Rift Valley Fever and the Changing Environment

2017 ◽  
pp. 178-204
Author(s):  
Johanna Lindahl ◽  
Bernard Bett ◽  
Timothy Robinson ◽  
Delia Grace
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Environmental Changes ◽  
Rift Valley Fever Virus ◽  
Severe Disease ◽  
Land Use Changes ◽  
Future Research ◽  
Valley Fever ◽  
Vector Borne Diseases ◽  
Vector Borne

Rift Valley fever is a severe disease affecting both humans and animals. The Rift Valley fever virus can be transmitted by body fluids, and the most common way for humans to get infected is from animals. The virus is also vector-borne and can be transmitted by many species of mosquitoes. As with other vector-borne diseases, the epidemiology may vary in response to environmental changes. Here the effects of climate and land use changes on Rift Valley fever, as well as on other vector-borne diseases, are discussed. The effect of irrigation in East Africa on inter-epidemic transmission of RVF is discussed in greater detail, followed by recommendations for future research and actions.

Rift Valley Fever and the Changing Environment

2020 ◽  
pp. 1496-1516
Author(s):  
Johanna Lindahl ◽  
Bernard Bett ◽  
Timothy Robinson ◽  
Delia Grace
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Environmental Changes ◽  
Rift Valley Fever Virus ◽  
Severe Disease ◽  
Land Use Changes ◽  
Future Research ◽  
Valley Fever ◽  
Vector Borne Diseases ◽  
Vector Borne

Rift Valley fever is a severe disease affecting both humans and animals. The Rift Valley fever virus can be transmitted by body fluids, and the most common way for humans to get infected is from animals. The virus is also vector-borne and can be transmitted by many species of mosquitoes. As with other vector-borne diseases, the epidemiology may vary in response to environmental changes. Here the effects of climate and land use changes on Rift Valley fever, as well as on other vector-borne diseases, are discussed. The effect of irrigation in East Africa on inter-epidemic transmission of RVF is discussed in greater detail, followed by recommendations for future research and actions.

scholarly journals Emerging vector-borne diseases in dromedaries in Tunisia: West Nile, bluetongue, epizootic haemorrhagic disease and Rift Valley fever

2017 ◽  
Vol 84 (1) ◽  
Author(s):  
Thameur B. Hassine ◽  
Jihane Amdouni ◽  
Federica Monaco ◽  
Giovanni Savini ◽  
Soufien Sghaier ◽  
...  
Keyword(s):  
Rift Valley ◽  
Bluetongue Virus ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
West Nile ◽  
Valley Fever ◽  
Vector Borne Diseases ◽  
Serotype 1 ◽  
Vector Borne ◽  
Haemorrhagic Disease

A total of 118 sera were collected during 2016 from two groups of dromedaries from Kebili and Medenine governorates in the south of Tunisia. The aim of this study was to provide the first serological investigation of four emerging vector-borne diseases in two groups of dromedaries in Tunisia. Sera were tested by ELISA and serum neutralisation test to identify West Nile virus (WNV), bluetongue virus (BTV), epizootic haemorrhagic disease virus (EHDV) and Rift Valley fever virus (RVFV). In the first group, the seroprevalence for BTV was 4.6%, while in the second group, it was 25.8% for WNV and 9.7% for BTV. Only serotype 1 was detected for BTV in the two groups. No evidence for circulation of RVF and EHD viruses was revealed. Results indicated that dromedaries can be infected with BTV and WNV, suggesting that this species might play a significant role in the epizootiology of these viral diseases in Tunisia and neighbouring countries.

scholarly journals Rift Valley Fever: Important Considerations for Risk Mitigation and Future Outbreaks

2020 ◽  
Vol 5 (2) ◽  
pp. 89 ◽  
Author(s):  
Elysse N. Grossi-Soyster ◽  
A. Desiree LaBeaud
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Risk Mitigation ◽  
Rift Valley Fever Virus ◽  
Severe Disease ◽  
Hemorrhagic Fever ◽  
Valley Fever ◽  
Great Opportunity ◽  
Exposure Risks ◽  
Psychological Impairment

Rift Valley fever virus (RVFV) is a zoonotic phlebovirus of the Phenuiviridae family with great opportunity for emergence in previously unaffected regions, despite its current geographical limits. Outbreaks of RVFV often infect humans or domesticated animals, such as livestock, concurrently and occur sporadically, ranging from localized outbreaks in villages to multi-country events that spread rapidly. The true burden of Rift Valley fever (RVF) is not well defined due to underreporting, misdiagnosis caused by the broad spectrum of disease presentation, and minimal access for rapid and accurate laboratory confirmation. Severe symptoms may include hemorrhagic fever, loss of vision, psychological impairment or disturbances, and organ failure. Those living in endemic areas and travelers should be aware of the potential for exposure to ongoing outbreaks or interepidemic transmission, and engage in behaviors to minimize exposure risks, as vaccinations in humans are currently unavailable and animal vaccinations are not used routinely or ubiquitously. The lack of vaccines approved for use in humans is concerning, as RVFV has proven to be highly pathogenic in naïve populations, causing severe disease in a large percent of confirmed cases, which could have considerable impact on human health.

scholarly journals An alphavirus replicon-derived candidate vaccine against Rift Valley fever virus

2009 ◽  
Vol 137 (9) ◽  
pp. 1309-1318 ◽  
Author(s):  
M. T. HEISE ◽  
A. WHITMORE ◽  
J. THOMPSON ◽  
M. PARSONS ◽  
A. A. GROBBELAAR ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Fluorescent Antibody ◽  
Severe Disease ◽  
Neutralizing Antibody ◽  
Fever Virus ◽  
Antibody Responses ◽  
Valley Fever

SUMMARYRift Valley fever virus (RVFV) is a mosquito-transmitted bunyavirus (genusPhlebovirus) associated with severe disease in livestock and fatal encephalitis or haemorrhagic fever in a proportion of infected humans. Although live attenuated and inactivated vaccines have been used in livestock, and on a limited scale in humans, there is a need for improved anti-RVFV vaccines. Towards this goal, Sindbis virus replicon vectors expressing the RVFV Gn and Gc glycoproteins, as well as the non-structural nsM protein, were constructed and evaluated for their ability to induce protective immune responses against RVFV. These replicon vectors were shown to produce the RVFV glycoproteins to high levelsin vitroand to induce systemic anti-RVFV antibody responses in immunized mice, as determined by RVFV-specific ELISA, fluorescent antibody tests, and demonstration of a neutralizing antibody response. Replicon vaccination also provided 100% protection against lethal RVFV challenge by either the intraperitoneal or intranasal route. Furthermore, preliminary results indicate that the replicon vectors elicit RVFV-specific neutralizing antibody responses in vaccinated sheep. These results suggest that alphavirus-based replicon vectors can induce protective immunity against RVFV, and that this approach merits further investigation into its potential utility as a RVFV vaccine.

scholarly journals Arbovirus Infections: the Challenges of Controlling an Ever-Present Enemy

2009 ◽  
Vol 4 (5) ◽  
pp. 322-328 ◽  
Author(s):  
Tomohiko Takasaki ◽  
◽  
Akira Kotaki ◽  
Chang-Kweng Lim ◽  
Shigeru Tajima ◽  
...  
Keyword(s):  
Global Warming ◽  
Dengue Fever ◽  
Yellow Fever ◽  
Japanese Encephalitis ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
West Nile Fever ◽  
Valley Fever ◽  
Vector Borne Diseases ◽  
Vector Borne

Arthropod-borne infections carried by mosquitoes and ticks are difficult to eradicate, once rooted, and have frequently caused wide-area epidemics such as dengue fever, West Nile fever, chikungunya fever, yellow fever, Japanese encephalitis and Rift Valley fever. Factors such as global warming and overpopulation have aggravated urban epidemics caused by dengue and chikungunya viruses. Measures against arthropods have their limitations, however, so nonepidemic areas must be protected against invasion by vector-borne diseases through quarantine, education and effective vaccination.

scholarly journals Interplay between the Virus and Host in Rift Valley Fever Pathogenesis

2015 ◽  
Vol 7 (5) ◽  
pp. 450-458 ◽  
Author(s):  
Kaori Terasaki ◽  
Shinji Makino
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Current Knowledge ◽  
Rift Valley Fever Virus ◽  
Severe Disease ◽  
Model Systems ◽  
High Rate ◽  
Valley Fever ◽  
Middle East Countries ◽  
Biosafety Level

Rift Valley fever virus (RVFV) belongs to the genus Phlebovirus, family Bunyaviridae, and carries single-stranded tripartite RNA segments. The virus is transmitted by mosquitoes and has caused large outbreaks among ruminants and humans in sub-Saharan African and Middle East countries. The disease is characterized by a sudden onset of fever, headache, muscle pain, joint pain, photophobia, and weakness. In most cases, patients recover from the disease after a period of weeks, but some also develop retinal or macular changes, which result in vision impairment that lasts for an undefined period of time, and severe disease, characterized by hemorrhagic fever or encephalitis. The virus also causes febrile illness resulting in a high rate of spontaneous abortions in ruminants. The handling of wild-type RVFV requires high-containment facilities, including biosafety level 4 or enhanced biosafety level 3 laboratories. Nonetheless, studies clarifying the mechanisms of the RVFV-induced diseases and preventing them are areas of active research throughout the world. By primarily referring to recent studies using several animal model systems, protein expression systems, and specific mutant viruses, this review describes the current knowledge about the mechanisms of pathogenesis of RVF and biological functions of various viral proteins that affect RVFV pathogenicity.

scholarly journals Inhibition of Rift Valley Fever Virus Replication and Perturbation of Nucleocapsid-RNA Interactions by Suramin

2014 ◽  
Vol 58 (12) ◽  
pp. 7405-7415 ◽  
Author(s):  
Mary Ellenbecker ◽  
Jean-Marc Lanchy ◽  
J. Stephen Lodmell
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rna Binding ◽  
Therapeutic Potential ◽  
Rift Valley Fever Virus ◽  
Severe Disease ◽  
Fever Virus ◽  
Valley Fever ◽  
Ribonucleoprotein Complexes

ABSTRACTRift Valley fever virus (RVFV) is an emerging infectious pathogen that causes severe disease in humans and livestock and has the potential for global spread. There are currently no proven safe and effective treatment options for RVFV infection. Inhibition of RNA binding to RVFV nucleocapsid protein (N) represents an attractive antiviral therapeutic strategy because several essential steps in the RVFV replication cycle involve N binding to viral RNA. In this study, we demonstrate the therapeutic potential of the drug suramin by showing that it functions well as an inhibitor of RVFV replication at multiple stages in human cell culture. Suramin has been used previously to treat trypanosomiasis in Africa. We characterize the dynamic and cooperative nature of N-RNA binding interactions and the dissociation of high-molecular-mass ribonucleoprotein complexes using suramin, which we previously identified as an N-RNA binding inhibitor in a high-throughput screen. Finally, we elucidate the molecular mechanism used by suraminin vitroto disrupt both specific and nonspecific binding events important for ribonucleoprotein formation.

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