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Nsengimana I, Juma J, Roesel K, Gasana MN, Ndayisenga F, Muvunyi CM, Hakizimana E, Hakizimana JN, Eastwood G, Chengula AA, Bett B, Kasanga CJ, Oyola SO. Genomic Epidemiology of Rift Valley Fever Virus Involved in the 2018 and 2022 Outbreaks in Livestock in Rwanda. Viruses 2024; 16:1148. [PMID: 39066310 PMCID: PMC11281637 DOI: 10.3390/v16071148] [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: 06/15/2024] [Revised: 07/09/2024] [Accepted: 07/11/2024] [Indexed: 07/28/2024] Open
Abstract
Rift Valley fever (RVF), a mosquito-borne transboundary zoonosis, was first confirmed in Rwanda's livestock in 2012 and since then sporadic cases have been reported almost every year. In 2018, the country experienced its first large outbreak, which was followed by a second one in 2022. To determine the circulating virus lineages and their ancestral origin, two genome sequences from the 2018 outbreak, and thirty-six, forty-one, and thirty-eight sequences of small (S), medium (M), and large (L) genome segments, respectively, from the 2022 outbreak were generated. All of the samples from the 2022 outbreak were collected from slaughterhouses. Both maximum likelihood and Bayesian-based phylogenetic analyses were performed. The findings showed that RVF viruses belonging to a single lineage, C, were circulating during the two outbreaks, and shared a recent common ancestor with RVF viruses isolated in Uganda between 2016 and 2019, and were also linked to the 2006/2007 largest East Africa RVF outbreak reported in Kenya, Tanzania, and Somalia. Alongside the wild-type viruses, genetic evidence of the RVFV Clone 13 vaccine strain was found in slaughterhouse animals, demonstrating a possible occupational risk of exposure with unknown outcome for people working in meat-related industry. These results provide additional evidence of the ongoing wide spread of RVFV lineage C in Africa and emphasize the need for an effective national and international One Health-based collaborative approach in responding to RVF emergencies.
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Affiliation(s)
- Isidore Nsengimana
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro P.O. Box 3000, Tanzania
- SACIDS Africa Centre of Excellence for Infectious Diseases, SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro P.O. Box 3297, Tanzania
- Rwanda Inspectorate, Competition and Consumer Protection Authority, Kigali P.O. Box 375, Rwanda
- Department of Entomology, and Center for Emerging Zoonotic & Arthropod-Borne Pathogens (CeZAP), Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - John Juma
- International Livestock Research Institute (ILRI), Nairobi P.O. Box 30709, Kenya
| | - Kristina Roesel
- International Livestock Research Institute (ILRI), Nairobi P.O. Box 30709, Kenya
| | - Methode N. Gasana
- Department of Animal Resource Research and Technology Transfer, Rwanda Agriculture and Animal Resources Development Board (RAB), Huye P.O. Box 5016, Rwanda
| | - Fabrice Ndayisenga
- Department of Animal Resource Research and Technology Transfer, Rwanda Agriculture and Animal Resources Development Board (RAB), Huye P.O. Box 5016, Rwanda
| | | | | | - Jean N. Hakizimana
- SACIDS Africa Centre of Excellence for Infectious Diseases, SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro P.O. Box 3297, Tanzania
| | - Gillian Eastwood
- Department of Entomology, and Center for Emerging Zoonotic & Arthropod-Borne Pathogens (CeZAP), Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Augustino A. Chengula
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro P.O. Box 3000, Tanzania
| | - Bernard Bett
- International Livestock Research Institute (ILRI), Nairobi P.O. Box 30709, Kenya
| | - Christopher J. Kasanga
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro P.O. Box 3000, Tanzania
| | - Samuel O. Oyola
- International Livestock Research Institute (ILRI), Nairobi P.O. Box 30709, Kenya
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González-Gordon L, Porphyre T, Muwonge A, Nantima N, Ademun R, Ochwo S, Mwiine NF, Boden L, Muhanguzi D, Bronsvoort BMDC. Identifying target areas for risk-based surveillance and control of transboundary animal diseases: a seasonal analysis of slaughter and live-trade cattle movements in Uganda. Sci Rep 2023; 13:18619. [PMID: 37903814 PMCID: PMC10616094 DOI: 10.1038/s41598-023-44518-4] [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: 05/31/2023] [Accepted: 10/09/2023] [Indexed: 11/01/2023] Open
Abstract
Animal movements are a major driver for the spread of Transboundary Animal Diseases (TADs). These movements link populations that would otherwise be isolated and hence create opportunities for susceptible and infected individuals to meet. We used social network analysis to describe the seasonal network structure of cattle movements in Uganda and unravel critical network features that identify districts or sub-regions for targeted risk-based surveillance and intervention. We constructed weighted, directed networks based on 2019 between-district cattle movements using official livestock mobility data; the purpose of the movement ('slaughter' vs. 'live trade') was used to subset the network and capture the risks more reliably. Our results show that cattle trade can result in local and long-distance disease spread in Uganda. Seasonal variability appears to impact the structure of the network, with high heterogeneity of node and edge activity identified throughout the seasons. These observations mean that the structure of the live trade network can be exploited to target influential district hubs within the cattle corridor and peripheral areas in the south and west, which would result in rapid network fragmentation, reducing the contact structure-related trade risks. Similar exploitable features were observed for the slaughter network, where cattle traffic serves mainly slaughter hubs close to urban centres along the cattle corridor. Critically, analyses that target the complex livestock supply value chain offer a unique framework for understanding and quantifying risks for TADs such as Foot-and-Mouth disease in a land-locked country like Uganda. These findings can be used to inform the development of risk-based surveillance strategies and decision making on resource allocation. For instance, vaccine deployment, biosecurity enforcement and capacity building for stakeholders at the local community and across animal health services with the potential to limit the socio-economic impact of outbreaks, or indeed reduce their frequency.
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Affiliation(s)
- Lina González-Gordon
- The Epidemiology, Economics and Risk Assessment (EERA) Group, The Roslin Institute at The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK.
- Global Academy of Agriculture and Food Systems, Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK.
| | - Thibaud Porphyre
- Laboratoire de Biométrie et Biologie Évolutive, UMR 5558, Universite Claude Bernard Lyon 1, CNRS, VetAgro Sup, Marcy l'Étoile, France
| | - Adrian Muwonge
- The Epidemiology, Economics and Risk Assessment (EERA) Group, The Roslin Institute at The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
- The Digital One Health Laboratory, The Roslin Institute at The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - Noelina Nantima
- Department of Animal Health, Ministry of Agriculture Animal Industry and Fisheries, Entebbe, Uganda
| | - Rose Ademun
- Department of Animal Health, Ministry of Agriculture Animal Industry and Fisheries, Entebbe, Uganda
| | - Sylvester Ochwo
- Center for Animal Health and Food Safety, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Norbert Frank Mwiine
- Department of Biomolecular Resources and Biolaboratory Sciences (BBS), College of Veterinary Medicine, Makerere University, Kampala, Uganda
| | - Lisa Boden
- Global Academy of Agriculture and Food Systems, Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - Dennis Muhanguzi
- Department of Biomolecular Resources and Biolaboratory Sciences (BBS), College of Veterinary Medicine, Makerere University, Kampala, Uganda
| | - Barend Mark de C Bronsvoort
- The Epidemiology, Economics and Risk Assessment (EERA) Group, The Roslin Institute at The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
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Nyakarahuka L, Kyondo J, Telford C, Whitesell A, Tumusiime A, Mulei S, Baluku J, Cossaboom CM, Cannon DL, Montgomery JM, Lutwama JJ, Nichol ST, Balinandi S, Klena JD, Shoemaker TR. A Countrywide Seroepidemiological Survey of Rift Valley Fever in Livestock, Uganda, 2017. Am J Trop Med Hyg 2023; 109:548-553. [PMID: 37524326 PMCID: PMC10484263 DOI: 10.4269/ajtmh.22-0504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 05/01/2023] [Indexed: 08/02/2023] Open
Abstract
In 2016, an outbreak of Rift Valley fever was reported in the Kabale District in Uganda for the first time in 48 years. Three human cases were confirmed by polymerase chain reaction, and subsequent serological investigations revealed an overall IgG seropositivity of 13% in humans and 13% in animals. In response to this reemergence, we designed a countrywide survey to determine the seropositivity of anti-Rift Valley fever virus (RVFV) IgG antibodies in livestock. Samples were collected from 27 districts and tested for RVFV anti-IgG antibodies. A total of 3,181 livestock samples were tested, of which 54.4% were cattle (1,732 of 3,181), 34.3% were goats (1,091 of 3,181), and 11.3% were sheep (358 of 3,181). Overall RVFV seropositivity was 6.9% (221 of 3,181). Seroprevalence was greater in cattle (10.7%) compared with goats (2.6%) and sheep (2.0%), among females (7.5%) compared with males (5.2%), and among adults (7.6%) compared with juveniles (4.9%) and nurslings (6.4%). Exotic breeds and animals with a history of abortion or stillbirth also had greater odds of RVFV seropositivity. Animals grazed under tethering and paddocking had greater RVFV seropositivity compared with animals that grazed communally, and livestock in the western and eastern regions had the greatest seroprevalence. In a multivariate regression model, animal species (odds ratio [OR], 6.4; 95% CI, 3.5-11.4) and age (OR, 2.3; 95% CI, 1.4-3.6) were associated significantly with RVFV seropositivity. This study could be important in developing risk-based surveillance for early outbreak detection to limit the spread of RVFV in both human and animal populations.
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Affiliation(s)
- Luke Nyakarahuka
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
- Department of Biosecurity, Ecosystems and Veterinary Public Health, Makerere University, Kampala, Uganda
| | - Jackson Kyondo
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | - Carson Telford
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, US Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Amy Whitesell
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, US Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Alex Tumusiime
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | - Sophia Mulei
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | - Jimmy Baluku
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | - Caitlin M. Cossaboom
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, US Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Deborah L. Cannon
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, US Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Joel M. Montgomery
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, US Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Julius J. Lutwama
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | - Stuart T. Nichol
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, US Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Stephen Balinandi
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | - John D. Klena
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, US Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Trevor R. Shoemaker
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, US Centers for Disease Control and Prevention, Atlanta, Georgia
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Kim D, Gan Y, Nedergaard M, Kelley DH, Tithof J. Image Analysis Techniques for In Vivo Quantification of Cerebrospinal Fluid Flow. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.20.549937. [PMID: 37546970 PMCID: PMC10401935 DOI: 10.1101/2023.07.20.549937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Over the last decade, there has been a tremendously increased interest in understanding the neurophysiology of cerebrospinal fluid (CSF) flow, which plays a crucial role in clearing metabolic waste from the brain. This growing interest was largely initiated by two significant discoveries: the glymphatic system (a pathway for solute exchange between interstitial fluid deep within the brain and the CSF surrounding the brain) and meningeal lymphatic vessels (lymphatic vessels in the layer of tissue surrounding the brain that drain CSF). These two CSF systems work in unison, and their disruption has been implicated in several neurological disorders including Alzheimer's disease, stoke, and traumatic brain injury. Here, we present experimental techniques for in vivo quantification of CSF flow via direct imaging of fluorescent microspheres injected into the CSF. We discuss detailed image processing methods, including registration and masking of stagnant particles, to improve the quality of measurements. We provide guidance for quantifying CSF flow through particle tracking and offer tips for optimizing the process. Additionally, we describe techniques for measuring changes in arterial diameter, which is an hypothesized CSF pumping mechanism. Finally, we outline how these same techniques can be applied to cervical lymphatic vessels, which collect fluid downstream from meningeal lymphatic vessels. We anticipate that these fluid mechanical techniques will prove valuable for future quantitative studies aimed at understanding mechanisms of CSF transport and disruption, as well as for other complex biophysical systems.
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Affiliation(s)
- Daehyun Kim
- Department of Mechanical Engineering, University of Minnesota, 111 Church St SE, Minneapolis, MN, 55455, United States
| | - Yiming Gan
- Department of Mechanical Engineering, University of Rochester, Hopeman Engineering Bldg, Rochester, NY, 14627, United States
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY, 14642, United States
| | - Douglas H. Kelley
- Department of Mechanical Engineering, University of Rochester, Hopeman Engineering Bldg, Rochester, NY, 14627, United States
| | - Jeffrey Tithof
- Department of Mechanical Engineering, University of Minnesota, 111 Church St SE, Minneapolis, MN, 55455, United States
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Mohapatra RK, Kutikuppala LVS, Kandi V, Mishra S, Rabaan AA, Costa S, Al‐qaim ZH, Padhi BK, Sah R. Rift valley fever (RVF) viral zoonotic disease steadily circulates in the Mauritanian animals and humans: A narrative review. Health Sci Rep 2023; 6:e1384. [PMID: 37404448 PMCID: PMC10315559 DOI: 10.1002/hsr2.1384] [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: 01/19/2023] [Revised: 04/14/2023] [Accepted: 04/16/2023] [Indexed: 07/06/2023] Open
Abstract
Background and Aim Rift valley fever (RVF) virus (RVFV) is reportedly steadily circulating in Mauritania being repeated in 1987, 2010, 2012, 2015, and 2020. Mauritania seems a preferred niche for RVF virus due to its persistent outbreak there. Lately, nine Mauritanian wilayas confirmed 47 (23 fatalities with 49% CFR) human cases between August 30 and October 17, 2022. Most of the cases were largely among livestock breeders associated with animal husbandry activities. The review aimed at understanding the origin, cause, and measures to counter the virus. Methods The facts and figures from the various published articles sourced from databases including Pubmed, Web of Science, and the Scopus as also some primary data from health agencies like WHO, CDC, and so forth were evaluated and the efficacy of countermeasures reviewed. Results Among the reported confirmed cases, it was found that 3-70 year age-group males outnumbered the females. Deaths after fever occurred primarily due to acute hemorrhagic thrombocytopenia. Human infections often occurred through zoonotic transmission mainly through mosquitoes in the population contiguous to cattle outbreak, a conducive site for local RVFV transmission. Many transmission cases were through direct or indirect contact with blood or organs of the infected animal. Conclusion RVFV infection was predominant in the Mauritanian regions bordering Mali, Senegal, and Algeria. High human and domesticated animal density as also the existing zoonotic vectors further contributed to RVF virus circulation. Mauritanian RVF infection data confirmed that RVFV was zoonotic that included small ruminants, cattle, and camel. This observation hints at the role of transborder animal mobility in RVFV transmission. In light of this, preventive approaches with effective surveillance and monitoring system following the One Health model is extremely beneficial for a free and fair healthy world for all.
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Affiliation(s)
| | | | - Venkataramana Kandi
- Department of MicrobiologyPrathima Institute of Medical SciencesKarimnagarTelanganaIndia
| | - Snehasish Mishra
- School of Biotechnology, Campus‐11, KIIT Deemed‐to‐be‐UniversityBhubaneswarOdishaIndia
| | - Ali A. Rabaan
- Molecular Diagnostic Laboratory, Johns Hopkins Aramco HealthcareDhahranSaudi Arabia
- College of MedicineAlfaisal UniversityRiyadhSaudi Arabia
- Department of Public Health and NutritionThe University of HaripurHaripurPakistan
| | - Sharo Costa
- College of Osteopathic MedicineMichigan State UniversityEast LansingMichiganUSA
| | | | - Bijaya K. Padhi
- Department of Community MedicineSchool of Public Health, Postgraduate Institute of Medical Education and ResearchChandigarhIndia
| | - Ranjit Sah
- Institute of Medicine, Tribhuvan University Teaching HospitalKathmanduNepal
- Dr. D. Y. Patil Medical College, Hospital and Research Centre, Dr. D. Y. Patil VidyapeethPuneMaharashtraIndia
- Department of Public Health DentistryDr. D. Y. Patil Dental College and Hospital, Dr. D. Y. Patil VidyapeethPuneMaharashtraIndia
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Tumusiime D, Isingoma E, Tashoroora OB, Ndumu DB, Bahati M, Nantima N, Mugizi DR, Jost C, Bett B. Mapping the risk of Rift Valley fever in Uganda using national seroprevalence data from cattle, sheep and goats. PLoS Negl Trop Dis 2023; 17:e0010482. [PMID: 37235591 DOI: 10.1371/journal.pntd.0010482] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 04/28/2023] [Indexed: 05/28/2023] Open
Abstract
Uganda has had repeated outbreaks of Rift Valley fever (RVF) since March 2016 when human and livestock cases were reported in Kabale after a long interval. The disease has a complex and poorly described transmission patterns which involves several mosquito vectors and mammalian hosts (including humans). We conducted a national serosurvey in livestock to determine RVF virus (RVFV) seroprevalence, risk factors, and to develop a risk map that could be used to guide risk-based surveillance and control measures. A total of 3,253 animals from 175 herds were sampled. Serum samples collected were screened at the National Animal Disease Diagnostics and Epidemiology Centre (NADDEC) using a competition multispecies anti-RVF IgG ELISA kit. Data obtained were analyzed using a Bayesian model that utilizes integrated nested Laplace approximation (INLA) and stochastic partial differential equation (SPDE) approaches to estimate posterior distributions of model parameters, and account for spatial autocorrelation. Variables considered included animal level factors (age, sex, species) and multiple environmental data including meteorological factors, soil types, and altitude. A risk map was produced by projecting fitted (mean) values, from a final model that had environmental factors onto a spatial grid that covered the entire domain. The overall RVFV seroprevalence was 11.39% (95% confidence interval: 10.35-12.51%). Higher RVFV seroprevalences were observed in older animals compared to the young, and cattle compared to sheep and goats. RVFV seroprevalence was also higher in areas that had (i) lower precipitation seasonality, (ii) haplic planosols, and (iii) lower cattle density. The risk map generated demonstrated that RVF virus was endemic in several regions including those that have not reported clinical outbreaks in the northeastern part of the country. This work has improved our understanding on spatial distribution of RVFV risk in the country as well as RVF burden in livestock.
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Affiliation(s)
- Dan Tumusiime
- Ministry of Agriculture, Animal Industry and Fisheries, Entebbe, Uganda
- International Livestock Research Institute, Kampala, Uganda
- Dahlem Research School (DRS) Biomedical Sciences, Faculty of Veterinary Medicine; Freie Universität Berlin, Berlin, Germany
| | - Emmanuel Isingoma
- Ministry of Agriculture, Animal Industry and Fisheries, Entebbe, Uganda
| | | | - Deo B Ndumu
- Ministry of Agriculture, Animal Industry and Fisheries, Entebbe, Uganda
| | - Milton Bahati
- Ministry of Agriculture, Animal Industry and Fisheries, Entebbe, Uganda
| | - Noelina Nantima
- Ministry of Agriculture, Animal Industry and Fisheries, Entebbe, Uganda
| | | | - Christine Jost
- United States Agency for International Development's Bureau for Humanitarian Assistance 14 (USAID/BHA), Washington, D.C., United States of America
- Global Health Support Initiative III, Social Solutions International, Washington, D.C., United States of America
| | - Bernard Bett
- International Livestock Research Institute, Nairobi, Kenya
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Isotype-Specific Fc Effector Functions Enhance Antibody-Mediated Rift Valley Fever Virus Protection In Vivo. mSphere 2021; 6:e0055621. [PMID: 34494884 PMCID: PMC8550229 DOI: 10.1128/msphere.00556-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Discovered in 1931, Rift Valley fever virus (RVFV) is an arbovirus that causes disease in humans and livestock. In humans, disease ranges from a self-limiting febrile illness to a more severe hepatitis or encephalitis. There are currently no licensed human therapeutics for RVFV disease. Given the recent advances in the use of monoclonal antibodies (MAbs) for treating infectious disease, a panel of anti-RVFV Gn glycoprotein MAbs was developed and characterized. RVFV MAbs spanned a range of neutralizing abilities and mapped to distinct epitopes along Gn. The contribution of Fc effector functions in providing MAb-mediated protection from RVFV was assessed. IgG2a version MAbs had increased capacity to induce effector functions and conferred better protection from RVFV challenge in a lethal mouse model than IgG1 version MAbs. Overall, this study shows that Fc-mediated functions are a critical component of humoral protection from RVFV. IMPORTANCE Rift Valley fever virus (RVFV) is a mosquito-borne virus found throughout Africa and into the Middle East. It has a substantial disease burden; in areas of endemicity, up to 60% of adults are seropositive. With a case fatality rate of up to 3% and the ability to cause hemorrhagic fever and encephalitis, RVFV poses a serious threat to human health. Despite the known human disease burden and the fact that it is a NIAID category A priority pathogen and a WHO priority disease for research and development, there are no vaccines or therapeutics available for RVF. In this study, we developed and characterized a panel of monoclonal antibodies against the RVFV surface glycoprotein, Gn. We then demonstrated therapeutic efficacy in the prevention of RVF in vivo in an otherwise lethal mouse model. Finally, we revealed a role for Fc-mediated function in augmenting the protection provided by these antibodies.
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