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Zika virus-related neurotropic flaviviruses infect human placental explants and cause fetal demise in mice.

Although Zika virus (ZIKV) infection in pregnant women can cause placental damage, intrauterine growth restriction, microcephaly, and fetal demise, these disease manifestations only became apparent in the context of a large epidemic in the Americas. We hypothesized that ZIKV is not unique among arboviruses in its ability to cause congenital infection. To evaluate this, we tested the capacity of four emerging arboviruses [West Nile virus (WNV), Powassan virus (POWV), chikungunya virus (CHIKV), and Mayaro virus (MAYV)] from related (flavivirus) and unrelated (alphavirus) genera to infect the pla…

Chikungunya Virus-Induced Arthritis: Role of Host and Viral Factors in the Pathogenesis.

Chikungunya virus (CHIKV), a member of Alphavirus genus, is responsible for chikungunya fever (CHIKF), which is characterized by the presence of fever, rash, myalgia, and arthralgia. Reemergence of CHIKV has become a significant public health concern in Asian and African countries and is newly emerging in the Middle East, Pacific, American, and European countries. Cytokines, innate (monocytes, natural killer cells) and adaptive immune response (role of B cells and T cells i.e. CD4+ and CD8+), and/or viral factors contribute to CHIKV-induced arthritis. Vector factors such as vector competence (…

Chikungunya virus fusion properties elucidated by single-particle and bulk approaches.

Chikungunya virus (CHIKV) is a rapidly spreading, enveloped alphavirus causing fever, rash and debilitating polyarthritis. No specific treatment or vaccines are available to treat or prevent infection. For the rational design of vaccines and antiviral drugs, it is imperative to understand the molecular mechanisms involved in CHIKV infection. A critical step in the life cycle of CHIKV is fusion of the viral membrane with a host cell membrane. Here, we elucidate this process using ensemble-averaging liposome-virus fusion studies, in which the fusion behaviour of a large virus population is measu…

Chikungunya virus and its mosquito vectors.

Chikungunya virus (CHIKV), a mosquito-borne alphavirus of increasing public health significance, has caused large epidemics in Africa and the Indian Ocean basin; now it is spreading throughout the Americas. The primary vectors of CHIKV are Aedes (Ae.) aegypti and, after the introduction of a mutation in the E1 envelope protein gene, the highly anthropophilic and geographically widespread Ae. albopictus mosquito. We review here research efforts to characterize the viral genetic basis of mosquito-vector interactions, the use of RNA interference and other strategies for the control of CHIKV in mo…

In silico models for predicting vector control chemicals targeting Aedes aegypti.

Human arboviral diseases have emerged or re-emerged in numerous countries worldwide due to a number of factors including the lack of progress in vaccine development, lack of drugs, insecticide resistance in mosquitoes, climate changes, societal behaviours, and economical constraints. Thus, Aedes aegypti is the main vector of the yellow fever and dengue fever flaviviruses and is also responsible for several recent outbreaks of the chikungunya alphavirus. As for the other mosquito species, the A. aegypti control relies heavily on the use of insecticides. However, because of increasing resistance…

Human-like antibodies neutralizing Western equine encephalitis virus.

This study describes the development of the first neutralizing antibodies against Western equine encephalitis virus (WEEV), a member of the genus Alphavirus. WEEV is transmitted by mosquitoes and can spread to the human central nervous system, causing symptoms ranging from mild febrile reactions to life-threatening encephalitis. WEEV has been classified as a biological warfare agent by the US Centers for Disease Control and Prevention. No anti-WEEV drugs are currently commercially available. Neutralizing antibodies are useful for the pre- and post-exposure treatment of WEEV infections. In this…

Prolonged myalgia in Sindbis virus infection: case description and in vitro infection of myotubes and myoblasts.

BACKGROUND: Sindbis virus (SINV) is a mosquito-borne alphavirus found in Eurasia, Africa, and Oceania. Clinical SINV infection is characterized by febrile rash and arthritis and sometimes prolonged arthralgia and myalgia. The pathophysiological mechanisms of musculoskeletal and rheumatic disease caused by SINV are inadequately understood. METHODS: We studied the muscle pathology of SINV infection ex vivo by examining a unique muscle biopsy obtained from a patient with chronic myalgia and arthralgia 6 months after acute SINV infection and assessed potential genetic predisposing factors by dete…

An assembly model of rift valley Fever virus.

Rift Valley fever virus (RVFV) is a bunyavirus endemic to Africa and the Arabian Peninsula that infects humans and livestock. The virus enco … posed arrangement of the two glycoproteins on the RVFV surface is similar to that described for the alphavirus E1-E2 proteins. Our models will provide guidance to better understand the assembly process of phleboviruses and such structural studies can also contribute to the design of targeted antivirals.

Chikungunya virus infection of cell lines: analysis of the East, Central and South African lineage.

Chikungunya virus (CHIKV) is a re-emerging mosquito borne alphavirus that has caused large scale epidemics in the countries around the Indian Ocean, as well as leading to autochthonous transmission in some European countries. The transmission of the disease has been driven by the emergence of an African lineage of CHIKV with enhanced transmission and dissemination in Aedes mosquito hosts. Two main genotypes of this lineage have been circulating, characterized by the presence of a substitution of a valine for an alanine at position 226 of the E1 protein. The outbreak, numbering in millions of c…

A mouse model of chikungunya virus-induced musculoskeletal inflammatory disease: evidence of arthritis, tenosynovitis, myositis, and persistence.

Chikungunya virus (CHIKV), an emerging mosquito-borne Alphavirus, causes debilitating rheumatic disease in humans that can last for weeks to months. Starting in 2004, a CHIKV outbreak in the Indian Ocean region affected millions of people, and infected travelers introduced CHIKV to new regions. The pathogenesis of CHIKV is poorly understood, and no approved vaccines or specific therapies exist. A major challenge to the study of CHIKV disease is the lack of a small animal model that recapitulates the major outcomes of human infection. In this study, the pathogenesis of CHIKV in C57BL/6J mice wa…

[West Nile virus and its vectors].

There are more than five hundred known arthropod-borne viruses (arboviruses) all around the world and approximately hundred of them may caus … obal climate changes. Mosquitoes are among the most important vectors carrying viruses belonging to Alphavirus, Flavivirus, Bunyavirus and Phlebovirus genera. All of the above factors have contributed to the increase in mosquito populations and closer contact between humans and mosquito vectors. West Nile virus notable after the epidemic of 1996 in Romania i …

Репликоны рекомбинантной РНК, полученные в результате ослабленного венесуэльского энцефалитного вируса, защищают морских свиней и мышей от вируса геморрагической лихорадки Эболы.

Репликоны РНК, полученные в результате ослабления штамма венесуэльского энцефалита (VEE), альфавируса, были разработаны как потенциальные вакцины от геморрагической лихорадки Эболы. Гены Эболы нуклеопротеина (NP) или гликпротеина (GP) были введены в VEE RNA вниз по течению от VEE 26S промоутер вместо VEE структурно-белковых генов. Полученные рекомбинантные репликоны, выражающие гены NP или GP, были упакованы в репликонные частицы VEE (соответственно NP-VRP и GP-VRP) с использованием двухпартийной системы поддержки, которая обеспечивала структурные белки VEE в трансе и предотвратила регенерацию

Совпадение в аннотации оригинала
RNA replicons derived from an attenuated strain of Venezuelan equine encephalitis virus (VEE), an alphavirus, were configured as candidate vaccines for Ebola hemorrhagic fever. The Ebola nucleoprotein (NP) or glycoprotein (GP) genes were introduced into the VEE RNA downstream from the VEE 26S promoter in place of the VEE structural protein genes. The resulti…

[Serological survey on arbovirus infection in residents of an ecological reserve].

OBJECTIVE: Serological inquires conducted in the Ribeira Valley, S. Paulo State, Brazil, showed an intense circulation of pathogenic arbovir … antibodies to ROC, ILH and EEE viruses. RESULTS: The prevalence of antibodies was 26.9% (21. 4% to alphavirus and 12.6% to flavivirus). There were no antibodies to WEE virus. IgM antibodies were not observed suggesting no recent infection in study population. Among the characteristics investigated, age, occupation, place of birth and the habit of going into …

Arboviruses causing human disease in the Australasian zoogeographic region.

Over 65 arboviruses have been reported from countries in the Australasian zoogeographic region, but only a few have been implicated in human disease. These include the flaviviruses Murray Valley encephalitis (MVE), Kunjin (KUN), Kokobera (KOK), and dengue, particularly types 1 and 2; the alphaviruses Ross River (RR), Barmah Forest (BF), and Sindbis (SIN); and the bunyaviruses, Gan Gan and Trubanaman. In this paper recent epidemiological and clinical results pertaining to these viruses are reviewed, with major emphasis on MVE and RR viruses. The extensive early studies of Australian arboviruses…

Vaccinations for Neuroinfectious Disease: A Global Health Priority.

Vaccines for neuroinfectious diseases are becoming an ever-increasing global health priority, as neurologic manifestations and sequelae from … discusses vaccines that are currently available or under development for zoonotic flaviviruses and alphaviruses, including Japanese and tick-borne encephalitis, yellow fever, West Nile, dengue, Zika, encephalitic equine viruses, and chikungunya. Also discussed are nonzoonotic agents, including measles and human herpesviruses, as well as select bacterial, fu …

Chikungunya virus 3' untranslated region: adaptation to mosquitoes and a population bottleneck as major evolutionary forces.

The 3' untranslated genome region (UTR) of arthropod-borne viruses is characterized by enriched direct repeats (DRs) and stem-loop structures. Despite many years of theoretical and experimental study, on-going positive selection on the 3'UTR had never been observed in 'real-time,' and the role of the arbovirus 3'UTR remains poorly understood. We observed a lineage-specific 3'UTR sequence pattern in all available Asian lineage of the mosquito-borne alphavirus, chikungunya virus (CHIKV) (1958-2009), including complicated mutation and duplication patterns of the long DRs. Given that a longer geno…

[Critical analysis of requirements for scientific assessment as a basis for good governance: case of the chikungunya epidemic on Reunion Island and Mayotte in 2005 and 2006].

The constitutional precautionary principle as applied in laws governing health care at the community level requires rigorous scientific assessment. The goal of this assessment is to provide authorities with sound evidence as a basis for implementing precautionary measures in function of degree of risk and other parameters such as the level of public health protection that is high in the EU. As the political authority, the government can act independently of conclusions issued by scientific commissions provided that the commission's level of expertise meets national and European standards and t

[An imported Chikungunya fever case from New Delhi, India to Ankara, Turkey: the first imported case of Turkey and review of the literature].

Chikungunya virus (CHIKV) is an arthropod-borne alphavirus that causes an acute febrile illness, chikungunya fever. CHIKV virus is geographically distributed in Africa, India, and South-East Asia. Chikungunya fever outbreaks have been reported from India since 2006. The incubation period is 3-7 days, and the disease is characterized by sudden onset of high fever and severe arthralgia. Other symptoms can be rash, headache, fatigue, nausea-vomiting, and myalgias. Here, we report the first Chikungunya case imported from India, New-Delhi to Ankara, Turkey. In December 2010, a 55-year-old female Tu…

Viruses isolated from mosquitoes collected in Sri Lanka.

Attempts to isolate viruses from 178,181 unengorged female mosquitoes collected from different ecologic areas of Sri Lanka yielded 31 isolates: 17 of Japanese encephalitis (JE) virus, nine of Getah virus, three of a Batai-related bunyavirus, and two of Arkonam virus. Culex tritaeniorhynchus and Mansonia uniformis mosquitoes were found to carry JE virus in a dry zone nonepidemic area, and Cx. pseudovishnui was found to carry it in a wet zone nonepidemic area. Japanese encephalitis virus was isolated from Cx. tritaeniorhynchus, Cx. gelidus, Cx. fuscocephala, and Cx. whitmorei during a human epid