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Infectious enveloped RNA virus antigenic chimeras.

Random insertion mutagenesis has been used to construct infectious Sindbis virus structural protein chimeras containing a neutralization epitope from a heterologous virus, Rift Valley fever virus. Insertion sites, permissive for recovery of chimeric viruses with growth properties similar to the parental virus, were found in the virion E2 glycoprotein and the secreted E3 glycoprotein. For the E2 chimeras, the epitope was expressed on the virion surface and stimulated a partially protective immune response to Rift Valley fever virus infection in vivo. Besides providing a possible approach for de…

Antibodies to haemorrhagic fever viruses in Madagascar populations.

Sera of 381 adult people from 5 areas in Madagascar were tested by the indirect immunofluorescence method for antibodies against Congo-Crimean haemorrhagic fever and Rift Valley fever viruses (Bunyaviridae), Ebola (strains Zaire and Sudan) and Marburg viruses (Filoviridae), and Lassa virus (Arenaviridae). The highest prevalence rate was that of Ebola virus (4.5%). As no haemorrhagic syndrome has been found associated with this virus, the possible presence of a less pathogenic, antigenically related, strain is discussed. The prevalences of Congo-Crimean haemorrhagic fever and Rift Valley viruse…

Quantification of RVFV Specific T Cell Responses in Mice Pre-immunized with Potential Vaccine Candidates.

Rift Valley fever (RVF) caused by Rift Valley fever virus (RVFV) is a major health concern for both domesticated animals and humans in certain endemic areas of Africa. With changing environmental conditions and identification of vectors capable of transmitting the virus, there is high risk of RVFV spreading into other parts of the world. Furthermore, unavailability of effective vaccines in the event of an outbreak can be a major challenge as witnessed recently in case of SARS-CoV2 pandemic. Hence, identifying potential vaccines and testing their protective efficacy in preclinical models before…

Adjuvant activity of a novel metabolizable lipid emulsion with inactivated viral vaccines.

Studies were conducted in mice, hamsters, sheep, and two species of nonhuman primates which demonstrate the adjuvant activity of a new metab … ccinated controls to lethal homologous virus challenge. Sheep given one dose of lipid emulsion plus Rift Valley fever vaccine developed significantly higher antibody titers than control sheep receiving only vaccine. Cynomolgous monkeys inoculated with lipid emulsion plus Rift Valley fever vaccine developed 16-fold greater peak primary and 20-fold greater secondary …

[Recent data on hemorrhagic fevers in West Africa].

Among the viruses which can provoke human haemorrhagic fevers, the Congo-Crimean Haemorrhagic Fever and Rift Valley Fever viruses have been discovered relatively recently in West Africa. Two human cases of severe haemorrhagic fever have been connected with Congo-CHF, in Mauritania and Burkina-Faso. The epidemiological enquiry performed in Mauritania, consequent to the appearance of the first case, has demonstrated that the patient had been contaminated by contact with camels. Twelve strains of Congo-CHF virus have been isolated from ticks taken on bovines and dromedaries in that area. The sero…

Replication Kinetics of a Candidate Live-Attenuated Vaccine for Cache Valley Virus in Aedes albopictus.

Background: The emergence or re-emergence of several orthobunyaviruses (order: Bunyavirales; family: Peribunyaviridae), including Cache Vall … al design of candidate LAVs for bunyaviruses across multiple families. In addition, the deletion of Rift Valley fever virus NSs and NSm genes has been shown to reduce transmission by mosquitoes. Results: In this study, the ability of a CVV mutant lacking the NSs and NSm genes (2delCVV) to replicate in intrathoracically injected Aedes albopictus was compared with th …

Species Diversity, Abundance, and Host Preferences of Mosquitoes (Diptera: Culicidae) in Two Different Ecotypes of Madagascar With Recent RVFV Transmission.

Mosquito diversity and abundance were examined in six Madagascan villages in either arid (Toliary II district) or humid (Mampikony district) ecotypes, each with a history of Rift Valley fever virus transmission. Centers for Disease Control and Prevention light traps without CO2 (LT) placed near ruminant parks and animal-baited net trap (NT) baited with either zebu or sheep/goat were used to sample mosquitoes, on two occasions between March 2011 and October 2011. Culex tritaeniorhynchus (Giles) was the most abundant species, followed by Culex antennatus (Becker) and Anopheles squamosus/cydippis…

Viral haemorrhagic fevers of man.

This article reviews the current state of knowledge on the viral haemorrhagic fevers that infect man, namely smallpox, chikungunya fever, dengue fever, Rift Valley fever, yellow fever, Crimean haemorrhagic fever, Kyasanur Forest disease, Omsk haemorrhagic fever, Argentinian haemorrhagic fever (Junin virus), Bolivian haemorrhagic fever (Machupo virus), Lassa fever, haemorrhagic fever with renal syndrome, and Marburg and Ebola virus diseases.

Контроль за инфекциями RVFV с использованием вирусов биолюминесцентного репортера в Виво.

Вирус лихорадки Рифт-Вэлли способен заразить несколько органов и типов клеток, а курс инфекции варьируется между вирусными штаммами и между отдельными лицами, в частности, в зависимости от возраста, генетического фона и физиологического состояния. Исследования вирусных и приемных факторов включают обнаружение и количественную оценку вирусной нагрузки в различных точках времени и в различных тканях. В то время как это классически выполняется путем количественного определения генома или вирусной титрации, методы визуализации в vivo с использованием рекомбинантных вирусов, выражающих биолюминесце

Совпадение в аннотации оригинала
Rift Valley fever virus is able to infect multiple organs and cell types, and the course of infection varies between viral strains and between individuals in particular according to age, genetic background, and physiological status. Studies on viral and host factors involve detecting and quantifying viral load at multiple time points and in multiple tissues.…

Viral haemorrhagic fever surveillance in Kenya, 1980-1981.

Following two cases of Marburg virus disease in Kenya in 1980, viral haemorrhagic fever surveillance was undertaken in western Kenya. Over a … tances. 741 human sera were tested for antibodies against Marburg, Ebola, Congo haemorrhagic fever, Rift Valley fever or Lassa fever viruses by indirect fluorescence. Eight sera were positive for Ebola virus antibodies, all of which were from suspected cases or contacts of suspected cases. Two sera were antibody positive to Congo virus and one had antibodies agains …

Arboviruses pathogenic for domestic and wild animals.

The objective of this chapter is to provide an updated and concise systematic review on taxonomy, history, arthropod vectors, vertebrate hos … ruses), Bunyaviridae (tick-borne Nairobi sheep disease, Soldado, and Bhanja viruses; mosquito-borne Rift Valley fever, La Crosse, Snowshoe hare, and Cache Valley viruses; biting midges-borne Main Drain, Akabane, Aino, Shuni, and Schmallenberg viruses), Reoviridae (biting midges-borne African horse sickness, Kasba, bluetongue, epizootic hemorrhagic disease of deer, …

Potential of Using Capripoxvirus Vectored Vaccines Against Arboviruses in Sheep, Goats, and Cattle.

The genus capripoxvirus consists of sheeppox virus, goatpox virus, and lumpy skin disease virus, which affect sheep, goats, and cattle, resp … ility of differentiating infected from vaccinated animals. Arboviruses such as bluetongue virus and Rift Valley fever viruses are also responsible for significant economic losses in endemic countries. In the case of Rift Valley fever virus, vaccination is not routinely practiced unless there is an outbreak making vaccination not as effective, therefore, incorporati …

Clinical aspects of African viral hemorrhagic fevers.

Three hemorrhagic fevers occur in southern Africa: Rift Valley fever, Marburg virus disease, and Crimean-Congo hemorrhagic fever. The patient's history of travel in Africa, visits to rural areas, contact with sick animals or their carcasses, or contact with a tick-infested environment or tick bites is important. Rift Valley fever is characterized by an incubation period of approximately 3 or 4 days, sudden onset of fever with a biphasic course, and signs and symptoms of liver and kidney disorder. The commonest complication is retinitis with a central scotoma. Severe cases may develop a hemorrh…

Screening of Neutralizing Antibodies Targeting Gc Protein of RVFV.

Rift Valley fever virus (RVFV) is a mosquito-transmitted bunyavirus that can cause substantial morbidity and mortality in livestock and humans, for which there are no currently available licensed human therapeutics or vaccines. Therefore, the development of safe and effective antivirals is both necessary and urgent. The Gc protein is the primary target of the neutralizing antibody response related to Rift Valley fever virus. Here, we report one Gc-specific neutralizing antibody (NA137) isolated from an alpaca and one bispecific antibody (E2-NA137), the protective efficacies of which we evaluat…

Imported mosquito-borne infectious diseases in travellers and migrants: Global patterns, clinical overlap, and prevention gaps-an umbrella review of 21 systematic reviews.

BACKGROUND: Imported mosquito-borne infectious diseases (MBIDs) pose public health challenges in nonendemic regions, but cross-disease evidence remains fragmented. We conducted an umbrella review of systematic reviews to identify gaps and inform clinical practice and research priorities. METHODS: Five databases (PubMed, Embase, Scopus, Web of Science, and the Cochrane Library) were searched from inception to December 3, 2025, for systematic reviews on nine imported MBIDs, including chikungunya, dengue, Rift Valley fever, yellow fever, Zika, lymphatic filariasis, malaria, Japanese encephalitis…

Enhanced arboviral transmission by mosquitoes that concurrently ingested microfilariae.

Infection, dissemination, and transmission of an arbovirus in mosquitoes are enhanced by concurrent ingestion of microfilariae. Ingestion of Rift Valley fever virus alone infected only 64 percent of female Aedes taeniorhynchus. Of these, only 5 percent of refeeding mosquitoes actually transmitted virus. In contrast, ingestion of the same amount of virus from concurrently microfilaremic (Brugia malayi) gerbils resulted in 88 percent infection and 31 percent transmission. Enhanced transmission of virus may be attributed to increased transit of virus across the midgut wall. Endemic filariasis may…

[Hemorrhagic fever viruses in Madagascar].

The authors remind, what are the viral haemorrhagic fevers, and explain the situation in Madagascar. The viruses of Crimée-Congo haemorrhagic fever, Rift valley fever and haemorrhagic fever with renal syndrome are present in Madagascar. There is no real proof about the presence of Dengue viruses. The yellow fever viruses have never been stown off. It seems that there was not diagnosed outbreak of haemorrhagic fever, since the beginning of our century.

Identification of RVFV Host Factors Using Quantitative Interaction Proteomics.

Affinity enrichment coupled with liquid chromatography-tandem mass spectrometry (AE-LC-MS/MS) enables a comprehensive study of virus-host protein-protein interactions in cells and tissues infected with Rift Valley fever virus (RVFV) or ectopically expressing RVFV proteins. Depending on the research question, different experimental setups with carefully chosen controls are needed. Here, we describe the detailed workflow of sample preparation, processing, and cleanup, while also outlining critical points to consider when designing and performing AE-LC-MS/MS experiments.

NSs Filament Formation Is Important but Not Sufficient for RVFV Virulence In Vivo.

Rift Valley fever virus (RVFV) is a mosquito-borne phlebovirus that represents as a serious health threat to both domestic animals and humans. The viral protein NSs is the key virulence factor of RVFV, and has been proposed that NSs nuclear filament formation is critical for its virulence. However, the detailed mechanisms are currently unclear. Here, we generated a T7 RNA polymerase-driven RVFV reverse genetics system based on a strain imported into China (BJ01). Several NSs mutations (T1, T3 and T4) were introduced into the system for investigating the correlation between NSs filament formati…

[Evaluation of the Viral Hemorrhagic Fever Surveillance System in the Assaba region, Mauritania (2020-2022)].

INTRODUCTION: Several arboviral diseases have been known to be endemic (e.g., Crimean-Congo hemorrhagic fever, Rift Valley fever) or are emerging (dengue fever, chikungunya, O'nyong-nyong) in human populations in Mauritania, while others have become rare in recent years (e.g. yellow fever). Moreover, domestic animals, especially cattle, camels, goats, and sheep, are also known to be infected with some of these arboviruses (e.g. Crimean-Congo hemorrhagic fever, Rift Valley fever). For these reasons, viral hemorrhagic fever surveillance in Mauritania is part of the Integrated Disease Surveillanc…