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Zhou CM, Jiang ZZ, Liu N, Yu XJ. Current insights into human pathogenic phenuiviruses and the host immune system. Virulence 2024; 15:2384563. [PMID: 39072499 PMCID: PMC11290763 DOI: 10.1080/21505594.2024.2384563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Revised: 07/09/2024] [Accepted: 07/18/2024] [Indexed: 07/30/2024] Open
Abstract
Phenuiviruses are a class of segmented negative-sense single-stranded RNA viruses, typically consisting of three RNA segments that encode four distinct proteins. The emergence of pathogenic phenuivirus strains, such as Rift Valley fever phlebovirus (RVFV) in sub-Saharan Africa, Severe Fever with Thrombocytopenia Syndrome Virus (SFTSV) in East and Southeast Asia, and Heartland Virus (HRTV) in the United States has presented considerable challenges to global public health in recent years. The innate immune system plays a crucial role as the initial defense mechanism of the host against invading pathogens. In addition to continued research aimed at elucidating the epidemiological characteristics of phenuivirus, significant advancements have been made in investigating its viral virulence factors (glycoprotein, non-structural protein, and nucleoprotein) and potential host-pathogen interactions. Specifically, efforts have focused on understanding mechanisms of viral immune evasion, viral assembly and egress, and host immune networks involving immune cells, programmed cell death, inflammation, nucleic acid receptors, etc. Furthermore, a plethora of technological advancements, including metagenomics, metabolomics, single-cell transcriptomics, proteomics, gene editing, monoclonal antibodies, and vaccines, have been utilized to further our understanding of phenuivirus pathogenesis and host immune responses. Hence, this review aims to provide a comprehensive overview of the current understanding of the mechanisms of host recognition, viral immune evasion, and potential therapeutic approaches during human pathogenic phenuivirus infections focusing particularly on RVFV and SFTSV.
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Affiliation(s)
- Chuan-Min Zhou
- Gastrointestinal Disease Diagnosis and Treatment Center, The First Hospital of Hebei Medical University, Shijiazhuang, China
- Department of General Surgery, Hebei Key Laboratory of Colorectal Cancer Precision Diagnosis and Treatment, The First Hospital of Hebei Medical University, Shijiazhuang, China
- Central Laboratory, The First Hospital of Hebei Medical University, Shijiazhuang, China
| | - Ze-Zheng Jiang
- State Key Laboratory of Virology, School of Public Health, Wuhan University, Wuhan, China
| | - Ning Liu
- Department of Quality and Operations Management, The First Hospital of Hebei Medical University, Shijiazhuang, China
| | - Xue-Jie Yu
- State Key Laboratory of Virology, School of Public Health, Wuhan University, Wuhan, China
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Koka H, Langat S, Oyola S, Cherop F, Rotich G, Mutisya J, Ofula V, Limbaso K, Ongus JR, Lutomiah J, Sang R. Detection and prevalence of a novel Bandavirus related to Guertu virus in Amblyomma gemma ticks and human populations in Isiolo County, Kenya. PLoS One 2024; 19:e0310862. [PMID: 39302958 DOI: 10.1371/journal.pone.0310862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Accepted: 09/06/2024] [Indexed: 09/22/2024] Open
Abstract
INTRODUCTION Emerging tick-borne viruses of medical and veterinary importance are increasingly being reported globally. This resurgence emphasizes the need for sustained surveillance to provide insights into tick-borne viral diversity and associated potential public health risks. We report on a virus tentatively designated Kinna virus (KIV) in the family Phenuiviridae and genus Bandavirus. The virus was isolated from a pool of Amblyomma gemma ticks from Kinna in Isiolo County, Kenya. High throughput sequencing of the virus isolate revealed close relatedness to the Guertu virus. The virus genome is consistent with the described genomes of other members of the genus Bandavirus, with nucleotides lengths of 6403, 3332 and 1752 in the Large (L), Medium (M) and Small (S) segments respectively. Phylogenetic analysis showed that the virus clustered with Guertu virus although it formed a distinct and well supported branch. The RdRp amino acid sequence had a 93.3% identity to that of Guertu virus, an indication that the virus is possibly novel. Neutralizing antibodies were detected in 125 (38.6%, 95% CI 33.3-44.1%) of the human sera from the communities in this region. In vivo experiments showed that the virus was lethal to mice with death occurring 6-9 days post-infection. The virus infected mammalian cells (Vero cells) but had reduced infectivity in the mosquito cell line (C636) tested. CONCLUSION Isolation of this novel virus with the potential to cause disease in human and animal populations necessitates the need to evaluate its public health significance and contribution to disease burden in the affected regions. This also points to the need for continuous monitoring of vector and human populations in high-risk ecosystems to update pathogen diversity.
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Affiliation(s)
- Hellen Koka
- Kenya Medical Research Institute, Centre for Virus Research, Nairobi, Kenya
- Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Solomon Langat
- Kenya Medical Research Institute, Centre for Virus Research, Nairobi, Kenya
| | - Samuel Oyola
- International Livestock Research Institute, Nairobi, Kenya
| | - Faith Cherop
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Gilbert Rotich
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - James Mutisya
- Kenya Medical Research Institute, Centre for Virus Research, Nairobi, Kenya
| | - Victor Ofula
- Kenya Medical Research Institute, Centre for Virus Research, Nairobi, Kenya
| | - Konongoi Limbaso
- Kenya Medical Research Institute, Centre for Virus Research, Nairobi, Kenya
| | - Juliette R Ongus
- Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Joel Lutomiah
- Kenya Medical Research Institute, Centre for Virus Research, Nairobi, Kenya
| | - Rosemary Sang
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
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O’Neill L, Gubbins S, Reynolds C, Limon G, Giorgakoudi K. The socioeconomic impacts of Rift Valley fever: A rapid review. PLoS Negl Trop Dis 2024; 18:e0012347. [PMID: 39207938 PMCID: PMC11361445 DOI: 10.1371/journal.pntd.0012347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2024] Open
Abstract
Rift Valley fever (RVF) is a neglected vector-borne disease which is endemic in many countries across Africa and has seen recent geographical expansions into the Arabian Peninsula. RVF can cause severe infections in both animals and humans. RVF infections in livestock can lead to mass fatalities. In humans, the symptoms are nonspecific and can often lead to misdiagnosis. However, a small proportion progresses to haemorrhagic infection with a significantly higher mortality rate. The culmination of this can cause severe socioeconomic impacts. This review aims to identify the main socioeconomic impacts caused by RVF outbreaks as well as existing knowledge gaps. Ninety-three academic and grey papers were selected, covering 19 countries and 10 methodological approaches. A variety of socioeconomic impacts were found across all levels of society: Livestock trade disruptions consequently impacted local food security, local and national economies. Most livestock farmers in endemic countries are subsistence farmers and so rely on their livestock for sustenance and income. RVF outbreaks resulted in a variety of socioeconomic impacts, e.g., the inability to pay for school fees. Main barriers to vaccine uptake in communities were lack of access, funds, interest along with other social aspects. The occupational risks for women (and pregnant women) are largely unknown. To our knowledge, this is the first review on RVF to highlight the clear knowledge gap surrounding the potential gender differences on risks of RVF exposure, as well as differences on occupational health risk in pastoral communities. Further work is required to fill the gaps identified in this review and inform control policies.
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Affiliation(s)
- Luke O’Neill
- HSRM Department, School of Health and Psychological Sciences, City, University of London, London, United Kingdom
- The Pirbright Institute, Pirbright, United Kingdom
| | | | - Christian Reynolds
- HSRM Department, School of Health and Psychological Sciences, City, University of London, London, United Kingdom
| | | | - Kyriaki Giorgakoudi
- HSRM Department, School of Health and Psychological Sciences, City, University of London, London, United Kingdom
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Gerken KN, Owuor KO, Ndenga B, Wambua S, Winter C, Chemutai S, Omukuti R, Arabu D, Miring’u I, Wilson WC, Mutuku F, Waggoner JJ, Pinsky B, Bosire C, LaBeaud AD. Expanding Understanding of Urban Rift Valley Fever Risk and Associated Vector Ecology at Slaughterhouses in Kisumu, Kenya. Pathogens 2024; 13:488. [PMID: 38921786 PMCID: PMC11206928 DOI: 10.3390/pathogens13060488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 06/01/2024] [Accepted: 06/04/2024] [Indexed: 06/27/2024] Open
Abstract
Rift Valley fever virus (RVFV) is an adaptable arbovirus that can be transmitted by a wide variety of arthropods. Widespread urban transmission of RVFV has not yet occurred, but peri-urban outbreaks of RVFV have recently been documented in East Africa. We previously reported low-level exposure in urban communities and highlighted the risk of introduction via live animal influx. We deployed a slaughtered animal testing framework in response to an early warning system at two urban slaughterhouses and tested animals entering the meat value chain for anti-RVFV IgG and IgM antibodies. We simultaneously trapped mosquitoes for RVFV and bloodmeal testing. Out of 923 animals tested, an 8.5% IgG seroprevalence was identified but no evidence of recent livestock exposure was detected. Mosquito species abundance varied greatly by slaughterhouse site, which explained 52% of the variance in blood meals. We captured many Culex spp., a known RVFV amplifying vector, at one of the sites (p < 0.001), and this species had the most diverse blood meals. No mosquito pools tested positive for RVFV antigen using a rapid VecTOR test. These results expand understanding of potential RVF urban disease ecology, and highlight that slaughterhouses are key locations for future surveillance, modelling, and monitoring efforts.
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Affiliation(s)
- Keli Nicole Gerken
- Department of Pediatrics, Division of Infectious Diseases, Stanford University School of Medicine, Stanford, CA 94305, USA; (B.P.); (A.D.L.)
| | - Kevin Omondi Owuor
- Kenya Medical Research Institute, Centre for Global Health Research, Kisumu 40100, Kenya; (K.O.O.); (B.N.); (C.W.)
| | - Bryson Ndenga
- Kenya Medical Research Institute, Centre for Global Health Research, Kisumu 40100, Kenya; (K.O.O.); (B.N.); (C.W.)
| | - Sammy Wambua
- Pwani University Biosciences Research Centre (PUBReC), Pwani University, Kilifi 80108, Kenya; (S.W.); (S.C.); (R.O.); (D.A.); (I.M.)
- Research and Conservation Support Society (RECOURSE), Kilifi 80108, Kenya
- School of Biodiversity One Health and Veterinary Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - Christabel Winter
- Kenya Medical Research Institute, Centre for Global Health Research, Kisumu 40100, Kenya; (K.O.O.); (B.N.); (C.W.)
| | - Salome Chemutai
- Pwani University Biosciences Research Centre (PUBReC), Pwani University, Kilifi 80108, Kenya; (S.W.); (S.C.); (R.O.); (D.A.); (I.M.)
- Research and Conservation Support Society (RECOURSE), Kilifi 80108, Kenya
| | - Rodney Omukuti
- Pwani University Biosciences Research Centre (PUBReC), Pwani University, Kilifi 80108, Kenya; (S.W.); (S.C.); (R.O.); (D.A.); (I.M.)
- Research and Conservation Support Society (RECOURSE), Kilifi 80108, Kenya
| | - Daniel Arabu
- Pwani University Biosciences Research Centre (PUBReC), Pwani University, Kilifi 80108, Kenya; (S.W.); (S.C.); (R.O.); (D.A.); (I.M.)
- Research and Conservation Support Society (RECOURSE), Kilifi 80108, Kenya
| | - Irene Miring’u
- Pwani University Biosciences Research Centre (PUBReC), Pwani University, Kilifi 80108, Kenya; (S.W.); (S.C.); (R.O.); (D.A.); (I.M.)
- Research and Conservation Support Society (RECOURSE), Kilifi 80108, Kenya
| | - William C. Wilson
- Foreign Arthropod-Borne Animal Disease Research, United States Department of Agriculture-Agriculture Research Service (USDA-ARS), Manhattan, KS 66502, USA;
| | - Francis Mutuku
- Department of Environment and Health Sciences, Technical University of Mombasa, Mombasa 80110, Kenya;
| | - Jesse J. Waggoner
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA;
| | - Benjamin Pinsky
- Department of Pediatrics, Division of Infectious Diseases, Stanford University School of Medicine, Stanford, CA 94305, USA; (B.P.); (A.D.L.)
| | - Carren Bosire
- Department of Pure and Applied Sciences, Technical University of Mombasa, Mombasa 80100, Kenya;
| | - Angelle Desiree LaBeaud
- Department of Pediatrics, Division of Infectious Diseases, Stanford University School of Medicine, Stanford, CA 94305, USA; (B.P.); (A.D.L.)
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Gachohi J, Njoki P, Mogoa E, Otieno F, Muturi M, Mwatondo A, Ngere I, Dawa J, Nasimiyu C, Osoro E, Bett B, Njenga K. Higher livestock abortion burden in arid and semi-arid lands, Kenya, 2019-2020. PLoS One 2024; 19:e0297274. [PMID: 38386647 PMCID: PMC10883554 DOI: 10.1371/journal.pone.0297274] [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: 06/06/2023] [Accepted: 01/02/2024] [Indexed: 02/24/2024] Open
Abstract
Tracking livestock abortion patterns over time and across factors such as species and agroecological zones (AEZs) could inform policies to mitigate disease emergence, zoonoses risk, and reproductive losses. We conducted a year-long population-based active surveillance of livestock abortion between 2019 and 2020, in administrative areas covering 52% of Kenya's landmass and home to 50% of Kenya's livestock. Surveillance sites were randomly selected to represent all AEZs in the country. Local animal health practitioners electronically transmitted weekly abortion reports from each ward, the smallest administrative unit, to a central server, using a simple short messaging service (SMS). Data were analyzed descriptively by administrative unit, species, and AEZ to reveal spatiotemporal patterns and relationships with rainfall and temperature. Of 23,766 abortions reported in all livestock species, sheep and goats contributed 77%, with goats alone contributing 53%. Seventy-seven per cent (n = 18,280) of these abortions occurred in arid and semi-arid lands (ASALs) that primarily practice pastoralism production systems. While spatiotemporal clustering of cases was observed in May-July 2019 in the ASALs, there was a substantial seasonal fluctuation across AEZs. Kenya experiences high livestock abortion rates, most of which go unreported. We recommend further research to document the national true burden of abortions. In ASALs, studies linking pathogen, climate, and environmental surveillance are needed to assign livestock abortions to infectious or non-infectious aetiologies and conducting human acute febrile illnesses surveillance to detect any links with the abortions.
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Affiliation(s)
- John Gachohi
- Department of Environmental Health and Disease Control, School of Public Health, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
- Washington State University Global Health Program, Washington State University, Nairobi, Kenya
- Paul G. Allen School of Global Health, Washington State University, Pullman, Washington, United States of America
| | - Peris Njoki
- Washington State University Global Health Program, Washington State University, Nairobi, Kenya
| | - Eddy Mogoa
- Department of Clinical Studies, Faculty of Veterinary Medicine, University of Nairobi, Nairobi, Kenya
| | - Fredrick Otieno
- Animal and human health Program, International Livestock Research Institute, Nairobi, Kenya
| | - Mathew Muturi
- Animal and human health Program, International Livestock Research Institute, Nairobi, Kenya
- Kenya Zoonotic Disease Unit, Nairobi, Kenya
- Dahlem Research School (DRS), Faculty of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Athman Mwatondo
- Animal and human health Program, International Livestock Research Institute, Nairobi, Kenya
- Kenya Zoonotic Disease Unit, Nairobi, Kenya
- Kenya One Health Platform, Ministry of Health, Nairobi, Kenya
| | - Isaac Ngere
- Washington State University Global Health Program, Washington State University, Nairobi, Kenya
- Paul G. Allen School of Global Health, Washington State University, Pullman, Washington, United States of America
| | - Jeanette Dawa
- Washington State University Global Health Program, Washington State University, Nairobi, Kenya
- Paul G. Allen School of Global Health, Washington State University, Pullman, Washington, United States of America
| | - Carolyne Nasimiyu
- Washington State University Global Health Program, Washington State University, Nairobi, Kenya
- Paul G. Allen School of Global Health, Washington State University, Pullman, Washington, United States of America
| | - Eric Osoro
- Washington State University Global Health Program, Washington State University, Nairobi, Kenya
- Paul G. Allen School of Global Health, Washington State University, Pullman, Washington, United States of America
| | - Bernard Bett
- Animal and human health Program, International Livestock Research Institute, Nairobi, Kenya
| | - Kariuki Njenga
- Washington State University Global Health Program, Washington State University, Nairobi, Kenya
- Paul G. Allen School of Global Health, Washington State University, Pullman, Washington, United States of America
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Nyamota R, Maina J, Akoko J, Nthiwa D, Mwatondo A, Muturi M, Wambua L, Middlebrook EA, Bartlow AW, Fair JM, Bett B. Seroprevalence of Brucella spp. and Rift Valley fever virus among slaughterhouse workers in Isiolo County, northern Kenya. PLoS Negl Trop Dis 2023; 17:e0011677. [PMID: 37797043 PMCID: PMC10581456 DOI: 10.1371/journal.pntd.0011677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 10/17/2023] [Accepted: 09/22/2023] [Indexed: 10/07/2023] Open
Abstract
Brucella spp. and Rift Valley fever virus (RVFV) are classified as priority zoonotic agents in Kenya, based on their public health and socioeconomic impact on the country. Data on the pathogen-specific and co-exposure levels is scarce due to limited active surveillance. This study investigated seroprevalence and co-exposure of Brucella spp. and RVFV and associated risk factors among slaughterhouse workers in Isiolo County, northern Kenya. A cross-sectional serosurvey was done in all 19 slaughterhouses in Isiolo County, enrolling 378 participants into the study. The overall seroprevalences for Brucella spp. and RVFV were 40.2% (95% CI: 35.2-45.4) and 18.3% (95% CI: 14.5-22.5), respectively while 10.3% (95% CI 7.4%-13.8%) of individuals were positive for antibodies against both Brucella spp. and RVFV. Virus neutralisation tests (VNT) confirmed anti-RVFV antibodies in 85% of ELISA-positive samples. Our seroprevalence results were comparable to community-level seroprevalences previously reported in the area. Since most of the study participants were not from livestock-keeping households, our findings attribute most of the detected infections to occupational exposure. The high exposure levels indicate slaughterhouse workers are the most at-risk population and there is need for infection, prevention, and control programs among this high-risk group. This is the first VNT confirmation of virus-neutralising antibodies among slaughterhouse workers in Isiolo County and corroborates reports of the area being a high-risk RVFV area as occasioned by previously reported outbreaks. This necessitates sensitization campaigns to enhance awareness of the risks involved and appropriate mitigation measures.
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Affiliation(s)
| | - Josphat Maina
- Kenya Zoonotic Disease Unit, Ministry of Health and Ministry of Agriculture, Livestock and Fisheries, Nairobi, Kenya
| | - James Akoko
- International Livestock Research Institute, Nairobi, Kenya
| | - Daniel Nthiwa
- Department of Biological Sciences, University of Embu, Embu, Kenya
| | - Athman Mwatondo
- International Livestock Research Institute, Nairobi, Kenya
- Kenya Zoonotic Disease Unit, Ministry of Health and Ministry of Agriculture, Livestock and Fisheries, Nairobi, Kenya
| | - Mathew Muturi
- International Livestock Research Institute, Nairobi, Kenya
- Kenya Zoonotic Disease Unit, Ministry of Health and Ministry of Agriculture, Livestock and Fisheries, Nairobi, Kenya
- Department of Veterinary Medicine, Dahlem Research School of Biomedical Sciences (DRS), Freie Universität Berlin, Berlin, Germany
| | - Lillian Wambua
- World Organization for Animal Health, Sub-Regional Representation for Eastern Africa, Nairobi, Kenya
| | - Earl A Middlebrook
- Genomics and Bioanalytic, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Andrew W Bartlow
- Genomics and Bioanalytic, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Jeanne M Fair
- Genomics and Bioanalytic, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Bernard Bett
- International Livestock Research Institute, Nairobi, Kenya
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Muturi M, Mwatondo A, Nijhof AM, Akoko J, Nyamota R, Makori A, Nyamai M, Nthiwa D, Wambua L, Roesel K, Thumbi SM, Bett B. Ecological and subject-level drivers of interepidemic Rift Valley fever virus exposure in humans and livestock in Northern Kenya. Sci Rep 2023; 13:15342. [PMID: 37714941 PMCID: PMC10504342 DOI: 10.1038/s41598-023-42596-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 09/12/2023] [Indexed: 09/17/2023] Open
Abstract
Nearly a century after the first reports of Rift Valley fever (RVF) were documented in Kenya, questions on the transmission dynamics of the disease remain. Specifically, data on viral maintenance in the quiescent years between epidemics is limited. We implemented a cross-sectional study in northern Kenya to determine the seroprevalence, risk factors, and ecological predictors of RVF in humans and livestock during an interepidemic period. Six hundred seventy-six human and 1,864 livestock samples were screened for anti-RVF Immunoglobulin G (IgG). Out of the 1,864 livestock samples tested for IgG, a subset of 1,103 samples was randomly selected for additional testing to detect the presence of anti-RVFV Immunoglobulin M (IgM). The anti-RVF virus (RVFV) IgG seropositivity in livestock and humans was 21.7% and 28.4%, respectively. RVFV IgM was detected in 0.4% of the livestock samples. Participation in the slaughter of livestock and age were positively associated with RVFV exposure in humans, while age was a significant factor in livestock. We detected significant interaction between rainfall and elevation's influence on livestock seropositivity, while in humans, elevation was negatively associated with RVF virus exposure. The linear increase of human and livestock exposure with age suggests an endemic transmission cycle, further corroborated by the detection of IgM antibodies in livestock.
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Affiliation(s)
- Mathew Muturi
- Department of Veterinary Medicine, Dahlem Research School of Biomedical Sciences (DRS), Freie Universität Berlin, Berlin, Germany.
- International Livestock Research Institute, Nairobi, Kenya.
- Kenya Zoonotic Disease Unit, Ministry of Health and Ministry of Agriculture, Nairobi, Kenya.
- Center for Epidemiological Modelling and Analysis-University of Nairobi, Nairobi, Kenya.
| | - Athman Mwatondo
- International Livestock Research Institute, Nairobi, Kenya
- Kenya Zoonotic Disease Unit, Ministry of Health and Ministry of Agriculture, Nairobi, Kenya
- Department of Medical Microbiology and Immunology, University of Nairobi, Nairobi, Kenya
| | - Ard M Nijhof
- Veterinary Centre for Resistance Research, Freie Universität Berlin, Berlin, Germany
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Univesität Berlin, Berlin, Germany
| | - James Akoko
- International Livestock Research Institute, Nairobi, Kenya
| | | | - Anita Makori
- Center for Epidemiological Modelling and Analysis-University of Nairobi, Nairobi, Kenya
- Paul G Allen School for Global Health, Washington State University, Pullman, WA, USA
| | - Mutono Nyamai
- Center for Epidemiological Modelling and Analysis-University of Nairobi, Nairobi, Kenya
- Paul G Allen School for Global Health, Washington State University, Pullman, WA, USA
| | - Daniel Nthiwa
- Department of Biological Sciences, University of Embu, Embu, Kenya
| | - Lilian Wambua
- International Livestock Research Institute, Nairobi, Kenya
| | | | - S M Thumbi
- Center for Epidemiological Modelling and Analysis-University of Nairobi, Nairobi, Kenya
- Paul G Allen School for Global Health, Washington State University, Pullman, WA, USA
- Institute for Immunology and Infection Research, University of Edinburgh, Edinburgh, Scotland, UK
| | - Bernard Bett
- International Livestock Research Institute, Nairobi, Kenya
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Johnson SAM, Asmah R, Awuni JA, Tasiame W, Mensah GI, Paweska JT, Weyer J, Hellferscee O, Thompson PN. Evidence of Rift Valley Fever Virus Circulation in Livestock and Herders in Southern Ghana. Viruses 2023; 15:1346. [PMID: 37376647 DOI: 10.3390/v15061346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 06/05/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
Rift Valley fever (RVF) is a re-emerging zoonotic disease of domestic ruminants and humans. While neighbouring countries have reported outbreaks of RVF, Ghana has not yet identified any cases. The aim of this study was to determine whether RVF virus (RVFV) was circulating in livestock and herders in the southern part of Ghana, to estimate its seroprevalence, and to identify associated risk factors. The study surveyed 165 livestock farms randomly selected from two districts in southern Ghana. Serum samples of 253 goats, 246 sheep, 220 cattle, and 157 herdsmen were tested to detect IgG and IgM antibodies against RVFV. The overall seroprevalence of anti-RVF antibodies in livestock was 13.1% and 30.9% of farms had RVFV seropositive animals. The species-specific prevalence was 24.1% in cattle, 8.5% in sheep, and 7.9% in goats. A RVFV IgG seroprevalence of 17.8% was found among the ruminant herders, with 8.3% of all herders being IgM positive. RVFV was shown, for the first time, to have been circulating in southern Ghana, with evidence of a recent outbreak in Kwahu East; however, it was clinically undetected despite significant recent human exposure. A One Health approach is recommended to better understand RVF epidemiology and socio-economic impact in Ghana.
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Affiliation(s)
- Sherry Ama Mawuko Johnson
- Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa
- School of Veterinary Medicine, University of Ghana, Legon, Accra 00233, Ghana
| | - Richard Asmah
- School of Biomedical & Allied Health Sciences, University of Ghana, Accra 00233, Ghana
| | - Joseph Adongo Awuni
- Accra Veterinary Laboratory, Ministry of Food and Agriculture, Accra P.O. Box M161, Ghana
| | - William Tasiame
- School of Veterinary Medicine, Kwame Nkrumah University of Science and Technology, Kumasi 00233, Ghana
| | - Gloria Ivy Mensah
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra 00233, Ghana
| | - Janusz T Paweska
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Sandringham, Johannesburg 2192, South Africa
- Department of Medical Virology, Faculty of Health Sciences, University of Pretoria, Pretoria 0002, South Africa
| | - Jacqueline Weyer
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Sandringham, Johannesburg 2192, South Africa
- Department of Medical Virology, Faculty of Health Sciences, University of Pretoria, Pretoria 0002, South Africa
| | - Orienka Hellferscee
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Sandringham, Johannesburg 2192, South Africa
- Department of Medical Virology, Faculty of Health Sciences, University of Witwatersrand, Johannesburg 2050, South Africa
| | - Peter N Thompson
- Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa
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Sankhe S, Talla C, Thiam MS, Faye M, Barry MA, Diarra M, Dia M, Ndiaye O, Sembene PM, Diop B, Fall G, Faye O, Faye O, Diagne MM, Loucoubar C. Seroprevalence of Crimean-Congo Hemorrhagic Fever Virus and Rift Valley Fever Virus in human population in Senegal from October to November 2020. IJID REGIONS 2023; 7:216-221. [PMID: 37153883 PMCID: PMC10160495 DOI: 10.1016/j.ijregi.2023.03.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/24/2023] [Accepted: 03/27/2023] [Indexed: 05/10/2023]
Abstract
Objectives Rift Valley Fever and Crimean-Congo Hemorrhagic Fever are two infections classified among the emerging diseases to be monitored with highest priority. Studies undertaken in human and animals have shown endemicity of these two arboviruses in several African countries. However, most of the investigations were carried out on domestic cattle and the studies conducted on human populations are either outdated or limited to a small number of well-known endemic areas. It is then critical to better evaluate the burden of these viruses in Senegal at a national scale. Methods This work relies on a previous seroprevalence survey undertaken in all regions of Senegal at the end of 2020. The existing biobank was used to determine the immunoglobulin G [IgG] Rift Valley Fever and Crimean-Congo Hemorrhagic Fever seroprevalences by indirect enzyme-linked immunosorbent assay. Results The crude seroprevalences of Rift Valley Fever and Crimean-Congo Hemorrhagic Fever were 3.94% and 0.7% respectively, with the northern and central part of the countries as the main exposed areas. However, acute infections reported in both high and low exposed regions suggest sporadic introductions. Conclusions This study gives updated information and could be of interest to support the stakeholders in the management of these zoonoses.
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Affiliation(s)
- Safietou Sankhe
- Arboviruses and Hemorrhagic Fever Viruses Unit, Virology Department, Institut Pasteur de Dakar, BP220 Dakar, Senegal
- Animal Biology Department, Faculty of Sciences and Techniques, Cheikh Anta Diop University of Dakar, Dakar, Senegal
| | - Cheikh Talla
- Epidemiology, Clinical Research and Data Science Department, Institut Pasteur de Dakar, BP220 Dakar, Senegal
| | - Mareme Seye Thiam
- Epidemiology, Clinical Research and Data Science Department, Institut Pasteur de Dakar, BP220 Dakar, Senegal
| | - Martin Faye
- Arboviruses and Hemorrhagic Fever Viruses Unit, Virology Department, Institut Pasteur de Dakar, BP220 Dakar, Senegal
| | - Mamadou Aliou Barry
- Epidemiology, Clinical Research and Data Science Department, Institut Pasteur de Dakar, BP220 Dakar, Senegal
| | - Maryam Diarra
- Epidemiology, Clinical Research and Data Science Department, Institut Pasteur de Dakar, BP220 Dakar, Senegal
| | - Moussa Dia
- Arboviruses and Hemorrhagic Fever Viruses Unit, Virology Department, Institut Pasteur de Dakar, BP220 Dakar, Senegal
| | - Oumar Ndiaye
- Arboviruses and Hemorrhagic Fever Viruses Unit, Virology Department, Institut Pasteur de Dakar, BP220 Dakar, Senegal
| | - Pape Mbacke Sembene
- Animal Biology Department, Faculty of Sciences and Techniques, Cheikh Anta Diop University of Dakar, Dakar, Senegal
| | - Boly Diop
- Epidemiological Surveillance Division, Prevention Department, Ministry of Health, Dakar, Senegal
| | - Gamou Fall
- Arboviruses and Hemorrhagic Fever Viruses Unit, Virology Department, Institut Pasteur de Dakar, BP220 Dakar, Senegal
| | - Oumar Faye
- Arboviruses and Hemorrhagic Fever Viruses Unit, Virology Department, Institut Pasteur de Dakar, BP220 Dakar, Senegal
| | - Ousmane Faye
- Arboviruses and Hemorrhagic Fever Viruses Unit, Virology Department, Institut Pasteur de Dakar, BP220 Dakar, Senegal
| | - Moussa Moise Diagne
- Arboviruses and Hemorrhagic Fever Viruses Unit, Virology Department, Institut Pasteur de Dakar, BP220 Dakar, Senegal
- Corresponding author
| | - Cheikh Loucoubar
- Epidemiology, Clinical Research and Data Science Department, Institut Pasteur de Dakar, BP220 Dakar, Senegal
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10
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Nyakarahuka L, Whitmer S, Klena J, Balinandi S, Talundzic E, Tumusiime A, Kyondo J, Mulei S, Patel K, Baluku J, Akurut G, Namanya D, Kamugisha K, Cossaboom C, Whitesell A, Telford C, Graziano J, Montgomery J, Nichol S, Lutwama J, Shoemaker T. Detection of Sporadic Outbreaks of Rift Valley Fever in Uganda through the National Viral Hemorrhagic Fever Surveillance System, 2017-2020. Am J Trop Med Hyg 2023; 108:995-1002. [PMID: 36913925 PMCID: PMC10160879 DOI: 10.4269/ajtmh.22-0410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 11/22/2022] [Indexed: 03/15/2023] Open
Abstract
Rift Valley fever (RVF) is a zoonotic disease of public health and economic importance. Uganda has reported sporadic outbreaks of RVF in both humans and animals across the country, especially in the southwestern part of the "cattle corridor" through an established viral hemorrhagic fever surveillance system. We report 52 human cases of laboratory-confirmed RVF from 2017 to 2020. The case fatality rate was 42%. Among those infected, 92% were males and 90% were adults (≥ 18 years). Clinical symptoms were characterized by fever (69%), unexplained bleeding (69%), headache (51%), abdominal pain (49%), and nausea and vomiting (46%). Most of the cases (95%) originated from central and western districts that are part of the cattle corridor of Uganda, where the main risk factor was direct contact with livestock (P = 0.009). Other predictors of RVF positivity were determined to be male gender (P = 0.001) and being a butcher (P = 0.04). Next-generation sequencing identified the predominant Ugandan clade as Kenya-2, observed previously across East Africa. There is need for further investigation and research into the effect and spread of this neglected tropical disease in Uganda and the rest of Africa. Control measures such as promoting vaccination and limiting animal-human transmission could be explored to reduce the impact of RVF in Uganda and globally.
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Affiliation(s)
- Luke Nyakarahuka
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
- Department of Biosecurity, Ecosystems and Veterinary Public Health, Makerere University, Kampala, Uganda
| | - Shannon Whitmer
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - John Klena
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Stephen Balinandi
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | - Emir Talundzic
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Alex Tumusiime
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | - Jackson Kyondo
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | - Sophia Mulei
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | - Ketan Patel
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Jimmy Baluku
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | | | | | | | - Caitlin Cossaboom
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Amy Whitesell
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Carson Telford
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - James Graziano
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Joel Montgomery
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Stuart Nichol
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Julius Lutwama
- Department of Arbovirology, Emerging and Reemerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | - Trevor Shoemaker
- Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
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11
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Development and Validation of Rapid Colorimetric Reverse Transcription Loop-Mediated Isothermal Amplification for Detection of Rift Valley Fever Virus. Adv Virol 2023; 2023:1863980. [PMID: 36755743 PMCID: PMC9902148 DOI: 10.1155/2023/1863980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 12/22/2022] [Accepted: 01/20/2023] [Indexed: 01/31/2023] Open
Abstract
Rift Valley fever virus (RVFV) is a high-priority zoonotic pathogen with the ability to cause massive loss during its outbreak within a very short period of time. Lack of a highly sensitive, instant reading diagnostic method for RVFV, which is more suitable for on-site testing, is a big gap that needs to be addressed. The aim of this study was to develop a novel one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) method for the rapid detection of RVFV. To achieve this, the selected RVFV M segment nucleotide sequences were aligned using Multiple Sequence Comparison by Log-Expectation (MUSCLE) software in MEGA11 version 11.0.11 program to identify conserved regions. A 211 pb sequence was identified and six different primers to amplify it were designed using NEB LAMP Primer design tool version 1.1.0. The specificity of the designed primers was tested using primer BLAST, and a primer set, specific to RVFV and able to form a loop, was selected. In this study, we developed a single-tube test based on calorimetric RT-LAMP that enabled the visual detection of RVFV within 30 minutes at 65°C. Diagnostic sensitivity and specificity of the newly developed kit were compared with RVFV qRT-PCR, using total RNA samples extracted from 118 blood samples. The colorimetric RT-LAMP assay had a sensitivity of 98.36% and a specificity of 96.49%. The developed RT-LAMP was found to be tenfold more sensitive compared to the RVFV qRT-PCR assay commonly used in the confirmatory diagnosis of RVFV.
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12
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Human and Livestock Surveillance Revealed the Circulation of Rift Valley Fever Virus in Agnam, Northern Senegal, 2021. Trop Med Infect Dis 2023; 8:tropicalmed8020087. [PMID: 36828503 PMCID: PMC9962223 DOI: 10.3390/tropicalmed8020087] [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: 11/15/2022] [Revised: 01/08/2023] [Accepted: 01/20/2023] [Indexed: 02/03/2023] Open
Abstract
The mosquito-borne disease caused by the Rift Valley Fever Virus (RVFV) is a viral hemorrhagic fever that affects humans and animals. In 1987, RVFV emerged in Mauritania, which caused the first RVFV outbreak in West Africa. This outbreak was shortly followed by reported cases in humans and livestock in Senegal. Animal trade practices with neighboring Mauritania suggest northern regions of Senegal are at high risk for RVF. In this study, we aim to conduct a molecular and serological survey of RVFV in humans and livestock in Agnam (northeastern Senegal) by RT-PCR (reverse transcription real-time polymerase chain reaction) and ELISA (Enzyme-Linked Immunosorbent Assay), respectively. Of the two hundred fifty-five human sera, one (0.39%) tested RVFV IgM positive, while fifty-three (20.78%) tested positive for RVFV IgG. For animal monitoring, out of 30 sheep recorded and sampled over the study period, 20 (66.67%) showed seroconversion to RVFV IgG antibodies, notably during the rainy season. The presence of antibodies increased significantly with age in both groups (p < 0.05), as the force of RVF infection (FOI), increased by 16.05% per year for humans and by 80.4% per month for livestock sheep. This study supports the usefulness of setting up a One Health survey for RVF management.
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13
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Lean FZX, Johnson N. JMM Profile: Rift Valley fever: a zoonotic viral haemorrhagic disease. J Med Microbiol 2022; 72. [PMID: 36748539 DOI: 10.1099/jmm.0.001619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Rift Valley fever (RVF) is caused by infection with Rift Valley fever virus (RVFV), a mosquito-borne RNA virus that affects both humans and livestock species. Humans can also acquire infection from contact with infected animals and contaminated bodily fluid. Veterinary vaccines are available for use in livestock, but no vaccines have been approved for humans to date. The virus is currently endemic in most sub-Saharan regions of Africa but numerous incursions into Middle Eastern countries and islands in the Indian Ocean, such as Mayotte (an overseas Department of France), have occurred in the past decade. The risk of further geographical expansion is high and therefore additional investigation is warranted to better understand disease transmission and pathogenic mechanisms to develop threat mitigation strategies.
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Affiliation(s)
- Fabian Z X Lean
- Pathology and Animal Sciences Department, Animal and Plant Health Agency, Woodham Lane, Addlestone, KT15 3NB, UK
| | - Nicholas Johnson
- Vector Borne Diseases, Virology Department, Animal and Plant Health Agency, Woodham Lane, Addlestone, KT15 3NB, UK
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14
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Mechanistic models of Rift Valley fever virus transmission: A systematic review. PLoS Negl Trop Dis 2022; 16:e0010339. [PMID: 36399500 PMCID: PMC9718419 DOI: 10.1371/journal.pntd.0010339] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 12/02/2022] [Accepted: 10/31/2022] [Indexed: 11/19/2022] Open
Abstract
Rift Valley fever (RVF) is a zoonotic arbovirosis which has been reported across Africa including the northernmost edge, South West Indian Ocean islands, and the Arabian Peninsula. The virus is responsible for high abortion rates and mortality in young ruminants, with economic impacts in affected countries. To date, RVF epidemiological mechanisms are not fully understood, due to the multiplicity of implicated vertebrate hosts, vectors, and ecosystems. In this context, mathematical models are useful tools to develop our understanding of complex systems, and mechanistic models are particularly suited to data-scarce settings. Here, we performed a systematic review of mechanistic models studying RVF, to explore their diversity and their contribution to the understanding of this disease epidemiology. Researching Pubmed and Scopus databases (October 2021), we eventually selected 48 papers, presenting overall 49 different models with numerical application to RVF. We categorized models as theoretical, applied, or grey, depending on whether they represented a specific geographical context or not, and whether they relied on an extensive use of data. We discussed their contributions to the understanding of RVF epidemiology, and highlighted that theoretical and applied models are used differently yet meet common objectives. Through the examination of model features, we identified research questions left unexplored across scales, such as the role of animal mobility, as well as the relative contributions of host and vector species to transmission. Importantly, we noted a substantial lack of justification when choosing a functional form for the force of infection. Overall, we showed a great diversity in RVF models, leading to important progress in our comprehension of epidemiological mechanisms. To go further, data gaps must be filled, and modelers need to improve their code accessibility.
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15
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Adaptation to a Multiplex Bead Assay and Seroprevalence to Rift Valley Fever N Protein: Nampula Province, Mozambique, 2013-2014. J Virol 2022; 96:e0067222. [PMID: 35894603 PMCID: PMC9400480 DOI: 10.1128/jvi.00672-22] [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: 01/29/2023] Open
Abstract
Rift Valley fever virus (RVFV) is endemic in sub-Saharan Africa (SSA), with outbreaks reported in the Arabian Peninsula and throughout SSA. The natural reservoir for RVFV are ruminants, with livestock populations exceeding 50% exposure rates in some areas of SSA. Transmission to humans can occur through exposure to infected livestock products or multiple species of mosquito vectors. In 2013 and 2014, cross-sectional surveys occurred in two districts of Nacala-a-Velha and Mecubúri in northern Mozambique, and participants provided blood samples for later serological assays. IgG against the N protein of RVFV was detected through multiplex bead assay (MBA). Of the 2,278 persons enrolled between the two surveys and study sites, 181 (7.9%, 95% confidence interval (CI): 6.9%-9.1%) were found to be IgG seropositive with increasing seroprevalence with older age and significantly higher seroprevalence in Nacala-a-Velha (10.5%, 8.8%-12.5%) versus Mecubúri (5.7%, 4.5%-7.1%). Seroprevalence estimates were not significantly different between the 2013 and 2014 surveys. Significant spatial clustering of IgG positive persons were consistent among surveys and within the two districts, pointing toward the consistency of serology data for making population-level assumptions regarding RVFV seroprevalence. A subset of persons (n = 539) provided samples for both the 2013 and 2014 surveys, and a low percentage (0.81%) of these were found to seroconvert between these two surveys. Including the RVFV N protein in an MBA antigen panel could assist elucidate RVFV exposure in SSA. IMPORTANCE Due to sporadic transmission, human contact with Rift Valley Fever Virus (RVFV) is difficult to ascertain at a population level. Detection of antibodies against RVFV antigens assist in estimating exposure as antibodies remain in the host long after the virus has been cleared. In this study, we show that antibodies against RVFV N protein can be detected from dried blood spot (DBS) samples being assayed by multiplex bead assay. DBS from two districts in northern Mozambique were tested for IgG against the N protein, and 7.9% of all enrolled persons were seropositive. Older persons, males, and persons residing closer to the coast had higher RVFV N protein seroprevalence. Spatial clustering of IgG positive persons was noted in both districts. These results show low exposure rates to RVFV in these two northern districts in Mozambique, and the ability to perform serology for the RVFV N protein from dried blood samples.
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16
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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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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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Bhuiyan MA, Quayum ST, Ahammad F, Alam R, Samad A, Nain Z. Discovery of potential immune epitopes and peptide vaccine design - a prophylactic strategy against Rift Valley fever virus. F1000Res 2020. [DOI: 10.12688/f1000research.24975.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Background: Rift Valley fever virus (RVFV) is an emerging arbovirus infecting both animals and humans. Any form of direct contact with body fluids, blood or tissue of infected animals is the mode of transmission of this pathogen. Despite being an emerging virus, no proper vaccinations are yet available for the public. Our objective is to compose a multiepitope vaccine utilizing immuno-bioinformatics as a strategy against RVFV. Methods: To identify immunodominant epitopes and design a potent vaccine candidate, we applied a series of immunoinformatic approaches with molecular dynamics and immune response simulation frameworks. Results: A glycoprotein with the highest antigenicity was selected and employed for determining promising epitopes. We selected T cell epitopes based on their immunological potencies and cytokine inducing properties, while B cell epitopes were selected based on their antigenic features. Finally, we selected four cytotoxic T-lymphocyte, two helper T-lymphocyte, and three linear B-lymphocyte epitopes that were arranged into a vaccine construct with appropriate adjuvants and linkers. The chimera protein was modeled, refined, and validated prior to docking against toll-like receptor 4. Docking studies suggest strong binding interactions while dynamics simulation revealed the stable nature of the docked complex. Furthermore, the immune simulation showed robust and prolonged immune responses with rapid antigen clearance. Finally, codon optimization and cloning conducted with Escherichia coli K12 suggests high translation efficiency within the host system. Conclusion: We believe that our designed multiepitope vaccine is a promising prophylactic candidate against RVFV pathogenesis.
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