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Epidemiology of hemorrhagic fever viruses.

Twelve distinct viruses associated with hemorrhagic fever in humans are classified among four families: Arenaviridae, which includes Lassa, Junin, and Machupo viruses; Bunyaviridae, which includes Rift Valley fever, Crimean-Congo hemorrhagic fever, and Hantaan viruses; Filoviridae, which includes Marburg and Ebola viruses; and Flaviviridae, which includes yellow fever, dengue, Kyasanur Forest disease, and Omsk viruses. Most hemorrhagic fever viruses are zoonoses, with the possible exception of the four dengue viruses, which may continually circulate among humans. Hemorrhagic fever viruses are …

Cell-Free Synthesis of Bunyavirales Proteins in View of Their Structural Characterization by Nuclear Magnetic Resonance.

The Rift Valley fever virus is one of the bunyaviruses on the WHO's priority list of pathogens that may cause future pandemics. A better understanding of disease progression and viral pathogenesis is urgently needed to develop treatments. The non-structural proteins NSs and NSm of human pathogenic bunyaviruses represent promising therapeutic targets, as they are often key virulence factors. However, their function is still poorly understood, and their structure is yet unknown, mainly because no successful production of these highly complex proteins has been reported. Here we propose a powerful…

Isolation and Identification of a Novel Phlebovirus, Hedi Virus, from Sandflies Collected in China.

We report the isolation of a newly recognized phlebovirus, Hedi virus (HEDV), from Phlebotomus chinensis sandflies collected in Shanxi Province, China. The virus' RNA is comprised of three segments. The greatest amino acid sequence similarity of the three gene segments between this virus and previously recognized phleboviruses is 40.85-63.52%, and the RNA-dependent RNA polymerase (RdRp) amino acid sequence has the greatest similarity (63.52%) to the Rift Valley fever virus (RVFV) ZH-548 strain. Phylogenetic analysis of the amino acid sequence of the virus RdRp indicated that HEDV is close to R…

Optical Imaging of Paramagnetic Bead-DNA Aggregation Inhibition Allows for Low Copy Number Detection of Infectious Pathogens.

DNA-paramagnetic silica bead aggregation in a rotating magnetic field facilitates the quantification of DNA with femtogram sensitivity, but … ection of notable food-borne pathogens Escherichia coli O157:H7 and Salmonella enterica, as well as Rift Valley fever virus, a weaponizable virus of national security concern. We also show the concentration dependence of aggregation inhibition, suggesting the potential for quantification of target nucleic acid in clinical and environmental samples. Lastly, we demon …

Antiviral autophagy restrictsRift Valley fever virus infection and is conserved from flies to mammals.

Autophagy has been implicated as a component of host defense, but the significance of antimicrobial autophagy in vivo and the mechanism by which it is regulated during infection are poorly defined. Here we found that antiviral autophagy was conserved in flies and mammals during infection with Rift Valley fever virus (RVFV), a mosquito-borne virus that causes disease in humans and livestock. In Drosophila, Toll-7 limited RVFV replication and mortality through activation of autophagy. RVFV infection also elicited autophagy in mouse and human cells, and viral replication was increased in the abse…

Simultaneous Detection of Ebola Virus and Pathogens Associated With Hemorrhagic Fever by an Oligonucleotide Microarray.

Ebola virus infection causes severe hemorrhagic fever, and its mortality rates varied from 25 to 90% in the previous outbreaks. The highly i … ted with hemorrhagic fever, including Marburg virus, Lassa fever virus, Junin virus, Machupo virus, Rift Valley fever virus, Crimean-Congo hemorrhagic fever virus, malaria parasite, hantavirus, severe fever with thrombocytopenia syndrome virus, dengue virus, yellow fever virus, Chikungunya virus, influenza A virus, and influenza B virus. This assay had an excellent …

An integrated computational antigen discovery pipeline with hierarchical filtering for emerging viral variants.

Emerging and evolving viral diseases, such as SARS-CoV-2, continue to pose significant global health challenges, underscoring the urgent nee … eutic potential. We demonstrate its utility by significantly narrowing the antigen search space for Rift Valley fever virus (RVFV) and Mayaro virus (MAYV), and by effectively identifying conserved neutralizing epitopes in SARS-CoV-2. Our proposed computational antigen pipeline offers a powerful framework for expediting the development of future vaccines and therape …

Genome-Wide CRISPR-Cas9 Screening for the Identification of Host Dependency Factors of Emerging Viruses.

Like all the RNA viruses, Rift Valley fever virus (RVFV) encodes only few viral proteins and relies heavily on the host cellular machinery for productive infection. This dependence creates a potential "Achille's heel" that may be exploited to develop new approaches to treat RVFV infection. The recent development of lentiviral sgRNAs pool has enabled the creation of genome-scale CRISPR-Cas9 knockout libraries that has been used to identify host factors required for virus replication. In this chapter, we describe the preparation and execution of a pooled CRISPR-Cas9 loss-of-function screen using…

Novel activities of safe-in-human broad-spectrum antiviral agents.

According to the WHO, there is an urgent need for better control of viral diseases. Re-positioning existing safe-in-human antiviral agents f … nd Zika virus, as well as azacitidine, cyclosporine, minocycline, oritavancin and ritonavir against Rift valley fever virus. Thus, the spectrum of antiviral activities of existing antiviral agents could be expanded towards other viral diseases.

[The mammals of Guinea as reservoirs and carriers of arboviruses].

A great body of data on the fauna and ecology of wild mammals and their participation in the circulation of arboviruses were collected when the ecology of the latter of the Republic of Guinea was studied in 1978 to 1989. A hundred and eighteen species belonging to 10 orders were identified. Over 2,000 biological specimens were virologically and serologically examined. Six arboviruses were isolated. These included Dugbe virus (from the hussar monkey Cercopithecus (Erythrocebus patas) and 5 viruses from chiropters: Rift valley fever, from Micropteropus pusillus, Miniopterus schreibersi, and Hipp…

[Surveillance of the circulation of arbovirus of medical interest in the region of eastern Senegal].

A study about the circulation of arboviruses of medical interest in southeastern Senegal was conducted from 1988 to 1991, during and around … was isolated in 1990. The other flaviviruses (West-Nile, Kedougou, Wesselsbron), Chikungunya virus, Rift Valley Fever virus and Crimean-Congo Hemorrhagic Fever virus did not seem to present a major public health concern in southeastern Senegal.

Antibodies against Schmallenberg virus detected in cattle in the Otjozondjupa region, Namibia.

Several ruminant species have been shown to be susceptible to Schmallenberg virus (SBV), but adult animals usually recover after showing mild or no clinical signs. However, transplacental infection can occur and lead to abortion, malformations and stillborn lambs, calves and goat kids. During November and December 2014, malformations were observed in 11 stillborn calves from two farms in the north-eastern region of Namibia. Blood samples were collected from 9 of the 11 cows that delivered stillborn and malformed calves. All these animals tested negative for Rift Valley fever, bovine viral diar…

Assessing the zoonotic potential of arboviruses of African origin.

Several African arboviruses have emerged over the past decade in new regions where they caused major outbreaks in humans and/or animals including West Nile virus, Chikungunya virus and Zika virus. This raise questions regarding the importance of less known zoonotic arboviruses in local epidemics in Africa and their potential to emerge internationally. Syndromic surveillance in animals may serve as an early warning system to detect zoonotic arbovirus outbreaks. Rift Valley fever and Wesselsbronvirus are for example associated with abortion storms in livestock while West Nile-virus, Shuni virus …

Rickettsial retinitis: Direct bacterial infection or an immune-mediated response?

Infectious retinitis postfebrile illness is known to be caused by chikungunya, dengue, West Nile virus, Bartonella, Lyme's disease, Rift Valley fever, rickettsia, Herpes viruses etc. Rickettsia is Gram-negative bacteria transmitted by arthropods vectors. Ocular involvement is common including conjunctivitis, keratitis, anterior uveitis, panuveitis, retinitis, retinal vascular changes, and optic nerve involvement. Retinitis lesions in rickettsia can occur because of an immunological response to the bacteria or because of direct invasion and proliferation of bacteria in the inner retina. We repo…

Clinical demodicosis in African buffalo (Syncerus caffer) in the Kruger National Park.

We investigated the relationship between prevalence and severity of clinical signs of Demodex cafferi infection in free-ranging African buffalo (Syncerus caffer) and other factors such as age, sex, pregnancy status, and concomitant infections with bovine tuberculosis (BTB), Rift Valley fever (RVF), and brucellosis (BA). Approximately half of 203 buffalo examined in this study had clinical signs of demodicosis (cutaneous nodules); younger age classes had the highest prevalence and severity of lesions (chi(2)=21.4, df=6, P=0.0015). Nodules were generally limited to the head and neck region, but …

Предварительная очистка водоемов Эйдеса (дамбо) в Кении с использованием устойчивого раствора метапрена.

Эффективность устойчивых эмиссий альтосидов (4% метаопрена АИ) против потопных комаров в дамбо, обработанных 5, 3, и 1 вк до и 1 день после затопления. Лишь 2% эдес пупаэ (главным образом Аедес мицинтоши) выжили у взрослых в районе, где лечили 5 вл., и ни один взрослый комар не появился из района, обработанного через 1 день после наводнения. С другой стороны, 12 и 16 процентов Айдеса пупаэ успешно выжили до стадии взрослого человека в районах, прошедших предварительную обработку, соответственно, на 3 и 1 вл. Эффективность Altosid упала по отношению к Culex spp. (главным образом Cx. annantus),

Совпадение в аннотации оригинала
Effectiveness of sustained-release Altosid pellets (4% AI methoprene) against floodwater mosquitoes in dambos treated at 5, 3, and 1 wk befo … er flooding. The potential for using preflood treatment with methoprene to control Aedes vectors of Rift Valley fever virus in endemic areas is discussed.

A new genotype of Japanese encephalitis virus from Indonesia.

Primer-extension sequencing of the RNA template of polio, dengue, Rift Valley fever, and Japanese encephalitis (JE) viruses has provided new information on their geographic distribution, origin, and evolution. In a previous study of 46 diverse JE virus strains, we demonstrated the existence of three distinct JE genotypes in Asia. We now report the occurrence of a fourth genotype. In the present study, 19 JE virus isolates, representing various geographic regions of Asia and a 50-year time span, were compared with each other and with Murray Valley encephalitis, West Nile, and Kunjin viruses. Tw…

Nuclear trafficking of proteins from RNA viruses: potential target for antivirals?

A key aspect of the infectious cycle of many viruses is the transport of specific viral proteins into the host cell nucleus to perturb the antiviral response. Examples include a number of RNA viruses that are significant human pathogens, such as human immunodeficiency virus (HIV)-1, influenza A, dengue, respiratory syncytial virus and rabies, as well agents that predominantly infect livestock, such as Rift valley fever virus and Venezuelan equine encephalitis virus. Inhibiting the nuclear trafficking of viral proteins as a therapeutic strategy offers an attractive possibility, with important r…

Создание и характеристика клеточной линии от комаровых комаров (Culex) тейлери (Diptera: Culicidae) и их подверженность инфекции арбовирусами.

Комары Culex (Culex) теилери Теобальд, вероятно, являются основным вектором вируса лихорадки Рифт-Вэлли (RVF) во время эпизоотии на внутреннем плато в южной части Африки. Из тканей этого вида комаров была установлена клеточная линия для облегчения лабораторных исследований на RVF и других арбовирусах. После предварительной обработки температуры яичные плоты из лабораторной колонии были дезинфицированы, механически повреждены и выращены в кондиционированном орехе минимум необходимой среды, дополненной 10% сыворотки тельца плода. Клетки характеризовались содержанием белка, кариологией и их воспр

Совпадение в аннотации оригинала
The mosquito Culex (Culex) theileri Theobald is probably the major vector of Rift Valley fever (RVF) virus during epizootics on the inland plateau of southern Africa. A cell line was established from the tissues of this mosquito species to facilitate laboratory studies on RVF and other arboviruses. After temperature pretreatment, egg rafts from a laboratory …

RDB--a new product of plant origin for cell culture dispersion.

RDB is a crude preparation extracted from a plant source. It is a very potent agent for dispersion of monolayer cell cultures as well as for … t cultures. RDB was found to have no adverse effects on viral replication and plating efficiency of Rift Valley Fever Virus, Sindbis Virus and West Nile Virus.