<P> Although many components of the RVFV's RNA play an important role in the virus' pathology, the nonstructural protein encoded on the S segment (NSs) is the only component that has been found to directly affect the host . NSs is hostile and combative against the hosts interferon (IFNs) antiviral response . IFNs are essential in order for the immune system to fight off viral infections in a host . This inhibitory mechanism is believed to be due to a number of reasons, the first being, competitive inhibition of the formation of the transcription factor . On this transcription factor, NSs interacts with and binds to a subunit that is needed for RNA polymerase I and II . This interaction cause competitive inhibition with another transcription factor component and prevents the assembly process of the transcription factor complex, which results in the suppression of the host antiviral response . Transcription suppression is believed to be another mechanism of this inhibitory process . This occurs when an area of NSs interacts with and binds to the host's protein, SAP30 and forms a complex . This complex causes histone acetylation to regress, which is needed for transcriptional activation of the IFN promoter . This causes IFN expression to be obstructed . Lastly, NSs has also been known to affect regular activity of double - stranded RNA - dependent protein kinase R...This protein is involved in cellular antiviral responses in the host . When RVFV is able to enter the hosts DNA, NSs forms a filamentous structure in the nucleus . This allows the virus to interact with specific areas of the hosts DNA that relates to segregation defects and induction of chromosome continuity . This increases host infectivity and decreases the host's antiviral response . </P> <P> Diagnosis relies on viral isolation from tissues, or serological testing with an ELISA . Other methods of diagnosis include Nucleic Acid Testing (NAT), cell culture, and IgM antibody assays . As of September 2016, the Kenya Medical Research Institute (KEMRI) has developed a product called Immunoline, designed to diagnose the disease in humans much faster than in previous methods . </P> <P> A vaccine has been conditionally approved for use in animals in the US . It has been shown that knockout of the NSs and NSm nonstructural proteins of this virus produces an effective vaccine in sheep as well . </P> <P> RVF outbreaks occur across sub-Saharan Africa, with outbreaks occurring elsewhere infrequently . In Egypt in 1977--78, an estimated 200,000 people were infected and there were at least 594 deaths . In Kenya in 1998, the virus killed over 400 Kenyans . In September 2000, an outbreak was confirmed in Saudi Arabia and Yemen . On 19 October 2011, a case of Rift Valley fever contracted in Zimbabwe was reported in a Caucasian female traveler who returned to France after a 26 - day stay in Marondera, Mashonaland East Province during July and August, 2011 but later classified as "not confirmed ." </P>

Is there a cure for rift valley fever