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Gharpure R, Vegvari C, Abdissa A, Alimi Y, Anyamba A, Auerbach J, Bett B, Bird BH, Bob NS, Breugelmans JG, Clark J, Cleaveland S, Cramer J, Dawa J, Fay PC, Formenty P, Gerdts V, Gerken KN, Gitonga J, Groschup M, Heighway J, Johnson SAM, Juma J, Kading RC, Kamau M, Kerama S, Lubisi BA, Lutwama J, Luyimbazi D, Marami D, Moore SM, Muturi M, Mwangoka G, Ndiu A, Njenga MK, Njouom R, Nyakarahuka L, Nzietchueng S, Oloo P, Otiende M, Oyola S, Paganini LS, Pandit PS, Punt C, Samy AM, Situma S, Sneddon H, Ten Bosch QA, Tezcan-Ulger S, Thompson PN, Tildesley M, Tinto B, Vesga JF, Wichgers Schreur PP, Hart P. Meeting report: CEPI workshop on Rift Valley fever epidemiology and modeling to inform human vaccine development, Nairobi, 4-5 June 2024. Vaccine 2025; 54:126860. [PMID: 40101455 DOI: 10.1016/j.vaccine.2025.126860] [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: 12/03/2024] [Revised: 01/31/2025] [Accepted: 02/05/2025] [Indexed: 03/20/2025]
Abstract
Rift Valley fever (RVF) is a zoonotic viral disease that causes epidemics and epizootics among humans and livestock, resulting in substantial health and socioeconomic consequences. Currently, there are no RVF vaccines licensed for humans, but several candidates show promise in early-stage development. Existing gaps in RVF epidemiological data and challenges associated with predicting RVF outbreak risk complicate the planning of efficacy studies, making the pathway to licensure for promising candidates unclear. In June 2024, the Coalition for Epidemic Preparedness Innovations (CEPI) convened a two-day workshop in Nairobi, Kenya, to discuss RVF epidemiology, modeling priorities, and specific gaps relevant to human RVF vaccine development. The workshop included representatives from multiple RVF-endemic countries, key global collaborators, and international health organizations. Workshop participants identified five key priorities: (1) Looking beyond outbreaks: There is a need to better characterize the complex One Health epidemiology of RVF and understand interepidemic persistence of the virus; (2) Better data for better models: Epidemiological modeling is crucial for research, prediction, and planning, but it requires accurate and representative data; (3) New, improved and accessible diagnostics and serological assays: These are needed to inform epidemiology and case definitions, without which RVF research will continue to suffer due to paucity of data and challenges in determining infection and exposure; (4) Defining use cases, regulatory pathways, and implementation strategies for human vaccines: Clarity on these topics will facilitate licensure and effective use of RVF vaccines; and (5) People-centered approaches: Community engagement and involvement of social and behavioral scientists are key to the success of human vaccine research and development and implementation, particularly as the virus impacts livestock and livelihoods. Workshop participants welcomed a renewed focus for RVF epidemiology and modeling, and expressed enthusiasm for continued multidisciplinary collaborations to support enabling sciences for human RVF vaccine research and development.
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Affiliation(s)
- Radhika Gharpure
- Coalition for Epidemic Preparedness Innovations, Oslo, Norway, London, UK, and Washington, DC, USA.
| | - Carolin Vegvari
- Coalition for Epidemic Preparedness Innovations, Oslo, Norway, London, UK, and Washington, DC, USA
| | | | - Yewande Alimi
- Africa Centres for Disease Control and Prevention, Addis Ababa, Ethiopia
| | - Assaf Anyamba
- University of Maryland Baltimore County and NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - Jochen Auerbach
- Coalition for Epidemic Preparedness Innovations, Oslo, Norway, London, UK, and Washington, DC, USA
| | - Bernard Bett
- International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Brian H Bird
- School of Veterinary Medicine, University of California Davis, Davis, California, USA
| | | | - J Gabrielle Breugelmans
- Coalition for Epidemic Preparedness Innovations, Oslo, Norway, London, UK, and Washington, DC, USA
| | - Jessica Clark
- School of Biodiversity, One Health and Veterinary Medicine, Univeristy of Glasgow, Glasgow, UK
| | - Sarah Cleaveland
- School of Biodiversity, One Health and Veterinary Medicine, Univeristy of Glasgow, Glasgow, UK
| | - Jakob Cramer
- Coalition for Epidemic Preparedness Innovations, Oslo, Norway, London, UK, and Washington, DC, USA
| | - Jeanette Dawa
- Center for Epidemiological Modelling and Analysis, University of Nairobi, Nairobi, Kenya
| | | | | | - Volker Gerdts
- Vaccine and Infectious Disease Organization, University of Saskachewan, Saskatoon, Canada
| | - Keli N Gerken
- University of Liverpool, Institute of Infection, Veterinary, and Ecological Sciences, Liverpool, UK
| | - John Gitonga
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Martin Groschup
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald, Germany
| | - James Heighway
- Coalition for Epidemic Preparedness Innovations, Oslo, Norway, London, UK, and Washington, DC, USA
| | | | - John Juma
- International Livestock Research Institute (ILRI), Nairobi, Kenya
| | | | | | | | | | | | | | - Dadi Marami
- Haramaya University, College of Health and Medical Sciences, Harar, Ethiopia
| | - Sean M Moore
- Fogarty International Center, National Institutes of Health, Bethesda, MD, USA
| | | | | | - Angela Ndiu
- Washington State University Global Health Kenya, Nairobi, Kenya
| | | | | | | | - Serge Nzietchueng
- Food and Agriculture Organization of the United Nations, Nairobi, Kenya
| | - Paul Oloo
- Coalition for Epidemic Preparedness Innovations, Oslo, Norway, London, UK, and Washington, DC, USA
| | - Mark Otiende
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Samuel Oyola
- International Livestock Research Institute (ILRI), Nairobi, Kenya
| | | | - Pranav S Pandit
- School of Veterinary Medicine, University of California Davis, Davis, California, USA
| | - Carine Punt
- Bunyavax, LARISSA II project, Lelystad, Netherlands
| | - Abdallah M Samy
- Medical Ain Shams Research Institute (MASRI), Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Silvia Situma
- Washington State University Global Health Kenya, Nairobi, Kenya
| | - Heidi Sneddon
- Coalition for Epidemic Preparedness Innovations, Oslo, Norway, London, UK, and Washington, DC, USA
| | | | | | | | - Mike Tildesley
- Zeeman Institute for Systems Biology and Infectious Disease Epidemiology Research, School of Life Sciences and Mathematics Institute, University of Warwick, Coventry, UK
| | - Bachirou Tinto
- Institit de recherche en sciences de la santé (IRSS), Ouagadougou, Burkina Faso
| | | | | | - Peter Hart
- Coalition for Epidemic Preparedness Innovations, Oslo, Norway, London, UK, and Washington, DC, USA.
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Mutambo IN, Bett B, Bukachi SA. "Without a man's decision, nothing works": Building resilience to Rift Valley fever in pastoralist communities in Isiolo Kenya. PLoS One 2025; 20:e0316015. [PMID: 39874348 PMCID: PMC11774392 DOI: 10.1371/journal.pone.0316015] [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: 02/05/2024] [Accepted: 12/04/2024] [Indexed: 01/30/2025] Open
Abstract
Rift Valley Fever (RVF) is a zoonotic disease that affects both livestock and humans. Men and women in pastoralist communities are vulnerable to RVF risk exposure because of their different roles and reliance on livestock products. This study sought to understand how ownership and decision-making in pastoralist male and female-headed households influence coping mechanisms and resilience to Rift Valley fever (RVF), using the three resilience capacities of absorptive, adaptive, and transformative. This study was conducted in two sub-counties (Garbatulla) and Merti), Isiolo County, Kenya. Data were collected through 16 focus group discussions and 13 key informant interviews with pastoralists and animal and human health stakeholders. The findings indicate that traditionally, men have the final say on decisions related to livestock ownership and make overall household decisions. Pastoralist men and women employ different approaches, including hygiene practices and mosquito nets, community knowledge dissemination, establishment of new businesses, utilization of healthcare, and indigenous medicines, to reduce the effects of RVF in both humans and livestock. They also collaborated with community disease surveillance initiatives to strengthen disease surveillance networks and gain access to county government support. This process fosters resilience, community empowerment, and transformative and sustainable adaptation responses to RVF.
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Affiliation(s)
- Irene N. Mutambo
- Institute of Anthropology, Gender and African Studies, University of Nairobi, Nairobi, Kenya
- One Health Research, Education and Outreach Centre in Africa, International Livestock Research Institute, Nairobi, Kenya
| | - Bernard Bett
- One Health Research, Education and Outreach Centre in Africa, International Livestock Research Institute, Nairobi, Kenya
| | - Salome A. Bukachi
- Institute of Anthropology, Gender and African Studies, University of Nairobi, Nairobi, Kenya
- Department of Anthropology, Durban University, Durban, United Kingdom
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Bakamutumaho B, Juma J, Clancey E, Nyakarahuka L, Situma S, Odinoh R, Dawa J, Nasimiyu C, Eskew EA, Balinandi S, Mulei S, Kayiwa J, Klena JD, Shoemaker TR, Whitmer SLM, Montgomery JM, Schieffelin J, Lutwama J, Muruta A, Bosa HK, Nuismer SL, Oyola SO, Breiman RF, Njenga MK. Atypical hyperendemicity of Rift Valley fever in Southwestern Uganda associated with the rapidly evolving lineage C viruses. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2025:2025.01.14.25320317. [PMID: 39867400 PMCID: PMC11759597 DOI: 10.1101/2025.01.14.25320317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2025]
Abstract
Introduction Recent Rift Valley fever (RVF) epidemiology in eastern Africa region is characterized by widening geographic range and increasing frequency of small disease clusters. Here we conducted studies in southwestern (SW) Uganda region that has since 2016 reported increasing RVF activities. Methods A 22-month long hospital-based study in three districts of SW Uganda targeting patients with acute febrile illness (AFI) or unexplained bleeding was followed by a cross-sectional population-based human-animal survey. We then estimated RVFV force of infection (FOI) and yearly cases using the age-structured seroprevalence data and conducted genomic phylodynamic modelling of RVFV isolates. Results Overall RVF prevalence was 10.5% (205 of 1,968) among febrile or hemorrhagic cases, including 5% with acute (PCR or IgM positive) infection, averaging 5 cases per month. Community-based serosurvey recorded prevalence of 11.8% (88 of 743) among humans and 14.6% (347 of 2,383) in livestock. Expected yearly human RVF cases were 314-2,111 per 1,369 km 2 in SW Uganda versus 0-711 in comparable regions of Kenya and Tanzania. Viral genomic studies identified RVFV lineage C, sub-clade C.2.2, as the circulating strain in SW Uganda since 2019. Lineage C strain has undergone recent rapid evolution and clonal expansion resulting in four sub-clades, C.1.1, C.1.2, C.2.1, and C.2.2, that are more adept at establishing endemicity in new territories. Conclusions We demonstrate an atypical RVF hyperendemic region in SW Uganda characterized by sustained human clinical RVF cases, unusually high population prevalence, and high number of expected yearly human cases, associated in part with emergence of new RVFV sub-lineages. Key points Rift Valley fever (RVF) studies in SW Uganda found atypical sustained human cases averaging 5 cases/month, >10% population prevalence, and expected yearly cases >3-fold higher (314-2,111 vs 0-711) than comparable regions in East Africa, associated with emerging RVFV sub-lineages.
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Nsengimana I, Hakizimana E, Mupfasoni J, Hakizimana JN, Chengula AA, Kasanga CJ, Eastwood G. Identification of Potential Vectors and Detection of Rift Valley Fever Virus in Mosquitoes Collected Before and During the 2022 Outbreak in Rwanda. Pathogens 2025; 14:47. [PMID: 39861008 PMCID: PMC11768297 DOI: 10.3390/pathogens14010047] [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: 12/18/2024] [Revised: 12/30/2024] [Accepted: 12/31/2024] [Indexed: 01/27/2025] Open
Abstract
Rift Valley fever virus (RVFV) is an emerging mosquito-borne arbovirus of One Health importance that caused two large outbreaks in Rwanda in 2018 and 2022. Information on vector species with a role in RVFV eco-epidemiology in Rwanda is scarce. Here we sought to identify potential mosquito vectors of RVFV in Rwanda, their distribution and abundance, as well as their infection status. Since an outbreak of RVF occurred during the study period, data were obtained both during an interepidemic period and during the 2022 Rwanda RVF outbreak. Five districts of the eastern province of Rwanda were prospected using a combination of unbaited light traps and Biogents (BG Sentinel and Pro) traps baited with an artificial human scent during three periods, namely mid-August to mid-September 2021, December 2021, and April to May 2022. Trapped mosquitoes were morphologically identified and tested for viral evidence using both RT-PCR and virus isolation methods on a Vero cell line. A total of 14,815 adult mosquitoes belonging to five genera and at least 17 species were collected and tested as 765 monospecific pools. Culex quinquefasciatus was the most predominant species representing 72.7% of total counts. Of 527 mosquito pools collected before the 2022 outbreak, a single pool of Cx. quinquefasciatus showed evidence of RVFV RNA. Of 238 pools collected during the outbreak, RVFV was detected molecularly from five pools (two pools of Cx. quinquefasciatus, two pools of Anopheles ziemanni, and one pool of Anopheles gambiae sensu lato), and RVFV was isolated from the two pools of Cx. quinquefasciatus, from Kayonza and Rwamagana districts, respectively. Minimum infection rates (per 1000 mosquitoes) of 0.4 before the outbreak and 0.6-7 during the outbreak were noted. Maximum-likelihood phylogenetic analysis indicates that RVFV detected in these mosquitoes is closely related to viral strains that circulated in livestock in Rwanda and in Burundi during the same RVF outbreak in 2022. The findings reveal initial evidence for the incrimination of several mosquito species in the transmission of RVFV in Rwanda and highlight the need for more studies to understand the role of each species in supporting the spread and persistence of RVFV in the country.
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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
- Rwanda Inspectorate, Competition and Consumer Protection Authority, Kigali P.O. Box 375, Rwanda
- SACIDS Africa Centre of Excellence for Infectious Diseases, SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro P.O. Box 3297, Tanzania
| | - Emmanuel Hakizimana
- Rwanda Biomedical Center (RBC), Ministry of Health, Kigali, P.O. Box 7162, Rwanda
| | - Jackie Mupfasoni
- Rwanda Biomedical Center (RBC), Ministry of Health, Kigali, P.O. Box 7162, Rwanda
| | - Jean Nepomuscene Hakizimana
- SACIDS Africa Centre of Excellence for Infectious Diseases, SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro P.O. Box 3297, Tanzania
| | - Augustino A. Chengula
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro P.O. Box 3000, Tanzania
| | - Christopher J. Kasanga
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro P.O. Box 3000, Tanzania
| | - Gillian Eastwood
- Department of Entomology; The Global Change Center at Virginia Tech; and the Center for Emerging Zoonotic & Arthropod-Borne Pathogens (CeZAP), Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
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5
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Situma S, Omondi E, Nyakarahuka L, Odinoh R, Mweu M, Mureithi MW, Mulinge MM, Clancey E, Dawa J, Ngere I, Osoro E, Gunn B, Konongoi L, Khamadi SA, Michiels J, Ariën KK, Bakamutumaho B, Breiman RF, Njenga K. Serological Evidence of Cryptic Rift Valley Fever Virus Transmission Among Humans and Livestock in Central Highlands of Kenya. Viruses 2024; 16:1927. [PMID: 39772234 PMCID: PMC11680181 DOI: 10.3390/v16121927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2024] [Revised: 12/04/2024] [Accepted: 12/12/2024] [Indexed: 01/11/2025] Open
Abstract
Although the highlands of East Africa lack the geo-ecological landmarks of Rift Valley fever (RVF) disease hotspots to participate in cyclic RVF epidemics, they have recently reported growing numbers of small RVF clusters. Here, we investigated whether RVF cycling occurred among livestock and humans in the central highlands of Kenya during inter-epidemic periods. A 2-year prospective hospital-based study among febrile patients (March 2022-February 2024) in Murang'a County of Kenya was followed by a cross-sectional human-animal survey. A total of 1468 febrile patients were enrolled at two clinics and sera tested for RVF virus RNA and antiviral antibodies. In the cross-sectional study, humans (n = 282) and livestock (n = 706) from randomly selected households were tested and questionnaire data were used to investigate sociodemographic and environmental risk factors by multivariate logistic regression. No human (n = 1750) or livestock (n = 706) sera tested positive for RVFV RNA. However, 4.4% livestock and 2.0% humans tested positive for anti-RVFV IgG, including 0.27% febrile patients who showed four-fold IgG increase and 2.4% young livestock (<12 months old), indicating recent virus exposure. Among humans, the odds of RVF exposure increased significantly (p < 0.05, 95% CI) in males (aOR: 4.77, 2.08-12.4), those consuming raw milk (aOR: 5.24, 1.13-17.9), milkers (aOR: 2.69, 1.23-6.36), and participants residing near quarries (aOR: 2.4, 1.08-5.72). In livestock, sheep and goats were less likely to be seropositive (aOR: 0.27, 0.12-0.60) than cattle. The increase in RVF disease activities in the highlands represents a widening geographic dispersal of the virus, and a greater risk of more widespread RVF epidemics in the future.
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Affiliation(s)
- Silvia Situma
- Department of Medical Microbiology and Immunology, University of Nairobi, Nairobi 00202, Kenya;
- Washington State University Global Health Program-Kenya, Nairobi 00200, Kenya; (R.O.); (J.D.); (I.N.); (E.O.)
- Department of Animal Science, Pwani University, Kilifi 80108, Kenya
| | - Evans Omondi
- African Population and Health Research Center (APHRC), Nairobi 00100, Kenya;
- Institute of Mathematical Sciences, Strathmore University, Nairobi 00200, Kenya
| | - Luke Nyakarahuka
- Uganda Virus Research Institute, Entebbe P.O. Box 49, Uganda; (L.N.); (B.B.)
- Department of Animal Resources and Biosecurity, Ecosystems and Veterinary Public Health, Makerere University, Kampala P.O. Box 7062, Uganda
| | - Raymond Odinoh
- Washington State University Global Health Program-Kenya, Nairobi 00200, Kenya; (R.O.); (J.D.); (I.N.); (E.O.)
| | - Marshal Mweu
- Department of Public Health, University of Nairobi, Nairobi 00202, Kenya;
| | - Marianne W. Mureithi
- Department of Medical Microbiology and Immunology, University of Nairobi, Nairobi 00202, Kenya;
| | - Martin M. Mulinge
- Department of Biochemistry, University of Nairobi, Nairobi 00100, Kenya;
| | - Erin Clancey
- Paul G. Allen School for Global Health, Washington State University, Pullman, WA 98165, USA; (E.C.); (B.G.)
| | - Jeanette Dawa
- Washington State University Global Health Program-Kenya, Nairobi 00200, Kenya; (R.O.); (J.D.); (I.N.); (E.O.)
- Center for Epidemiological Modelling and Analysis, University of Nairobi, Nairobi 00202, Kenya
| | - Isaac Ngere
- Washington State University Global Health Program-Kenya, Nairobi 00200, Kenya; (R.O.); (J.D.); (I.N.); (E.O.)
- Paul G. Allen School for Global Health, Washington State University, Pullman, WA 98165, USA; (E.C.); (B.G.)
| | - Eric Osoro
- Washington State University Global Health Program-Kenya, Nairobi 00200, Kenya; (R.O.); (J.D.); (I.N.); (E.O.)
- Paul G. Allen School for Global Health, Washington State University, Pullman, WA 98165, USA; (E.C.); (B.G.)
| | - Bronwyn Gunn
- Paul G. Allen School for Global Health, Washington State University, Pullman, WA 98165, USA; (E.C.); (B.G.)
| | - Limbaso Konongoi
- Kenya Medical Research Institute, Nairobi 00200, Kenya; (L.K.); (S.A.K.)
| | - Samoel A. Khamadi
- Kenya Medical Research Institute, Nairobi 00200, Kenya; (L.K.); (S.A.K.)
| | - Johan Michiels
- Virology Unit, Department of Biomedical Sciences, Institute of Tropical Medicine, 2000 Antwerp, Belgium; (J.M.); (K.K.A.)
| | - Kevin K. Ariën
- Virology Unit, Department of Biomedical Sciences, Institute of Tropical Medicine, 2000 Antwerp, Belgium; (J.M.); (K.K.A.)
| | | | - Robert F. Breiman
- Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA;
| | - Kariuki Njenga
- Washington State University Global Health Program-Kenya, Nairobi 00200, Kenya; (R.O.); (J.D.); (I.N.); (E.O.)
- Paul G. Allen School for Global Health, Washington State University, Pullman, WA 98165, USA; (E.C.); (B.G.)
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Madut DB, Rubach MP, Allan KJ, Thomas KM, de Glanville WA, Halliday JEB, Costales C, Carugati M, Rolfe RJ, Bonnewell JP, Maze MJ, Mremi AR, Amsi PT, Kalengo NH, Lyamuya F, Kinabo GD, Mbwasi R, Kilonzo KG, Maro VP, Mmbaga BT, Lwezaula B, Mosha C, Marandu A, Kibona TJ, Zhu F, Chawla T, Chia WN, Anderson DE, Wang LF, Liu J, Houpt ER, Martines RB, Zaki SR, Leach A, Gibbons A, Chiang CF, Patel K, Klena JD, Cleaveland S, Crump JA. Epidemiologic and genomic characterization of an outbreak of Rift Valley fever among humans and dairy cattle in northern Tanzania. J Infect Dis 2024:jiae562. [PMID: 39535803 PMCID: PMC12069657 DOI: 10.1093/infdis/jiae562] [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: 06/12/2024] [Revised: 11/02/2024] [Accepted: 11/12/2024] [Indexed: 11/16/2024] Open
Abstract
BACKGROUND A peri-urban outbreak of Rift Valley fever virus (RVFV) among dairy cattle from May through August 2018 in northern Tanzania was detected through testing samples from prospective livestock abortion surveillance. We sought to identify concurrent human infections, their phylogeny, and epidemiologic characteristics in a cohort of febrile patients enrolled from 2016-2019 at hospitals serving the epizootic area. METHODS From September 2016 through May 2019, we conducted a prospective cohort study that enrolled febrile patients hospitalized at two hospitals in Moshi, Tanzania. Archived serum, plasma, or whole blood samples were retrospectively tested for RVFV by PCR. Human samples positive for RVFV were sequenced and compared to RVFV sequences obtained from cattle through a prospective livestock abortion study. Phylogenetic analysis was performed on complete RVFV genomes. RESULTS Among 656 human participants, we detected RVFV RNA in four (0.6%), including one death with hepatic necrosis and other end-organ damage at autopsy. Humans infected with RVFV were enrolled from June through August 2018, and all resided in or near urban areas. Phylogenetic analysis of human and cattle RVFV sequences demonstrated that most clustered to lineage B, a lineage previously described in East Africa. A lineage E strain clustering with lineages in Angola was also identified in cattle. CONCLUSION We provide evidence that an apparently small RVFV outbreak among dairy cattle in northern Tanzania was associated with concurrent severe and fatal infections among humans. Our findings highlight the unidentified scale and diversity of inter-epizootic RVFV transmission, including near and within an urban area.
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Affiliation(s)
- Deng B. Madut
- Division of Infectious Diseases and International Health, Department of Medicine, Duke University, Durham, North Carolina, USA
| | - Matthew P. Rubach
- Division of Infectious Diseases and International Health, Department of Medicine, Duke University, Durham, North Carolina, USA
| | - Kathryn J. Allan
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Kate M. Thomas
- Centre for International Health, University of Otago, Dunedin, New Zealand
| | - William A. de Glanville
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Jo E. B. Halliday
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Cristina Costales
- Division of Infectious Diseases and International Health, Department of Medicine, Duke University, Durham, North Carolina, USA
| | - Manuela Carugati
- Division of Infectious Diseases and International Health, Department of Medicine, Duke University, Durham, North Carolina, USA
| | - Robert J. Rolfe
- Division of Infectious Diseases and International Health, Department of Medicine, Duke University, Durham, North Carolina, USA
| | - John P. Bonnewell
- Division of Infectious Diseases and International Health, Department of Medicine, Duke University, Durham, North Carolina, USA
| | - Michael J. Maze
- Department of Medicine, University of Otago, Christchurch, New Zealand
| | - Alex R. Mremi
- Kilimanjaro Christian Medical Centre, Moshi, Tanzania
| | | | | | | | | | - Ronald Mbwasi
- Kilimanjaro Christian Medical Centre, Moshi, Tanzania
| | | | - Venance P. Maro
- Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | | | | | - Calvin Mosha
- Mawenzi Regional Referral Hospital, Moshi, Tanzania
| | | | - Tito J. Kibona
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Feng Zhu
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Tanu Chawla
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Wan Ni Chia
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Danielle E. Anderson
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Lin-Fa Wang
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Jie Liu
- School of Public Health, Qingdao University, Qingdao, China
| | - Eric R. Houpt
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia, USA
| | - Roosecelis B. Martines
- Infectious Diseases Pathology Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Sherif R. Zaki
- Infectious Diseases Pathology Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Austin Leach
- Viral Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Aridth Gibbons
- Viral Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Cheng-Feng Chiang
- Viral Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Ketan Patel
- Viral Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - John D. Klena
- Viral Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Sarah Cleaveland
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - John A. Crump
- Centre for International Health, University of Otago, Dunedin, New Zealand
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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] [Download PDF] [Figures] [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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Situma S, Nyakarahuka L, Omondi E, Mureithi M, Mweu MM, Muturi M, Mwatondo A, Dawa J, Konongoi L, Khamadi S, Clancey E, Lofgren E, Osoro E, Ngere I, Breiman RF, Bakamutumaho B, Muruta A, Gachohi J, Oyola SO, Njenga MK, Singh D. Widening geographic range of Rift Valley fever disease clusters associated with climate change in East Africa. BMJ Glob Health 2024; 9:e014737. [PMID: 38857944 PMCID: PMC11168176 DOI: 10.1136/bmjgh-2023-014737] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Accepted: 05/25/2024] [Indexed: 06/12/2024] Open
Abstract
BACKGROUND Recent epidemiology of Rift Valley fever (RVF) disease in Africa suggests growing frequency and expanding geographic range of small disease clusters in regions that previously had not reported the disease. We investigated factors associated with the phenomenon by characterising recent RVF disease events in East Africa. METHODS Data on 100 disease events (2008-2022) from Kenya, Uganda and Tanzania were obtained from public databases and institutions, and modelled against possible geoecological risk factors of occurrence including altitude, soil type, rainfall/precipitation, temperature, normalised difference vegetation index (NDVI), livestock production system, land-use change and long-term climatic variations. Decadal climatic variations between 1980 and 2022 were evaluated for association with the changing disease pattern. RESULTS Of 100 events, 91% were small RVF clusters with a median of one human (IQR, 1-3) and three livestock cases (IQR, 2-7). These clusters exhibited minimal human mortality (IQR, 0-1), and occurred primarily in highlands (67%), with 35% reported in areas that had never reported RVF disease. Multivariate regression analysis of geoecological variables showed a positive correlation between occurrence and increasing temperature and rainfall. A 1°C increase in temperature and a 1-unit increase in NDVI, one months prior were associated with increased RVF incidence rate ratios of 1.20 (95% CI 1.1, 1.2) and 1.93 (95% CI 1.01, 3.71), respectively. Long-term climatic trends showed a significant decadal increase in annual mean temperature (0.12-0.3°C/decade, p<0.05), associated with decreasing rainfall in arid and semi-arid lowlands but increasing rainfall trends in highlands (p<0.05). These hotter and wetter highlands showed increasing frequency of RVF clusters, accounting for 76% and 43% in Uganda and Kenya, respectively. CONCLUSION These findings demonstrate the changing epidemiology of RVF disease. The widening geographic range of disease is associated with climatic variations, with the likely impact of wider dispersal of virus to new areas of endemicity and future epidemics.
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Affiliation(s)
- Silvia Situma
- Washington State University Global Health Program-Kenya, Nairobi, Kenya
- University of Nairobi, Faculty of Health Sciences, Nairobi, Kenya
- Department of Animal Science, Pwani University, Kilifi, Kenya
| | - Luke Nyakarahuka
- Uganda Virus Research Institute, Entebbe, Uganda
- Emory University, Atlanta, Georgia, USA
- Department of Biosecurity, Ecosystems and Veterinary Public Health, Makerere University, Kampala, Uganda
| | - Evans Omondi
- African Population and Health Research Center, Nairobi, Kenya
- Strathmore University, Nairobi, Kenya
| | | | | | | | | | - Jeanette Dawa
- Washington State University Global Health Program-Kenya, Nairobi, Kenya
| | | | | | - Erin Clancey
- Washington State University, Pullman, Washington, USA
| | - Eric Lofgren
- Washington State University, Pullman, Washington, USA
| | - Eric Osoro
- Washington State University Global Health Program-Kenya, Nairobi, Kenya
| | - Isaac Ngere
- Washington State University Global Health Program-Kenya, Nairobi, Kenya
| | | | | | | | - John Gachohi
- Washington State University Global Health Program-Kenya, Nairobi, Kenya
| | - Samuel O Oyola
- International Livestock Research Institute, Nairobi, Kenya
| | - M Kariuki Njenga
- Washington State University Global Health Program-Kenya, Nairobi, Kenya
- Washington State University, Pullman, Washington, USA
| | - Deepti Singh
- Washington State University, Pullman, Washington, USA
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9
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Situma S, Nyakarahuka L, Omondi E, Mureithi M, Mweu M, Muturi M, Mwatondo A, Dawa J, Konongoi L, Khamadi S, Clancey E, Lofgren E, Osoro E, Ngere I, Breiman RF, Bakamutumaho B, Muruta A, Gachohi J, Oyola SO, Njenga MK, Singh D. Widening geographic range of Rift Valley fever disease clusters associated with climate change in East Africa. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.05.17.24307534. [PMID: 38798521 PMCID: PMC11118650 DOI: 10.1101/2024.05.17.24307534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Background Recent epidemiology of Rift Valley fever (RVF) disease in Africa suggests growing frequency and expanding geographic range of small disease clusters in regions that previously had not reported the disease. We investigated factors associated with the phenomenon by characterizing recent RVF disease events in East Africa. Methods Data on 100 disease events (2008 - 2022) from Kenya, Uganda, and Tanzania were obtained from public databases and institutions, and modeled against possible geo-ecological risk factors of occurrence including altitude, soil type, rainfall/precipitation, temperature, normalized difference vegetation index (NDVI), livestock production system, land-use change, and long-term climatic variations. Decadal climatic variations between 1980-2022 were evaluated for association with the changing disease pattern. Results Of 100 events, 91% were small RVF clusters with a median of one human (IQR, 1-3) and 3 livestock cases (IQR, 2-7). These clusters exhibited minimal human mortality (IQR 0-1), and occurred primarily in highlands (67%), with 35% reported in areas that had never reported RVF disease. Multivariate regression analysis of geo-ecological variables showed a positive correlation between occurrence and increasing temperature and rainfall. A 1oC increase in temperature and 1-unit increase in NDVI, 1-3 months prior were associated with increased RVF incidence rate ratios (IRR) of 1.20 (95% CI 1.1,1.2) and 9.88 (95% CI 0.85, 119.52), respectively. Long-term climatic trends showed significant decadal increase in annual mean temperature (0.12 to 0.3oC/decade, P<0.05), associated with decreasing rainfall in arid and semi-arid lowlands but increasing rainfall trends in highlands (P<0.05). These hotter and wetter highlands showed increasing frequency of RVF clusters, accounting for 76% and 43% in Uganda and Kenya, respectively. Conclusion These findings demonstrate the changing epidemiology of RVF disease. The widening geographic range of disease is associated with climatic variations, with the likely impact of wider dispersal of virus to new areas of endemicity and future epidemics. Key questions What is already known on this topic?: Rift Valley fever is recognized for its association with heavy rainfall, flooding, and El Niño rains in the East African region. A growing body of recent studies has highlighted a shifting landscape of the disease, marked by an expanding geographic range and an increasing number of small RVF clusters.What this study adds: This study challenges previous beliefs about RVF, revealing that it predominantly occurs in small clusters rather than large outbreaks, and its association with El Niño is not as pronounced as previously thought. Over 65% of these clusters are concentrated in the highlands of Kenya and Uganda, with 35% occurring in previously unaffected regions, accompanied by an increase in temperature and total rainfall between 1980 and 2022, along with a rise in the annual number of rainy days. Notably, the observed rainfall increases are particularly significant during the short-rains season (October-December), aligning with a secondary peak in RVF incidence. In contrast, the lowlands of East Africa, where typical RVF epidemics occur, display smaller and more varied trends in annual rainfall.How this study might affect research, practice, or policy: The worldwide consequence of the expanding RVF cluster is the broader dispersion of the virus, leading to the establishment of new regions with virus endemicity. This escalation heightens the risk of more extensive extreme-weather-associated RVF epidemics in the future. Global public health institutions must persist in developing preparedness and response strategies for such scenarios. This involves the creation and approval of human RVF vaccines and therapeutics, coupled with a rapid distribution plan through regional banks.
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Marzok M, Alkashif K, Kandeel M, Salem M, Sayed-Ahmed MZ, Selim A. Seroprevalence of Rift Valley Fever virus in one-humped camels (Camelus dromedaries) in Egypt. Trop Anim Health Prod 2023; 55:345. [PMID: 37789189 DOI: 10.1007/s11250-023-03765-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 09/12/2023] [Indexed: 10/05/2023]
Abstract
Rift Valley fever (RVF) is a mosquito-borne viral disease that affects a variety of domestic animals, including cattle, sheep, goats, and camels, and has zoonotic potential. Although the rift valley fever virus (RVFV) is usually asymptomatic in camels, it can induce abortion in some pregnant animals. In the current study, a serosurvey was carried out to investigate the prevalence of RVFV antibodies and related risk factors in camels from four Egyptian governorates. A total of 400 serum samples were examined for anti-RVFV antibodies using a competitive enzyme-linked immunosorbent assay (c-ELISA). The results revealed that the overall prevalence of RVF among examined camels was 21.5% and the disease was more prevalent in Kafr ElSheikh governorate in Nile Delta of Egypt. In addition, the age group of camels with more than 5 years (OR=4.49, 95%CI: 1.39-14.49), the female sex (OR=3.38, 95%CI: 1.51-7.58), the emaciated animals (OR=1.52, 95%CI: 0.86-2.66), the summer season's infection (OR=5.98, 95%CI: 1.79-19.93), the presence of mosquitoes (OR= 2.88, 95%CI: 1.39-5.95), and the absence of mosquitoes control (OR=3.97, 95%CI: 2.09-7.57) were identified as risk factors for RVFV infection. The results of this study support knowledge on the risk factors for RVFV infection and demonstrate that camels raising in Egypt have RVFV antibodies. Quarantine measures or vaccination program should be implemented to reduce the likelihood of RVFV introduction, dissemination among susceptible animals, and ultimately transmission to humans.
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Affiliation(s)
- Mohamed Marzok
- Department of Clinical Sciences, College of Veterinary Medicine, King Faisal University, Al-Ahsa, 31982, Saudi Arabia.
- Department of Surgery, Faculty of Veterinary Medicine, Kafr El Sheikh University, Kafr El Sheikh, Egypt.
| | - Khalid Alkashif
- Department of Pharmacology and Toxicology, College of Pharmacy, Jazan University, Jazan, 82722, Saudi Arabia
| | - Mahmoud Kandeel
- Department of Pharmacology, Faculty of Veterinary Medicine, Kafr elsheikh University, Kafrelsheikh, Egypt
- Department of Biomedical Sciences, College of Veterinary Medicine, King Faisal University, Al-Ahsa, Saudi Arabia
| | - Mohamed Salem
- Department of Clinical Pharmacy, College of Pharmacy, Jazan University, Jazan, 45142, Saudi Arabia
- Department of Medicine and Infectious Diseases, Faculty of Veterinary Medicine, Cairo University, Cairo, 12613, Egypt
| | - Mohamed Z Sayed-Ahmed
- Department of Internal Medicine and Infectious Diseases, Faculty of Veterinary Medicine, Mansoura University, Mansoura, 35516, Egypt
- Department of Animal Medicine (Infectious Diseases), Faculty of Veterinary Medicine, Benha University, Toukh, 13736, Egypt
| | - Abdelfattah Selim
- Department of Animal Medicine (Infectious Diseases), Faculty of Veterinary Medicine, Benha University, Toukh, 13736, Egypt.
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11
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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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12
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Ithinji DG, Buchholz DW, Ezzatpour S, Monreal IA, Cong Y, Sahler J, Bangar AS, Imbiakha B, Upadhye V, Liang J, Ma A, Bradel-Tretheway B, Kaza B, Yeo YY, Choi EJ, Johnston GP, Huzella L, Kollins E, Dixit S, Yu S, Postnikova E, Ortega V, August A, Holbrook MR, Aguilar HC. Multivalent viral particles elicit safe and efficient immunoprotection against Nipah Hendra and Ebola viruses. NPJ Vaccines 2022; 7:166. [PMID: 36528644 PMCID: PMC9759047 DOI: 10.1038/s41541-022-00588-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 12/05/2022] [Indexed: 12/23/2022] Open
Abstract
Experimental vaccines for the deadly zoonotic Nipah (NiV), Hendra (HeV), and Ebola (EBOV) viruses have focused on targeting individual viruses, although their geographical and bat reservoir host overlaps warrant creation of multivalent vaccines. Here we explored whether replication-incompetent pseudotyped vesicular stomatitis virus (VSV) virions or NiV-based virus-like particles (VLPs) were suitable multivalent vaccine platforms by co-incorporating multiple surface glycoproteins from NiV, HeV, and EBOV onto these virions. We then enhanced the vaccines' thermotolerance using carbohydrates to enhance applicability in global regions that lack cold-chain infrastructure. Excitingly, in a Syrian hamster model of disease, the VSV multivalent vaccine elicited safe, strong, and protective neutralizing antibody responses against challenge with NiV, HeV, or EBOV. Our study provides proof-of-principle evidence that replication-incompetent multivalent viral particle vaccines are sufficient to provide protection against multiple zoonotic deadly viruses with high pandemic potential.
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Affiliation(s)
- Duncan G Ithinji
- School for Global Animal Health, Washington State University, Pullman, WA, USA.,Kenya Agricultural and Livestock Research Organization, Nairobi, Kenya
| | - David W Buchholz
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, USA
| | - Shahrzad Ezzatpour
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, USA
| | - I Abrrey Monreal
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, USA
| | - Yu Cong
- National Institute of Allergy and Infectious Diseases (NIAID) Integrated Research Facility, Ft Detrick, Frederick, MD, 21702, USA
| | - Julie Sahler
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, USA
| | | | - Brian Imbiakha
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, USA
| | - Viraj Upadhye
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, USA
| | - Janie Liang
- National Institute of Allergy and Infectious Diseases (NIAID) Integrated Research Facility, Ft Detrick, Frederick, MD, 21702, USA
| | - Andrew Ma
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, USA
| | | | - Benjamin Kaza
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, USA
| | - Yao Yu Yeo
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, USA
| | - Eun Jin Choi
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, USA
| | - Gunner P Johnston
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, USA
| | - Louis Huzella
- National Institute of Allergy and Infectious Diseases (NIAID) Integrated Research Facility, Ft Detrick, Frederick, MD, 21702, USA
| | - Erin Kollins
- National Institute of Allergy and Infectious Diseases (NIAID) Integrated Research Facility, Ft Detrick, Frederick, MD, 21702, USA
| | - Saurabh Dixit
- National Institute of Allergy and Infectious Diseases (NIAID) Integrated Research Facility, Ft Detrick, Frederick, MD, 21702, USA
| | - Shuiqing Yu
- National Institute of Allergy and Infectious Diseases (NIAID) Integrated Research Facility, Ft Detrick, Frederick, MD, 21702, USA
| | - Elena Postnikova
- National Institute of Allergy and Infectious Diseases (NIAID) Integrated Research Facility, Ft Detrick, Frederick, MD, 21702, USA
| | - Victoria Ortega
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, USA
| | - Avery August
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, USA
| | - Michael R Holbrook
- National Institute of Allergy and Infectious Diseases (NIAID) Integrated Research Facility, Ft Detrick, Frederick, MD, 21702, USA
| | - Hector C Aguilar
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, USA.
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13
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de Glanville WA, Allan KJ, Nyarobi JM, Thomas KM, Lankester F, Kibona TJ, Claxton JR, Brennan B, Carter RW, Crump JA, Halliday JEB, Ladbury G, Mmbaga BT, Mramba F, Nyasebwa OM, Rubach MP, Rostal MK, Sanka P, Swai ES, Szemiel AM, Willett BJ, Cleaveland S. An outbreak of Rift Valley fever among peri-urban dairy cattle in northern Tanzania. Trans R Soc Trop Med Hyg 2022; 116:1082-1090. [PMID: 36040309 PMCID: PMC9623736 DOI: 10.1093/trstmh/trac076] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 07/12/2022] [Accepted: 08/01/2022] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Human and animal cases of Rift Valley fever (RVF) are typically only reported during large outbreaks. The occurrence of RVF cases that go undetected by national surveillance systems in the period between these outbreaks is considered likely. The last reported cases of RVF in Tanzania occurred during a large outbreak in 2007-2008. METHODS Samples collected between 2017 and 2019 from livestock suffering abortion across northern Tanzania were retrospectively tested for evidence of RVF virus infection using serology and reverse transcription quantitative polymerase chain reaction (RT-qPCR). RESULTS A total of 14 RVF-associated cattle abortions were identified among dairy cattle in a peri-urban area surrounding the town of Moshi. RVF cases occurred from May to August 2018 and were considered to represent an undetected, small-scale RVF outbreak. Milk samples from 3 of 14 cases (21%) were found to be RT-qPCR positive. Genotyping revealed circulation of RVF viruses from two distinct lineages. CONCLUSIONS RVF outbreaks can occur more often in endemic settings than would be expected on the basis of detection by national surveillance. The occurrence of RVF cases among peri-urban dairy cattle and evidence for viral shedding in milk, also highlights potentially emerging risks for RVF associated with increasing urban and peri-urban livestock populations.
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Affiliation(s)
- William A de Glanville
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
- University of Global Health Equity, Kigali 6955, Rwanda
| | - Kathryn J Allan
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
- School of Veterinary Medicine, University of Glasgow, Glasgow G61 1QH, UK
| | - James M Nyarobi
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
- Nelson Mandela African Institution of Science and Technology, Arusha 255, Tanzania
| | - Kate M Thomas
- Centre for International Health, University of Otago, Dunedin 9054, New Zealand
- Kilimanjaro Clinical Research Institute, Moshi 2236, Tanzania
| | - Felix Lankester
- Paul G. Allen School for Global Health, Washington State University, Pullman, WA 99164, USA
- Global Animal Health Tanzania, Arusha 1642, Tanzania
| | - Tito J Kibona
- Nelson Mandela African Institution of Science and Technology, Arusha 255, Tanzania
| | - John R Claxton
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Benjamin Brennan
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, G61 1QH, UK
| | - Ryan W Carter
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
| | - John A Crump
- Centre for International Health, University of Otago, Dunedin 9054, New Zealand
- Division of Infectious Diseases and International Health, Duke University Medical Center, Durham, NC 27710, USA
- Duke Global Health Institute, Duke University, Durham, NC 27710, USA
- Kilimanjaro Christian Medical University College, Tumaini University, Moshi 3010, Tanzania
| | - Jo E B Halliday
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Georgia Ladbury
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Blandina T Mmbaga
- Kilimanjaro Clinical Research Institute, Moshi 2236, Tanzania
- Division of Infectious Diseases and International Health, Duke University Medical Center, Durham, NC 27710, USA
- Kilimanjaro Christian Medical University College, Tumaini University, Moshi 3010, Tanzania
| | - Furaha Mramba
- Tanzania Veterinary Laboratory Agency, Dar es Salaam 9254, Tanzania
| | | | - Matthew P Rubach
- Division of Infectious Diseases and International Health, Duke University Medical Center, Durham, NC 27710, USA
- Duke Global Health Institute, Duke University, Durham, NC 27710, USA
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore, Singapore 169857, Singapore
| | - Melinda K Rostal
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
- EcoHealth Alliance, New York, NY 10018, USA
| | - Paul Sanka
- Tanzania Veterinary Laboratory Agency, Dar es Salaam 9254, Tanzania
| | | | - Agnieszka M Szemiel
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, G61 1QH, UK
| | - Brian J Willett
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, G61 1QH, UK
| | - Sarah Cleaveland
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
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14
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de Glanville WA, Nyarobi JM, Kibona T, Halliday JEB, Thomas KM, Allan KJ, Johnson PCD, Davis A, Lankester F, Claxton JR, Rostal MK, Carter RW, de Jong RMF, Rubach MP, Crump JA, Mmbaga BT, Nyasebwa OM, Swai ES, Willett B, Cleaveland S. Inter-epidemic Rift Valley fever virus infection incidence and risks for zoonotic spillover in northern Tanzania. PLoS Negl Trop Dis 2022; 16:e0010871. [PMID: 36306281 PMCID: PMC9665400 DOI: 10.1371/journal.pntd.0010871] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 11/15/2022] [Accepted: 10/06/2022] [Indexed: 11/06/2022] Open
Abstract
Rift Valley fever virus (RVFV) is a mosquito-borne pathogen that has caused epidemics involving people and animals across Africa and the Arabian Peninsula. A number of studies have found evidence for the circulation of RVFV among livestock between these epidemics but the population-level incidence of infection during this inter-epidemic period (IEP) is rarely reported. General force of infection (FOI) models were applied to age-adjusted cross-sectional serological data to reconstruct the annual FOI and population-level incidence of RVFV infection among cattle, goats, and sheep in northern Tanzania from 2009 through 2015, a period without reported Rift Valley fever (RVF) cases in people or animals. To evaluate the potential for zoonotic RVFV spillover during this period, the relationship between village-level livestock RVFV FOI and human RVFV seropositivity was quantified using multi-level logistic regression. The predicted average annual incidence was 72 (95% Credible Interval [CrI] 63, 81) RVFV infections per 10,000 animals and 96 (95% CrI 81, 113), 79 (95% CrI 62, 98), and 39 (95% CrI 28, 52) per 10,000 cattle, sheep, and goats, respectively. There was variation in transmission intensity between study villages, with the highest estimated village-level FOI 2.49% (95% CrI 1.89, 3.23) and the lowest 0.12% (95% CrI 0.02, 0.43). The human RVFV seroprevalence was 8.2% (95% Confidence Interval 6.2, 10.9). Human seropositivity was strongly associated with the village-level FOI in livestock, with the odds of seropositivity in an individual person increasing by around 1.2 times (95% CrI 1.1, 1.3) for each additional annual RVFV seroconversion per 1,000 animals. A history of raw milk consumption was also positively associated with human seropositivity. RVFV has circulated at apparently low levels among livestock in northern Tanzania in the period since the last reported epidemic. Although our data do not allow us to confirm human RVFV infections during the IEP, a strong association between human seropositivity and the FOI in cattle, goats, and sheep supports the hypothesis that RVFV circulation among livestock during the IEP poses a risk for undetected zoonotic spillover in northern Tanzania. We provide further evidence for the likely role of raw milk consumption in RVFV transmission from animals to people.
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Affiliation(s)
- William A. de Glanville
- School of Biodiversity, One Health, and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- University of Global Health Equity, Kigali, Rwanda
- * E-mail: (WAdG); (SC)
| | - James M. Nyarobi
- School of Biodiversity, One Health, and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Tito Kibona
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Jo E. B. Halliday
- School of Biodiversity, One Health, and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Kate M. Thomas
- Centre for International Health, University of Otago, Dunedin, New Zealand
- Kilimanjaro Clinical Research Institute, Moshi, United Republic of Tanzania
| | - Kathryn J. Allan
- School of Biodiversity, One Health, and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Paul C. D. Johnson
- School of Biodiversity, One Health, and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Alicia Davis
- School of Social and Political Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Felix Lankester
- Paul G. Allen School for Global Health, Washington State University, Pullman, Washington, United States of America
- Global Animal Health Tanzania, Arusha, Tanzania
| | - John R. Claxton
- School of Biodiversity, One Health, and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Melinda K. Rostal
- School of Biodiversity, One Health, and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- EcoHealth Alliance, New York, New York, United States of America
| | - Ryan W. Carter
- School of Biodiversity, One Health, and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Rosanne M. F. de Jong
- School of Biodiversity, One Health, and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Matthew P. Rubach
- Division of Infectious Diseases and International Health, Duke University Medical Center, Durham, North Carolina, United States of America
- Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore, Singapore
| | - John A. Crump
- Centre for International Health, University of Otago, Dunedin, New Zealand
- Division of Infectious Diseases and International Health, Duke University Medical Center, Durham, North Carolina, United States of America
- Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America
- Kilimanjaro Christian Medical University College, Tumaini University, Moshi, Tanzania
| | - Blandina T. Mmbaga
- Kilimanjaro Clinical Research Institute, Moshi, United Republic of Tanzania
- Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America
- Kilimanjaro Christian Medical University College, Tumaini University, Moshi, Tanzania
| | - Obed M. Nyasebwa
- Ministry of Livestock and Fisheries, Dodoma, United Republic of Tanzania
| | - Emanuel S. Swai
- Ministry of Livestock and Fisheries, Dodoma, United Republic of Tanzania
| | - Brian Willett
- MRC University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Sarah Cleaveland
- School of Biodiversity, One Health, and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- * E-mail: (WAdG); (SC)
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15
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Alzuheir I, Helal BA, Helal MA, Fayyad A, Jalboush N. No evidence of Rift Valley fever antibodies in veterinarians and sheep in Northern Palestine. Vet World 2022; 15:1990-1995. [PMID: 36313834 PMCID: PMC9615502 DOI: 10.14202/vetworld.2022.1990-1995] [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: 04/13/2022] [Accepted: 07/05/2022] [Indexed: 11/16/2022] Open
Abstract
Background and Aim: Rift Valley fever virus (RVFV) is a vector-borne virus that causes RVF in humans and ruminants. The clinical symptoms in humans and animals are non-specific and often misdiagnosed, but abortions in ruminants and high mortality in young animals are characteristic. Since the initial outbreak in the Rift Valley area in Kenya, the disease has spread to most African countries and the Middle East. The presence and epidemiological status of RVFV in humans and animals in Palestine are unknown. This study aimed to investigate the presence and risk factors for RVF seroprevalence in veterinarians, as occupational hazard professionals, and sheep, as highly susceptible animals, in Northern Palestine. Materials and Methods: A cross-sectional study was conducted. Data and blood samples of 280 Assaf sheep and 100 veterinarians in close occupational contact with sheep were collected between August and September 2020 using an indirect enzyme-linked immunosorbent assay. Results: No evidence of RVF antibodies was found in any human or animal sample. Conclusion: Our results suggest that RVFV has not circulated in livestock in Northern Palestine, yet. Surveillance and response capabilities and cooperation with the nearby endemic regions are recommended. The distribution of competent vectors in Palestine, associated with global climate change and the role of wild animals, might be a possible route for RVF spreading to Palestine from neighboring countries.
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Affiliation(s)
- Ibrahim Alzuheir
- Department of Veterinary Medicine, An-Najah National University, P.O. Box 7 Nablus, Palestine
| | - Belal Abu Helal
- Department of Veterinary Medicine, An-Najah National University, P.O. Box 7 Nablus, Palestine
| | - Mohammad Abu Helal
- Department of Public Health Sciences, Faculty of Graduate Studies, An-Najah National University, P.O. Box 7 Nablus, Palestine
| | - Adnan Fayyad
- Department of Veterinary Medicine, An-Najah National University, P.O. Box 7 Nablus, Palestine
| | - Nasr Jalboush
- Department of Veterinary Medicine, An-Najah National University, P.O. Box 7 Nablus, Palestine
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16
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Adamu AM, Allam L, Sackey AKB, Nma AB, Mshelbwala PP, Mambula-Machunga S, Idoko SI, Adikwu AA, Nafarnda WD, Garba BS, Owolodun OA, Dzikwi AA, Balogun EO, Simon YA. Risk factors for Rift Valley fever virus seropositivity in one-humped camels ( Camelus dromedarius) and pastoralist knowledge and practices in Northern Nigeria. One Health 2021; 13:100340. [PMID: 34820498 PMCID: PMC8600062 DOI: 10.1016/j.onehlt.2021.100340] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 10/16/2021] [Accepted: 10/17/2021] [Indexed: 12/21/2022] Open
Abstract
Rift Valley fever (RVF) is a complex emerging arboviral hemorrhagic disease that causes significant illness in animals and humans. Camel trade across the land borders between Nigeria and the Niger Republic occurs frequently and poses a significant risk for RVF transmission to pastoralists and traders. We carried a cross-sectional study between November 2016 and April 2017 in two northern States (Katsina and Jigawa) known for camel trade in Nigeria to investigate the seroprevalence and potential risk factors for RVFV occurrence. We collected 720 sera and administered questionnaire to pastoralists. We used the competitive enzyme-linked immunosorbent assay (c-ELISA) to determine the previous exposure to RVFV infection. We retrieved environmental information from public data sources that might explain RVFV seropositivity at the LGA level. To asses potential risk factors,we categorized LGAs with RVFV as "1" and those without a case" 0". We fitted a logistic model to the data and estimated odds ratios and 95% confidence intervals. An overall 19.9% prevalence was reported among camel herd-the highest seropositivity (33.3%) was recorded in SuleTankarkar LGA. In the multivariable model, only rain-fed croplands was significantly associated with RVFV antibodies occurrence p = 0.048 (OR = 0.87, 95% CI: 0.76-0.99). Only a minority of the respondents, 19.3% (n = 17/88), knew that RVF is zoonotic. Separation of healthy animals from the infected animals was carried out by 53.4% (47/88) pastoralists while 59.1% (52/88) pastoralists still use ethnoveterinary practices to control or mitigate disease outbreaks. Our study demonstrates the presence of RVFV antibodies among camel in Nigeria and the associated risk factors. These findings highlight the need for enhancing surveillance and control efforts and the public health education of camel pastoralists. Further investigation to unravel the zoonotic transmission potential to pastoralists and other animal species is pertinent.
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Affiliation(s)
- Andrew Musa Adamu
- Department of Veterinary Public Health and Preventive Medicine, University of Abuja, Nigeria.,Department of Veterinary Medicine, Ahmadu Bello University Zaria, Nigeria
| | - Lushakyaa Allam
- Veterinary Teaching Hospital, Ahmadu Bello University, Zaria, Nigeria
| | - Anthony K B Sackey
- Department of Veterinary Medicine, Ahmadu Bello University Zaria, Nigeria
| | - Alhaji Bida Nma
- Department of Veterinary Public Health and Preventive Medicine, University of Abuja, Nigeria
| | - Philip Paul Mshelbwala
- UQ Spatial Epidemiology Laboratory, School of Veterinary Science, The University of Queensland, Australia
| | | | | | - Alex Adikwu Adikwu
- Department of Veterinary Public Health and Preventive Medicine, University of Agriculture, Makurdi, Benue State, Nigeria
| | - Wesley Daniel Nafarnda
- Department of Veterinary Public Health and Preventive Medicine, University of Abuja, Nigeria
| | | | | | - Asabe Adamu Dzikwi
- Department of Veterinary Public Health and Preventive Medicine, University of Jos, Nigeria
| | | | - Yila Ayo Simon
- Center for Blood Research and Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada.,National Centers for Animal Disease Research, Lethbridge Laboratory, Science Branch, Canadian Food Inspection Agency, Government of Canada, Lethbridge, Alberta, Canada
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17
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Musa HI, Kudi CA, Gashua MM, Muhammad AS, Tijjani AO, Saidu AS, Mohammed S, Jajere SM, Adamu SG. Survey of antibodies to Rift Valley fever virus and associated risk factors in one-humped camels (Camelus dromedarius) slaughtered in Maiduguri abattoir, Borno State, Nigeria. Trop Anim Health Prod 2021; 53:500. [PMID: 34613460 DOI: 10.1007/s11250-021-02956-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 09/30/2021] [Indexed: 11/28/2022]
Abstract
Rift Valley fever (RVF) is an emerging mosquito-borne zoonosis that threatens public health and animal agriculture in the endemic areas causing devastating epizootics characterized by abortion storms and high mortalities, especially in newborn animals. A cross-sectional study was conducted to determine the seroprevalence and investigate risk factors associated with exposure to the virus in camels slaughtered in Maiduguri abattoir, Borno State of Nigeria. Camels presented for slaughtered were sampled and data on age, sex, source or origin, utility, presence of post-mortem lesions, body weights and body condition score were collected. Blood samples were collected and sera were harvested and stored at - 20 °C until tested. The sera were tested using a commercial ELISA kit based on the manufacturer's instructions. The overall seroprevalence in the study was 20.7% (95% CI, 13.6-30.0). The analysis showed no significant differences between the presence of antibodies and variables that included the sex of camels (χ2 = 0.015, df = 1, p = 0.904) and the presence of post-mortem lesion on the carcass (χ2 = 0.009, df = 1, p = 0.925). There were significant differences between presence of antibodies and three variables that included the age (χ2 = 4.89, df = 1, p = 0.027), the source (χ2 = 7.077, df = 2, p = 0.029) and the main utility (χ2 = 8.057, df = 3, p = 0.045) of the camels. It was concluded that camels presented for slaughter at the Maiduguri abattoir have evidence of exposure to the RVF virus and maybe means of transmission of the virus. Regular monitoring and control of transboundary animal movements were recommended in the study area.
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Affiliation(s)
- Hassan Ismail Musa
- Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Maiduguri, Borno State, Nigeria.
| | - Caleb Ayuba Kudi
- Department of Veterinary Medicine, Faculty of Veterinary Medicine, Ahmadu Bello University, Zaria, Kaduna State, Nigeria
| | - Muhammad Mamman Gashua
- Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Maiduguri, Borno State, Nigeria
| | - Abubakar Sadiq Muhammad
- Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Maiduguri, Borno State, Nigeria
| | - Abdulyeken Olawale Tijjani
- Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Maiduguri, Borno State, Nigeria
| | - Adamu Saleh Saidu
- Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Maiduguri, Borno State, Nigeria
| | - Sani Mohammed
- Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Maiduguri, Borno State, Nigeria
| | - Saleh Mohammed Jajere
- Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Maiduguri, Borno State, Nigeria
| | - Shuaibu Gidado Adamu
- Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Maiduguri, Borno State, Nigeria
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18
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Abstract
PURPOSE OF REVIEW The purpose of the review is to summarize recent advances in understanding the origins, drivers and clinical context of zoonotic disease epidemics and pandemics. In addition, we aimed to highlight the role of clinicians in identifying sentinel cases of zoonotic disease outbreaks. RECENT FINDINGS The majority of emerging infectious disease events over recent decades, including the COVID-19 pandemic, have been caused by zoonotic viruses and bacteria. In particular, coronaviruses, haemorrhagic fever viruses, arboviruses and influenza A viruses have caused significant epidemics globally. There have been recent advances in understanding the origins and drivers of zoonotic epidemics, yet there are gaps in diagnostic capacity and clinical training about zoonoses. SUMMARY Identifying the origins of zoonotic pathogens, understanding factors influencing disease transmission and improving the diagnostic capacity of clinicians will be crucial to early detection and prevention of further epidemics of zoonoses.
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Affiliation(s)
| | - Peter M Rabinowitz
- Department of Medicine
- Department of Environmental and Occupational Health Sciences, Department of Global Health, University of Washington, Seattle, Washington, USA
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19
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Maduray K, Parboosing R. Metal Nanoparticles: a Promising Treatment for Viral and Arboviral Infections. Biol Trace Elem Res 2021; 199:3159-3176. [PMID: 33029761 PMCID: PMC7540915 DOI: 10.1007/s12011-020-02414-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/28/2020] [Indexed: 12/12/2022]
Abstract
Globally, viral diseases continue to pose a significant threat to public health. Recent outbreaks, such as influenza, coronavirus, Ebola, and dengue, have emphasized the urgent need for new antiviral therapeutics. Considerable efforts have focused on developing metal nanoparticles for the treatment of several pathogenic viruses. As a result of these efforts, metal nanoparticles are demonstrating promising antiviral activity against pathogenic surrogates and clinical isolates. This review summarizes the application of metal nanoparticles for the treatment of viral infections. It provides information on synthesis methods, size-related properties, nano-bio-interaction, and immunological effects of metal nanoparticles. This article also addresses critical criteria and considerations for developing clinically translatable nanosized metal particles to treat viral diseases.
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Affiliation(s)
- Kaminee Maduray
- Department of Virology, University of KwaZulu-Natal/National Health Laboratory Service, Durban, South Africa.
| | - Raveen Parboosing
- Department of Virology, University of KwaZulu-Natal/National Health Laboratory Service, Durban, South Africa
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20
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Gortázar C, Barroso P, Nova R, Cáceres G. The role of wildlife in the epidemiology and control of Foot-and-mouth-disease And Similar Transboundary (FAST) animal diseases: A review. Transbound Emerg Dis 2021; 69:2462-2473. [PMID: 34268873 DOI: 10.1111/tbed.14235] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/28/2021] [Accepted: 07/10/2021] [Indexed: 12/19/2022]
Abstract
Transboundary Animal Diseases (TADs) are notifiable diseases which are highly transmissible and have the potential for rapid spread regardless of national borders. Many TADs are shared between domestic animals and wildlife, with the potential to affect both livestock sector and wildlife conservation and eventually, public health in the case of zoonosis. The European Commission for the Control of Foot-and-Mouth Disease (EuFMD), a commission of the Food and Agriculture Organization of the United Nations (FAO), has grouped six TADs as 'Foot-and-mouth disease (FMD) And Similar Transboundary animal diseases' (FAST diseases). FAST diseases are ruminant infections caused by viruses, for which vaccination is a control option. The EuFMD hold-FAST strategy aims primarily at addressing the threat represented by FAST diseases for Europe. Prevention and control of FAST diseases might benefit from assessing the role of wildlife. We reviewed the role of wildlife as indicators, victims, bridge hosts or maintenance hosts for the six TADs included in the EuFMD hold-FAST strategy: FMD, peste des petits ruminants, lumpy skin disease, sheep and goatpox, Rift Valley fever and bovine ephemeral fever. We observed that wildlife can act as indicator species. In addition, they are occasionally victims of disease outbreaks, and they are often relevant for disease management as either bridge or maintenance hosts. Wildlife deserves to become a key component of future integrated surveillance and disease control strategies in an ever-changing world. It is advisable to increase our knowledge on wildlife roles in relevant TADs to improve our preparedness in case of an outbreak in previously disease-free regions, where wildlife may be significant for disease surveillance and control.
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Affiliation(s)
- Christian Gortázar
- Grupo Sanidad y Biotecnología (SaBio), Instituto de Investigación en Recursos Cinegéticos (IREC; CSIC-UCLM-JCCM), Ciudad Real, Spain
| | - Patricia Barroso
- Grupo Sanidad y Biotecnología (SaBio), Instituto de Investigación en Recursos Cinegéticos (IREC; CSIC-UCLM-JCCM), Ciudad Real, Spain
| | - Rodrigo Nova
- School of Veterinary Medicine and Science, Sutton Bonington Campus, University of Nottingham, Leicestershire, UK
| | - Germán Cáceres
- European Commission for the Control of Foot-and-Mouth Disease, Rome, Italy
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21
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Preliminary Evaluation of a Recombinant Rift Valley Fever Virus Glycoprotein Subunit Vaccine Providing Full Protection against Heterologous Virulent Challenge in Cattle. Vaccines (Basel) 2021; 9:vaccines9070748. [PMID: 34358166 PMCID: PMC8310273 DOI: 10.3390/vaccines9070748] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/15/2021] [Accepted: 06/16/2021] [Indexed: 01/15/2023] Open
Abstract
Rift Valley fever virus (RVFV) is a mosquito-borne zoonotic pathogen that causes periodic outbreaks of abortion in ruminant species and hemorrhagic disease in humans in sub-Saharan Africa. These outbreaks have a significant impact on veterinary and public health. Its introduction to the Arabian Peninsula in 2003 raised concerns of further spread of this transboundary pathogen to non-endemic areas. These concerns are supported by the presence of competent vectors in many non-endemic countries. There is no licensed RVF vaccine available for humans and only a conditionally licensed veterinary vaccine available in the United States. Currently employed modified live attenuated virus vaccines in endemic countries lack the ability for differentiating infected from vaccinated animals (DIVA). Previously, the efficacy of a recombinant subunit vaccine based on the RVFV Gn and Gc glycoproteins, derived from the 1977 human RVFV isolate ZH548, was demonstrated in sheep. In the current study, cattle were vaccinated subcutaneously with the Gn only, or Gn and Gc combined, with either one or two doses of the vaccine and then subjected to heterologous virus challenge with the virulent Kenya-128B-15 RVFV strain, isolated from Aedes mosquitoes in 2006. The elicited immune responses by some vaccine formulations (one or two vaccinations) conferred complete protection from RVF within 35 days after the first vaccination. Vaccines given 35 days prior to RVFV challenge prevented viremia, fever and RVFV-associated histopathological lesions. This study indicates that a recombinant RVFV glycoprotein-based subunit vaccine platform is able to prevent and control RVFV infections in target animals.
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22
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Otieno FT, Gachohi J, Gikuma-Njuru P, Kariuki P, Oyas H, Canfield SA, Bett B, Njenga MK, Blackburn JK. Modeling the Potential Future Distribution of Anthrax Outbreaks under Multiple Climate Change Scenarios for Kenya. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:4176. [PMID: 33920863 PMCID: PMC8103515 DOI: 10.3390/ijerph18084176] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 03/17/2021] [Accepted: 03/23/2021] [Indexed: 11/16/2022]
Abstract
The climate is changing, and such changes are projected to cause global increase in the prevalence and geographic ranges of infectious diseases such as anthrax. There is limited knowledge in the tropics with regards to expected impacts of climate change on anthrax outbreaks. We determined the future distribution of anthrax in Kenya with representative concentration pathways (RCP) 4.5 and 8.5 for year 2055. Ecological niche modelling (ENM) of boosted regression trees (BRT) was applied in predicting the potential geographic distribution of anthrax for current and future climatic conditions. The models were fitted with presence-only anthrax occurrences (n = 178) from historical archives (2011-2017), sporadic outbreak surveys (2017-2018), and active surveillance (2019-2020). The selected environmental variables in order of importance included rainfall of wettest month, mean precipitation (February, October, December, July), annual temperature range, temperature seasonality, length of longest dry season, potential evapotranspiration and slope. We found a general anthrax risk areal expansion i.e., current, 36,131 km2, RCP 4.5, 40,012 km2, and RCP 8.5, 39,835 km2. The distribution exhibited a northward shift from current to future. This prediction of the potential anthrax distribution under changing climates can inform anticipatory measures to mitigate future anthrax risk.
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Affiliation(s)
- Fredrick Tom Otieno
- Animal Health Program, International Livestock Research Institute, P.O. Box 30709 Nairobi 00100, Kenya;
- School of Environment, Water and Natural Resources, South Eastern Kenya University, P.O. Box 17, Kitui 90200, Kenya; (P.G.-N.); (P.K.)
| | - John Gachohi
- Paul Allen School for Global Health, Washington State University-Global Health Kenya, One Padmore Place, George Padmore Lane, P.O. Box 19676 Nairobi 00100, Kenya; (J.G.); (M.K.N.)
- School of Public Health, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000, Nairobi 00200, Kenya
| | - Peter Gikuma-Njuru
- School of Environment, Water and Natural Resources, South Eastern Kenya University, P.O. Box 17, Kitui 90200, Kenya; (P.G.-N.); (P.K.)
| | - Patrick Kariuki
- School of Environment, Water and Natural Resources, South Eastern Kenya University, P.O. Box 17, Kitui 90200, Kenya; (P.G.-N.); (P.K.)
| | - Harry Oyas
- Veterinary Epidemiology and Economics Unit, Kenya Ministry of Agriculture, Livestock and Fisheries, P.O. Box 30028 Nairobi 00100, Kenya;
| | - Samuel A. Canfield
- Spatial Epidemiology and Ecology Research Laboratory, Department of Geography, University of Florida, Gainesville, FL 32611, USA; (S.A.C.); (J.K.B.)
- Emerging Pathogens Institute, University of Florida, 2055 Mowry Road, Gainesville, FL 32611, USA
| | - Bernard Bett
- Animal Health Program, International Livestock Research Institute, P.O. Box 30709 Nairobi 00100, Kenya;
| | - Moses Kariuki Njenga
- Paul Allen School for Global Health, Washington State University-Global Health Kenya, One Padmore Place, George Padmore Lane, P.O. Box 19676 Nairobi 00100, Kenya; (J.G.); (M.K.N.)
| | - Jason K. Blackburn
- Spatial Epidemiology and Ecology Research Laboratory, Department of Geography, University of Florida, Gainesville, FL 32611, USA; (S.A.C.); (J.K.B.)
- Emerging Pathogens Institute, University of Florida, 2055 Mowry Road, Gainesville, FL 32611, USA
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23
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Rostal MK, Cleaveland S, Cordel C, van Staden L, Matthews L, Anyamba A, Karesh WB, Paweska JT, Haydon DT, Ross N. Farm-Level Risk Factors of Increased Abortion and Mortality in Domestic Ruminants during the 2010 Rift Valley Fever Outbreak in Central South Africa. Pathogens 2020; 9:E914. [PMID: 33158214 PMCID: PMC7694248 DOI: 10.3390/pathogens9110914] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 10/25/2020] [Accepted: 10/30/2020] [Indexed: 11/28/2022] Open
Abstract
(1) Background: Rift Valley fever (RVF) outbreaks in domestic ruminants have severe socio-economic impacts. Climate-based continental predictions providing early warnings to regions at risk for RVF outbreaks are not of a high enough resolution for ruminant owners to assess their individual risk. (2) Methods: We analyzed risk factors for RVF occurrence and severity at the farm level using the number of domestic ruminant deaths and abortions reported by farmers in central South Africa during the 2010 RVF outbreaks using a Bayesian multinomial hurdle framework. (3) Results: We found strong support that the proportion of days with precipitation, the number of water sources, and the proportion of goats in the herd were positively associated with increased severity of RVF (the numbers of deaths and abortions). We did not find an association between any risk factors and whether RVF was reported on farms. (4) Conclusions: At the farm level we identified risk factors of RVF severity; however, there was little support for risk factors of RVF occurrence. The identification of farm-level risk factors for Rift Valley fever virus (RVFV) occurrence would support and potentially improve current prediction methods and would provide animal owners with critical information needed in order to assess their herd's risk of RVFV infection.
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Affiliation(s)
- Melinda K. Rostal
- EcoHealth Alliance, New York, NY 10018, USA; (W.B.K.); (N.R.)
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK; (S.C.); (L.M.); (D.T.H.)
| | - Sarah Cleaveland
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK; (S.C.); (L.M.); (D.T.H.)
| | - Claudia Cordel
- ExecuVet PTY LTD., Bloemfontein 9301, Free State, South Africa; (C.C.); (L.v.S.)
| | - Lara van Staden
- ExecuVet PTY LTD., Bloemfontein 9301, Free State, South Africa; (C.C.); (L.v.S.)
| | - Louise Matthews
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK; (S.C.); (L.M.); (D.T.H.)
| | - Assaf Anyamba
- Universities Space Research Association, Columbia, MD 21046, USA;
- NASA Goddard Space Flight Center, Biospheric Sciences Laboratory, Greenbelt, MD 20771, USA
| | | | - Janusz T. Paweska
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg 2192, South Africa;
| | - Daniel T. Haydon
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK; (S.C.); (L.M.); (D.T.H.)
| | - Noam Ross
- EcoHealth Alliance, New York, NY 10018, USA; (W.B.K.); (N.R.)
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Kar S, Rodriguez SE, Akyildiz G, Cajimat MNB, Bircan R, Mears MC, Bente DA, Keles AG. Crimean-Congo hemorrhagic fever virus in tortoises and Hyalomma aegyptium ticks in East Thrace, Turkey: potential of a cryptic transmission cycle. Parasit Vectors 2020; 13:201. [PMID: 32307010 PMCID: PMC7168965 DOI: 10.1186/s13071-020-04074-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 04/10/2020] [Indexed: 11/09/2022] Open
Abstract
Background Recent reports have demonstrated the presence of Crimean-Congo hemorrhagic fever virus (CCHFV) genomic material in Hyalomma aegyptium ticks feeding primarily on tortoises belonging to the genus Testudo. This raises the question if these ticks and their hosts play a role in the natural transmission dynamics of CCHFV. However, the studies are limited, and assessing the relevance of H. aegyptium in perpetuating the virus in nature, and a potential spillover to humans remains unknown. This study aimed to detect CCHFV in H. aegyptium ticks and their tortoise hosts in the East Thrace region of Turkey, where H. aegyptium is the most common human-biting tick and where a high density of tortoises of the genus Testudo can be found. Methods During the study period, 21 blood samples from different tortoises (2 T. hermanni and 19 T. graeca), 106 tick pools (containing 448 males, 152 females, 93 nymphs and 60 larvae) collected from 65 tortoises (5 T. hermanni and 60 T. graeca), 38 adult unfed questing ticks (25 males and 13 females, screened individually) and 14 pools (containing 8 nymphs and 266 larvae) of immature unfed questing ticks collected from the ground were screened for CCHFV genome by nested PCR and partial genomes sequenced. Results As a result of the screening of these 179 samples, 17 (9.5%) were detected as positive as follows: 2 of 21 blood samples (9.52%), 13 (containing 18 nymphs in 3 pools, and 52 males and 8 females in 10 pools) of 106 tick pools from tortoises (12.26%), and 2 of 38 adult questing ticks (5.26%). No positive result was determined in 14 pools of immature questing ticks. Conclusions Previous studies have shown that reptiles can participate in the transmission of arthropod-borne viruses, but they may contribute to different aspects of the disease ecology and evolution of tick-borne viral pathogens. Our results indicate the presence of CCHFV in questing and feeding H. aegyptium ticks as well as tortoise hosts. This may indicate that CCHFV circulates in a cryptic transmission cycle in addition to the primary transmission cycle that could play a role in the natural dynamic of the virus and the transmission to humans.![]()
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Affiliation(s)
- Sirri Kar
- Galveston National Laboratory, Department of Microbiology and Immunology, Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, USA.,Department of Biology, Tekirdag Namik Kemal University, Tekirdag, Turkey
| | - Sergio E Rodriguez
- Galveston National Laboratory, Department of Microbiology and Immunology, Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, USA
| | - Gurkan Akyildiz
- Department of Biology, Tekirdag Namik Kemal University, Tekirdag, Turkey
| | - Maria N B Cajimat
- Galveston National Laboratory, Department of Microbiology and Immunology, Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, USA.,Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA
| | - Rifat Bircan
- Department of Biology, Tekirdag Namik Kemal University, Tekirdag, Turkey
| | - Megan C Mears
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA
| | - Dennis A Bente
- Galveston National Laboratory, Department of Microbiology and Immunology, Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, USA.
| | - Aysen G Keles
- Faculty of Health Sciences, Marmara University, Istanbul, Turkey
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Abstract
Introduction: Rift Valley fever (RVF) outbreaks can cause devastating economic loss and public health concerns. RVF virus (RVFV: genus Phlebovirus family Phenuiviridae) is transmitted by mosquitoes, causes abortion in sheep, cattle, and goats, and severe diseases in humans including hemorrhagic fever, encephalitis, or retinitis. RVFV has spread from sub-Saharan Africa into Madagascar, Egypt, Saudi Arabia, and Yemen.Area covered: There are a few licensed veterinary RVF vaccines in endemic countries, whereas no licensed RVF vaccines are available for human use. There are two Investigational New Drug (IND) RVF candidate vaccines used in clinical trials. This review will discuss the development of two IND vaccines for RVF over the past 20-40 years, and further innovation for future RVF vaccines applicable for the use in endemic areas.Expert opinion: Vaccination for human RVF can protect at-risk personnel against severe RVF illness. Formalin-inactivated RVF candidate vaccine requires three doses to induce protective immunity, whereas the live-attenuated MP-12 candidate vaccine retains strong immunogenicity. Further innovation in safety, immunogenicity, and thermostability will facilitate future RVF vaccines for humans.
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Affiliation(s)
- Tetsuro Ikegami
- Department of Pathology, The University of Texas Medical Branch, Galveston, TX, USA.,Sealy Center for Vaccine Development, The University of Texas Medical Branch, Galveston, TX, USA.,Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch, Galveston, TX, USA
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