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Pavulraj S, Stout RW, Barras ED, Paulsen DB, Chowdhury SI. A Novel Quadruple Gene-Deleted BoHV-1-Vectored RVFV Subunit Vaccine Induces Humoral and Cell-Mediated Immune Response against Rift Valley Fever in Calves. Viruses 2023; 15:2183. [PMID: 38005861 PMCID: PMC10674938 DOI: 10.3390/v15112183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 10/23/2023] [Accepted: 10/27/2023] [Indexed: 11/26/2023] Open
Abstract
Rift Valley fever virus (RVFV) is considered to be a high biodefense priority based on its threat to livestock and its ability to cause human hemorrhagic fever. RVFV-infected livestock are also a significant risk factor for human infection by direct contact with contaminated blood, tissues, and aborted fetal materials. Therefore, livestock vaccination in the affected regions has the direct dual benefit and one-health approach of protecting the lives of millions of animals and eliminating the risk of severe and sometimes lethal human Rift Valley fever (RVF) disease. Recently, we have developed a bovine herpesvirus type 1 (BoHV-1) quadruple gene mutant virus (BoHV-1qmv) vector that lacks virulence and immunosuppressive properties due to the deletion of envelope proteins UL49.5, glycoprotein G (gG), gE cytoplasmic tail, and US9 coding sequences. In the current study, we engineered the BoHV-1qmv further by incorporating a chimeric gene sequence to express a proteolytically cleavable polyprotein: RVFV envelope proteins Gn ectodomain sequence fused with bovine granulocyte-macrophage colony-stimulating factor (GMCSF) and Gc, resulting in a live BoHV-1qmv-vectored subunit vaccine against RVFV for livestock. In vitro, the resulting recombinant virus, BoHV-1qmv Sub-RVFV, was replicated in cell culture with high titers. The chimeric Gn-GMCSF and Gc proteins expressed by the vaccine virus formed the Gn-Gc complex. In calves, the BoHV-1qmv Sub-RVFV vaccination was safe and induced moderate levels of the RVFV vaccine strain, MP12-specific neutralizing antibody titers. Additionally, the peripheral blood mononuclear cells from the vaccinated calves had six-fold increased levels of interferon-gamma transcription compared with that of the BoHV-1qmv (vector)-vaccinated calves when stimulated with heat-inactivated MP12 antigen in vitro. Based on these findings, we believe that a single dose of BoHV-1qmv Sub-RVFV vaccine generated a protective RVFV-MP12-specific humoral and cellular immune response. Therefore, the BoHV-1qmv sub-RVFV can potentially be a protective subunit vaccine for cattle against RVFV.
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Affiliation(s)
| | | | | | | | - Shafiqul I. Chowdhury
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA; (S.P.); (R.W.S.); (E.D.B.); (D.B.P.)
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2
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Experimental Infection of Domestic Pigs ( Sus scrofa) with Rift Valley Fever Virus. Viruses 2023; 15:v15020545. [PMID: 36851759 PMCID: PMC9964260 DOI: 10.3390/v15020545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 02/09/2023] [Accepted: 02/13/2023] [Indexed: 02/18/2023] Open
Abstract
Rift valley fever (RVF), caused by the RVF virus (RVFV), is a vector-borne zoonotic disease that primarily affects domestic ruminants. Abortion storms and neonatal deaths characterise the disease in animals. Humans develop flu-like symptoms, which can progress to severe disease. The susceptibility of domestic pigs (Sus scrofa domesticus) to RVFV remains unresolved due to conflicting experimental infection results. To address this, we infected two groups of pregnant sows, neonates and weaners, each with a different RVFV isolate, and a third group of weaners with a mixture of the two viruses. Serum, blood and oral, nasal and rectal swabs were collected periodically, and two neonates and a weaner from group 1 and 2 euthanised from 2 days post infection (DPI), with necropsy and histopathology specimens collected. Sera and organ pools, blood and oronasorectal swabs were tested for RVFV antibodies and RNA. Results confirmed that pigs can be experimentally infected with RVFV, although subclinically, and that pregnant sows can abort following infection. Presence of viral RNA in oronasorectal swab pools on 28 DPI suggest that pigs may shed RVFV for at least one month. It is concluded that precautions should be applied when handling pig body fluids and carcasses during RVF outbreaks.
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Gerken KN, Ndenga BA, Owuor KO, Winter CA, Seetah K, LaBeaud AD. Leveraging livestock movements to urban slaughterhouses for wide-spread Rift Valley fever virus surveillance in Western Kenya. One Health 2022; 15:100457. [PMID: 36532672 PMCID: PMC9754961 DOI: 10.1016/j.onehlt.2022.100457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 11/11/2022] [Accepted: 11/12/2022] [Indexed: 11/16/2022] Open
Abstract
Rift Valley fever virus (RVFV) is an economically devastating, zoonotic arbovirus endemic across Africa with potential to cause severe disease in livestock and humans. Viral spread is primarily driven by movement of domestic ruminants and there is a high potential for transboundary spread. Despite influx of livestock to urban areas in response to the high demand for meat and animal products, RVFV has not been detected in any urban center. The objectives of this study were to determine the feasibility of assessing risk of RVFV introduction to urban Kisumu, Kenya, by testing slaughtered livestock for RVFV exposure and mapping livestock origins. Blood was collected from cattle, sheep, and goats directly after slaughter and tested for anti-RVFV IgG antibodies. Slaughterhouse businessmen responded to a questionnaire on their individual animals' origin, marketplace, and transport means. Thereafter, we mapped livestock flow from origin to slaughterhouse using participatory methods in focus group discussions with stakeholders. Qualitative data on route choice and deviations were spatially integrated into the map. A total of 304 blood samples were collected from slaughtered livestock in October and November 2021. Most (99%) of animals were purchased from 28 different markets across eight counties in Western Kenya. The overall RVFV seroprevalence was 9% (19% cattle, 3% in sheep, and 7% in goats). Migori County bordering Tanzania had the highest county-level seroprevalence (34%) and 80% of all seropositive cattle were purchased at the Suba Kuria market in Migori County. Road quality and animal health influenced stakeholders' decisions for choice of transport means. Overall, this proof-of-concept study offers a sampling framework for RVFV that can be locally implemented and rapidly deployed in response to regional risk. This system can be used in conjunction with participatory maps to improve active livestock surveillance and monitoring of RVFV in Western Kenya, and these methods could be extrapolated to other urban centers or livestock diseases.
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Affiliation(s)
- Keli Nicole Gerken
- Department of Pediatrics, Division of Infectious Disease, Stanford University School of Medicine, Stanford, CA, USA,Corresponding author at: LaBeaud Research Lab, Stanford University School of Medicine, Biomedical Innovation BMI Building, 2 Floor, Room 2400, 1291 Welch Road, Stanford, CA -, USA.
| | | | - Kevin Omondi Owuor
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | | | - Krish Seetah
- Department of Anthropology, Stanford University, USA
| | - Angelle Desiree LaBeaud
- Department of Pediatrics, Division of Infectious Disease, Stanford University School of Medicine, Stanford, CA, USA
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4
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Eckstein S, Ehmann R, Gritli A, Ben Rhaiem M, Ben Yahia H, Diehl M, Wölfel R, Handrick S, Ben Moussa M, Stoecker K. Viral and Bacterial Zoonotic Agents in Dromedary Camels from Southern Tunisia: A Seroprevalence Study. Microorganisms 2022; 10:microorganisms10040727. [PMID: 35456778 PMCID: PMC9028256 DOI: 10.3390/microorganisms10040727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/17/2022] [Accepted: 03/28/2022] [Indexed: 12/10/2022] Open
Abstract
The rapid spread of SARS-CoV-2 clearly demonstrated the potential of zoonotic diseases to cause severe harm to public health. Having limited access to medical care combined with severe underreporting and a lack of active surveillance, Africa carries a high burden of neglected zoonotic diseases. Therefore, the epidemiological monitoring of pathogen circulation is essential. Recently, we found extensive Middle East respiratory syndrome coronavirus (MERS-CoV) prevalence in free-roaming dromedary camels from southern Tunisia. In this study, we aimed to investigate the seroprevalence, and thus the risk posed to public health, of two additional viral and two bacterial pathogens in Tunisian dromedaries: Rift Valley fever virus (RVFV), foot-and-mouth disease virus (FMDV), Coxiella burnetii and Brucella spp. via ELISA. With 73.6% seropositivity, most animals had previously been exposed to the causative agent of Q fever, C. burnetii. Additionally, 7.4% and 1.0% of the dromedaries had antibodies against Brucella and RVFV, respectively, while no evidence was found for the occurrence of FMDV. Our studies revealed considerable immunological evidence of various pathogens within Tunisian dromedary camels. Since these animals have intense contact with humans, they pose a high risk of transmitting serious zoonotic diseases during active infection. The identification of appropriate countermeasures is therefore highly desirable.
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Affiliation(s)
- Simone Eckstein
- Bundeswehr Institute of Microbiology (IMB), 80937 Munich, Germany; (R.E.); (M.D.); (R.W.); (S.H.); (K.S.)
- Correspondence: ; Tel.: +49-992692-3990
| | - Rosina Ehmann
- Bundeswehr Institute of Microbiology (IMB), 80937 Munich, Germany; (R.E.); (M.D.); (R.W.); (S.H.); (K.S.)
| | - Abderraouf Gritli
- Veterinary Service, General Directorate of Military Health, Ministry of National Defense, Tunis 1000, Tunisia; (A.G.); (M.B.R.); (H.B.Y.)
| | - Mohamed Ben Rhaiem
- Veterinary Service, General Directorate of Military Health, Ministry of National Defense, Tunis 1000, Tunisia; (A.G.); (M.B.R.); (H.B.Y.)
| | - Houcine Ben Yahia
- Veterinary Service, General Directorate of Military Health, Ministry of National Defense, Tunis 1000, Tunisia; (A.G.); (M.B.R.); (H.B.Y.)
| | - Manuel Diehl
- Bundeswehr Institute of Microbiology (IMB), 80937 Munich, Germany; (R.E.); (M.D.); (R.W.); (S.H.); (K.S.)
| | - Roman Wölfel
- Bundeswehr Institute of Microbiology (IMB), 80937 Munich, Germany; (R.E.); (M.D.); (R.W.); (S.H.); (K.S.)
| | - Susann Handrick
- Bundeswehr Institute of Microbiology (IMB), 80937 Munich, Germany; (R.E.); (M.D.); (R.W.); (S.H.); (K.S.)
| | - Mohamed Ben Moussa
- Department of Virology, Military Hospital of Instruction of Tunis, Tunis 1008, Tunisia;
| | - Kilian Stoecker
- Bundeswehr Institute of Microbiology (IMB), 80937 Munich, Germany; (R.E.); (M.D.); (R.W.); (S.H.); (K.S.)
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Bracci N, de la Fuente C, Saleem S, Pinkham C, Narayanan A, García-Sastre A, Balaraman V, Richt JA, Wilson W, Kehn-Hall K. Rift Valley fever virus Gn V5-epitope tagged virus enables identification of UBR4 as a Gn interacting protein that facilitates Rift Valley fever virus production. Virology 2022; 567:65-76. [PMID: 35032865 PMCID: PMC8877469 DOI: 10.1016/j.virol.2021.12.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 11/15/2021] [Accepted: 12/31/2021] [Indexed: 02/03/2023]
Abstract
Rift Valley fever virus (RVFV) is an arbovirus that was first reported in the Rift Valley of Kenya which causes significant disease in humans and livestock. RVFV is a tri-segmented, negative-sense RNA virus consisting of a L, M, and S segments with the M segment encoding the glycoproteins Gn and Gc. Host factors that interact with Gn are largely unknown. To this end, two viruses containing an epitope tag (V5) on the Gn protein in position 105 or 229 (V5Gn105 and V5Gn229) were generated using the RVFV MP-12 vaccine strain as a backbone. The V5-tag insertion minimally impacted Gn functionality as measured by replication kinetics, Gn localization, and antibody neutralization assays. A proteomics-based approach was used to identify novel Gn-binding host proteins, including the E3 ubiquitin-protein ligase, UBR4. Depletion of UBR4 resulted in a significant decrease in RVFV titers and a reduction in viral RNA production.
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Affiliation(s)
- Nicole Bracci
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University,National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University
| | - Cynthia de la Fuente
- The National Institutes of Health, National Institute of Allergy and Infectious Diseases, DEA,National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University
| | - Sahar Saleem
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University
| | - Chelsea Pinkham
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University
| | - Aarthi Narayanan
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University
| | | | - Velmurugan Balaraman
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University
| | - Juergen A. Richt
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University
| | - William Wilson
- National Bio and Agro-Defense Facility, Agricultural Research Service, USDA
| | - Kylene Kehn-Hall
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University,National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University,Center for Zoonotic and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University,Corresponding Author: Kylene Kehn-Hall, Ph.D., Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Integrated Life Sciences Building, 1981 Kraft Drive, Blacksburg, VA 24060 USA,
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6
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Sindato C, Karimuribo ED, Swai ES, Mboera LEG, Rweyemamu MM, Paweska JT, Salt J. Safety, Immunogenicity and Antibody Persistence of Rift Valley Fever Virus Clone 13 Vaccine in Sheep, Goats and Cattle in Tanzania. Front Vet Sci 2022; 8:779858. [PMID: 34977212 PMCID: PMC8718550 DOI: 10.3389/fvets.2021.779858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 11/22/2021] [Indexed: 11/29/2022] Open
Abstract
Background: Vaccination is considered to be the best approach to control Rift Valley fever (RVF) in animals and consequently in humans. This study assessed the efficacy and safety of the RVF virus (RVFV) Clone 13 vaccine under field conditions. Methodology: A vaccine trial was conducted in sheep (230), goats (230), and cattle (140) in Ngorongoro district, Tanzania. Half of each of the animal species were vaccinated and the other half received the placebo. Animals were clinically monitored and bled before vaccination and at days 15, 30, 60, 180 and 360 (+/– 10) post-vaccination to measure Immunoglobulin M (IgM) and IgG antibody responses to RVFV. Survival analysis was conducted using cox-proportional hazard regression model to measure the time until an event of interest had occurred and to compare the cumulative proportion of events over time. Results: Of 600 animals included in the study, 120 animals were lost during the study, leaving a total of 480 (243 in the vaccinated group and 237 in the control group) for complete follow-up sampling. There was no adverse reaction reported at the injection site of the vaccine/placebo in all animals. Abortions, deaths, or body temperature variations were not associated with vaccination (p > 0.05). By day 15 post-inoculation, the IgG seroconversion in vaccinated goats, cattle and sheep was 27.0% (n = 115), 20.0% (n = 70) and 10.4% (n = 115), respectively. By day 30 post-inoculation, it was 75.0% (n = 113), 74.1% (n = 112) and 57.1% (n = 70) in vaccinated sheep, goats and cattle, respectively. By day 60 post-inoculation, IgG seroconversion in sheep, goats and cattle was 88.1% (n = 109), 84.3% (n = 108) and 64.60% (n = 65), respectively. By day 180, the IgG seroconversion in sheep, goats and cattle was 88.0% (n = 108), 83.8% (n = 105) and 66.1% (n = 62), respectively. By day 360, the IgG seroconversion in sheep, goats and cattle was 87.2% (n = 94), 85.6% (n = 90) and 66.1% (n = 59), respectively. Only five animals from the vaccinated group were RVFV IgM positive, which included four sheep and a goat. Conclusion: RVFV Clone 13 vaccine was well tolerated by sheep, goats, and cattle. The vaccine induced detectable, but variable levels of IgG responses, and of different duration. The vaccine is considered safe, with high immunogenicity in sheep and goats and moderate in cattle.
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Affiliation(s)
- Calvin Sindato
- National Institute for Medical Research, Tabora Research Centre, Tabora, Tanzania.,SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Esron D Karimuribo
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania.,College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
| | | | - Leonard E G Mboera
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Mark M Rweyemamu
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Janusz T Paweska
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania.,National Health Laboratory Service, Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, Sandringham, South Africa.,Department of Medical Virology, Centre for Viral Zoonoses, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.,Faculty of Health Sciences, School of Pathology, University of Witwatersrand, Johannesburg, South Africa
| | - Jeremy Salt
- Global Alliance for Livestock Veterinary Medicines, Edinburgh, United Kingdom
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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] [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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8
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Gogovi GK, Silayi S, Shehu A. Computing the Structural Dynamics of RVFV L Protein Domain in Aqueous Glycerol Solutions. Biomolecules 2021; 11:biom11101427. [PMID: 34680060 PMCID: PMC8533350 DOI: 10.3390/biom11101427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 09/24/2021] [Accepted: 09/25/2021] [Indexed: 11/23/2022] Open
Abstract
Many biological and biotechnological processes are controlled by protein–protein and protein–solvent interactions. In order to understand, predict, and optimize such processes, it is important to understand how solvents affect protein structure during protein–solvent interactions. In this study, all-atom molecular dynamics are used to investigate the structural dynamics and energetic properties of a C-terminal domain of the Rift Valley Fever Virus L protein solvated in glycerol and aqueous glycerol solutions in different concentrations by molecular weight. The Generalized Amber Force Field is modified by including restrained electrostatic potential atomic charges for the glycerol molecules. The peptide is considered in detail by monitoring properties like the root-mean-squared deviation, root-mean-squared fluctuation, radius of gyration, hydrodynamic radius, end-to-end distance, solvent-accessible surface area, intra-potential energy, and solvent–peptide interaction energies for hundreds of nanoseconds. Secondary structure analysis is also performed to examine the extent of conformational drift for the individual helices and sheets. We predict that the peptide helices and sheets are maintained only when the modeling strategy considers the solvent with lower glycerol concentration. We also find that the solvent-peptide becomes more cohesive with decreasing glycerol concentrations. The density and radial distribution function of glycerol solvent calculated when modeled with the modified atomic charges show a very good agreement with experimental results and other simulations at 298.15K.
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Affiliation(s)
- Gideon K. Gogovi
- Department of Mathematics and Statistics, University of Houston—Downtown, Houston, TX 77054, USA
- Correspondence:
| | - Swabir Silayi
- Office of Research Computing, George Mason University, Fairfax, VA 22030, USA;
| | - Amarda Shehu
- Department of Computer Science, George Mason University, Fairfax, VA 22030, USA;
- Department of Bioengineering, George Mason University, Fairfax, VA 22030, USA
- School of Systems Biology, George Mason University, Fairfax, VA 22030, USA
- Center for Advancing Human-Machine Partnerships, George Mason University, Fairfax, VA 22030, USA
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9
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Over 100 Years of Rift Valley Fever: A Patchwork of Data on Pathogen Spread and Spillover. Pathogens 2021; 10:pathogens10060708. [PMID: 34198898 PMCID: PMC8227530 DOI: 10.3390/pathogens10060708] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 05/28/2021] [Accepted: 06/01/2021] [Indexed: 11/17/2022] Open
Abstract
During the past 100 years, Rift Valley fever virus (RVFV), a mosquito-borne virus, has caused potentially lethal disease in livestock, and has been associated with significant economic losses and trade bans. Spillover to humans occurs and can be fatal. Here, we combined data on RVF disease in humans (22 countries) and animals (37 countries) from 1931 to 2020 with seroprevalence studies from 1950 to 2020 (n = 228) from publicly available databases and publications to draw a more complete picture of the past and current RVFV epidemiology. RVFV has spread from its original locus in Kenya throughout Africa and into the Arabian Peninsula. Throughout the study period seroprevalence increased in both humans and animals, suggesting potentially increased RVFV exposure. In 24 countries, animals or humans tested positive for RVFV antibodies even though outbreaks had never been reported there, suggesting RVFV transmission may well go unnoticed. Among ruminants, sheep were the most likely to be exposed during RVF outbreaks, but not during periods of cryptic spread. We discuss critical data gaps and highlight the need for detailed study descriptions, and long-term studies using a one health approach to further convert the patchwork of data to the tale of RFV epidemiology.
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10
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Moreno S, Calvo-Pinilla E, Devignot S, Weber F, Ortego J, Brun A. Recombinant Rift Valley fever viruses encoding bluetongue virus (BTV) antigens: Immunity and efficacy studies upon a BTV-4 challenge. PLoS Negl Trop Dis 2020; 14:e0008942. [PMID: 33275608 PMCID: PMC7744063 DOI: 10.1371/journal.pntd.0008942] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 12/16/2020] [Accepted: 11/02/2020] [Indexed: 12/18/2022] Open
Abstract
Background Many ruminant diseases of viral aetiology can be effectively prevented using appropriate vaccination measures. For diseases such as Rift Valley fever (RVF) the long inter-epizootic periods make routine vaccination programs unfeasible. Coupling RVF prophylaxis with seasonal vaccination programmes by means of multivalent vaccine platforms would help to reduce the risk of new RVF outbreaks. Methodology/Principal findings In this work we generated recombinant attenuated Rift Valley fever viruses (RVFVs) encoding in place of the virulence factor NSs either the VP2 capsid protein or a truncated form of the non-structural NS1 protein of bluetongue virus serotype 4 (BTV-4). The recombinant viruses were able to carry and express the heterologous BTV genes upon consecutive passages in cell cultures. In murine models, a single immunization was sufficient to protect mice upon RVFV challenge and to elicit a specific immune response against BTV-4 antigens that was fully protective after a BTV-4 boost. In sheep, a natural host for RVFV and BTV, both vaccines proved immunogenic although conferred only partial protection after a virulent BTV-4 reassortant Morocco strain challenge. Conclusions/Significance Though additional optimization will be needed to improve the efficacy data against BTV in sheep, our findings warrant further developments of attenuated RVFV as a dual vaccine platform carrying heterologous immune relevant antigens for ruminant diseases in RVF risk areas. Live attenuated Rift Valley fever (RVF) vaccines constitute a reliable intervention measure to reduce the burden of the disease in endemic countries. In this work we report the generation of attenuated Rift Valley fever virus (RVFV) that express vaccine antigens of bluetongue virus (BTV) instead of the virulence factor NSs. The recombinant viruses were able to induce protective immune responses against both RVFV and BTV when administered as vaccines in mice and sheep respectively. Though further optimization is needed to enhance the level of protection in sheep upon a single dose, these results demonstrate the potential of attenuated RVFV as a vaccine vector for other ruminant diseases, in this case enabling bluetongue vaccination while immunizing against RVF. Since RVF outbreaks are sporadic events, preventive vaccination is often not perceived as a real need. In such scenario a bivalent vaccine strategy would make RVF vaccination more appealing.
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Affiliation(s)
- Sandra Moreno
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos (Madrid), Spain
| | - Eva Calvo-Pinilla
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos (Madrid), Spain
| | - Stephanie Devignot
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, Giessen, Germany
| | - Friedemann Weber
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, Giessen, Germany
| | - Javier Ortego
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos (Madrid), Spain
- * E-mail: (JO); (AB)
| | - Alejandro Brun
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Valdeolmos (Madrid), Spain
- * E-mail: (JO); (AB)
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11
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Asebe G, Mamo G, Michlmayr D, Abegaz WE, Endale A, Medhin G, Larrick JW, Legesse M. Seroprevalence of Rift Valley Fever and West Nile Fever in Cattle in Gambella Region, South West Ethiopia. VETERINARY MEDICINE (AUCKLAND, N.Z.) 2020; 11:119-130. [PMID: 33244452 PMCID: PMC7683499 DOI: 10.2147/vmrr.s278867] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 10/27/2020] [Indexed: 01/19/2023]
Abstract
INTRODUCTION Rift Valley fever (RVF) and West Nile fever (WNF) are re-emerging mosquito-borne zoonotic diseases that cause public health and economic crises. Ethiopia shares borders with South Sudan and Kenya, where these diseases are often documented. The free movement of animals and humans across these borders expects to increase the spread of these diseases. The current study was conducted to assess the occurrence of these diseases in the Gambella region of Ethiopia. METHODOLOGY We collected a total of 368 cattle serum samples from the Lare district on the border of South Sudan and measured the presence of IgG antibody against RVF and WNF virus infections using enzyme-linked immunosorbent assays (ELISA). RESULTS The prevalence of anti-RVF virus IgG antibody was 7.6% (95% CI: 5.3-10.82%), while that of anti-WNF virus IgG antibody was 5.4% (95% CI: 3.52-8.29%). In this study higher seroprevalence of IgG antibodies to RVF virus infection was observed comparing to the WNF virus in cattle. There was no significant association between the prevalence and the cattle age, sex or sampled locations. CONCLUSION The detection of IgG antibody to RVF and WNF virus infections in the Gambella region warrants further study of active case findings and the dynamics of transmission.
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Affiliation(s)
- Getahun Asebe
- Department of Veterinary Microbiology, Immunology and Public Health, College of Veterinary Medicine, Addis Ababa University, Bishoftu, Ethiopia
- College of Agriculture and Natural Resources, Gambella University, Gambella, Ethiopia
| | - Gezahegne Mamo
- Department of Veterinary Microbiology, Immunology and Public Health, College of Veterinary Medicine, Addis Ababa University, Bishoftu, Ethiopia
| | - Daniela Michlmayr
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California Berkeley, Berkeley, CA, USA
| | - Woldaregay Erku Abegaz
- Department of Microbiology, Immunology & Parasitology, School of Medicine, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Adugna Endale
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
- School of Medicine, College of Medicine and Health Sciences, Dire Dawa University, Dire Dawa, Ethiopia
| | - Girmay Medhin
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | | | - Mengistu Legesse
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
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12
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Kroeker AL, Babiuk S, Pickering BS, Richt JA, Wilson WC. Livestock Challenge Models of Rift Valley Fever for Agricultural Vaccine Testing. Front Vet Sci 2020; 7:238. [PMID: 32528981 PMCID: PMC7266933 DOI: 10.3389/fvets.2020.00238] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 04/07/2020] [Indexed: 11/13/2022] Open
Abstract
Since the discovery of Rift Valley Fever virus (RVFV) in Kenya in 1930, the virus has become widespread throughout most of Africa and is characterized by sporadic outbreaks. A mosquito-borne pathogen, RVFV is poised to move beyond the African continent and the Middle East and emerge in Europe and Asia. There is a risk that RVFV could also appear in the Americas, similar to the West Nile virus. In light of this potential threat, multiple studies have been undertaken to establish international surveillance programs and diagnostic tools, develop models of transmission dynamics and risk factors for infection, and to develop a variety of vaccines as countermeasures. Furthermore, considerable efforts to establish reliable challenge models of Rift Valley fever virus have been made and platforms for testing potential vaccines and therapeutics in target species have been established. This review emphasizes the progress and insights from a North American perspective to establish challenge models in target livestock such as cattle, sheep, and goats in comparisons to other researchers' reports. A brief summary of the potential role of wildlife, such as buffalo and white-tailed deer as reservoir species will also be discussed.
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Affiliation(s)
- Andrea Louise Kroeker
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB, Canada
| | - Shawn Babiuk
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB, Canada.,Department of Immunology, University of Manitoba, Winnipeg, MB, Canada
| | - Bradley S Pickering
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, MB, Canada.,Department of Medical Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - Juergen A Richt
- Center of Excellence for Emerging and Zoonotic Animal Diseases (CEEZAD), Manhattan, KS, United States
| | - William C Wilson
- USDA, Arthropod-Borne Animal Diseases Research Unit (ABADRU), Manhattan, KS, United States
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13
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MVA Vectored Vaccines Encoding Rift Valley Fever Virus Glycoproteins Protect Mice against Lethal Challenge in the Absence of Neutralizing Antibody Responses. Vaccines (Basel) 2020; 8:vaccines8010082. [PMID: 32059491 PMCID: PMC7157666 DOI: 10.3390/vaccines8010082] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 02/07/2020] [Accepted: 02/10/2020] [Indexed: 01/01/2023] Open
Abstract
In vitro neutralizing antibodies have been often correlated with protection against Rift Valley fever virus (RVFV) infection. We have reported previously that a single inoculation of sucrose-purified modified vaccinia Ankara (MVA) encoding RVFV glycoproteins (rMVAGnGc) was sufficient to induce a protective immune response in mice after a lethal RVFV challenge. Protection was related to the presence of glycoprotein specific CD8+ cells, with a low-level detection of in vitro neutralizing antibodies. In this work we extended those observations aimed to explore the role of humoral responses after MVA vaccination and to study the contribution of each glycoprotein antigen to the protective efficacy. Thus, we tested the efficacy and immune responses in BALB/c mice of recombinant MVA viruses expressing either glycoprotein Gn (rMVAGn) or Gc (rMVAGc). In the absence of serum neutralizing antibodies, our data strongly suggest that protection of vaccinated mice upon the RVFV challenge can be achieved by the activation of cellular responses mainly directed against Gc epitopes. The involvement of cellular immunity was stressed by the fact that protection of mice was strain dependent. Furthermore, our data suggest that the rMVA based single dose vaccination elicits suboptimal humoral immune responses against Gn antigen since disease in mice was exacerbated upon virus challenge in the presence of rMVAGnGc or rMVAGn immune serum. Thus, Gc-specific cellular immunity could be an important component in the protection after the challenge observed in BALB/c mice, contributing to the elimination of infected cells reducing morbidity and mortality and counteracting the deleterious effect of a subneutralizing antibody immune response.
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14
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Allen ER, Krumm SA, Raghwani J, Halldorsson S, Elliott A, Graham VA, Koudriakova E, Harlos K, Wright D, Warimwe GM, Brennan B, Huiskonen JT, Dowall SD, Elliott RM, Pybus OG, Burton DR, Hewson R, Doores KJ, Bowden TA. A Protective Monoclonal Antibody Targets a Site of Vulnerability on the Surface of Rift Valley Fever Virus. Cell Rep 2019; 25:3750-3758.e4. [PMID: 30590046 PMCID: PMC6315105 DOI: 10.1016/j.celrep.2018.12.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 10/30/2018] [Accepted: 11/29/2018] [Indexed: 12/31/2022] Open
Abstract
The Gn subcomponent of the Gn-Gc assembly that envelopes the human and animal pathogen, Rift Valley fever virus (RVFV), is a primary target of the neutralizing antibody response. To better understand the molecular basis for immune recognition, we raised a class of neutralizing monoclonal antibodies (nAbs) against RVFV Gn, which exhibited protective efficacy in a mouse infection model. Structural characterization revealed that these nAbs were directed to the membrane-distal domain of RVFV Gn and likely prevented virus entry into a host cell by blocking fusogenic rearrangements of the Gn-Gc lattice. Genome sequence analysis confirmed that this region of the RVFV Gn-Gc assembly was under selective pressure and constituted a site of vulnerability on the virion surface. These data provide a blueprint for the rational design of immunotherapeutics and vaccines capable of preventing RVFV infection and a model for understanding Ab-mediated neutralization of bunyaviruses more generally.
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Affiliation(s)
- Elizabeth R Allen
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Stefanie A Krumm
- Kings College London, Department of Infectious Diseases, 2nd Floor, Borough Wing, Guy's Hospital, Great Maze Pond, London SE1 9RT, UK
| | - Jayna Raghwani
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Old Road, Oxford OX3 7LF, UK
| | - Steinar Halldorsson
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Angela Elliott
- MRC-University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, 464 Bearsden Road, Glasgow G61 1QH, UK
| | - Victoria A Graham
- National Infection Service, Virology & Pathogenesis, Public Health England, Porton Down, Salisbury, SP4 0JG Wiltshire, UK
| | - Elina Koudriakova
- MRC-University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, 464 Bearsden Road, Glasgow G61 1QH, UK
| | - Karl Harlos
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Daniel Wright
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - George M Warimwe
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford OX3 7FZ, UK; Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Benjamin Brennan
- MRC-University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, 464 Bearsden Road, Glasgow G61 1QH, UK
| | - Juha T Huiskonen
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Stuart D Dowall
- National Infection Service, Virology & Pathogenesis, Public Health England, Porton Down, Salisbury, SP4 0JG Wiltshire, UK
| | - Richard M Elliott
- MRC-University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, 464 Bearsden Road, Glasgow G61 1QH, UK
| | - Oliver G Pybus
- Department of Zoology, University of Oxford, South Parks Road, Oxford, UK
| | - Dennis R Burton
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA; Ragon Institute of MGH, Harvard, and MIT, Cambridge, MA 02139, USA
| | - Roger Hewson
- National Infection Service, Virology & Pathogenesis, Public Health England, Porton Down, Salisbury, SP4 0JG Wiltshire, UK
| | - Katie J Doores
- Kings College London, Department of Infectious Diseases, 2nd Floor, Borough Wing, Guy's Hospital, Great Maze Pond, London SE1 9RT, UK.
| | - Thomas A Bowden
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK; Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA.
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15
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Li S, Zhu X, Guan Z, Huang W, Zhang Y, Kortekaas J, Lozach PY, Peng K. NSs Filament Formation Is Important but Not Sufficient for RVFV Virulence In Vivo. Viruses 2019; 11:v11090834. [PMID: 31500343 PMCID: PMC6783917 DOI: 10.3390/v11090834] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 08/28/2019] [Accepted: 09/03/2019] [Indexed: 02/06/2023] Open
Abstract
Rift Valley fever virus (RVFV) is a mosquito-borne phlebovirus that represents as a serious health threat to both domestic animals and humans. The viral protein NSs is the key virulence factor of RVFV, and has been proposed that NSs nuclear filament formation is critical for its virulence. However, the detailed mechanisms are currently unclear. Here, we generated a T7 RNA polymerase-driven RVFV reverse genetics system based on a strain imported into China (BJ01). Several NSs mutations (T1, T3 and T4) were introduced into the system for investigating the correlation between NSs filament formation and virulence in vivo. The NSs T1 mutant showed distinct NSs filament in the nuclei of infected cells, the T3 mutant diffusively localized in the cytoplasm and the T4 mutant showed fragmented nuclear filament formation. Infection of BALB/c mice with these NSs mutant viruses revealed that the in vivo virulence was severely compromised for all three NSs mutants, including the T1 mutant. This suggests that NSs filament formation is not directly correlated with RVFV virulence in vivo. Results from this study not only shed new light on the virulence mechanism of RVFV NSs but also provided tools for future in-depth investigations of RVFV pathogenesis and anti-RVFV drug screening.
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Affiliation(s)
- Shufen Li
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
- Wuhan National Biosafety Laboratory, Mega-Science Center for Bio-Safety Research, CAS, Wuhan 430071, China.
| | - Xiangtao Zhu
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Zhenqiong Guan
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Wenfeng Huang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Yulan Zhang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
- Wuhan National Biosafety Laboratory, Mega-Science Center for Bio-Safety Research, CAS, Wuhan 430071, China.
| | - Jeroen Kortekaas
- Department of Virology, Wageningen Bioveterinary Research, 8211 Lelystad, The Netherlands.
- Laboratory of Virology, Wageningen University, 6701 Wageningen, The Netherlands.
| | - Pierre-Yves Lozach
- Cell Networks-Cluster of Excellence and Center for Integrative Infectious Disease Research, University Hospital Heidelberg, 69115 Heidelberg, Germany.
- IVPC UMR754, INRA, Univ. Lyon, EPHE, 50 Av. Tony Garnier, 69007 Lyon, France.
| | - Ke Peng
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
- Wuhan National Biosafety Laboratory, Mega-Science Center for Bio-Safety Research, CAS, Wuhan 430071, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
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16
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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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17
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Modeling the Tertiary Structure of the Rift Valley Fever Virus L Protein. Molecules 2019; 24:molecules24091768. [PMID: 31067727 PMCID: PMC6539450 DOI: 10.3390/molecules24091768] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 04/13/2019] [Accepted: 05/03/2019] [Indexed: 01/09/2023] Open
Abstract
A tertiary structure governs, to a great extent, the biological activity of a protein in the living cell and is consequently a central focus of numerous studies aiming to shed light on cellular processes central to human health. Here, we aim to elucidate the structure of the Rift Valley fever virus (RVFV) L protein using a combination of in silico techniques. Due to its large size and multiple domains, elucidation of the tertiary structure of the L protein has so far challenged both dry and wet laboratories. In this work, we leverage complementary perspectives and tools from the computational-molecular-biology and bioinformatics domains for constructing, refining, and evaluating several atomistic structural models of the L protein that are physically realistic. All computed models have very flexible termini of about 200 amino acids each, and a high proportion of helical regions. Properties such as potential energy, radius of gyration, hydrodynamics radius, flexibility coefficient, and solvent-accessible surface are reported. Structural characterization of the L protein enables our laboratories to better understand viral replication and transcription via further studies of L protein-mediated protein-protein interactions. While results presented a focus on the RVFV L protein, the following workflow is a more general modeling protocol for discovering the tertiary structure of multidomain proteins consisting of thousands of amino acids.
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18
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The One Health Approach is Necessary for the Control of Rift Valley Fever Infections in Egypt: A Comprehensive Review. Viruses 2019; 11:v11020139. [PMID: 30736362 PMCID: PMC6410127 DOI: 10.3390/v11020139] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 02/02/2019] [Accepted: 02/03/2019] [Indexed: 11/17/2022] Open
Abstract
Rift Valley fever (RVF) is an emerging transboundary, mosquito-borne, zoonotic viral disease caused high morbidity and mortality in both human and ruminant populations. It is considered an important threat to both agriculture and public health in African and the Middle Eastern countries including Egypt. Five major RVF epidemics have been reported in Egypt (1977, 1993, 1994, 1997, and 2003). The virus is transmitted in Egypt by different mosquito’s genera such as Aedes, Culex, Anopheles, and Mansonia, leading to abortions in susceptible animal hosts especially sheep, goat, cattle, and buffaloes. Recurrent RVF outbreaks in Egypt have been attributed in part to the lack of routine surveillance for the virus. These periodic epizootics have resulted in severe economic losses. We posit that there is a critical need for new approaches to RVF control that will prevent or at least reduce future morbidity and economic stress. One Health is an integrated approach for the understanding and management of animal, human, and environmental determinants of complex problems such as RVF. Employing the One Health approach, one might engage local communities in surveillance and control of RVF efforts, rather than continuing their current status as passive victims of the periodic RVF incursions. This review focuses upon endemic and epidemic status of RVF in Egypt, the virus vectors and their ecology, transmission dynamics, risk factors, and the ecology of the RVF at the animal/human interface, prevention, and control measures, and the use of environmental and climate data in surveillance systems to predict disease outbreaks.
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Terasaki K, Juelich TL, Smith JK, Kalveram B, Perez DD, Freiberg AN, Makino S. A single-cycle replicable Rift Valley fever phlebovirus vaccine carrying a mutated NSs confers full protection from lethal challenge in mice. Sci Rep 2018; 8:17097. [PMID: 30459418 PMCID: PMC6244155 DOI: 10.1038/s41598-018-35472-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 11/05/2018] [Indexed: 11/09/2022] Open
Abstract
Rift Valley fever phlebovirus (RVFV) is a pathogen of Rift Valley fever, which is a mosquito-borne zoonotic disease for domestic livestock and humans in African countries. Currently, no approved vaccine is available for use in non-endemic areas. The MP-12 strain is so far the best live attenuated RVFV vaccine candidate because of its good protective efficacy in animal models. However, there are safety concerns for use of MP-12 in humans. We previously developed a single-cycle replicable MP-12 (scMP-12) which lacks NSs gene and undergoes only a single round of viral replication because of its impaired ability to induce membrane-membrane fusion. In the present study, we generated an scMP-12 mutant (scMP-12-mutNSs) carrying a mutant NSs, which degrades double-stranded RNA-dependent protein kinase R but does not inhibit host transcription. Immunization of mice with a single dose (105 PFU) of scMP-12-mutNSs elicited RVFV neutralizing antibodies and high titers of anti-N IgG production and fully protected the mice from lethal wild-type RVFV challenge. Immunogenicity and protective efficacy of scMP-12-mutNSs were better than scMP-12, demonstrating that scMP-12-mutNSs is a more efficacious vaccine candidate than scMP-12. Furthermore, our data suggested that RVFV vaccine efficacy can be improved by using this specific NSs mutant.
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Affiliation(s)
- Kaori Terasaki
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,Institute for Human Infection and Immunity, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Terry L Juelich
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Jennifer K Smith
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Birte Kalveram
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - David D Perez
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Alexander N Freiberg
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,UTMB Center for Tropical Diseases, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,The Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,Institute for Human Infection and Immunity, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Shinji Makino
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States. .,Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States. .,UTMB Center for Tropical Diseases, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States. .,The Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States. .,Institute for Human Infection and Immunity, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.
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Alhaji NB, Babalobi OO, Wungak Y, Ularamu HG. Participatory survey of Rift Valley fever in nomadic pastoral communities of North-central Nigeria: The associated risk pathways and factors. PLoS Negl Trop Dis 2018; 12:e0006858. [PMID: 30376568 PMCID: PMC6207297 DOI: 10.1371/journal.pntd.0006858] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 09/18/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Rift Valley fever (RVF) is an emerging neglected mosquito-borne viral zoonotic disease of domestic animals and humans, with potential for global expansion. The objectives of this study were: to assess perceived relative burden and seasonality of RVF in nomadic cattle herds and validate the burden with sero-prevalence impact; and assess perceived risk factors associated with the disease and risk pathways for RVF virus in nomadic pastoral herds of North-central Nigeria using pastoralists' existing veterinary knowledge. METHODS Participatory Epidemiology (PE) survey was conducted in Fulani nomadic pastoral communities domiciled in Niger State between January and December 2015. A cross-sectional sero-prevalence investigation was also carried out in nomadic pastoral cattle herds to validate outcomes of PE. A total of nine nomadic pastoral communities were purposively selected for qualitative impact assessment using Participatory Rural Appraisal tools, while 97 cattle randomly sampled from 15 purposively selected nomadic herds and had their sera analyzed using c-ELISA. Kendall's Coefficient of Concordance W statistics and OpenEpi 2.3.1 were used for statistical analyses. RESULTS Mean proportional piles (relative burden) of RVF (Gabi-gabiF) was 8.3%, and nomads agreement on the burden was strong (W = 0.6855) and statistically significant (P<0.001). This was validated by 11.3% (11/97; 95% CI: 6.1-18.9) sero-positivity (quantitative impact). Mean matrix scores of prominent clinical signs associated with RVF were fever (3.1), anorexia (2.1), abortion (4.1), nasal discharge (3.3), neurological disorder (8.4), diarrhoea (3.2), and sudden death (4.4), with strong agreement (W = 0.6687) and statistically significant (p<0.001). Mean proportional piles of pastoralists' perceived risk factors identified to influenced RVF occurrence were: availability of mosquitoes (18 piles, 17.6%), high cattle density (16 piles, 15.9%) and high rainfall (12 piles, 12.2%). Agreement on the risk factors was strong (W = 0.8372) and statistically significant (p<0.01). Mean matrix scores for the Entry pathway of RVF virus into the nomadic pastoral herds were: presence of RVFV infected mosquitoes (tiny biting flies) (7.9), presence of infected cattle in herds (8.4), and contacts of herd with infected wild animals at grazing (10.1). Mean matrix scores for the Spread pathway of RVF virus in herds were bites of infected mosquitoes (5.1), contacts with infected aborted fetuses/fluids (7.8), and contaminated pasture with aborted fetuses/fluids (9.7). Agreement on risk pathways was strong (W = 0.6922) and statistically significant (p<0.03). Key informants scored RVF to occurred more in Damina or late rainy season (5.3), followed by Kaka or early dry season (3.3), with strong agreement (W = 0.8719) and statistically significant (P<0.01). This study highlighted the significant existing knowledge level about RVF contained in nomadic pastoralists. CONCLUSIONS The use of PE approach is needful in active surveillance of livestock diseases in pastoral communities domiciled in highly remote areas. RVF surveillance system, control and prevention programmes that take the identified risk factors and pathways into consideration will be beneficial to the livestock industry in Nigeria, and indeed Africa. An 'OneHealth' approach is needed to improve efficiency of RVF research, surveillance, prevention and control systems, so as to assure food security and public health in developing countries.
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Affiliation(s)
- Nma Bida Alhaji
- Public Health and Epidemiology Department, Niger State Ministry of Livestock and Fisheries, Minna, Nigeria
- Department of Veterinary Public Health and Preventive Medicine, University of Ibadan, Ibadan, Nigeria
- * E-mail:
| | - Olutayo Olajide Babalobi
- Department of Veterinary Public Health and Preventive Medicine, University of Ibadan, Ibadan, Nigeria
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Pinkham C, Ahmed A, Bracci N, Narayanan A, Kehn-Hall K. Host-based processes as therapeutic targets for Rift Valley fever virus. Antiviral Res 2018; 160:64-78. [PMID: 30316916 DOI: 10.1016/j.antiviral.2018.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 09/27/2018] [Accepted: 10/05/2018] [Indexed: 12/28/2022]
Abstract
Rift Valley fever virus (RVFV) is an enveloped, segmented, negative sense RNA virus that replicates within the host's cytoplasm. To facilitate its replication, RVFV must utilize host cell processes and as such, these processes may serve as potential therapeutic targets. This review summarizes key host cell processes impacted by RVFV infection. Specifically the influence of RVFV on host transcriptional regulation, post-transcriptional regulation, protein half-life and availability, host signal transduction, trafficking and secretory pathways, cytoskeletal modulation, and mitochondrial processes and oxidative stress are discussed. Therapeutics targeted towards host processes that are essential for RVFV to thrive as well as their efficacy and importance to viral pathogenesis are highlighted.
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Affiliation(s)
- Chelsea Pinkham
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Aslaa Ahmed
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Nicole Bracci
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Aarthi Narayanan
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Kylene Kehn-Hall
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA.
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22
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Kim HJ, Lyoo HR, Choi JS, Lee YH, Kim BH, Yoo HS. Development of a Quantitative RT-PCR Assay to Differentiate Rift Valley Fever Virus Smithburn Vaccine Strain from Clone 13 Vaccine Strain. Vector Borne Zoonotic Dis 2018; 19:121-127. [PMID: 30300113 DOI: 10.1089/vbz.2018.2342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A new quantitative RT-PCR assay was developed to differentiate Rift Valley fever (RVF) Smithburn vaccine strain from Clone 13 vaccine strain. The new qRT-PCR assay targeting the S segment (NSs and N gene) was tested on synthesized standard RNA and MP-12 strain viruses. The detection limit of the new qRT-PCR assay is 1 copy/μL of NSs and N, and is able to differentiate the Smithburn vaccine strain of RVF from the Clone 13 vaccine strain. No cross-reactivity with other vector-borne viruses was observed, a factor that is especially important in the Republic of Korea (ROK). To examine the performance of the qRT-PCR, intra- and inter-assay variability data were analyzed and showed high reproducibility. These results indicate that the new qRT-PCR can be used as a safe and cost-effective test. Furthermore, this result suggests the possibility of differentiation between infected and vaccinated animals diagnostic test in RVF-free countries including ROK.
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Affiliation(s)
- Hyun-Joo Kim
- 1 Foreign Animal Disease Division, Animal and Plant Quarantine Agency , Gimcheon-si, Republic of Korea.,2 Department of Infectious Diseases, Colleges of Veterinary Medicine, Seoul National University , Seoul, Republic of Korea
| | - Hye-Rhyoung Lyoo
- 3 Department of Infectious Diseases and Immunology, Virology Division, Faculty of Veterinary Medicine, Utrecht University , Utrecht, the Netherlands
| | - Jeong-Soo Choi
- 1 Foreign Animal Disease Division, Animal and Plant Quarantine Agency , Gimcheon-si, Republic of Korea
| | - Yoon-Hee Lee
- 1 Foreign Animal Disease Division, Animal and Plant Quarantine Agency , Gimcheon-si, Republic of Korea
| | - Byoung-Han Kim
- 1 Foreign Animal Disease Division, Animal and Plant Quarantine Agency , Gimcheon-si, Republic of Korea
| | - Han Sang Yoo
- 2 Department of Infectious Diseases, Colleges of Veterinary Medicine, Seoul National University , Seoul, Republic of Korea
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23
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Seroprevalence and Virus Activity of Rift Valley Fever in Cattle in Eastern Region of Democratic Republic of the Congo. J Vet Med 2018; 2018:4956378. [PMID: 30050953 PMCID: PMC6046122 DOI: 10.1155/2018/4956378] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 05/08/2018] [Accepted: 05/17/2018] [Indexed: 11/17/2022] Open
Abstract
Rift Valley fever (RVF) is a zoonotic disease that is characterized by periodic and severe outbreaks in humans and animals. Published information on the occurrence of RVF in domestic animals is very scarce in the Democratic Republic of the Congo (DRC). To assess possible circulation of Rift Valley fever virus (RVFV) in cattle in the eastern province of DRC, 450 sera collected from cattle in North Kivu, South Kivu, and Ituri provinces were analyzed using the enzyme-linked immunosorbent assay (ELISA), for the detection of viral Immunoglobulin (Ig) G and M, and reverse transcriptase polymerase chain reaction (RT-PCR), for detection of viral RVF RNA. A cumulative anti-RVF IgG prevalence of 6.22% (95% CI 4.25–8.97) was recorded from the three provinces sampled. In North Kivu and Ituri provinces the anti-RVF IgG prevalence was 12.67% [95% CI 7.80–19.07] and 6% [95% CI 2.78–11.08], respectively, while all the sera collected from South Kivu province were negative for anti-RVF IgG antibodies. Anti-RVF IgM prevalence of 1.8% was obtained among sampled animals in the three provinces. None of the positive anti-RVF IgM samples (n=8) was positive for viral RVFV RNA using RT-PCR. Our findings suggest that RVFV is widely distributed among cattle in eastern province of DRC particularly in North Kivu and Ituri provinces although the epidemiological factors supporting this virus circulation remain unknown in these areas.
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24
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Kanouté YB, Gragnon BG, Schindler C, Bonfoh B, Schelling E. Reprint of "Epidemiology of brucellosis, Q Fever and Rift Valley Fever at the human and livestock interface in northern Côte d'Ivoire". Acta Trop 2017; 175:121-129. [PMID: 28867393 DOI: 10.1016/j.actatropica.2017.08.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Northern Côte d'Ivoire is the main livestock breeding zone and has the highest livestock cross-border movements in Côte d'Ivoire. The aim of this study was to provide updated epidemiological data on three neglected zoonotic diseases, namely brucellosis, Q Fever and Rift Valley Fever (RVF). We conducted three-stage cross-sectional cluster surveys in livestock and humans between 2012 and 2014 in a random selection of 63 villages and a sample of 633 cattle, 622 small ruminants and 88 people. We administered questionnaires to capture risk factors and performed serological tests including the Rose Bengal Plate Test (RBPT), Brucella spp. indirect and competitive ELISAs, Coxiella burnetii indirect ELISA and RVF competitive ELISA. The human seroprevalence for Brucella spp. was 5.3%. RBPT-positive small ruminants tested negative by the indirect ELISA. The seroprevalence of Brucella spp. in cattle adjusted for clustering was 4.6%. Cattle aged 5-8 years had higher odds of seropositivity (OR=3.5) than those aged ≤4years. The seropositivity in cattle was associated with having joint hygromas (OR=9), sharing the pastures with small ruminants (OR=5.8) and contact with pastoralist herds (OR=11.3). The seroprevalence of Q Fever was 13.9% in cattle, 9.4% in sheep and 12.4% in goats. The seroprevalence of RVF was 3.9% in cattle, 2.4% in sheep and 0% in goats. Seropositive ewes had greater odds (OR=4.7) of abortion than seronegative ones. In cattle, a shorter distance between the night pens and nearest permanent water bodies was a protective factor (OR=0.1). The study showed that the exposure to the three zoonoses is rather low in northern Côte d'Ivoire. Within a One Health approach, cost-benefit and cost-effectiveness of control measures should be assessed for an integrated control.
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Affiliation(s)
- Youssouf B Kanouté
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
| | - Biégo G Gragnon
- Laboratoire National d'Appui au Développement Agricole, Lanada, Korhogo, Côte d'Ivoire, Côte d'Ivoire
| | - Christian Schindler
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland
| | - Bassirou Bonfoh
- Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire, Côte d'Ivoire
| | - Esther Schelling
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland
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25
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Atkins C, Freiberg AN. Recent advances in the development of antiviral therapeutics for Rift Valley fever virus infection. Future Virol 2017; 12:651-665. [PMID: 29181086 DOI: 10.2217/fvl-2017-0060] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 07/26/2017] [Indexed: 12/25/2022]
Abstract
Rift Valley fever virus (RVFV) is a mosquito-borne bunyavirus endemic to sub-Saharan Africa and the Arabian Peninsula and the etiological agent of Rift Valley fever. Rift Valley fever is a disease of major public health and economic concern, affecting livestock and humans. In ruminants, RVFV infection is characterized by high mortality rates in newborns and near 100% abortion rates in pregnant animals. Infection in humans is typically manifested as a self-limiting febrile illness, but can lead to severe and fatal hepatitis, encephalitis, hemorrhagic fever or retinitis with partial or complete blindness. Currently, there are no specific treatment options available for RVFV infection. This review presents a summary of the therapeutic approaches that have been explored on the treatment of RVFV infection.
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Affiliation(s)
- Colm Atkins
- Department of Pathology, The University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555, USA.,Department of Pathology, The University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555, USA
| | - Alexander N Freiberg
- Department of Pathology, The University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555, USA.,The Sealy Center for Vaccine Development, The University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555, USA.,The Center for Biodefense & Emerging Infectious Diseases, The University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555, USA.,Department of Pathology, The University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555, USA.,The Sealy Center for Vaccine Development, The University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555, USA.,The Center for Biodefense & Emerging Infectious Diseases, The University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555, USA
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26
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Current Status of Rift Valley Fever Vaccine Development. Vaccines (Basel) 2017; 5:vaccines5030029. [PMID: 28925970 PMCID: PMC5620560 DOI: 10.3390/vaccines5030029] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 09/16/2017] [Accepted: 09/18/2017] [Indexed: 01/08/2023] Open
Abstract
Rift Valley Fever (RVF) is a mosquito-borne zoonotic disease that presents a substantial threat to human and public health. It is caused by Rift Valley fever phlebovirus (RVFV), which belongs to the genus Phlebovirus and the family Phenuiviridae within the order Bunyavirales. The wide distribution of competent vectors in non-endemic areas coupled with global climate change poses a significant threat of the transboundary spread of RVFV. In the last decade, an improved understanding of the molecular biology of RVFV has facilitated significant progress in the development of novel vaccines, including DIVA (differentiating infected from vaccinated animals) vaccines. Despite these advances, there is no fully licensed vaccine for veterinary or human use available in non-endemic countries, whereas in endemic countries, there is no clear policy or practice of routine/strategic livestock vaccinations as a preventive or mitigating strategy against potential RVF disease outbreaks. The purpose of this review was to provide an update on the status of RVF vaccine development and provide perspectives on the best strategies for disease control. Herein, we argue that the routine or strategic vaccination of livestock could be the best control approach for preventing the outbreak and spread of future disease.
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Abstract
Rift Valley fever (RVF) is a severe veterinary disease of livestock that also causes moderate to severe illness in people. The life cycle of RVF is complex and involves mosquitoes, livestock, people, and the environment. RVF virus is transmitted from either mosquitoes or farm animals to humans, but is generally not transmitted from person to person. People can develop different diseases after infection, including febrile illness, ocular disease, hemorrhagic fever, or encephalitis. There is a significant risk for emergence of RVF into new locations, which would affect human health and livestock industries.
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Affiliation(s)
- Amy Hartman
- Center for Vaccine Research, Infectious Diseases and Microbiology, University of Pittsburgh Graduate School of Public Health, University of Pittsburgh, 3501 Fifth Avenue, Pittsburgh, PA 15260, USA.
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28
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Ikegami T. Rift Valley fever vaccines: an overview of the safety and efficacy of the live-attenuated MP-12 vaccine candidate. Expert Rev Vaccines 2017; 16:601-611. [PMID: 28425834 DOI: 10.1080/14760584.2017.1321482] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Rift Valley fever (RVF) is a mosquito-borne zoonotic viral disease endemic to Africa and the Arabian Peninsula. High rates of abortion among infected ruminants and hemorrhagic fever in infected humans are major public health concerns. Commercially available veterinary RVF vaccines are important for preventing the spread of the Rift Valley fever virus (RVFV) in endemic countries; however, RVFV outbreaks continue to occur frequently in endemic countries in the 21st century. In the U.S., the live-attenuated MP-12 vaccine has been developed for both animal and human vaccination. This vaccine strain is well attenuated, and a single dose induces neutralizing antibodies in both ruminants and humans. Areas covered: This review describes scientific evidences of MP-12 vaccine efficacy and safety, as well as MP-12 variants recently developed by reverse genetics, in comparison with other RVF vaccines. Expert commentary: The containment of active RVF outbreaks and long-term protection from RVF exposure to infected mosquitoes are important goals for RVF vaccination. MP-12 vaccine will allow immediate vaccination of susceptible animals in case of an unexpected RVF outbreak in the U.S., whereas MP-12 vaccine may be also useful for the RVF control in endemic regions.
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Affiliation(s)
- Tetsuro Ikegami
- a Department of Pathology, Sealy Center for Vaccine Development, Center for Biodefense and Emerging Infectious Diseases , The University of Texas Medical Branch , Galveston , TX , USA
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29
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Hassan OA, Affognon H, Rocklöv J, Mburu P, Sang R, Ahlm C, Evander M. The One Health approach to identify knowledge, attitudes and practices that affect community involvement in the control of Rift Valley fever outbreaks. PLoS Negl Trop Dis 2017; 11:e0005383. [PMID: 28207905 PMCID: PMC5332088 DOI: 10.1371/journal.pntd.0005383] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 03/01/2017] [Accepted: 02/03/2017] [Indexed: 11/18/2022] Open
Abstract
Rift Valley fever (RVF) is a viral mosquito-borne disease with the potential for global expansion, causes hemorrhagic fever, and has a high case fatality rate in young animals and in humans. Using a cross-sectional community-based study design, we investigated the knowledge, attitudes and practices of people living in small village in Sudan with respect to RVF outbreaks. A special One Health questionnaire was developed to compile data from 235 heads of household concerning their knowledge, attitudes, and practices with regard to controlling RVF. Although the 2007 RVF outbreak in Sudan had negatively affected the participants' food availability and livestock income, the participants did not fully understand how to identify RVF symptoms and risk factors for both humans and livestock. For example, the participants mistakenly believed that avoiding livestock that had suffered spontaneous abortions was the least important risk factor for RVF. Although the majority noticed an increase in mosquito population during the 2007 RVF outbreak, few used impregnated bed nets as preventive measures. The community was reluctant to notify the authorities about RVF suspicion in livestock, a sentinel for human RVF infection. Almost all the respondents stressed that they would not receive any compensation for their dead livestock if they notified the authorities. In addition, the participants believed that controlling RVF outbreaks was mainly the responsibility of human health authorities rather than veterinary authorities. The majority of the participants were aware that RVF could spread from one region to another within the country. Participants received most their information about RVF from social networks and the mass media, rather than the health system or veterinarians. Because the perceived role of the community in controlling RVF was fragmented, the probability of RVF spread increased.
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Affiliation(s)
- Osama Ahmed Hassan
- Umeå University, Clinical Microbiology, Virology, Umeå, Sweden
- Public Health Institute, Khartoum, Sudan
- * E-mail:
| | - Hippolyte Affognon
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Bamako, Mali
| | - Joacim Rocklöv
- Umeå University, Public Health and Clinical Medicine, Epidemiology and Global Health and Umeå Centre for Global Health Research, Umeå, Sweden
| | - Peter Mburu
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Rosemary Sang
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Clas Ahlm
- Umeå University, Clinical Microbiology, Infectious Diseases, Umeå, Sweden
| | - Magnus Evander
- Umeå University, Clinical Microbiology, Virology, Umeå, Sweden
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30
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Kanouté YB, Gragnon BG, Schindler C, Bonfoh B, Schelling E. Epidemiology of brucellosis, Q Fever and Rift Valley Fever at the human and livestock interface in northern Côte d'Ivoire. Acta Trop 2017; 165:66-75. [PMID: 26899680 DOI: 10.1016/j.actatropica.2016.02.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 02/10/2016] [Accepted: 02/14/2016] [Indexed: 12/26/2022]
Abstract
Northern Côte d'Ivoire is the main livestock breeding zone and has the highest livestock cross-border movements in Côte d'Ivoire. The aim of this study was to provide updated epidemiological data on three neglected zoonotic diseases, namely brucellosis, Q Fever and Rift Valley Fever (RVF). We conducted three-stage cross-sectional cluster surveys in livestock and humans between 2012 and 2014 in a random selection of 63 villages and a sample of 633 cattle, 622 small ruminants and 88 people. We administered questionnaires to capture risk factors and performed serological tests including the Rose Bengal Plate Test (RBPT), Brucella spp. indirect and competitive ELISAs, Coxiella burnetii indirect ELISA and RVF competitive ELISA. The human seroprevalence for Brucella spp. was 5.3%. RBPT-positive small ruminants tested negative by the indirect ELISA. The seroprevalence of Brucella spp. in cattle adjusted for clustering was 4.6%. Cattle aged 5-8 years had higher odds of seropositivity (OR=3.5) than those aged ≤4years. The seropositivity in cattle was associated with having joint hygromas (OR=9), sharing the pastures with small ruminants (OR=5.8) and contact with pastoralist herds (OR=11.3). The seroprevalence of Q Fever was 13.9% in cattle, 9.4% in sheep and 12.4% in goats. The seroprevalence of RVF was 3.9% in cattle, 2.4% in sheep and 0% in goats. Seropositive ewes had greater odds (OR=4.7) of abortion than seronegative ones. In cattle, a shorter distance between the night pens and nearest permanent water bodies was a protective factor (OR=0.1). The study showed that the exposure to the three zoonoses is rather low in northern Côte d'Ivoire. Within a One Health approach, cost-benefit and cost-effectiveness of control measures should be assessed for an integrated control.
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Affiliation(s)
- Youssouf B Kanouté
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
| | - Biégo G Gragnon
- Laboratoire National d'Appui au Développement Agricole, Lanada, Korhogo, Côte d'Ivoire, Côte d'Ivoire
| | - Christian Schindler
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland
| | - Bassirou Bonfoh
- Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire, Côte d'Ivoire
| | - Esther Schelling
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland
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31
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Abstract
Rift Valley fever virus (RVFV) (genus Phlebovirus, family Bunyaviridae) is an arbovirus that causes severe disease in humans and livestock in sub-Saharan African countries. The virus carries a tripartite, single-stranded, and negative-sense RNA genome, designated as L, M, and S RNAs. RVFV spread can be prevented by the effective vaccination of animals and humans. Although the MP-12 strain of RVFV is a live attenuated vaccine candidate, MP-12 showed neuroinvasiveness and neurovirulence in young mice and immunodeficiency mice. Hence, there is a concern for the use of MP-12 to certain individuals, especially those that are immunocompromised. To improve MP-12 safety, we have generated a single-cycle, replicable MP-12 (scMP-12), which carries L RNA, S RNA encoding green fluorescent protein in place of a viral nonstructural protein NSs, and an M RNA encoding a mutant envelope protein lacking an endoplasmic reticulum retrieval signal and defective for membrane fusion function. The scMP-12 undergoes efficient amplification in the Vero-G cell line, which is a Vero cell line stably expressing viral envelope proteins, while it undergoes single-cycle replication in naïve cells and completely lacks neurovirulence in suckling mice after intracranial inoculation. A single-dose vaccination of mice with scMP-12 confers protective immunity. Thus, scMP-12 represents a new, promising RVF vaccine candidate. Here we describe protocols for scMP-12 generation by using a reverse genetics system, establishment of Vero-G cells, and titration of scMP-12 in Vero-G cells.
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32
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Yamaoka S, Ebihara H. The two faces of Rift Valley fever virus virulence factor NSs: The development of a vaccine and the elucidation of pathogenesis. Virulence 2016; 7:856-859. [PMID: 27432532 DOI: 10.1080/21505594.2016.1213938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- Satoko Yamaoka
- a Molecular Virology and Host-Pathogen Interaction Unit, Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Hamilton , MT , USA
| | - Hideki Ebihara
- a Molecular Virology and Host-Pathogen Interaction Unit, Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Hamilton , MT , USA
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33
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Terasaki K, Ramirez SI, Makino S. Mechanistic Insight into the Host Transcription Inhibition Function of Rift Valley Fever Virus NSs and Its Importance in Virulence. PLoS Negl Trop Dis 2016; 10:e0005047. [PMID: 27711108 PMCID: PMC5053439 DOI: 10.1371/journal.pntd.0005047] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 09/17/2016] [Indexed: 11/18/2022] Open
Abstract
Rift Valley fever virus (RVFV), a member of the genus Phlebovirus within the family Bunyaviridae, causes periodic outbreaks in livestocks and humans in countries of the African continent and Middle East. RVFV NSs protein, a nonstructural protein, is a major virulence factor that exhibits several important biological properties. These include suppression of general transcription, inhibition of IFN-β promoter induction and degradation of double-stranded RNA-dependent protein kinase R. Although each of these biological functions of NSs are considered important for countering the antiviral response in the host, the individual contributions of these functions towards RVFV virulence remains unclear. To examine this, we generated two RVFV MP-12 strain-derived mutant viruses. Each carried mutations in NSs that specifically targeted its general transcription inhibition function without affecting its ability to degrade PKR and inhibit IFN-β promoter induction, through its interaction with Sin3-associated protein 30, a part of the repressor complex at the IFN-β promoter. Using these mutant viruses, we have dissected the transcription inhibition function of NSs and examined its importance in RVFV virulence. Both NSs mutant viruses exhibited a differentially impaired ability to inhibit host transcription when compared with MP-12. It has been reported that NSs suppresses general transcription by interfering with the formation of the transcription factor IIH complex, through the degradation of the p62 subunit and sequestration of the p44 subunit. Our study results lead us to suggest that the ability of NSs to induce p62 degradation is the major contributor to its general transcription inhibition property, whereas its interaction with p44 may not play a significant role in this function. Importantly, RVFV MP-12-NSs mutant viruses with an impaired general transcription inhibition function showed a reduced cytotoxicity in cell culture and attenuated virulence in young mice, compared with its parental virus MP-12, highlighting the contribution of NSs-mediated general transcription inhibition towards RVFV virulence. Rift Valley fever virus (RVFV) has a significant impact on the livestock industry because of its high mortality rate in young ruminants and causation of a high abortion rate in pregnant animals. Human RVFV infections generally manifest as self-limiting and non-fatal illnesses. However, a small percentage of patients develop encephalitis, vision loss and hemorrhagic fever with a high mortality rate. Currently, there is no commercially available vaccine for human use or effective antiviral drug for RVFV treatment. The non-structural protein NSs is a major virulence factor of RVFV, which mediates suppression of host general transcription, inhibition of IFN-β transcription and degradation of PKR, to block host antiviral responses. To examine the contribution of host transcription inhibition to RVFV virulence, we generated RVFV MP-12 strain-derived mutants that have attenuated inhibitory activity on host transcription due to amino acid mutations in NSs. The mutant viruses showed attenuated cytotoxicity in cell culture and attenuated virulence in young mice, demonstrating the contribution of NSs-mediated host transcription inhibition to the virulence of RVFV.
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Affiliation(s)
- Kaori Terasaki
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Sydney I. Ramirez
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Shinji Makino
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch, Galveston, Texas, United States of America
- UTMB Center for Tropical Diseases, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Sealy Center for Vaccine Development, The University of Texas Medical Branch, Galveston, Texas, United States of America
- The Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, Texas, United States of America
- * E-mail:
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34
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Safety and Efficacy Profile of Commercial Veterinary Vaccines against Rift Valley Fever: A Review Study. J Immunol Res 2016; 2016:7346294. [PMID: 27689098 PMCID: PMC5027037 DOI: 10.1155/2016/7346294] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 05/13/2016] [Accepted: 06/06/2016] [Indexed: 11/25/2022] Open
Abstract
Rift Valley Fever (RVF) is an infectious illness with serious clinical manifestations and health consequences in humans as well as a wide range of domestic ruminants. This review provides significant information about the prevention options of RVF along with the safety-efficacy profile of commercial vaccines and some of RVF vaccination strategies. Information presented in this paper was obtained through a systematic investigation of published data about RVF vaccines. Like other viral diseases, the prevention of RVF relies heavily on immunization of susceptible herds with safe and cost-effective vaccine that is able to confer long-term protective immunity. Several strains of RVF vaccines have been developed and are available in commercial production including Formalin-Inactivated vaccine, live attenuated Smithburn vaccine, and the most recent Clone13. Although Formalin-Inactivated vaccine and live attenuated Smithburn vaccine are immunogenic and widely used in prevention programs, they proved to be accompanied by significant concerns. Despite Clone13 vaccine being suggested as safe in pregnant ewes and as highly immunogenic along with its potential for differentiating infected from vaccinated animals (DIVA), a recent study raised concerns about the safety of the vaccine during the first trimester of gestation. Accordingly, RVF vaccines that are currently available in the market to a significant extent do not fulfill the requirements of safety, potency, and DIVA. These adverse effects stressed the need for developing new vaccines with an excellent safety profile to bridge the gap in safety and immunity. Bringing RVF vaccine candidates to local markets besides the absence of validated serological test for DIVA remain the major challenges of RVF control.
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Bird BH, McElroy AK. Rift Valley fever virus: Unanswered questions. Antiviral Res 2016; 132:274-80. [PMID: 27400990 DOI: 10.1016/j.antiviral.2016.07.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 07/02/2016] [Accepted: 07/06/2016] [Indexed: 12/31/2022]
Abstract
This mosquito-borne pathogen of humans and animals respects no international or geographic boundaries. It is currently found in parts of Africa and the Arabian Peninsula where periodic outbreaks of severe and fatal disease occur, and threatens to spread into other geographic regions. In recent years, modern molecular techniques have led to many breakthroughs deepening our understanding of the mechanisms of RVFV virulence, phylogenetics, and the creation of several next-generation vaccine candidates. Despite tremendous progress in these areas, other challenges remain in RVF disease pathogenesis, the virus life-cycle, and outbreak response preparedness that deserve our attention. Here we discuss and highlight ten key knowledge gaps and challenges in RVFV research. Answers to these key questions may lead to the development of new effective therapeutics and enhanced control strategies for this serious human and veterinary health threat.
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Affiliation(s)
- Brian H Bird
- Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA; One Health Institute, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
| | - Anita K McElroy
- Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA; Pediatric Infectious Disease, Emory University Atlanta, GA 30322, USA
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Arabidopsis thaliana plants expressing Rift Valley fever virus antigens: Mice exhibit systemic immune responses as the result of oral administration of the transgenic plants. Protein Expr Purif 2016; 127:61-67. [PMID: 27402440 DOI: 10.1016/j.pep.2016.07.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 07/01/2016] [Accepted: 07/05/2016] [Indexed: 11/17/2022]
Abstract
The zoonotic Rift Valley fever virus affects livestock and humans in Africa and on the Arabian Peninsula. The economic impact of this pathogen due to livestock losses, as well as its relevance to public health, underscores the importance of developing effective and easily distributed vaccines. Vaccines that can be delivered orally are of particular interest. Here, we report the expression in transformed plants (Arabidopsis thaliana) of Rift Valley fever virus antigens. The antigens used in this study were the N protein and a deletion mutant of the Gn glycoprotein. Transformed lines were analysed for specific mRNA and protein content by RT-PCR and Western blotting, respectively. Furthermore, the plant-expressed antigens were evaluated for their immunogenicity in mice fed the transgenic plants. After oral intake of fresh transgenic plant material, a proportion of the mice elicited specific IgG antibody responses, as compared to the control animals that were fed wild-type plants and of which none sero-converted. Thus, we show that transgenic plants can be readily used to express and produce Rift Valley Fever virus proteins, and that the plants are immunogenic when given orally to mice. These are promising findings and provide a basis for further studies on edible plant vaccines against the Rift Valley fever virus.
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Hossain MM, Wilson WC, Faburay B, Richt J, McVey DS, Rowland RR. Multiplex Detection of IgG and IgM to Rift Valley Fever Virus Nucleoprotein, Nonstructural Proteins, and Glycoprotein in Ovine and Bovine. Vector Borne Zoonotic Dis 2016; 16:550-7. [PMID: 27380552 DOI: 10.1089/vbz.2014.1721] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A multiplex fluorescence microsphere immunoassay (FMIA) was used to detect bovine and ovine IgM and IgG antibodies to several Rift Valley fever virus (RVFV) proteins, including the major surface glycoprotein, Gn; the nonstructural proteins, NSs and NSm; and the nucleoprotein, N. Target antigens were assembled into a multiplex and tested in serum samples from infected wild-type RVFV or MP12, a modified live virus vaccine. As expected, the N protein was immunodominant and the best target for early detection of infection. Antibody activity against the other targets was also detected. The experimental results demonstrate the capabilities of FMIA for the detection of antibodies to RVFV structural and nonstructural proteins, which can be applied to future development and validation of diagnostic tests that can be used to differentiate vaccinated from infected animals.
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Affiliation(s)
- Mohammad M Hossain
- 1 Department of Diagnostic Medicine/Pathobiology, Center of Excellence for Emerging and Zoonotic Animal Diseases (CEEZAD), College of Veterinary Medicine, Kansas State University , Manhattan, Kansas.,2 USDA-ARS Arthropod-Borne Animal Disease Research Unit (ABADRU), Center for Grain and Animal Health Research , Manhattan, Kansas
| | - William C Wilson
- 2 USDA-ARS Arthropod-Borne Animal Disease Research Unit (ABADRU), Center for Grain and Animal Health Research , Manhattan, Kansas
| | - Bonto Faburay
- 1 Department of Diagnostic Medicine/Pathobiology, Center of Excellence for Emerging and Zoonotic Animal Diseases (CEEZAD), College of Veterinary Medicine, Kansas State University , Manhattan, Kansas
| | - Jürgen Richt
- 1 Department of Diagnostic Medicine/Pathobiology, Center of Excellence for Emerging and Zoonotic Animal Diseases (CEEZAD), College of Veterinary Medicine, Kansas State University , Manhattan, Kansas
| | - David S McVey
- 2 USDA-ARS Arthropod-Borne Animal Disease Research Unit (ABADRU), Center for Grain and Animal Health Research , Manhattan, Kansas
| | - Raymond R Rowland
- 1 Department of Diagnostic Medicine/Pathobiology, Center of Excellence for Emerging and Zoonotic Animal Diseases (CEEZAD), College of Veterinary Medicine, Kansas State University , Manhattan, Kansas
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Chimpanzee Adenovirus Vaccine Provides Multispecies Protection against Rift Valley Fever. Sci Rep 2016; 6:20617. [PMID: 26847478 PMCID: PMC4742904 DOI: 10.1038/srep20617] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 01/08/2016] [Indexed: 02/07/2023] Open
Abstract
Rift Valley Fever virus (RVFV) causes recurrent outbreaks of acute life-threatening human and livestock illness in Africa and the Arabian Peninsula. No licensed vaccines are currently available for humans and those widely used in livestock have major safety concerns. A ‘One Health’ vaccine development approach, in which the same vaccine is co-developed for multiple susceptible species, is an attractive strategy for RVFV. Here, we utilized a replication-deficient chimpanzee adenovirus vaccine platform with an established human and livestock safety profile, ChAdOx1, to develop a vaccine for use against RVFV in both livestock and humans. We show that single-dose immunization with ChAdOx1-GnGc vaccine, encoding RVFV envelope glycoproteins, elicits high-titre RVFV-neutralizing antibody and provides solid protection against RVFV challenge in the most susceptible natural target species of the virus-sheep, goats and cattle. In addition we demonstrate induction of RVFV-neutralizing antibody by ChAdOx1-GnGc vaccination in dromedary camels, further illustrating the potency of replication-deficient chimpanzee adenovirus vaccine platforms. Thus, ChAdOx1-GnGc warrants evaluation in human clinical trials and could potentially address the unmet human and livestock vaccine needs.
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Chamchod F, Cosner C, Cantrell RS, Beier JC, Ruan S. Transmission Dynamics of Rift Valley Fever Virus: Effects of Live and Killed Vaccines on Epizootic Outbreaks and Enzootic Maintenance. Front Microbiol 2016; 6:1568. [PMID: 26869999 PMCID: PMC4740790 DOI: 10.3389/fmicb.2015.01568] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 12/27/2015] [Indexed: 01/14/2023] Open
Abstract
Rift Valley fever virus (RVFV) is an arthropod-borne viral pathogen that causes significant morbidity and mortality in small ruminants throughout Africa and the Middle East. Due to the sporadic and explosive nature of RVF outbreaks, vaccination has proved challenging to reduce RVFV infection in the ruminant population. Currently, there are two available types of vaccines, live and killed, in endemic areas. In this study, two mathematical models have been developed to explore the impact of live and killed vaccines on the transmission dynamics of RVFV. We demonstrate in general that vaccination helps reduce the severity of RVF outbreaks and that less delay in implementation and more vaccination attempts and effective vaccines can reduce the outbreak magnitude and the endemic number of RVFV. However, an introduction of a number of ruminants vaccinated by live vaccines in RVFV-free areas may cause an outbreak and RVFV may become endemic if there is sustained use of live vaccines. Other factors that are the important determinants of RVF outbreaks include: unsustained vaccination programs, recruitment of susceptible ruminants, and the seasonal abundance of mosquitoes.
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Affiliation(s)
- Farida Chamchod
- Department of Mathematics, Faculty of Science, Mahidol University Bangkok, Thailand
| | - Chris Cosner
- Department of Mathematics, University of Miami Coral Gables, FL, USA
| | | | - John C Beier
- Department of Public Health Sciences, Miller School of Medicine, University of Miami Miami, FL, USA
| | - Shigui Ruan
- Department of Mathematics, University of Miami Coral Gables, FL, USA
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Kim HJ, Lyoo HR, Park JY, Choi JS, Lee JY, Jeoung HY, Cho YS, Cho IS, Yoo HS. Surveillance of Rift Valley Fever Virus in Mosquito Vectors of the Republic of Korea. Vector Borne Zoonotic Dis 2016; 16:131-5. [DOI: 10.1089/vbz.2015.1843] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Hyun-Joo Kim
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Anyang, Republic of Korea
| | - Hye-Rhyoung Lyoo
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Anyang, Republic of Korea
| | - Jee-Yong Park
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Anyang, Republic of Korea
| | - Jeong-Soo Choi
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Anyang, Republic of Korea
| | - Ji-Youn Lee
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Anyang, Republic of Korea
| | - Hye-Young Jeoung
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Anyang, Republic of Korea
| | - Yun-Sang Cho
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Anyang, Republic of Korea
| | - In-Soo Cho
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Anyang, Republic of Korea
| | - Han Sang Yoo
- College of Veterinary Medicine and BK21 PLUS, Seoul National University, Seoul, Republic of Korea
- Institute of Green Bio Science and Technology, Seoul National University, Pyeongchang, Republic of Korea
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41
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Wiley CA, Bhardwaj N, Ross TM, Bissel SJ. Emerging Infections of CNS: Avian Influenza A Virus, Rift Valley Fever Virus and Human Parechovirus. Brain Pathol 2015; 25:634-50. [PMID: 26276027 PMCID: PMC4538697 DOI: 10.1111/bpa.12281] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 06/22/2015] [Indexed: 11/28/2022] Open
Abstract
History is replete with emergent pandemic infections that have decimated the human population. Given the shear mass of humans that now crowd the earth, there is every reason to suspect history will repeat itself. We describe three RNA viruses that have recently emerged in the human population to mediate severe neurological disease. These new diseases are results of new mutations in the infectious agents or new exposure pathways to the agents or both. To appreciate their pathogenesis, we summarize the essential virology and immune response to each agent. Infection is described in the context of known host defenses. Once the viruses evade immune defenses and enter central nervous system (CNS) cells, they rapidly co-opt host RNA processing to a cataclysmic extent. It is not clear why the brain is particularly susceptible to RNA viruses; but perhaps because of its tremendous dependence on RNA processing for physiological functioning, classical mechanisms of host defense (eg, interferon disruption of viral replication) are diminished or not available. Effectiveness of immunity, immunization and pharmacological therapies is reviewed to contextualize the scope of the public health challenge. Unfortunately, vaccines that confer protection from systemic disease do not necessarily confer protection for the brain after exposure through unconventional routes.
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Affiliation(s)
| | - Nitin Bhardwaj
- Department of Infectious Diseases and MicrobiologyUniversity of PittsburghPittsburghPA
- Present address:
Sanofi Pasteur1755 Steeles Avenue WestTorontoOntarioCanadaM2R 3T4
| | - Ted M. Ross
- Center for Vaccine DevelopmentUniversity of GeorgiaAthensGA
- Department of Infectious DiseasesUniversity of GeorgiaAthensGA
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Mansfield KL, Banyard AC, McElhinney L, Johnson N, Horton DL, Hernández-Triana LM, Fooks AR. Rift Valley fever virus: A review of diagnosis and vaccination, and implications for emergence in Europe. Vaccine 2015; 33:5520-5531. [PMID: 26296499 DOI: 10.1016/j.vaccine.2015.08.020] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 06/12/2015] [Accepted: 08/05/2015] [Indexed: 12/14/2022]
Abstract
Rift Valley fever virus (RVFV) is a mosquito-borne virus, and is the causative agent of Rift Valley fever (RVF), a zoonotic disease characterised by an increased incidence of abortion or foetal malformation in ruminants. Infection in humans can also lead to clinical manifestations that in severe cases cause encephalitis or haemorrhagic fever. The virus is endemic throughout much of the African continent. However, the emergence of RVFV in the Middle East, northern Egypt and the Comoros Archipelago has highlighted that the geographical range of RVFV may be increasing, and has led to the concern that an incursion into Europe may occur. At present, there is a limited range of veterinary vaccines available for use in endemic areas, and there is no licensed human vaccine. In this review, the methods available for diagnosis of RVFV infection, the current status of vaccine development and possible implications for RVFV emergence in Europe, are discussed.
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Affiliation(s)
- Karen L Mansfield
- Wildlife Zoonoses and Vector-borne Diseases Research Group, Animal and Plant Health Agency, Woodham Lane, New Haw KT15 3NB, UK.
| | - Ashley C Banyard
- Wildlife Zoonoses and Vector-borne Diseases Research Group, Animal and Plant Health Agency, Woodham Lane, New Haw KT15 3NB, UK
| | - Lorraine McElhinney
- Wildlife Zoonoses and Vector-borne Diseases Research Group, Animal and Plant Health Agency, Woodham Lane, New Haw KT15 3NB, UK; NIHR Health Protection Research Unit in Emerging and Zoonotic Infections, University of Liverpool, Liverpool L69 7BE, UK
| | - Nicholas Johnson
- Wildlife Zoonoses and Vector-borne Diseases Research Group, Animal and Plant Health Agency, Woodham Lane, New Haw KT15 3NB, UK
| | - Daniel L Horton
- School of Veterinary Medicine, University of Surrey, Guildford GU2 7XH, UK
| | - Luis M Hernández-Triana
- Wildlife Zoonoses and Vector-borne Diseases Research Group, Animal and Plant Health Agency, Woodham Lane, New Haw KT15 3NB, UK
| | - Anthony R Fooks
- Wildlife Zoonoses and Vector-borne Diseases Research Group, Animal and Plant Health Agency, Woodham Lane, New Haw KT15 3NB, UK; NIHR Health Protection Research Unit in Emerging and Zoonotic Infections, University of Liverpool, Liverpool L69 7BE, UK; Department of Clinical Infection, Microbiology and Immunology, University of Liverpool, Liverpool L69 7BE, UK
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Kim HJ, Park JY, Jeoung HY, Yeh JY, Cho YS, Choi JS, Lee JY, Cho IS, Yoo HS. Serological surveillance studies confirm the Rift Valley fever virus free status in South Korea. Trop Anim Health Prod 2015; 47:1427-30. [PMID: 26024956 DOI: 10.1007/s11250-015-0858-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 05/18/2015] [Indexed: 11/27/2022]
Abstract
Rift Valley fever is a mosquito-borne zoonotic disease of domestic ruminants. This disease causes abortions in pregnant animals, and it has a high mortality rate in newborn animals. Recently, a Rift Valley fever virus (RVFV) outbreak in the Arabian Peninsula increased its potential spread to new regions worldwide. In non-endemic or disease-free countries, early detection and surveillance are important for preventing the introduction of RVFV. In this study, a serological surveillance was conducted to detect antibodies against RVFV. A total of 2382 serum samples from goats and cattle were randomly collected from nine areas in South Korea from 2011 to 2013. These samples were tested for antibodies against RVFV, using commercial ELISA kits. None of the goats and cattle were positive for antibodies against RVFV. This finding suggests that this disease is not present in South Korea, and furthermore presents the evidence of the RVFV-free status of this country.
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Affiliation(s)
- Hyun Joo Kim
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Anyang, 430-757, Republic of Korea
| | - Jee-Yong Park
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Anyang, 430-757, Republic of Korea
| | - Hye-Young Jeoung
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Anyang, 430-757, Republic of Korea
| | - Jung-Yong Yeh
- Incheon National University, Incheon, 406-772, Republic of Korea
| | - Yun-Sang Cho
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Anyang, 430-757, Republic of Korea
| | - Jeong-Soo Choi
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Anyang, 430-757, Republic of Korea
| | - Ji-Youn Lee
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Anyang, 430-757, Republic of Korea
| | - In-Soo Cho
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Anyang, 430-757, Republic of Korea
| | - Han-Sang Yoo
- Department of Infectious Diseases, College of Veterinary Medicine, Seoul National University, Seoul, 151-742, Republic of Korea.
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Lo MM, Mbao V, Sierra P, Thiongane Y, Diop M, Donadeu M, Dungu B. Safety and immunogenicity of Onderstepoort Biological Products' Rift Valley fever Clone 13 vaccine in sheep and goats under field conditions in Senegal. ACTA ACUST UNITED AC 2015; 82:857. [PMID: 26244679 PMCID: PMC6238691 DOI: 10.4102/ojvr.v82i1.857] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Revised: 01/06/2015] [Accepted: 01/07/2015] [Indexed: 11/29/2022]
Abstract
This blinded field safety study was conducted in Senegal to assess safety and immunogenicity of administration of the registered dose of Rift Valley fever virus (RVFV) Clone 13 vaccine (Onderstepoort Biological Products) to sheep and goats of West African breeds under natural conditions. A total of 267 small ruminants (220 sheep, 47 goats) were included; half received RVFV Clone 13 vaccine at the recommended dose and half received the diluent (as placebo) only. The study was performed on three commercial farms in the northern and eastern region of Senegal in accordance with veterinary good clinical practices. The animals were observed daily for 3 days after vaccination, and then weekly for 1 year. In both sheep and goats vaccinated against RVFV seroconversion rates above 70% were recorded. No seroconversion related to RVFV was observed in placebo-treated animals. No statistically significant differences were determined between placebo and vaccinated groups for mean rectal temperatures for the first 3 days after administration (p > 0.05). No abnormal clinical signs related to treatment were noted, and only one slight injection site reaction was observed in one vaccinated animal for 2 days after vaccination. Out of 176 births assessed over 1 year (93 from the vaccinated group, 83 from the placebo group), 9 were abnormal in the placebo group and 3 in the vaccinated group (p > 0.05). The frequency of adverse events was similar in the placebo and vaccinated groups. RVFV Clone 13 vaccine administered according to the manufacturer's instructions was safe and well tolerated in West African breeds of sheep and goats, including animals of approximately 6 months of age and pregnant females, under field conditions in Senegal. Antibody levels persisted up to 1 year after vaccination.
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Affiliation(s)
| | - Victor Mbao
- Global Alliance for Livestock Veterinary Medicines.
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45
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Wichgers Schreur PJ, Kant J, van Keulen L, Moormann RJM, Kortekaas J. Four-segmented Rift Valley fever virus induces sterile immunity in sheep after a single vaccination. Vaccine 2015; 33:1459-64. [PMID: 25665959 DOI: 10.1016/j.vaccine.2015.01.077] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 01/23/2015] [Accepted: 01/25/2015] [Indexed: 11/17/2022]
Abstract
Rift Valley fever virus (RVFV), a mosquito-borne virus in the Bunyaviridae family, causes recurrent outbreaks with severe disease in ruminants and occasionally humans. The virus comprises a segmented genome consisting of a small (S), medium (M) and large (L) RNA segment of negative polarity. The M-segment encodes a glycoprotein precursor (GPC) protein that is co-translationally cleaved into Gn and Gc, which are required for virus entry and fusion. Recently we developed a four-segmented RVFV (RVFV-4s) by splitting the M-genome segment, and used this virus to study RVFV genome packaging. Here we evaluated the potential of a RVFV-4s variant lacking the NSs gene (4s-ΔNSs) to induce protective immunity in sheep. Groups of seven lambs were either mock-vaccinated or vaccinated with 10(5) or 10(6) tissue culture infective dose (TCID50) of 4s-ΔNSs via the intramuscular (IM) or subcutaneous (SC) route. Three weeks post-vaccination all lambs were challenged with wild-type RVFV. Mock-vaccinated lambs developed high fever and high viremia within 2 days post-challenge and three animals eventually succumbed to the infection. In contrast, none of the 4s-ΔNSs vaccinated animals developed clinical signs during the course of the experiment. Vaccination with 10(5) TCID50 via the IM route provided sterile immunity, whereas a 10(6) dose was required to induce sterile immunity via SC vaccination. Protection was strongly correlated with the presence of RVFV neutralizing antibodies. This study shows that 4s-ΔNSs is able to induce sterile immunity in the natural target species after a single vaccination, preferably administrated via the IM route.
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MESH Headings
- Animals
- Antibodies, Neutralizing/blood
- Antibodies, Neutralizing/immunology
- Antibodies, Viral/blood
- Antibodies, Viral/immunology
- Immunity, Active
- Injections, Intramuscular
- Injections, Subcutaneous
- Mutation
- Rift Valley Fever/prevention & control
- Rift Valley fever virus/genetics
- Rift Valley fever virus/immunology
- Sheep
- Sheep Diseases/prevention & control
- Sheep Diseases/virology
- Sheep, Domestic/immunology
- Sheep, Domestic/virology
- Vaccination/veterinary
- Vaccines, Attenuated
- Viral Vaccines/immunology
- Viremia/veterinary
- Viremia/virology
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Affiliation(s)
- Paul J Wichgers Schreur
- Department of Virology, Central Veterinary Institute, Part of Wageningen University and Research Centre, Lelystad, The Netherlands.
| | - Jet Kant
- Department of Virology, Central Veterinary Institute, Part of Wageningen University and Research Centre, Lelystad, The Netherlands
| | - Lucien van Keulen
- Department of Virology, Central Veterinary Institute, Part of Wageningen University and Research Centre, Lelystad, The Netherlands
| | - Rob J M Moormann
- Department of Virology, Central Veterinary Institute, Part of Wageningen University and Research Centre, Lelystad, The Netherlands; Department of Infectious Diseases and Immunology, Virology Division, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Jeroen Kortekaas
- Department of Virology, Central Veterinary Institute, Part of Wageningen University and Research Centre, Lelystad, The Netherlands
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Arsevska E, Hellal J, Mejri S, Hammami S, Marianneau P, Calavas D, Hénaux V. Identifying Areas Suitable for the Occurrence of Rift Valley Fever in North Africa: Implications for Surveillance. Transbound Emerg Dis 2015; 63:658-674. [PMID: 25655790 DOI: 10.1111/tbed.12331] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Indexed: 12/01/2022]
Abstract
Rift Valley fever (RVF) is a vector-borne zoonotic disease that has caused widespread outbreaks throughout Africa and the Arabian Peninsula, with serious consequences for livestock-based economies and public health. Although there have never been any reports of RVF in Morocco, Algeria, Tunisia and Libya, it is a priority disease in the Maghreb, due to the threat of introduction of the virus through transboundary livestock movements or infected mosquito vectors. However, the implementation of surveillance activities and early warning contingency plans requires better knowledge of the epidemiological situation. We conducted a multicriteria decision analysis, integrating host distribution with a combination of important ecological factors that drive mosquito abundance, to identify hotspots and suitable time periods for RVF enzootic circulation (i.e. stable transmission at a low to moderate level for an extended period of time) and an RVF epizootic event (i.e. a sudden occurrence of a large number of infected animals over a large geographic area) in the Maghreb. We also modelled vector species distribution using available information on vector presence and habitat preference. We found that the northern regions of the Maghreb were moderately suitable for RVF enzootics, but highly suitable for RVF epizootics. The vector species distribution model identified these regions as the most favourable mosquito habitats. Due to the low density of animal hosts and arid conditions, the desert region showed low RVF suitability, except in oases. However, the presence of competent vectors in putative unsuitable areas underlines the need for further assessments of mosquito habitat preference. This study produced monthly RVF suitability maps useful for animal health managers and veterinary services involved in designing risk-based surveillance programmes. The suitability maps can be further enhanced using existing country-specific sources of information and by incorporating knowledge - as it becomes available - on the epidemiology of the disease and distribution of vectors in the Maghreb.
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Affiliation(s)
- E Arsevska
- Unité Epidémiologie, Laboratoire de Lyon, Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES), Lyon, France
| | - J Hellal
- Institut de Recherche Vétérinaire de Tunisie (IRVT), Tunis, Tunisie
| | - S Mejri
- Institut de Recherche Vétérinaire de Tunisie (IRVT), Tunis, Tunisie
| | - S Hammami
- Centre Nationale de Veille Zoosanitaire (CNVZ), Tunis, Tunisie
| | - P Marianneau
- Unité Virologie, Laboratoire de Lyon, Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES), Lyon, France
| | - D Calavas
- Unité Epidémiologie, Laboratoire de Lyon, Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES), Lyon, France
| | - V Hénaux
- Unité Epidémiologie, Laboratoire de Lyon, Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES), Lyon, France.
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Springer YP, Taylor JR, Travers PD. Variation in Baiting Intensity Among CO2-Baited Traps Used to Collect Hematophagous Arthropods. JOURNAL OF INSECT SCIENCE (ONLINE) 2015; 15:iev073. [PMID: 26160803 PMCID: PMC4535580 DOI: 10.1093/jisesa/iev073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 06/11/2015] [Indexed: 05/07/2023]
Abstract
Hematophagous arthropods transmit the etiological agents of numerous diseases and as a result are frequently the targets of sampling to characterize vector and pathogen populations. Arguably, the most commonly used sampling approach involves traps baited with carbon dioxide. We report results of a laboratory study in which the performance of carbon dioxide-baited traps was evaluated using measures of baiting intensity, the amount of carbon dioxide released per unit time during trap deployment. We evaluated the effects of trap design, carbon dioxide source, and wind speed on baiting intensity and documented significant effects of these factors on the length of sampling (time to baiting intensity = 0), maximum baiting intensity, and variation in baiting intensity during experimental trials. Among the three dry ice-baited trap types evaluated, traps utilizing insulated beverage coolers as dry ice containers sampled for the longest period of time, had the lowest maximum but most consistent baiting intensity within trials and were least sensitive to effects of wind speed and dry ice form (block vs. pellet) on baiting intensity. Results of trials involving traps baited with carbon dioxide released from pressurized cylinders suggested that this trap type had performance comparable to dry ice-baited insulated cooler traps but at considerably higher cost.
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Affiliation(s)
- Yuri P Springer
- National Ecological Observatory Network (NEON), Inc., 1685 38th St., Suite 100, Boulder, CO 80301
| | - Jeffrey R Taylor
- National Ecological Observatory Network (NEON), Inc., 1685 38th St., Suite 100, Boulder, CO 80301 Institute of Arctic and Alpine Research, University of Colorado Boulder, 1560 30 St., Boulder, CO 80303 Aspen Global Change Institute, 104 Midland Ave., Suite 205, Basalt, CO 81632
| | - Patrick D Travers
- National Ecological Observatory Network (NEON), Inc., 1685 38th St., Suite 100, Boulder, CO 80301 Dolan Integration Group, 2520 55th St. #101, Boulder, CO 80301
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Emerging and Reemerging Infectious Disease Threats. MANDELL, DOUGLAS, AND BENNETT'S PRINCIPLES AND PRACTICE OF INFECTIOUS DISEASES 2015. [PMCID: PMC7151803 DOI: 10.1016/b978-1-4557-4801-3.00014-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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49
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Peyre M, Chevalier V, Abdo-Salem S, Velthuis A, Antoine-Moussiaux N, Thiry E, Roger F. A Systematic Scoping Study of the Socio-Economic Impact of Rift Valley Fever: Research Gaps and Needs. Zoonoses Public Health 2014; 62:309-25. [PMID: 25256804 DOI: 10.1111/zph.12153] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Indexed: 12/27/2022]
Abstract
Rift Valley fever (RVF) is a severe mosquito-borne disease affecting humans and domestic ruminants. RVF virus has been reported in most African countries, as well as in the Arabic Peninsula. This paper reviews the different types of socio-economic impact induced by RVF disease and the attempts to evaluate them. Of the 52 papers selected for this review, 13 types of socio-economic impact were identified according to the sector impacted, the level and temporal scale of the impact. RVF has a dramatic impact on producers and livestock industries, affecting public and animal health, food security and the livelihood of the pastoralist communities. RVF also has an impact on international trade and other agro-industries. The risk of introducing RVF into disease-free countries via the importation of an infected animal or mosquito is real, and the consequent restriction of access to export markets may induce dramatic economic consequences for national and local economies. Despite the important threat of RVF, few studies have been conducted to assess the socio-economic impact of the disease. The 17 studies identified for quantitative analysis in this review relied only on partial cost analysis, with limited reference to mid- and long-term impact, public health or risk mitigation measures. However, the estimated impacts were high (ranging from $5 to $470 million USD losses). To reduce the impact of RVF, early detection and rapid response should be implemented. Comprehensive disease impact studies are required to provide decision-makers with science-based information on the best intervention measure to implement ensuring efficient resource allocation. Through the analysis of RVF socio-economic impact, this scoping study proposes insights into the mechanisms underpinning its often-underestimated importance. This study highlights the need for comparative socio-economic studies to help decision-makers with their choices related to RVF disease management.
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Affiliation(s)
- M Peyre
- CIRAD, UPR AGIRs, Montpellier, France
| | | | - S Abdo-Salem
- CIRAD, UPR AGIRs, Montpellier, France.,College of Agriculture and Veterinary Science, University of Dhamar, Dhamar, Yemen
| | - A Velthuis
- Wageningen University, Wageningen, The Netherlands.,GD Animal Health Service, Deventer, The Netherlands
| | | | - E Thiry
- Faculty of Veterinary Medicine, University of Liege, Liege, Belgium
| | - F Roger
- CIRAD, UPR AGIRs, Montpellier, France
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50
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Kortekaas J, Oreshkova N, van Keulen L, Kant J, Bosch B, Bouloy M, Moulin V, Goovaerts D, Moormann R. Comparative efficacy of two next-generation Rift Valley fever vaccines. Vaccine 2014; 32:4901-8. [DOI: 10.1016/j.vaccine.2014.07.037] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 06/11/2014] [Accepted: 07/09/2014] [Indexed: 12/17/2022]
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