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Cotton rats and house sparrows as hosts for North and South American strains of eastern equine encephalitis virus.

Eastern equine encephalitis virus (EEEV; family Togaviridae, genus Alphavirus) is an arbovirus that causes severe disease in humans in North America and in equids throughout the Americas. The enzootic transmission cycle of EEEV in North America involves passerine birds and the ornithophilic mosquito vector, Culiseta melanura, in freshwater swamp habitats. However, the ecology of EEEV in South America is not well understood. Culex (Melanoconion) spp. mosquitoes are considered the principal vectors in Central and South America; however, a primary vertebrate host for EEEV in South America has not…

[Two virus strains of isolated in China are recombinant alphaviruses].

OBJECTIVE: To determine the classification, phylogenetic and genetic type of XJ-90260 and XJ-91006 viruses isolated in China. METHODS: Two pairs of specific primers were designed to amplify the NSP4 and E1-3' UTR genes of XJ-90260 and XJ-91006 viruses and the nucleotide sequences between them and with that of other Alphavirus were compared. RESULTS: The nucleotide sequences identity between XJ-90260 and XJ-91006 viruses was 100% and has showed the highest with WEE, comparing with the other 26 Alphaviruses in 3'-UTR. NSP4 gene of XJ-90260 and XJ-91006 viruses high homologous with EEE virus an…

Necrotizing myocarditis in mice infected with Western equine encephalitis virus: Clinical, electrocardiographic, and histopathologic correlations.

Western equine encephalitis (WEE) virus was found in myocardial tissue of adult mice during the first five days after inoculation of the vir … he ST segment, and low voltage. Myocarditis has not been previously recognized as a complication of alphavirus infection in humans. and we found no evidence for myocardial damage in 11 persons with acute WEE virus infections studied electrocardiographically in 1975. Demonstration of myocarditis in the WEE virus-infected mouse, however, suggests the need to m …

Anti-Chikungunya Virus Monoclonal Antibody That Inhibits Viral Fusion and Release.

Chikungunya fever, a mosquito-borne disease manifested by fever, rash, myalgia, and arthralgia, is caused by chikungunya virus (CHIKV), which belongs to the genus Alphavirus of the family Togaviridae Anti-CHIKV IgG from convalescent patients is known to directly neutralize CHIKV, and the state of immunity lasts throughout life. Here, we examined the epitope of a neutralizing mouse monoclonal antibody against CHIKV, CHE19, which inhibits viral fusion and release. In silico docking analysis showed that the epitope of CHE19 was localized in the viral E2 envelope and consisted of two separate segm…

Entry Sites of Venezuelan and Western Equine Encephalitis Viruses in the Mouse Central Nervous System following Peripheral Infection.

UNLABELLED: Venezuelan and western equine encephalitis viruses (VEEV and WEEV; Alphavirus; Togaviridae) are mosquito-borne pathogens causing central nervous system (CNS) disease in humans and equids. Adult CD-1 mice also develop CNS disease after infection with VEEV and WEEV. Adult CD-1 mice infected by the intranasal (i.n.) route, showed that VEEV and WEEV enter the brain through olfactory sensory neurons (OSNs). In this study, we injected the mouse footpad with recombinant WEEV (McMillan) or VEEV (subtype IC strain 3908) expressing firefly luciferase (fLUC) to simulate mosquito infection and…

Adenoviral-Vectored Mayaro and Chikungunya Virus Vaccine Candidates Afford Partial Cross-Protection From Lethal Challenge in A129 Mouse Model.

Mayaro (MAYV) and chikungunya viruses (CHIKV) are vector-borne arthritogenic alphaviruses that cause acute febrile illnesses. CHIKV is widespread and has recently caused large urban outbreaks, whereas the distribution of MAYV is restricted to tropical areas in South America with small and sporadic outbreaks. Because MAYV and CHIKV are closely related and have high amino acid similarity, we investigated whether vaccination against one could provide cross-protection against the other. We vaccinated A129 mice (IFNAR -/-) with vaccines based on chimpanzee adenoviral vectors encoding the structural…

A self-amplifying RNA vector based on rubella virus for mRNA therapeutics and vaccine applications.

Significant efforts have been made in the burgeoning field of RNA therapies since the COVID-19 pandemic. Self-amplifying RNA (saRNA)-based t … otentially offers a better safety profile with reduced risk of adverse events compared with current alphavirus-derived saRNAs. We further optimized this RuV saRNA by screening the capsid region, the nonstructural polyprotein p200 codon, and the 3' untranslated region. This RuV saRNA has great potential to be used as a vaccine vector and in other applications …

Western equine encephalitis, a report of two cases in pediatric patients.

Western equine encephalitis (WEE) is vector-borne infection caused by an RNA virus of the genus Alphavirus, disseminated by mosquitoes that can cause WEE in humans. There are two cycles of transmission, a maintenance cycle and an occasional amplification with vector augmentation, where equines and humans are terminal hosts. In Argentina, no human cases had been reported since 1983. Here we describe 2 pediatric patients with brain symptoms and serological diagnosis of WEE. Both samples of cerebrospinal fluid (CSF) showed pleocytosis, while the neuroimaging test showed alterations in the basal g…

Developing a direct acting, orally available antiviral agent in a pandemic: the evolution of molnupiravir as a potential treatment for COVID-19.

Despite the availability of vaccines, there remains an urgent need for antiviral drugs with potent activity against SARS-CoV-2, the cause of COVID-19. Millions of people are immune-suppressed and may not be able to mount a fully protective immune response after vaccination. There is also an increasingly critical need for a drug to cover emerging SARS-CoV-2 variants, against which existing vaccines may be less effective. Here, we describe the evolution of molnupiravir (EIDD-2801, MK-4482), a broad-spectrum antiviral agent originally designed for the treatment of Alphavirus infections, into a po…

Modified Vaccinia Virus Ankara as a Viral Vector for Vaccine Candidates against Chikungunya Virus.

There is a need to develop a highly effective vaccine against the emerging chikungunya virus (CHIKV), a mosquito-borne Alphavirus that causes severe disease in humans consisting of acute febrile illness, followed by chronic debilitating polyarthralgia and polyarthritis. In this review, we provide a brief history of the development of the first poxvirus vaccines that led to smallpox eradication and its implications for further vaccine development. As an example, we summarize the development of vaccine candidates based on the modified vaccinia virus Ankara (MVA) vector expressing different CHIKV…

New Insights into Chikungunya Virus Infection and Pathogenesis.

Chikungunya virus (CHIKV) is a re-emerging mosquito-borne alphavirus responsible for major outbreaks of disease since 2004 in the Indian Ocean islands, South east Asia, and the Americas. CHIKV causes debilitating musculoskeletal disorders in humans that are characterized by fever, rash, polyarthralgia, and myalgia. The disease is often self-limiting and nonlethal; however, some patients experience atypical or severe clinical manifestations, as well as a chronic rheumatic syndrome. Unfortunately, no efficient antivirals against CHIKV infection are available so far, highlighting the importance o…

Venezuelan equine encephalitis virus: the problem is not over for tropical America.

The equine encephalitis viruses, Venezuelan (VEEV), East (EEEV) and West (WEEV), belong to the genus alphavirus, family Togaviridae and still represent a threat for human and animal public health in the Americas. In both, these infections are characterized by high viremia, rash, fever, encephalitis and death. VEEV encephalitis is similar, clinically, to other arboviral diseases, such as dengue, Zika or chikungunya. Most of the alphaviruses are transmitted between vertebrates and mosquitoes. They are able to replicate in a wide number of hosts, including mammals, birds, reptiles, amphibian and …

Human monoclonal antibodies against chikungunya virus target multiple distinct epitopes in the E1 and E2 glycoproteins.

Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that causes persistent arthritis in a subset of human patients. We report the isolation and functional characterization of monoclonal antibodies (mAbs) from two patients infected with CHIKV in the Dominican Republic. Single B cell sorting yielded a panel of 46 human mAbs of diverse germline lineages that targeted epitopes within the E1 or E2 glycoproteins. MAbs that recognized either E1 or E2 proteins exhibited neutralizing activity. Viral escape mutations localized the binding epitopes for two E1 mAbs to sites within domain I or t…

An overview of the immune response and Arginase I on CHIKV immunopathogenesis.

Chikungunya virus (CHIKV) is mosquito-borne alphavirus that has caused epidemics around the world. Many individuals affected by the disease may experience joint pain that persists for months after the acute phase. The pathophysiology of viral arthritis is not completely elucidated. And it is important to emphasize that the effects of the viral infection in each host may depend on host factors that include immune response, as well as factors specific to the virus as tissue tropism. The main pathway for the response against viral infection is through induction of type I interferon (IFN-I), whose…

A Case Report on Chikungunya Virus-Associated Encephalomyelitis.

Chikungunya is a rerising alphavirus infection that has resulted from enhanced vector competence. Alphaviruses are divided into arthritogenic viruses (old world) and encephalitogenic viruses (new world) including equine encephalitis viruses. Chikungunya is a dengue-like illness characterized by acute febrile polyarthralgia, arthritis, malaise, body ache, rash, headache, and nausea. The illness is self-limiting. The neurological manifestations are uncommon and incorporate meningoencephalitis, myelitis, Guillain-Barre syndrome, cranial nerve palsies, myelopathy, and neuropathy; MRI abnormalities…

Chikungunya Virus: Current Perspectives on a Reemerging Virus.

Chikungunya virus (CHIKV) is a mosquito-borne alphavirus in the family Togaviridae that causes outbreaks of debilitating acute and chronic arthralgia in humans. Although historically associated with localized outbreaks in Africa and Asia, recent epidemics in the Indian Ocean region and the Americas have led to the recognition that CHIKV is capable of moving into previously unaffected areas and causing significant levels of human suffering. The severity of CHIKV rheumatic disease, which can severely impact life quality of infected individuals for weeks, months, or even years, combined with the …

Передача вируса Денге и Западного Нила детям и взрослым в прибрежной Кении.

Вирус денге (DENV) и вирус Западного Нила (WNV) являются важными новообразующимися арбовирусами, которые не признаются во многих частях Африки из-за отсутствия наблюдения. В рамках исследования по флавирусу, альфавирусу и воздействию паразитов в прибрежной Кении мы измеряли нейтрализацию антител против DENV и, чтобы оценить специфичность анализа, WNV в образцах сыворотки, которые тестировали на сыворотку против DENV IgG с помощью энзимно привязанного иммуносорбента. Из 830 образцов с положительной реакцией на ДЕНВ, которые были испытаны на нейтрализацию, 488 (58,8 процента) нейтрализовали ДЕНВ

Совпадение в аннотации оригинала
Dengue virus (DENV) and West Nile virus (WNV) are important reemerging arboviruses that are under-recognized in many parts of Africa due to lack of surveillance. As a part of a study on flavivirus, alphavirus, and parasite exposure in coastal Kenya, we measured neutralizing antibody against DENV and, to evaluate assay specificity, WNV in serum samples that t…

Eastern equine encephalitis cases among horses in Brazil between 2005 and 2009.

Eastern equine encephalitis is a viral zoonosis that exhibits complex distribution and epidemiology, and greater importance should be given … een 2005 and 2009. Viral RNA was identified using semi-nested RT-PCR to detect members of the genus Alphavirus, and by genetic sequencing. The gene encoding NSP1 was partially amplified, and after genetic sequencing, eighteen sequences were generated. All eighteen strains were classified as belonging to lineage III of American EEEV. These findings could be a …

Development of a high-throughput antiviral assay for screening inhibitors of chikungunya virus and generation of drug-resistant mutations in cultured cells.

Chikungunya virus (CHIKV) is a mosquito-borne Alphavirus that has already infected millions of people in recent large-scale epidemics in Africa, the islands of the Indian Ocean, South and Southeast Asia, and northern Italy. The infection is still ongoing in many countries, such as India. Although the fatal rate is approximately 0.1% in the La Réunion outbreak, it causes painful arthritis-like symptoms that can last for months or even years. Currently, neither vaccine nor approved antiviral therapy exists to protect humans from chikungunya infection. Therefore, there is an urgent unmet medical …

Zoonotic encephalitides caused by arboviruses: transmission and epidemiology of alphaviruses and flaviviruses.

In this review, we mainly focus on zoonotic encephalitides caused by arthropod-borne viruses (arboviruses) of the families Flaviviridae (genus Flavivirus) and Togaviridae (genus Alphavirus) that are important in both humans and domestic animals. Specifically, we will focus on alphaviruses (Eastern equine encephalitis virus, Western equine encephalitis virus, Venezuelan equine encephalitis virus) and flaviviruses (Japanese encephalitis virus and West Nile virus). Most of these viruses were originally found in tropical regions such as Africa and South America or in some regions in Asia. However,…