Molecular Epidemiology and Emergence of Rift Valley Fever

Sall, Amadou Alpha; Zanotto, Paolo Marinho de Andrade; Vialat, Pierre; Sène, O. K.; Bouloy, Michèle

doi:10.1590/s0074-02761998000500009

Cited by 17 publications

(20 citation statements)

References 23 publications

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“…Their findings indicate that genetic reassortment with wild-type viruses during a vaccination program in endemic areas would also be expected to yield attenuated variants [53]. …”

Section: Discussionmentioning

confidence: 99%

Observations on rift valley fever virus and vaccines in Egypt

Kamal¹

2011

Virol J

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Rift Valley Fever virus (RVFV, genus: Phlebovirus, family: Bunyaviridae), is an arbovirus which causes significant morbidity and mortality in animals and humans. RVFV was introduced for the first time in Egypt in 1977. In endemic areas, the insect vector control and vaccination is considering appropriate measures if applied properly and the used vaccine is completely safe and the vaccination programs cover all the susceptible animals. Egypt is importing livestock and camels from the African Horn & the Sudan for human consumption. The imported livestock and camels were usually not vaccinated against RVFV. But in rare occasions, the imported livestock were vaccinated but with unknown date of vaccination and the unvaccinated control contacts were unavailable for laboratory investigations. Also, large number of the imported livestock and camels are often escaped slaughtering for breeding which led to the spread of new strains of FMD and the introduction of RVFV from the enzootic African countries. This article provide general picture about the present situation of RVFV in Egypt to help in controlling this important disease.

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“…Their findings indicate that genetic reassortment with wild-type viruses during a vaccination program in endemic areas would also be expected to yield attenuated variants [53]. …”

Section: Discussionmentioning

confidence: 99%

Observations on rift valley fever virus and vaccines in Egypt

Kamal¹

2011

Virol J

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“…To test the specificity of the amplification, we carried out the reaction with RNAs from RVFV strains clustered in the three groups referred to as West Africa, East-Central Africa, and Egypt (31,32,34). These strains were ZH501, ZH548, ArD38661, 74HB59, and clone 13.…”

Section: Real-time Rtd-pcr Of Rvfvmentioning

confidence: 99%

Quantitative Real-Time PCR Detection of Rift Valley Fever Virus and Its Application to Evaluation of Antiviral Compounds

et al. 2001

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The Rift Valley fever virus (RVFV), a member of the genus Phlebovirus (family Bunyaviridae) is an enveloped negative-strand RNA virus with a tripartite genome. Until 2000, RVFV circulation was limited to the African continent, but the recent deadly outbreak in the Arabian Peninsula dramatically illustrated the need for rapid diagnostic methods, effective treatments, and prophylaxis. A method for quantifying the small RNA segment by a real-time detection reverse transcription (RT)-PCR using TaqMan technology and targeting the nonstructural protein-coding region was developed, and primers and a probe were designed. After optimization of the amplification reaction and establishment of a calibration curve with synthetic RNA transcribed in vitro from a plasmid containing the gene of interest, real-time RT-PCR was assessed with samples consisting of RVFV from infected Vero cells. The method was found to be specific for RVFV, and it was successfully applied to the detection of the RVFV genome in animal sera infected with RVFV as well as to the assessment of the efficiency of various drugs (ribavirin, alpha interferon, 6-azauridine, and glycyrrhizin) for antiviral activity. Altogether, the results indicated a strong correlation between the infectious virus titer and the amount of viral genome assayed by real time RT-PCR. This novel method could be of great interest for the rapid diagnosis and screening of new antiviral compounds, as it is sensitive and time saving and does not require manipulation of infectious material.The Rift Valley fever (RVF) virus (RVFV), a member of the genus Phlebovirus, belongs to the Bunyaviridae family and possesses a negative-stranded, tripartite RNA genome composed of a large, a medium, and a small (S) segment (for reviews, see references 9 and 37). Like other phleboviruses, the S segment utilizes an ambisense strategy to code for two proteins, the nucleocapsid protein and the nonstructural protein (NS s ), which are synthesized from subgenomic viral complementary and viral sense mRNA, respectively.RVF is a mosquito-borne zoonosis predominantly provoking the death of young animals and abortion (e.g., sheep and goats) (for reviews, see references 24, 39 and 41). The disease was first identified in sheep by Daubney et al. in Kenya in 1931, and it is endemic almost everywhere in subtropical Africa (6). Transmission to humans occurs primarily by contact with infected animal body fluids and by mosquito bites. Infection is usually asymptomatic or associated with a brief self-limited febrile illness. However, complications such as retinitis, encephalitis, or hemorrhagic fever occur in some patients with mortality rates of up to 10 to 12% (21, 28).The potential of RVF as a disease emerging in new areas was first documented in Egypt in 1977 (16), and since then, epidemics have occurred in Mauritania (1987Mauritania ( to 1988Mauritania ( and 1998, Madagascar (1990to 1991), Egypt (1993, and eastern Africa (in Kenya, Somalia, and Tanzania) (references 33 and 34 and references therein). Recently, the...

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“…The study of emerging viruses is often invoked by Molecular Epidemiology, using phylogenetic methods to infer the origin, emergence, spread and disease dynamics [16,39,51]. Evolutionary and ecological dynamics of emerging viruses are so linked that viral diversity is correlated with the epidemic dynamics [52].…”

Section: The Study Of Risk Factors and Eco-epidemiologymentioning

confidence: 99%