Pedarrieu
- ASTRE, Univ Montpellier, CIRAD, INRA, Montpellier, France
- CIRAD, UMR ASTRE, F-34398 Montpellier Cedex, France
| | - Fatiha El Mellouli
- Laboratoire Régional d’Analyses et de Recherches de Casablanca, Office National de la Sécurité Sanitaire des aliments), Nouaceur, Casablanca, Morocco
| | - Hanane Khallouki
- Laboratoire Régional d’Analyses et de Recherches de Casablanca, Office National de la Sécurité Sanitaire des aliments), Nouaceur, Casablanca, Morocco
| | | | | | - Soufien Sghaier
- Département de Virologie, Institut de la Recherche Vétérinaire de Tunisie (IRVT), Université de Tunis El Manar, Tunis, Tunisia
| | - Hafsa Madani
- Laboratoire Central Vétérinaire d’Alger, Institut National de Médecine Vétérinaire (INMV), Mohammadia, Algeria
| | - Nadera Bouayed
- Laboratoire Central Vétérinaire d’Alger, Institut National de Médecine Vétérinaire (INMV), Mohammadia, Algeria
| | - Modou Moustapha Lo
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l’Elevage et de Recherches Vétérinaires (ISRA-LNERV), Dakar, Senegal
| | - Mariame Diop
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l’Elevage et de Recherches Vétérinaires (ISRA-LNERV), Dakar, Senegal
| | | | - Yahya Barry
- Office National de Recherches et de Développement de l’Elevage (ONARDEL), Nouakchott, Mauritania
| | | | | | - Haladou Gagara
- Laboratoire Central de l’Elevage (LABOCEL), Niamey, Niger
| | | | - Sara Acha
- Agrarian Research Institute of Mozambique, Directorate of Aninal Science, Central Veterinary Laboratory, Maputo, Mozambique
| | - Laurenco Mapaco
- Agrarian Research Institute of Mozambique, Directorate of Aninal Science, Central Veterinary Laboratory, Maputo, Mozambique
| | - Jelly Chang’a
- Centre for Infectious Diseases and Biotechnology, Tanzania Veterinary Laboratory Agency, Dar es Salaam, Tanzania
| | - Denis Nyakilinga
- Centre for Infectious Diseases and Biotechnology, Tanzania Veterinary Laboratory Agency, Dar es Salaam, Tanzania
| | - Baratang A. Lubisi
- Agricultural Research Council-Onderstepoort Veterinary Research (ARC-OVR), Onderstepoort, South Africa
| | - Thabisile Tshabalala
- Agricultural Research Council-Onderstepoort Veterinary Research (ARC-OVR), Onderstepoort, South Africa
| | - Claudia Filippone
- Institut Pasteur de Madagascar, Unité de Virologie, Antananarivo, Madagascar
| | - Jean Michel Heraud
- Institut Pasteur de Madagascar, Unité de Virologie, Antananarivo, Madagascar
| | | | - Abdou Achiraffi
- Laboratoire vétérinaire et d’analyses départemental (LVAD976), Mayotte, France
| | - Nicolas Keck
- Laboratoire Départemental Vétérinaire (LDV34), Montpellier, France
| | - Gilda Grard
- Centre National de Référence sur les arboviruses (CNR Arbovirus), Institut de Recherche Biomédicale des Armées (IRBA), Marseille, France
- Unité des Virus Émergents (UVE: Aix-Marseille Univ-IRD 190-Inserm 1207-IHU Méditerranée Infection), Marseille, France
| | | | - Abdulwahed Mohammed Alrizqi
- The Ministry of Environment, Water and Agriculture (MEWA), Jazan Veterinary Diagnostic Laboratory, Jizan, Kingdom of Saudi Arabia
| | - Catherine Cetre-Sossah
- ASTRE, Univ Montpellier, CIRAD, INRA, Montpellier, France
- CIRAD, UMR ASTRE, F-97490 Sainte-Clotilde, La Réunion, France
- * E-mail:
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Ndumu DB, Bakamutumaho B, Miller E, Nakayima J, Downing R, Balinandi S, Monje F, Tumusiime D, Nanfuka M, Meunier N, Arinaitwe E, Rutebarika C, Kidega E, Kyondo J, Ademun R, Njenga KM, Veas F, Gonzalez JP. Serological evidence of Rift Valley fever virus infection among domestic ruminant herds in Uganda. BMC Vet Res 2021; 17:157. [PMID: 33849526 PMCID: PMC8045185 DOI: 10.1186/s12917-021-02867-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 03/31/2021] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Prior to the first recorded outbreak of Rift Valley fever (RVF) in Uganda, in March 2016, earlier studies done until the 1970's indicated the presence of the RVF virus (RVFV) in the country, without any recorded outbreaks in either man or animals. While severe outbreaks of RVF occurred in the neighboring countries, none were reported in Uganda despite forecasts that placed some parts of Uganda at similar risk. The Ministry of Agriculture, Animal Industry and Fisheries (MAAIF) undertook studies to determine the RVF sero-prevalence in risk prone areas. Three datasets from cattle sheep and goats were obtained; one from retrospective samples collected in 2010-2011 from the northern region; the second from the western region in 2013 while the third was from a cross-sectional survey done in 2016 in the south-western region. Laboratory analysis involved the use of the Enzyme Linked Immunosorbent Assays (ELISA). Data were subjected to descriptive statistical analyses, including non-parametric chi-square tests for comparisons between districts and species in the regions. RESULTS During the Yellow Fever outbreak investigation of 2010-2011 in the northern region, a total sero-prevalence of 6.7% was obtained for anti RVFV reacting antibodies (IgG and IgM) among the domestic ruminant population. The 2013 sero-survey in the western region showed a prevalence of 18.6% in cattle and 2.3% in small ruminants. The 2016 sero-survey in the districts of Kabale, Kanungu, Kasese, Kisoro and Rubirizi, in the south-western region, had the respective district RVF sero-prevalence of 16.0, 2.1, 0.8, 15.1and 2.7% among the domestic ruminants combined for this region; bovines exhibited the highest cumulative sero-prevalence of 15.2%, compared to 5.3 and 4.0% respectively for sheep and goats per species for the region. CONCLUSIONS The absence of apparent outbreaks in Uganda, despite neighboring enzootic areas, having minimal restrictions to the exchange of livestock and their products across borders, suggest an unexpected RVF activity in the study areas that needs to be unraveled. Therefore, more in-depth studies are planned to mitigate the risk of an overt RVF outbreak in humans and animals as has occurred in neighboring countries.
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Affiliation(s)
- Deo B. Ndumu
- Department of Animal Health, Ministry of Agriculture, Animal Industry and Fisheries (MAAIF), P. O. Box 513, Entebbe, Uganda
| | - Barnabas Bakamutumaho
- Uganda National Health Research Organization (UNHRO), Uganda Virus Research Institute (UVRI), P. O. Box 49, Entebbe, Uganda
| | | | - Jesca Nakayima
- National Livestock Resources Research Institute (NaLiRRI), Nakyesasa, Uganda
| | - Robert Downing
- Centers for Disease Control and Prevention (CDC) – UVRI, Entebbe, Uganda
| | - Stephen Balinandi
- Centers for Disease Control and Prevention (CDC) – UVRI, Entebbe, Uganda
| | - Fred Monje
- Department of Animal Health, Ministry of Agriculture, Animal Industry and Fisheries (MAAIF), P. O. Box 513, Entebbe, Uganda
| | - Dan Tumusiime
- Department of Animal Health, Ministry of Agriculture, Animal Industry and Fisheries (MAAIF), P. O. Box 513, Entebbe, Uganda
| | - Mary Nanfuka
- Department of Animal Health, Ministry of Agriculture, Animal Industry and Fisheries (MAAIF), P. O. Box 513, Entebbe, Uganda
| | - Natascha Meunier
- Royal Veterinary College, University of London, Royal College Street, London, NW1 0TU UK
| | - Eugene Arinaitwe
- Department of Animal Health, Ministry of Agriculture, Animal Industry and Fisheries (MAAIF), P. O. Box 513, Entebbe, Uganda
| | - Chris Rutebarika
- Department of Animal Health, Ministry of Agriculture, Animal Industry and Fisheries (MAAIF), P. O. Box 513, Entebbe, Uganda
| | - Eugene Kidega
- Department of Animal Health, Ministry of Agriculture, Animal Industry and Fisheries (MAAIF), P. O. Box 513, Entebbe, Uganda
| | - Jackson Kyondo
- Uganda National Health Research Organization (UNHRO), Uganda Virus Research Institute (UVRI), P. O. Box 49, Entebbe, Uganda
| | - Rose Ademun
- Department of Animal Health, Ministry of Agriculture, Animal Industry and Fisheries (MAAIF), P. O. Box 513, Entebbe, Uganda
| | | | - Francisco Veas
- Molecular Comparative Immuno-Physiopathology Lab (LIPMC), Joint Research Unit-Ministry of Defense (UMR-MD), Faculty of Pharmacy, French Research Institute for Development (IRD), Montpellier University, 34093 Montpellier, France
| | - Jean-Paul Gonzalez
- Metabiota Inc., San Francisco, USA
- Georgetown University, School of Medicine, 3900 Reservoir Rd. NW, Washington, DC, 20007 USA
- Centaurus Biotech LLC., Commonwealth Trading Partners, CTP Inc. Alexandria, Virginia, USA
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Muturi M, Akoko J, Nthiwa D, Chege B, Nyamota R, Mutiiria M, Maina J, Thumbi SM, Nyamai M, Kahariri S, Sitawa R, Kimutai J, Kuria W, Mwatondo A, Bett B. Serological evidence of single and mixed infections of Rift Valley fever virus, Brucella spp. and Coxiella burnetii in dromedary camels in Kenya. PLoS Negl Trop Dis 2021; 15:e0009275. [PMID: 33770095 PMCID: PMC7997034 DOI: 10.1371/journal.pntd.0009275] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 02/26/2021] [Indexed: 12/21/2022] Open
Abstract
Camels are increasingly becoming the livestock of choice for pastoralists reeling from effects of climate change in semi-arid and arid parts of Kenya. As the population of camels rises, better understanding of their role in the epidemiology of zoonotic diseases in Kenya is a public health priority. Rift Valley fever (RVF), brucellosis and Q fever are three of the top priority diseases in the country but the involvement of camels in the transmission dynamics of these diseases is poorly understood. We analyzed 120 camel serum samples from northern Kenya to establish seropositivity rates of the three pathogens and to characterize the infecting Brucella species using molecular assays. We found seropositivity of 24.2% (95% confidence interval [CI]: 16.5–31.8%) for Brucella, 20.8% (95% CI: 13.6–28.1%) and 14.2% (95% CI: 7.9–20.4%) for Coxiella burnetii and Rift valley fever virus respectively. We found 27.5% (95% CI: 19.5–35.5%) of the animals were seropositive for at least one pathogen and 13.3% (95% CI: 7.2–19.4%) were seropositive for at least two pathogens. B. melitensis was the only Brucella spp. detected. The high sero-positivity rates are indicative of the endemicity of these pathogens among camel populations and the possible role the species has in the epidemiology of zoonotic diseases. Considering the strong association between human infection and contact with livestock for most zoonotic infections in Kenya, there is immediate need to conduct further research to determine the role of camels in transmission of these zoonoses to other livestock species and humans. This information will be useful for designing more effective surveillance systems and intervention measures. Dromedary camels are well adapted to the arid and semi-arid environment that makes up about 80% of Kenya’s landmass. As such, camels play an important role in the socio-economic wellbeing and food security of pastoralists in the country. However, the species remains relatively neglected in scientific research, one of the main reasons being camels are mostly found in remote, low-income, arid regions of Africa and Asia. We carried out a study to determine the levels of exposure of camels in northern Kenya to Brucella spp., Coxiella burnetii and Rift Valley fever virus, three priority zoonotic pathogens in the country. We found high levels of exposure to the three pathogens, indicating the important role camels might play in the epidemiology of the zoonotic diseases in humans and other livestock. Based on the study findings, we argue for the immediate need for investments in disease surveillance and control strategies for priority zoonotic disease in camels in Kenya.
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Affiliation(s)
- Mathew Muturi
- Zoonotic Disease Unit Nairobi, Nairobi, Kenya
- International Livestock Research Institute, Nairobi, Kenya
- * E-mail:
| | - James Akoko
- International Livestock Research Institute, Nairobi, Kenya
| | - Daniel Nthiwa
- Department of Biological Sciences, University of Embu, Embu, Kenya
| | | | | | | | - Josphat Maina
- Zoonotic Disease Unit Nairobi, Nairobi, Kenya
- International Livestock Research Institute, Nairobi, Kenya
| | - S. M. Thumbi
- Center for Epidemiological and Modelling Analysis, University of Nairobi Institute of Tropical and Infectious Diseases, Nairobi, Kenya
- Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
- Paul G Allen School for Global Health, Washington State University, Pullman, Washington, United States of America
| | - Mutono Nyamai
- Center for Epidemiological and Modelling Analysis, University of Nairobi Institute of Tropical and Infectious Diseases, Nairobi, Kenya
- Paul G Allen School for Global Health, Washington State University, Pullman, Washington, United States of America
| | - Samuel Kahariri
- Kenya Directorate of Veterinary Services, Ministry of Agriculture, Livestock and Fisheries, Nairobi, Kenya
| | - Rinah Sitawa
- Food and Agriculture Organization of the United Nations, Nairobi, Kenya
| | - Joshua Kimutai
- Food and Agriculture Organization of the United Nations, Nairobi, Kenya
| | - Wilson Kuria
- Kenya Directorate of Veterinary Services, Ministry of Agriculture, Livestock and Fisheries, Nairobi, Kenya
| | - Athman Mwatondo
- Zoonotic Disease Unit Nairobi, Nairobi, Kenya
- International Livestock Research Institute, Nairobi, Kenya
| | - Bernard Bett
- International Livestock Research Institute, Nairobi, Kenya
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Kim Y, Métras R, Dommergues L, Youssouffi C, Combo S, Le Godais G, Pfeiffer DU, Cêtre-Sossah C, Cardinale E, Filleul L, Youssouf H, Subiros M, Fournié G. The role of livestock movements in the spread of Rift Valley fever virus in animals and humans in Mayotte, 2018-19. PLoS Negl Trop Dis 2021; 15:e0009202. [PMID: 33684126 PMCID: PMC7939299 DOI: 10.1371/journal.pntd.0009202] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 02/03/2021] [Indexed: 11/18/2022] Open
Abstract
Rift Valley fever (RVF) is a vector-borne viral disease of major animal and public health importance. In 2018–19, it caused an epidemic in both livestock and human populations of the island of Mayotte. Using Bayesian modelling approaches, we assessed the spatio-temporal pattern of RVF virus (RVFV) infection in livestock and human populations across the island, and factors shaping it. First, we assessed if (i) livestock movements, (ii) spatial proximity from communes with infected animals, and (iii) livestock density were associated with the temporal sequence of RVFV introduction into Mayotte communes’ livestock populations. Second, we assessed whether the rate of human infection was associated with (a) spatial proximity from and (b) livestock density of communes with infected animals. Our analyses showed that the temporal sequence of RVFV introduction into communes’ livestock populations was associated with livestock movements and spatial proximity from communes with infected animals, with livestock movements being associated with the best model fit. Moreover, the pattern of human cases was associated with their spatial proximity from communes with infected animals, with the risk of human infection sharply increasing if livestock in the same or close communes were infected. This study highlights the importance of understanding livestock movement networks in informing the design of risk-based RVF surveillance programs. Rift Valley fever (RVF) is a vector-borne zoonotic disease, endemic in many sub-Saharan Africa regions with substantial outbreaks. RVF virus (RVFV) is transmitted to animals primarily by the bite of infected mosquitos, whereas direct or indirect contact with infected animals forms the primary route of RVFV transmission to humans. In 2018–19, Mayotte, an archipelago in the Indian Ocean between Madagascar and the coast of Eastern Africa, experienced an RVF epidemic in both livestock and humans. In this study, we investigated factors shaping the spatio-temporal pattern of RVFV infection in livestock and human populations across Mayotte. The diffusion of RVFV through Mayotte’s livestock population was associated with livestock movements and, potentially to a lesser extent, spatial proximity from communes with infected animals. Moreover, the pressure of infection on humans was the highest if nearby livestock were infected. This study highlights the value of accounting for the structure of livestock movement networks in the surveillance of zoonotic diseases at the human-animal interface, and the need for One Health approaches.
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Affiliation(s)
- Younjung Kim
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong, China
- * E-mail:
| | - Raphaëlle Métras
- INSERM, Sorbonne Université, Institut Pierre Louis d’Épidémiologie et de Santé Publique (UMRS-1136), Paris, France
| | | | | | - Soihibou Combo
- Direction de l’Alimentation, de l’Agriculture et de la Forêt de Mayotte, Mamoudzou, France
| | - Gilles Le Godais
- Direction de l’Alimentation, de l’Agriculture et de la Forêt de Mayotte, Mamoudzou, France
| | - Dirk U. Pfeiffer
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong, China
- Veterinary Epidemiology, Economics and Public Health group, Department of Pathobiology and Population Sciences, The Royal Veterinary College, Hatfield, United Kingdom
| | - Catherine Cêtre-Sossah
- CIRAD, UMR ASTRE, Sainte Clotilde, La Réunion, France
- ASTRE, CIRAD, Univ Montpellier, INRAE, Montpellier, France
| | - Eric Cardinale
- CIRAD, UMR ASTRE, Sainte Clotilde, La Réunion, France
- ASTRE, CIRAD, Univ Montpellier, INRAE, Montpellier, France
| | | | | | | | - Guillaume Fournié
- Veterinary Epidemiology, Economics and Public Health group, Department of Pathobiology and Population Sciences, The Royal Veterinary College, Hatfield, United Kingdom
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Cosseddu GM, Magwedere K, Molini U, Pinoni C, Khaiseb S, Scacchia M, Marcacci M, Capobianco Dondona A, Valleriani F, Polci A, Monaco F. Genetic Diversity of Rift Valley Fever Strains Circulating in Namibia in 2010 and 2011. Viruses 2020; 12:v12121453. [PMID: 33339456 PMCID: PMC7765780 DOI: 10.3390/v12121453] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 12/10/2020] [Accepted: 12/15/2020] [Indexed: 11/30/2022] Open
Abstract
Outbreaks of Rift Valley fever (RVF) occurred in Namibia in 2010 and 2011. Complete genome characterization was obtained from virus isolates collected during disease outbreaks in southern Namibia in 2010 and from wildlife in Etosha National Park in 2011, close to the area where RVF outbreaks occurred in domestic livestock. The virus strains were sequenced using Sanger sequencing (Namibia_2010) or next generation sequencing (Namibia_2011). A sequence-independent, single-primer amplification (SISPA) protocol was used in combination with the Illumina Next 500 sequencer. Phylogenetic analysis of the sequences of the small (S), medium (M), and large (L) genome segments of RVF virus (RVFV) provided evidence that two distinct RVFV strains circulated in the country. The strain collected in Namibia in 2010 is genetically similar to RVFV strains circulating in South Africa in 2009 and 2010, confirming that the outbreaks reported in the southern part of Namibia in 2010 were caused by possible dissemination of the infection from South Africa. Isolates collected in 2011 were close to RVFV isolates from 2010 collected in humans in Sudan and which belong to the large lineage containing RVFV strains that caused an outbreak in 2006–2008 in eastern Africa. This investigation showed that the RVFV strains circulating in Namibia in 2010 and 2011 were from two different introductions and that RVFV has the ability to move across regions. This supports the need for risk-based surveillance and monitoring.
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Affiliation(s)
- Gian Mario Cosseddu
- Istituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise “G. Caporale”—IZSAM, Campo Boario, 64100 Teramo, Italy; (C.P.); (M.S.); (M.M.); (A.C.D.); (F.V.); (A.P.); (F.M.)
- Correspondence: ; Tel.: +39-0861-332280
| | - Kudakwashe Magwedere
- Central Veterinary Laboratory (CVL), 13187 Windhoek, Namibia; (K.M.); (U.M.); (S.K.)
| | - Umberto Molini
- Central Veterinary Laboratory (CVL), 13187 Windhoek, Namibia; (K.M.); (U.M.); (S.K.)
| | - Chiara Pinoni
- Istituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise “G. Caporale”—IZSAM, Campo Boario, 64100 Teramo, Italy; (C.P.); (M.S.); (M.M.); (A.C.D.); (F.V.); (A.P.); (F.M.)
| | - Sigfried Khaiseb
- Central Veterinary Laboratory (CVL), 13187 Windhoek, Namibia; (K.M.); (U.M.); (S.K.)
| | - Massimo Scacchia
- Istituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise “G. Caporale”—IZSAM, Campo Boario, 64100 Teramo, Italy; (C.P.); (M.S.); (M.M.); (A.C.D.); (F.V.); (A.P.); (F.M.)
| | - Maurilia Marcacci
- Istituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise “G. Caporale”—IZSAM, Campo Boario, 64100 Teramo, Italy; (C.P.); (M.S.); (M.M.); (A.C.D.); (F.V.); (A.P.); (F.M.)
| | - Andrea Capobianco Dondona
- Istituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise “G. Caporale”—IZSAM, Campo Boario, 64100 Teramo, Italy; (C.P.); (M.S.); (M.M.); (A.C.D.); (F.V.); (A.P.); (F.M.)
| | - Fabrizia Valleriani
- Istituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise “G. Caporale”—IZSAM, Campo Boario, 64100 Teramo, Italy; (C.P.); (M.S.); (M.M.); (A.C.D.); (F.V.); (A.P.); (F.M.)
| | - Andrea Polci
- Istituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise “G. Caporale”—IZSAM, Campo Boario, 64100 Teramo, Italy; (C.P.); (M.S.); (M.M.); (A.C.D.); (F.V.); (A.P.); (F.M.)
| | - Federica Monaco
- Istituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise “G. Caporale”—IZSAM, Campo Boario, 64100 Teramo, Italy; (C.P.); (M.S.); (M.M.); (A.C.D.); (F.V.); (A.P.); (F.M.)
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Tucker CJ, Melocik KA, Anyamba A, Linthicum KJ, Fagbo SF, Small JL. Reanalysis of the 2000 Rift Valley fever outbreak in Southwestern Arabia. PLoS One 2020; 15:e0233279. [PMID: 33315866 PMCID: PMC7735616 DOI: 10.1371/journal.pone.0233279] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 05/01/2020] [Indexed: 11/18/2022] Open
Abstract
The first documented Rift Valley hemorrhagic fever outbreak in the Arabian Peninsula occurred in northwestern Yemen and southwestern Saudi Arabia from August 2000 to September 2001. This Rift Valley fever outbreak is unique because the virus was introduced into Arabia during or after the 1997–1998 East African outbreak and before August 2000, either by wind-blown infected mosquitos or by infected animals, both from East Africa. A wet period from August 2000 into 2001 resulted in a large number of amplification vector mosquitoes, these mosquitos fed on infected animals, and the outbreak occurred. More than 1,500 people were diagnosed with the disease, at least 215 died, and widespread losses of domestic animals were reported. Using a combination of satellite data products, including 2 x 2 m digital elevation images derived from commercial satellite data, we show rainfall and potential areas of inundation or water impoundment were favorable for the 2000 outbreak. However, favorable conditions for subsequent outbreaks were present in 2007 and 2013, and very favorable conditions were also present in 2016–2018. The lack of subsequent Rift Valley fever outbreaks in this area suggests that Rift Valley fever has not been established in mosquito species in Southwest Arabia, or that strict animal import inspection and quarantine procedures, medical and veterinary surveillance, and mosquito control efforts put in place in Saudi Arabia following the 2000 outbreak have been successful. Any area with Rift Valley fever amplification vector mosquitos present is a potential outbreak area unless strict animal import inspection and quarantine proceedures are in place.
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Affiliation(s)
- Compton J. Tucker
- Earth Sciences Division, NASA/Goddard Space Flight Center, Greenbelt, Maryland, United States of America
- * E-mail:
| | - Katherine A. Melocik
- Earth Sciences Division, NASA/Goddard Space Flight Center, Greenbelt, Maryland, United States of America
| | - Assaf Anyamba
- Earth Sciences Division, NASA/Goddard Space Flight Center, Greenbelt, Maryland, United States of America
| | - Kenneth J. Linthicum
- Center for Medical, Agricultural, and Veterinary Entomology, U.S. Department of Agriculture, Gainesville, Florida, United States of America
| | - Shamsudeen F. Fagbo
- One Health Unit, Executive Directorate for Response and Surveillance, National Centre for Disease Prevention and Control, Riyadh, Saudi Arabia
- Department of Public Health, Nigerian Institute of Medical Research, Yaba, Lagos, Nigeria
| | - Jennifer L. Small
- Earth Sciences Division, NASA/Goddard Space Flight Center, Greenbelt, Maryland, United States of America
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Abstract
An isolated Rift Valley fever (RVF) outbreak was reported in 2018 in Free State Province, South Africa. Phylogenetic analyses based on complete genome sequences of 3 RVF viruses from blood and tissue samples indicated that they were related to a virus isolated in 2016 from a man returning to China from Angola.
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Budodo RM, Horumpende PG, Mkumbaye SI, Mmbaga BT, Mwakapuja RS, Chilongola JO. Serological evidence of exposure to Rift Valley, Dengue and Chikungunya Viruses among agropastoral communities in Manyara and Morogoro regions in Tanzania: A community survey. PLoS Negl Trop Dis 2020; 14:e0008061. [PMID: 32687540 PMCID: PMC7402518 DOI: 10.1371/journal.pntd.0008061] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 08/04/2020] [Accepted: 06/11/2020] [Indexed: 11/19/2022] Open
Abstract
Tanzania has recently experienced outbreaks of dengue in two coastal regions of Dar es Salaam and Tanga. Chikungunya and Rift Valley Fever outbreaks have also been recorded in the past decade. Little is known on the burden of the arboviral disease causing viruses (Dengue, Rift Valley and Chikungunya) endemically in the inter-epidemic periods. We aimed at determining the prevalence of the dengue, rift valley and chikungunya among humans in two geo ecologically distinct sites. The community-based cross-sectional study was conducted in Magugu in Manyara region and Wami-Dakawa in Morogoro region in Tanzania. Venous blood was collected from participants of all age groups, serum prepared from samples and subjected to ELISA tests for RVFV IgG/IgM, DENV IgG/IgM, and CHIKV IgM/IgG. Samples that were positive for IgM ELISA tests were subjected to a quantitative RT PCR for each virus. A structured questionnaire was used to collect socio-demographic information. Data analysis was performed by using SPSSv22. A total of 191 individuals from both sites participated in the study. Only one individual was CHIKV seropositive in Magugu, but none was seropositive or positive for either RVFV or DENV. Of the 122 individuals from Wami-Dakawa site, 16.39% (n = 20) had recent exposure to RVFV while 9.83% (n = 12) were seropositive for CHIKV. All samples were negative by RVFV and CHIKV qPCR. Neither infection nor exposure to DENV was observed in participants from both sites. Being more than 5 in a household, having no formal education and having recently travelled to an urban area were risk factors associated with RVFV and CHIKV seropositivity. We report a considerable exposure to RVFV and CHIKV among Wami-Dakawa residents during the dry season and an absence of exposure of the viruses among humans in Magugu site. In both sites, neither DENV exposure nor infection was detected.
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Affiliation(s)
- Rule M. Budodo
- Kilimanjaro Clinical Research Institute, Moshi, Tanzania
| | - Pius G. Horumpende
- Kilimanjaro Clinical Research Institute, Moshi, Tanzania
- Department of Public Health and Research, Lugalo Military College of Medical Sciences (MCMS) and General Military Hospital (GMH), Dar es Salaam, Tanzania
| | - Sixbert I. Mkumbaye
- Kilimanjaro Clinical Research Institute, Moshi, Tanzania
- Department of Medical Biochemistry and Molecular Biology, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Blandina T. Mmbaga
- Kilimanjaro Clinical Research Institute, Moshi, Tanzania
- Directorate of Research and Consultancies, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | | | - Jaffu O. Chilongola
- Kilimanjaro Clinical Research Institute, Moshi, Tanzania
- Department of Medical Biochemistry and Molecular Biology, Kilimanjaro Christian Medical University College, Moshi, Tanzania
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Durand B, Lo Modou M, Tran A, Ba A, Sow F, Belkhiria J, Fall AG, Biteye B, Grosbois V, Chevalier V. Rift Valley fever in northern Senegal: A modelling approach to analyse the processes underlying virus circulation recurrence. PLoS Negl Trop Dis 2020; 14:e0008009. [PMID: 32479505 PMCID: PMC7289439 DOI: 10.1371/journal.pntd.0008009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 06/11/2020] [Accepted: 04/22/2020] [Indexed: 01/12/2023] Open
Abstract
Rift Valley fever (RVF) is endemic in northern Senegal, a Sahelian area characterized by a temporary pond network that drive both RVF mosquito population dynamics and nomadic herd movements. To investigate the mechanisms that explain RVF recurrent circulation, we modelled a realistic epidemiological system at the pond level integrating vector population dynamics, resident and nomadic ruminant herd population dynamics, and nomadic herd movements recorded in Younoufere area. To calibrate the model, serological surveys were performed in 2015–2016 on both resident and nomadic domestic herds in the same area. Mosquito population dynamics were obtained from a published model trained in the same region. Model comparison techniques were used to compare five different scenarios of virus introduction by nomadic herds associated or not with vertical transmission in Aedes vexans. Our serological results confirmed a long lasting RVF endemicity in resident herds (IgG seroprevalence rate of 15.3%, n = 222), and provided the first estimation of RVF IgG seroprevalence in nomadic herds in West Africa (12.4%, n = 660). Multivariate analysis of serological data suggested an amplification of the transmission cycle during the rainy season with a peak of circulation at the end of that season. The best scenario of virus introduction combined yearly introductions of RVFV from 2008 to 2015 (the study period) by nomadic herds, with a proportion of viraemic individuals predicted to be larger in animals arriving during the 2nd half of the rainy season (3.4%). This result is coherent with the IgM prevalence rate (4%) found in nomadic herds sampled during the 2nd half of the rainy season. Although the existence of a vertical transmission mechanism in Aedes cannot be ruled out, our model demonstrates that nomadic movements are sufficient to account for this endemic circulation in northern Senegal. Rift Valley fever (RVF) is one of the most important vector borne disease in Africa, seriously affecting the health of domestic ruminants and humans and leading to severe economic consequences. This disease is endemic in northern Senegal, a Sahelian area characterized by a temporary pond network that drive both RVF mosquito population dynamics and nomadic herd movements. Two non-exclusive mechanisms may support this endemicity: recurrent introductions of the virus by nomadic animals, and vertical transmission of the virus (i.e. from infected female mosquito to eggs) in local Aedes populations. The authors followed resident and nomadic domestic herds for 1 year. They used the data thus obtained to model a realistic epidemiological system at the pond level integrating vector population dynamics, resident and nomadic ruminant herd population dynamics. They found that the best scenario explaining RVF remanence combined yearly introductions of RVFV by nomadic herds, with a viraemic proportion predicted to be larger in animals arriving during the 2nd half of the rainy season, which is consistent with an amplification of virus circulation in the area during the rainy season. Although the existence of a vertical transmission mechanism in Aedes cannot be ruled out, their results demonstrates that nomadic movements are sufficient to account for this endemic circulation in northern Senegal.
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Affiliation(s)
- Benoit Durand
- Epidemiology Unit, Laboratory for Animal Health, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), University Paris-Est, Maisons-Alfort, France
- * E-mail: (BD); (VC)
| | | | - Annelise Tran
- CIRAD, UMR TETIS, Sainte-Clotilde, Réunion, France
- CIRAD, UMR ASTRE, Montpellier, France
- Université Montpellier, Montpellier, France
| | - Aminata Ba
- Institut Sénégalais de Recherche Agricole (ISRA), Dakar, Sénégal
| | - Fafa Sow
- Institut Sénégalais de Recherche Agricole (ISRA), Dakar, Sénégal
| | - Jaber Belkhiria
- Center for Animal Disease Modeling and Surveillance, Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California Davis, California, United States of America
| | | | - Biram Biteye
- Institut Sénégalais de Recherche Agricole (ISRA), Dakar, Sénégal
| | | | - Véronique Chevalier
- CIRAD, UMR ASTRE, Montpellier, France
- CIRAD, UMR ASTRE, Phnom Penh, Cambodia
- Epidemiology and Public Health Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
- * E-mail: (BD); (VC)
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Tigoi C, Sang R, Chepkorir E, Orindi B, Arum SO, Mulwa F, Mosomtai G, Limbaso S, Hassan OA, Irura Z, Ahlm C, Evander M. High risk for human exposure to Rift Valley fever virus in communities living along livestock movement routes: A cross-sectional survey in Kenya. PLoS Negl Trop Dis 2020; 14:e0007979. [PMID: 32084127 PMCID: PMC7055907 DOI: 10.1371/journal.pntd.0007979] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 03/04/2020] [Accepted: 12/09/2019] [Indexed: 11/18/2022] Open
Abstract
Introduction Multiple outbreaks of Rift Valley Fever (RVF) with devastating effects have occurred in East Africa. These outbreaks cause disease in both livestock and humans and affect poor households most severely. Communities living in areas practicing nomadic livestock movement may be at higher risk of infection. This study sought to i) determine the human exposure to Rift Valley fever virus (RVFV) in populations living within nomadic animal movement routes in Kenya; and ii) identify risk factors for RVFV infection in these communities. Methods A cross-sectional descriptive study design was used. Samples were collected from the year 2014 to 2015 in a community-based sampling exercise involving healthy individuals aged ≥18 years from Isiolo, Tana River, and Garissa counties. In total, 1210 samples were screened by ELISA for the presence of immunoglobulin IgM and IgG antibodies against RVFV. Positive results were confirmed by plaque reduction neutralization test. Results Overall, IgM and IgG prevalence for all sites combined was 1.4% (95% CI 0.8–2.3%) and 36.4% (95% CI 33.8–39.2%), respectively. Isiolo County recorded a non-significant higher IgG prevalence of 38.8% than Garissa 35.9% and Tana River 32.2% (Chi square = 2.5, df = 2, p = 0.287). Males were significantly at higher risk of infection by RVFV than females (OR = 1.67, 95% CI 1.17–2.39, p<0.005). Age was significantly associated with RVFV infection (Wald Chi = 94.2, df = 5, p<0.0001). Individuals who had regular contact with cattle (OR = 1.38, 95%CI 1.01–1.89) and donkeys (OR = 1.38, 95%CI 1.14–1.67), or contact with animals through birthing (OR = 1.69, 95%CI 1.14–2.51) were significantly at a greater risk of RVFV infection than those who did not. Conclusion This study demonstrated that although the Isiolo County has been classified as being at medium risk for RVF, virus infection appeared to be as prevalent in humans as in Tana River and Garissa, which have been classified as being at high risk. Populations in these counties live within nomadic livestock movement routes and therefore at risk of being exposed to the RVFV. Interventions to control RVFV infections therefore, should target communities living along livestock movement pathways. Rift Valley fever (RVF) is a neglected mosquito-borne zoonotic disease that causes major outbreaks and economic harm to human and ruminants health leading to increased poverty within affected communities. RVF is caused by RVF virus (RVFV) affecting humans and a wide range of ruminants. The virus is transmitted through bites from mosquitoes and exposure to blood, body fluids, or tissues of infected ruminants. It was first isolated in Kenya in 1930 and several outbreaks have been recorded in many countries in sub-Saharan Africa. We studied pastoralist communities living along livestock migratory routes. Migratory livestock do move long distances in search of water and pasture and may be at higher risk of exposure to RVFV. We also determined risk factors for RVFV infection by studying age, gender, contact with animals through birthing, and occupation. Prevention and control of RVFV infection can target significant risk factors to prevent spread and re-occurrence of outbreaks.
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Affiliation(s)
- Caroline Tigoi
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- * E-mail:
| | - Rosemary Sang
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- Center for Virus Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Edith Chepkorir
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Benedict Orindi
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | | | - Francis Mulwa
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Gladys Mosomtai
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Samson Limbaso
- Center for Virus Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Osama A. Hassan
- Department of Clinical Microbiology, Virology, Umeå University, Umeå, Sweden
| | - Zephania Irura
- Ministry of Public Health and Sanitation, Nairobi, Kenya
| | - Clas Ahlm
- Department of Clinical Microbiology, Infection and Immunology, Umeå University, Umeå, Sweden
| | - Magnus Evander
- Department of Clinical Microbiology, Virology, Umeå University, Umeå, Sweden
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Simons RRL, Croft S, Rees E, Tearne O, Arnold ME, Johnson N. Using species distribution models to predict potential hot-spots for Rift Valley Fever establishment in the United Kingdom. PLoS One 2019; 14:e0225250. [PMID: 31869335 PMCID: PMC6927579 DOI: 10.1371/journal.pone.0225250] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 10/31/2019] [Indexed: 12/02/2022] Open
Abstract
Vector borne diseases are a continuing global threat to both human and animal health. The ability of vectors such as mosquitos to cover large distances and cross country borders undetected provide an ever-present threat of pathogen spread. Many diseases can infect multiple vector species, such that even if the climate is not hospitable for an invasive species, indigenous species may be susceptible and capable of transmission such that one incursion event could lead to disease establishment in these species. Here we present a consensus modelling methodology to estimate the habitat suitability for presence of mosquito species in the UK deemed competent for Rift Valley fever virus (RVF) and demonstrate its application in an assessment of the relative risk of establishment of RVF virus in the UK livestock population. The consensus model utilises observed UK mosquito surveillance data, along with climatic and geographic prediction variables, to inform six independent species distribution models; the results of which are combined to produce a single prediction map. As a livestock host is needed to transmit RVF, we then combine the consensus model output with existing maps of sheep and cattle density to predict the areas of the UK where disease is most likely to establish in local mosquito populations. The model results suggest areas of high suitability for RVF competent mosquito species across the length and breadth of the UK. Notable areas of high suitability were the South West of England and coastal areas of Wales, the latter of which was subsequently predicted to be at higher risk for establishment of RVF due to higher livestock densities. This study demonstrates the applicability of outputs of species distribution models to help predict hot-spots for risk of disease establishment. While there is still uncertainty associated with the outputs we believe that the predictions are an improvement on just using the raw presence points from a database alone. The outputs can also be used as part of a multidisciplinary approach to inform risk based disease surveillance activities.
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Affiliation(s)
- Robin R. L. Simons
- Animal and Plant Health Agency, New Haw, Surrey, United Kingdom
- * E-mail:
| | - Simon Croft
- National Wildlife Management Centre, Animal and Plant Health Agency, Sand Hutton York, United Kingdom
| | - Eleanor Rees
- Animal and Plant Health Agency, New Haw, Surrey, United Kingdom
| | - Oliver Tearne
- Animal and Plant Health Agency, New Haw, Surrey, United Kingdom
| | - Mark E. Arnold
- Animal and Plant Health Agency, New Haw, Surrey, United Kingdom
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Campbell LP, Reuman DC, Lutomiah J, Peterson AT, Linthicum KJ, Britch SC, Anyamba A, Sang R. Predicting Abundances of Aedes mcintoshi, a primary Rift Valley fever virus mosquito vector. PLoS One 2019; 14:e0226617. [PMID: 31846495 PMCID: PMC6917266 DOI: 10.1371/journal.pone.0226617] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 12/02/2019] [Indexed: 11/18/2022] Open
Abstract
Rift Valley fever virus (RVFV) is a mosquito-borne zoonotic arbovirus with important livestock and human health, and economic consequences across Africa and the Arabian Peninsula. Climate and vegetation monitoring guide RVFV forecasting models and early warning systems; however, these approaches make monthly predictions and a need exists to predict primary vector abundances at finer temporal scales. In Kenya, an important primary RVFV vector is the mosquito Aedes mcintoshi. We used a zero-inflated negative binomial regression and multimodel averaging approach with georeferenced Ae. mcintoshi mosquito counts and remotely sensed climate and topographic variables to predict where and when abundances would be high in Kenya and western Somalia. The data supported a positive effect on abundance of minimum wetness index values within 500 m of a sampling site, cumulative precipitation values 0 to 14 days prior to sampling, and elevated land surface temperature values ~3 weeks prior to sampling. The probability of structural zero counts of mosquitoes increased as percentage clay in the soil decreased. Weekly retrospective predictions for unsampled locations across the study area between 1 September and 25 January from 2002 to 2016 predicted high abundances prior to RVFV outbreaks in multiple foci during the 2006-2007 epizootic, except for two districts in Kenya. Additionally, model predictions supported the possibility of high Ae. mcintoshi abundances in Somalia, independent of Kenya. Model-predicted abundances were low during the 2015-2016 period when documented outbreaks did not occur, although several surveillance systems issued warnings. Model predictions prior to the 2018 RVFV outbreak indicated elevated abundances in Wajir County, Kenya, along the border with Somalia, but RVFV activity occurred west of the focus of predicted high Ae. mcintoshi abundances.
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Affiliation(s)
- Lindsay P. Campbell
- Florida Medical Entomology Laboratory, IFAS, University of Florida, Vero Beach, Florida, United States of America
- Department of Entomology and Nematology, IFAS, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
| | - Daniel C. Reuman
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas, United States of America
- Kansas Biological Survey, University of Kansas, Lawrence, Kansas, United States of America
- Laboratory of Populations, Rockefeller University, New York, New York, United States of America
| | - Joel Lutomiah
- Kenya Medical Research Institute, Nairobi, Kenya
- United States Army Medical Research Directorate – Africa, Nairobi, Kenya
| | - A. Townsend Peterson
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas, United States of America
- Biodiversity Institute, University of Kansas, Lawrence, Kansas, United States of America
| | - Kenneth J. Linthicum
- United States Department of Agriculture, Agricultural Research Service Center for Medical, Agricultural, and Veterinary Entomology, Gainesville, Florida, United States of America
| | - Seth C. Britch
- United States Department of Agriculture, Agricultural Research Service Center for Medical, Agricultural, and Veterinary Entomology, Gainesville, Florida, United States of America
| | - Assaf Anyamba
- Universities Space Research Association, Columbia, Maryland, United States of America
- NASA Goddard Space Flight Center, Biospheric Sciences Laboratory, Greenbelt, Maryland, United States of America
| | - Rosemary Sang
- Kenya Medical Research Institute, Nairobi, Kenya
- United States Army Medical Research Directorate – Africa, Nairobi, Kenya
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Biteye B, Fall AG, Seck MT, Ciss M, Diop M, Gimonneau G. Host-feeding patterns of Aedes (Aedimorphus) vexans arabiensis, a Rift Valley Fever virus vector in the Ferlo pastoral ecosystem of Senegal. PLoS One 2019; 14:e0215194. [PMID: 31584948 PMCID: PMC6777780 DOI: 10.1371/journal.pone.0215194] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 09/20/2019] [Indexed: 12/02/2022] Open
Abstract
Background Host-vector contact is a key factor in vectorial capacity assessment and thus the transmission of mosquito-borne viruses such as Rift Valley Fever (RVF), an emerging zoonotic disease of interest in West Africa. The knowledge of the host-feeding patterns of vector species constitutes a key element in the assessment of their epidemiological importance in a given environment. The aim of this work was to identify the blood meal origins of the mosquito Aedes vexans arabiensis, the main vector of RVF virus in the Ferlo pastoral ecosystem of Senegal. Methodology/principal findings Engorged female mosquitoes were collected in Younouféré in the pastoral ecosystem in the Ferlo region during the 2014 rainy season. CO2-baited CDC light traps were set at six points for two consecutive nights every month from July to November. Domestic animals present around traps were identified and counted for each trapping session. Blood meal sources of engorged mosquitoes were identified using a vertebrate-specific multiplexed primer set based on cytochrome b. Blood meal sources were successfully identified for 319 out of 416 blood-fed females (76.68%), of which 163 (51.1%) were single meals, 146 (45.77%) mixed meals from two different hosts and 10 (3.13%) mixed meals from three different hosts. Aedes vexans arabiensis fed preferentially on mammals especially on horse compared to other hosts (FR = 46.83). Proportions of single and mixed meals showed significant temporal and spatial variations according to the availability of the hosts. Conclusion Aedes vexans arabiensis shows an opportunistic feeding behavior depending on the host availability. This species fed preferentially on mammals especially on horses (primary hosts) and ruminants (secondary hosts).
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Affiliation(s)
- Biram Biteye
- Institut Sénégalais de Recherches Agricoles/Laboratoire National de l’Elevage et de Recherches Vétérinaires BP 2057 Dakar-Hann, Sénégal
- * E-mail:
| | - Assane Gueye Fall
- Institut Sénégalais de Recherches Agricoles/Laboratoire National de l’Elevage et de Recherches Vétérinaires BP 2057 Dakar-Hann, Sénégal
| | - Momar Talla Seck
- Institut Sénégalais de Recherches Agricoles/Laboratoire National de l’Elevage et de Recherches Vétérinaires BP 2057 Dakar-Hann, Sénégal
| | - Mamadou Ciss
- Institut Sénégalais de Recherches Agricoles/Laboratoire National de l’Elevage et de Recherches Vétérinaires BP 2057 Dakar-Hann, Sénégal
| | - Mariame Diop
- Institut Sénégalais de Recherches Agricoles/Laboratoire National de l’Elevage et de Recherches Vétérinaires BP 2057 Dakar-Hann, Sénégal
| | - Geoffrey Gimonneau
- CIRAD, UMR INTERTRYP, Montpellier, France
- Centre International de Recherche–Développement sur l’Elevage en zone subhumide, Bobo-Dioulasso 01, Burkina Faso
- INTERTRYP, Univ Montpellier, CIRAD, IRD, Montpellier, France
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Abstract
Rift Valley fever (RVF) is a mosquito-borne viral zoonosis that was first discovered in Kenya in 1930 and is now endemic throughout multiple African countries and the Arabian Peninsula. RVF virus primarily infects domestic livestock (sheep, goats, cattle) causing high rates of neonatal mortality and abortion, with human infection resulting in a wide variety of clinical outcomes, ranging from self-limiting febrile illness to life-threatening haemorrhagic diatheses, and miscarriage in pregnant women. Since its discovery, RVF has caused many outbreaks in Africa and the Arabian Peninsula with major impacts on human and animal health. However, options for the control of RVF outbreaks are limited by the lack of licensed human vaccines or therapeutics. For this reason, RVF is prioritized by the World Health Organization for urgent research and development of countermeasures for the prevention and control of future outbreaks. In this review, we highlight the current understanding of RVF, including its epidemiology, pathogenesis, clinical manifestations and status of vaccine development.
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Affiliation(s)
- Daniel Wright
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- The Jenner Institute, University of Oxford, Oxford OX1 2JD, UK
| | - Jeroen Kortekaas
- Wageningen Bioveterinary Research, Lelystad, The Netherlands
- Laboratory of Virology, Wageningen University, Wageningen, The Netherlands
| | - Thomas A. Bowden
- Wellcome Centre for Human Genetics, Division of Structural Biology, University of Oxford, Oxford OX1 2JD, UK
| | - George M. Warimwe
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford OX1 2JD, UK
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Abstract
Phylogenetic analysis of Rift Valley fever virus partial genomic sequences from a patient infected in South Africa in May 2018 suggests reemergence of an endemic lineage different from that of the epidemic in South Africa during 2010–2011. Surveillance during interepidemic periods should be intensified to better predict future epidemics.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Maluleke MR, Phosiwa M, van Schalkwyk A, Michuki G, Lubisi BA, Kegakilwe PS, Kemp SJ, Majiwa PAO. A comparative genome analysis of Rift Valley Fever virus isolates from foci of the disease outbreak in South Africa in 2008-2010. PLoS Negl Trop Dis 2019; 13:e0006576. [PMID: 30897082 PMCID: PMC6445458 DOI: 10.1371/journal.pntd.0006576] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 04/02/2019] [Accepted: 10/25/2018] [Indexed: 01/14/2023] Open
Abstract
Rift Valley fever (RVF) is a re-emerging zoonotic disease responsible for major losses in livestock production, with negative impact on the livelihoods of both commercial and resource-poor farmers in sub-Sahara African countries. The disease remains a threat in countries where its mosquito vector thrives. Outbreaks of RVF usually follow weather conditions which favour increase in mosquito populations. Such outbreaks are usually cyclical, occurring every 10–15 years. Recent outbreaks of the disease in South Africa have occurred unpredictably and with increased frequency. In 2008, outbreaks were reported in Mpumalanga, Limpopo and Gauteng provinces, followed by 2009 outbreaks in KwaZulu-Natal, Mpumalanga and Northern Cape provinces and in 2010 in the Eastern Cape, Northern Cape, Western Cape, North West, Free State and Mpumalanga provinces. By August 2010, 232 confirmed infections had been reported in humans, with 26 confirmed deaths.To investigate the evolutionary dynamics of RVF viruses (RVFVs) circulating in South Africa, we undertook complete genome sequence analysis of isolates from animals at discrete foci of the 2008–2010 outbreaks. The genome sequences of these viruses were compared with those of the viruses from earlier outbreaks in South Africa and in other countries. The data indicate that one 2009 and all the 2008 isolates from South Africa and Madagascar (M49/08) cluster in Lineage C or Kenya-1. The remaining of the 2009 and 2010 isolates cluster within Lineage H, except isolate M259_RSA_09, which is a probable segment M reassortant. This information will be useful to agencies involved in the control and management of Rift Valley fever in South Africa and the neighbouring countries. A single RVF virus serotype exists, yet differences in virulence and pathogenicity of the virus have been observed. This necessitates the need for detailed genetic characterization of various isolates of the virus. Some of the RVF virus isolates that caused the 2008–2010 disease outbreaks in South Africa were most probably reassortants resulting from exchange of portions of the genome, particularly those of segment M. Although clear association between RVFV genotype and phenotype has not been established, various amino acid substitutions have been implicated in the phenotype. Viruses with amino acid substitutions from glycine to glutamic acid at position 277 of segment M have been shown to be more virulent in mice in comparison to viruses with glycine at the same position. Phylogenetic analysis carried out in this study indicated that the viruses responsible for the 2008–2010 RVF outbreaks in South Africa were not introduced from outside the country, but mutated over time and caused the outbreaks when environmental conditions became favourable.
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Affiliation(s)
- Moabi R. Maluleke
- ARC-Onderstepoort Veterinary Research, Gauteng, South Africa
- Department of Veterinary Tropical Diseases, University of Pretoria, Gauteng, South Africa
| | - Maanda Phosiwa
- ARC-Onderstepoort Veterinary Research, Gauteng, South Africa
| | | | - George Michuki
- International Livestock Research Institute, Nairobi, Kenya
| | | | - Phemelo S. Kegakilwe
- Department of Agriculture, Land Reform and Rural Development, Veterinary Services, Northern Cape Province, South Africa
| | - Steve J. Kemp
- Department of Veterinary Tropical Diseases, University of Pretoria, Gauteng, South Africa
| | - Phelix A. O. Majiwa
- ARC-Onderstepoort Veterinary Research, Gauteng, South Africa
- Department of Veterinary Tropical Diseases, University of Pretoria, Gauteng, South Africa
- * E-mail:
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Grossi-Soyster EN, Lee J, King CH, LaBeaud AD. The influence of raw milk exposures on Rift Valley fever virus transmission. PLoS Negl Trop Dis 2019; 13:e0007258. [PMID: 30893298 PMCID: PMC6443189 DOI: 10.1371/journal.pntd.0007258] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 04/01/2019] [Accepted: 02/23/2019] [Indexed: 02/07/2023] Open
Abstract
Rift Valley fever virus (RVFV) is a zoonotic phlebovirus that can be transmitted to humans or livestock by mosquitoes or through direct contact with contaminated bodily fluids and tissues. Exposure to bodily fluids and tissues varies by types of behaviors engaged for occupational tasks, homestead responsibilities, or use in dietary or therapeutic capacities. While previous studies have included milk exposures in their analyses, their primary focus on livestock exposures has been on animal handling, breeding, and slaughter. We analyzed data from multiple field surveys in Kenya with the aim of associating RVFV infection to raw milk exposures from common animal species. Of those with evidence of prior RVFV infection by serology (n = 267), 77.2% engaged in milking livestock compared to 32.0% for 3,956 co-local seronegative individuals (p < 0.001), and 86.5% of seropositive individuals consumed raw milk compared to 33.4% seronegative individuals (p < 0.001). Individuals who milked and also consumed raw milk had greater odds of RVFV exposure than individuals whose only contact to raw milk was through milking. Increased risks were associated with exposure to milk sourced from cows (p < 0.001), sheep (p < 0.001), and goats (p < 0.001), but not camels (p = 0.98 for consuming, p = 0.21 for milking). Our data suggest that exposure to raw milk may contribute to a significant number of cases of RVFV, especially during outbreaks and in endemic areas, and that some animal species may be associated with a higher risk for RVFV exposure. Livestock trade is regulated to limit RVFV spread from endemic areas, yet further interventions designed to fully understand the risk of RVFV exposure from raw milk are imperative.
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Affiliation(s)
- Elysse N. Grossi-Soyster
- Department of Pediatrics, Division of Infectious Diseases, Stanford University School of Medicine, Stanford, CA, United States of America
- * E-mail:
| | - Justin Lee
- Quantitative Sciences Unit, Stanford University School of Medicine, Stanford, CA, United States of America
| | - Charles H. King
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, United States of America
| | - A. Desiree LaBeaud
- Department of Pediatrics, Division of Infectious Diseases, Stanford University School of Medicine, Stanford, CA, United States of America
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Msimang V, Thompson PN, Jansen van Vuren P, Tempia S, Cordel C, Kgaladi J, Khosa J, Burt FJ, Liang J, Rostal MK, Karesh WB, Paweska JT. Rift Valley Fever Virus Exposure amongst Farmers, Farm Workers, and Veterinary Professionals in Central South Africa. Viruses 2019; 11:v11020140. [PMID: 30736488 PMCID: PMC6409972 DOI: 10.3390/v11020140] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/01/2019] [Accepted: 02/05/2019] [Indexed: 12/21/2022] Open
Abstract
Rift Valley fever (RVF) is a re-emerging arboviral disease of public health and veterinary importance in Africa and the Arabian Peninsula. Major RVF epidemics were documented in South Africa in 1950⁻1951, 1974⁻1975, and 2010⁻2011. The number of individuals infected during these outbreaks has, however, not been accurately estimated. A total of 823 people in close occupational contact with livestock were interviewed and sampled over a six-month period in 2015⁻2016 within a 40,000 km² study area encompassing parts of the Free State and Northern Cape provinces that were affected during the 2010⁻2011 outbreak. Seroprevalence of RVF virus (RVFV) was 9.1% (95% Confidence Interval (CI95%): 7.2⁻11.5%) in people working or residing on livestock or game farms and 8.0% in veterinary professionals. The highest seroprevalence (SP = 15.4%; CI95%: 11.4⁻20.3%) was detected in older age groups (≥40 years old) that had experienced more than one known large epidemic compared to the younger participants (SP = 4.3%; CI95%: 2.6⁻7.3%). The highest seroprevalence was in addition found in people who injected animals, collected blood samples (Odds ratio (OR) = 2.3; CI95%: 1.0⁻5.3), slaughtered animals (OR = 3.9; CI95%: 1.2⁻12.9) and consumed meat from an animal found dead (OR = 3.1; CI95%: 1.5⁻6.6), or worked on farms with dams for water storage (OR = 2.7; CI95%: 1.0⁻6.9). We estimated the number of historical RVFV infections of farm staff in the study area to be most likely 3849 and 95% credible interval between 2635 and 5374 based on seroprevalence of 9.1% and national census data. We conclude that human RVF cases were highly underdiagnosed and heterogeneously distributed. Improving precautions during injection, sample collection, slaughtering, and meat processing for consumption, and using personal protective equipment during outbreaks, could lower the risk of RVFV infection.
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Affiliation(s)
- Veerle Msimang
- Epidemiology Section, Department of Animal Production Studies; Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa.
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, National Health Laboratory Service, Sandringham 2192, South Africa.
| | - Peter N Thompson
- Epidemiology Section, Department of Animal Production Studies; Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa.
| | - Petrus Jansen van Vuren
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, National Health Laboratory Service, Sandringham 2192, South Africa.
| | - Stefano Tempia
- MassGenics, Duluth, GA 30026, USA.
- Influenza Division, Centers for Disease Control and Prevention, Pretoria 0001, South Africa; Influenza Division and Centers for Disease Control and Prevention, Atlanta, GA 30301, USA.
| | | | - Joe Kgaladi
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, National Health Laboratory Service, Sandringham 2192, South Africa.
| | - Jimmy Khosa
- National Institute for Communicable Diseases, National Health Laboratory Service, Sandringham 2192, South Africa.
| | - Felicity J Burt
- Division of Virology, National Health Laboratory Service and Faculty of Health Sciences, University of the Free State, Bloemfontein 9300, South Africa.
| | | | | | | | - Janusz T Paweska
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, National Health Laboratory Service, Sandringham 2192, South Africa.
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Matiko MK, Salekwa LP, Kasanga CJ, Kimera SI, Evander M, Nyangi WP. Serological evidence of inter-epizootic/inter-epidemic circulation of Rift Valley fever virus in domestic cattle in Kyela and Morogoro, Tanzania. PLoS Negl Trop Dis 2018; 12:e0006931. [PMID: 30418975 PMCID: PMC6258417 DOI: 10.1371/journal.pntd.0006931] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 11/26/2018] [Accepted: 10/17/2018] [Indexed: 11/19/2022] Open
Abstract
Background Tanzania is among the Rift Valley fever (RVF) epizootic/endemic countries in sub Saharan Africa, where RVF disease outbreaks occur within a range of 3 to 17-year intervals. Detection of Rift Valley fever virus (RVFV) antibodies in animals in regions with no previous history of outbreaks raises the question of whether the disease is overlooked due to lack-of effective surveillance systems, or if there are strains of RVFV with low pathogenicity. Furthermore, which vertebrate hosts are involved in the inter-epidemic and inter-epizootic maintenance of RVFV? In our study region, the Kyela and Morogoro districts in Tanzania, no previous RVF outbreaks have been reported. Methodology The study was conducted from June 2014 to October 2015 in the Kyela and Morogoro districts, Tanzania. Samples (n = 356) were retrieved from both the local breed of zebu cattle (Bos indicus) and Bos indicus/Bos Taurus cross breed. RVFV antibodies were analyzed by two enzyme-linked immunosorbent assay (ELISA) approaches. Initially, samples were analyzed by a RVFV multi-species competition ELISA (cELISA), which detected both RVFV IgG and IgM antibodies. All serum samples that were positive with the cELISA method were specifically analysed for the presence of RVFV IgM antibodies to trace recent infection. A plaque reduction neutralization assay (PRNT80) was performed to determine presence of RVFV neutralizing antibodies in all cELISA positive samples. Findings Overall RVFV seroprevalence rate in cattle by cELISA in both districts was 29.2% (104 of 356) with seroprevalence rates of 33% (47/147) in the Kyela district and 27% (57/209) in the Morogoro district. In total, 8.4% (30/356) of all cattle sampled had RVFV IgM antibodies, indicating current disease transmission. When segregated by districts, the IgM antibody seroprevalence was 2.0% (3/147) and 12.9% (27/209) in Kyela and Morogoro districts respectively. When the 104 cELISA positive samples were analyzed by PRNT80 to confirm that RVFV-specific antibodies were present, the majority (89%, 93/104) had RVFV neutralising antibodies. Conclusion The results provided evidence of widespread prevalence of RVFV antibody among cattle during an inter-epizootic/inter-epidemic period in Tanzania in regions with no previous history of outbreaks. There is a need for further investigations of RVFV maintenance and transmission in vertebrates and vectors during the long inter-epizootic/inter-epidemic periods. The RVFV maintenance between inter-epizootic/inter-epidemic periods is not fully understood, despite the widely hypothesized belief of maintenance via transovarially infected Aedes mosquito eggs. Increasing serological evidence however, suggests that there could be continuous virus circulation throughout these periods in domestic ruminants, wild animals and humans both in areas with and without known history of RVF outbreaks. In some countries, RVFV antibodies have been demonstrated in livestock raised in areas where no clinical disease has ever been reported. However, in Tanzania, RVFV antibodies in livestock have been demonstrated only in areas with history of RVF outbreaks, raising the question of whether the disease is not present, is overlooked due to lack of effective surveillance systems, or whether there are strains of RVFV with low pathogenicity that do not cause detectable clinical cases in non-outbreak areas. We report here inter-epizootic/inter-epidemic RVFV antibody prevalence in non-vaccinated cattle from areas with no previous RVF outbreak in Tanzania and demonstrate recent virus circulation by detection of IgM antibodies. The differences in RVFV seroprevalence in different study locations suggest local factors that favour the virus amplification and transmission within those areas.
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Affiliation(s)
- Mirende Kichuki Matiko
- Department of Veterinary Surgery and Theriogenology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
- * E-mail:
| | - Linda Peniel Salekwa
- Department of Veterinary Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Christopher Jacob Kasanga
- Department of Veterinary Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Sharadhuli Idd Kimera
- Department of Veterinary Medicine and Public Health, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Magnus Evander
- Department of Clinical Microbiology, Division of Virology, Umeå University, Umeå, Sweden
| | - Wambura Philemon Nyangi
- Department of Veterinary Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
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