Rift Valley fever virus (RVFV) is an important cause of epizootics and epidemics in Africa and a potential agent of bioterrorism. A better understanding of the factors that govern RVFV virulence and pathogenicity is required, given the urgent need for antiviral therapies and safe vaccines. We have previously shown that RVFV strains with mutations in the NSs gene are excellent inducers of alpha/...

The Rift Valley fever virus (RVFV) encodes the structural proteins nucleoprotein (N), aminoterminal glycoprotein (Gn), carboxyterminal glycoprotein (Gc), and L protein, 78-kD, and the nonstructural proteins NSm and NSs. Using the baculovirus system, we expressed the full-length coding sequence of N, NSs, NSm, Gc, and the ectodomain of the coding sequence of the Gn glycoprotein derived from the ...

Toscana virus (TOSV), which is transmitted by Phlebotomus spp. sandflies, is a major etiologic agent of aseptic meningitis and encephalitis in the Mediterranean. Like other members of the genus Phlebovirus of the family Bunyaviridae, TOSV encodes a nonstructural protein (NSs) in its small RNA segment. Although the NSs of Rift Valley fever virus (RVFV) has been identified as an important virulen...

Rift Valley fever virus (RVFV; family Bunyaviridae) is a clinically important, mosquito-borne pathogen of both livestock and humans, which is found mainly in sub-Saharan Africa and the Arabian Peninsula. RVFV has a trisegmented single-stranded RNA (ssRNA) genome. The L and M segments are negative sense and encode the L protein (viral polymerase) on the L segment and the virion glycoproteins Gn ...

The aim of this work was to evaluate the immunogenicity and efficacy of DNA and MVA vaccines encoding the RVFV glycoproteins Gn and Gc in an ovine model of RVFV infection. Adult sheep of both sexes were challenged 12 weeks after the last immunization and clinical, virological, biochemical and immunological consequences, were analyzed. Strategies based on immunization with homologous DNA or hete...

Rift Valley fever (RVF) is endemic in most parts of Africa and has also been reported to occur in the Arabian Peninsula. It is responsible for significant morbidity and mortality, particularly in livestock, but also in humans. During the last two decades several outbreaks of RVF have been reported in countries in Southern Africa. In contrast to other countries, no clinical disease has been repo...

Rift Valley fever virus (RVFV) nonstructural protein NSs acts as the major determinant of virulence by antagonizing interferon beta (IFN-beta) gene expression. We demonstrate here that NSs interacts with the host protein SAP30, which belongs to Sin3A/NCoR/HDACs repressor complexes and interacts with the transcription factor YY1 that regulates IFN-beta gene expression. Using confocal microscopy ...

Rift Valley fever (RVF), a mosquito-borne zoonosis, is a major public health and veterinary problem in sub-Saharan Africa. Surveillance to monitor mosquito populations during the inter-epidemic period (IEP) and viral activity in these vectors is critical to informing public health decisions for early warning and control of the disease. Using a combination of field bioassays, electrophysiologica...

The viral RNA-dependent RNA polymerase (RdRp; L protein) of Rift Valley fever virus (RVFV; family Bunyaviridae) is a 238 kDa protein that is crucial for the life cycle of the virus, as it catalyses both transcription of viral mRNAs and replication of the tripartite genome. Despite its importance, little is known about the intracellular distribution of the polymerase or its other roles during in...

We evaluated Aedes atlanticus Dyar and Knab, Aedes infirmatus Dyar and Knab, Aedes vexans (Meigen), Anopheles crucians Wiedemann, Coquillettidia perturbans (Walker), Culex nigripalpus Theobald, Mansonia dyari Belkin, Heinemann, and Page, and Psorophora ferox (Von Humboldt) from Florida to determine which of these species should be targeted for control should Rift Valley fever virus (RVFV) be de...