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Development of a multi-target TaqMan assay to detect eastern equine encephalitis virus variants in mosquitoes.

Disease outbreaks caused by eastern equine encephalitis virus (EEEV; Togaviridae, Alphavirus) may be prevented by implementing effective surveillance and intervention strategies directed against the mosquito vector. Methods for EEEV detection in mosquitoes include a real-time reverse transcriptase PCR technique (TaqMan assay), but we report its failure to detect variants isolated in Connecticut in 2011, due to a single base-pair mismatch in the probe-binding site. To improve the molecular detection of EEEV, we developed a multi-target TaqMan assay by adding a second primer/probe set to provide…

Arbovirus infections in several Ontario mammals, 1975-1980.

Serological studies for arboviruses were conducted on 725 animal sera collected in 22 Ontario townships between 1975 and 1980 including 44 c … in 12% of fox, 7% of skunk, 7% of raccoon and 5% of coyote sera. No antibodies were detected to two alphavirus, namely eastern equine encephalitis and western equine encephalitis, antigens. This study affirms the endemic presence of Powassan and snowshoe hare virus and further delineates the scope of St. Louis encephalitis activity in Ontario.

Modulating Chikungunya and Mayaro virus-induced disease severity in mice using low concentrations of anti-IFNAR1 antibodies.

The laboratory mouse (Mus musculus) is the most widely used animal model for preclinical research, with numerous wild-type and genetically modified mouse strains available. Chikungunya virus (CHIKV), a mosquito-borne arthritogenic alphavirus, has emerged in various new regions and caused several millions of cases within the last decade. Mayaro virus (MAYV), an arthritogenic alphaviruses closely related to CHIKV, remains geographically restricted to the Americas. Existing mouse models rely on immunodeficient mice, leading to lethal illness, or footpad injection, which induces localized arthropa…

[Mayaro: a re-emerging Arbovirus in Venezuela and Latin America].

Mayaro virus produces nonspecific, sublethal disease symptoms, often confused with dengue, but with symptoms of arthalgias that can cause incapacitating disability. Outbreaks have been localized and sporadic in the Pan-Amazonia forest since its first isolation in 1954 (Trinidad and Tobago). The literature available is scarce, diverse and dispersed. Mayaro virus is an alphavirus, phylogenetically related to the Semliki forest antigenic complex. UNA and Mayaro viruses are the only viruses of this complex that have been isolated in the New World. Mayaro consists of single-stranded RNA of positive…

Getah virus capsid protein undergoes co-condensation with viral genomic RNA to facilitate virion assembly.

Getah virus (GETV) belongs to the Alphavirus genus in the Togaviridae family and is a zoonotic arbovirus causing disease in both humans and animals. The capsid protein (CP) of GETV regulates the viral core assembly, but the mechanism underlying this process is poorly understood. In this study, we demonstrate that CP undergoes liquid-liquid phase separation (LLPS) with the GETV genome RNA (gRNA) in vitro and forms cytoplasmic puncta in cells. Two regions of GETV gRNA (nucleotides 1-4000 and 5000-8000) enhance CP droplet formation in vitro and the lysine-rich Link region of CP is essential for i…

The biology of chikungunya: a brief review of what we still do not know.

Responsible for a massive outbreak in the Indian Ocean in 2005-2006, the chikungunya virus is also reemerging in India where it has already infected over a million persons. Imported cases of the disease are reported in Asia, USA, and Europe, where a small epidemic occurred, due to transmission by local mosquitoes. Chikungunya virus is an alphavirus (Togaviridae family) that usually induces an acute illness characterized by fever, rash, and painful, incapacitating arthralgia a few days after being bitten by an infected mosquito, but recurrent joint pains are frequent. Unusual severe forms of th…

Update: chikungunya fever diagnosed among international travelers--United States, 2006.

Chikungunya virus (CHIKV) is a mosquitoborne alphavirus indigenous to tropical Africa and Asia, where it causes endemic and epidemic chikungunya (CHIK) fever, an acute illness characterized by fever, arthralgias, and sometimes arthritis, commonly accompanied by conjunctivitis and rash. Although symptoms of CHIKV infection usually last days to weeks, joint symptoms and signs usually last for months and occasionally for 1 year or longer; deaths from CHIKV infection are rare. No specific antiviral treatment exists for CHIKV infection; treatment consists of supportive care, including analgesics an…

Chikungunya virus infection.

Chikungunya virus (CHIKV) is a mosquito-borne alphavirus which causes epidemic fever, rash and polyarthralgia in Africa and Asia. Two outbreaks have been reported in Malaysia, in Klang, Selangor (1998) and Bagan Panchor, Perak (2006). It is not known if the outbreaks were caused by the recent introduction of CHIKV, or if the virus was already circulating in Malaysia. Seroprevalence studies from the 1960s suggested previous disease activity in certain parts of the country. In Asia, CHIKV is thought to be transmitted by the same mosquitoes as dengue, Aedes aegypti and Ae. albopictus. Due to simi…

Reevaluation of the western equine encephalitis antigenic complex of alphaviruses (family Togaviridae) as determined by neutralization tests.

Fourteen viruses closely related to the Fleming strain of western equine encephalitis (WEE) virus were cross-tested by serum dilution-plaque reduction neutralization. The results demonstrate that strains McMillan, R-43738, AG80-646, BeAr 102091, and Y62-33 are subtypes or varieties of western equine encephalitis virus strain Fleming. Ockelbo, Kyzylagach, and Babanki are subtypes of the prototype strain (EgAr 339) of Sindbis virus. Fort Morgan and Buggy Creek viruses are closely related to each other, whereas Highlands J and Aura viruses are distinct from other members of this antigenic complex

Susceptibility of two turtle species to eastern equine encephalitis virus.

Two species of turtle collected in southern New England were inoculated subcutaneously with eastern equine encephalitis virus. The spotted turtles (Clemmys guttata) developed viremia and neutralizing antibody after exposure to 3 logs or more of virus. Viremia was not detected in the eastern painted turtles (Chrysemys picta), and neutralizing antibody was detected in only 1 of 15 inoculated C. picta; however, since pre-inoculation serum was not obtained from this animal, the possibility of natural infection cannot be eliminated.

Fatal Human Infection with Evidence of Intrahost Variation of Eastern Equine Encephalitis Virus, Alabama, USA, 2019.

Eastern equine encephalitis virus (EEEV) is an arbovirus in the family Togaviridae, genus Alphavirus, found in North America and associated with freshwater/hardwood swamps in the Atlantic, Gulf Coast, and Great Lakes regions. EEEV disease in humans is rare but causes substantial illness and death. To investigate the molecular epidemiology and microevolution of EEEV from a fatal case in Alabama, USA, in 2019, we used next-generation sequencing of serum and cerebrospinal fluid (CSF). Phylogenetic inference indicated that the infecting strain may be closely related to isolates from Florida detect…

Текущее понимание молекулярной основы венесуэльского энцефалита вируса патогенеза и разработки вакцин.

Венесуэльский энцефалит (VEV) — альфавирус семейства тогавирид. VEEV является высокозаразным в аэрозольной форме и известным биовоенным агентом, который может вызывать сильный энцефалит у человека. Периодические вспышки VEEV происходят главным образом в Центральной и Южной Америке. Повышение интереса к VEEV привело к более глубокому пониманию патогенеза этой болезни. Воспаление играет парадоксальную роль в антивирусной реакции, а также в развитии смертоносного энцефалита на основе взаимодействия между принимающим и вирусными факторами, которые диктуют репликацию вируса. VEEV имеет эффективный

Совпадение в аннотации оригинала
Venezuelan equine encephalitis virus (VEEV) is an alphavirus in the family Togaviridae. VEEV is highly infectious in aerosol form and a known bio-warfare agent that can cause severe encephalitis in humans. Periodic outbreaks of VEEV occur predominantly in Central and South America. Increased interest in VEEV has resulted in a more thorough understanding of t…

Rift Valley fever virus: strategies for maintenance, survival and vertical transmission in mosquitoes.

Rift Valley fever virus (RVFV) is a mosquito-borne arbovirus causing severe disease in humans and ruminants. Spread of RVFV out of Africa ha … ection in natural and experimental data. The observations of VT for other arboviruses in the genera Alphavirus, Flavivirus and Orthobunyavirus are discussed within the context of RVFV. The review concludes that VT of RVFV is likely but that current data are insufficient to irrefutably prove this hypothesis.

A human genome-wide loss-of-function screen identifies effective chikungunya antiviral drugs.

Chikungunya virus (CHIKV) is a globally spreading alphavirus against which there is no commercially available vaccine or therapy. Here we use a genome-wide siRNA screen to identify 156 proviral and 41 antiviral host factors affecting CHIKV replication. We analyse the cellular pathways in which human proviral genes are involved and identify druggable targets. Twenty-one small-molecule inhibitors, some of which are FDA approved, targeting six proviral factors or pathways, have high antiviral activity in vitro, with low toxicity. Three identified inhibitors have prophylactic antiviral effects in …

Chikungunya Virus Vaccines: Viral Vector-Based Approaches.

In 2013, a major chikungunya virus (CHIKV) epidemic reached the Americas. In the past 2 years, >1.7 million people have been infected. In li … bed vectors such as modified vaccinia virus Ankara, complex adenovirus, vesicular stomatitis virus, alphavirus-based chimeras, and measles vaccine Schwarz strain (MV/Schw) have been described as potential vaccines. We summarize here the recent data on these experimental vaccines, with a focus on the preclinical and clinical activities on the MV/Schw-based ca …

1,5-Iodonaphthyl azide-inactivated V3526 protects against aerosol challenge with virulent venezuelan equine encephalitis virus.

Venezuelan equine encephalitis virus (VEEV) is a New World alphavirus. VEEV is highly infectious in aerosolized form and has been identified as a bio-terrorism agent. There is no licensed vaccine for prophylaxis against VEEV. The current IND vaccine is poorly immunogenic and does not protect against an aerosol challenge with virulent VEEV. We have previously shown that VEEV inactivated by 1,5-iodonaphthyl azide (INA) protects against footpad challenge with virulent VEEV. In this study, we inactivated an attenuated strain of VEEV, V3526, with INA and evaluated its protective efficacy against ae…

Identification of germline transcriptional regulatory elements in Aedes aegypti.

The mosquito Aedes aegypti is the principal vector for the yellow fever and dengue viruses, and is also responsible for recent outbreaks of the alphavirus chikungunya. Vector control strategies utilizing engineered gene drive systems are being developed as a means of replacing wild, pathogen transmitting mosquitoes with individuals refractory to disease transmission, or bringing about population suppression. Several of these systems, including Medea, UD(MEL), and site-specific nucleases, which can be used to drive genes into populations or bring about population suppression, utilize transcript…

Chikungunya vaccine candidate is highly attenuated and protects nonhuman primates against telemetrically monitored disease following a single dose.

Chikungunya virus (CHIKV) is a mosquito-borne alphavirus that causes major epidemics of rash, fever, and debilitating arthritis. Currently, there are no vaccines or antivirals available for prevention or treatment. We therefore generated 2 live-attenuated vaccine candidates based on the insertion of a picornavirus internal ribosome entry site (IRES) sequence into the genome of CHIKV. Vaccination of cynomolgus macaques with a single dose of either vaccine produced no signs of disease but was highly immunogenic. After challenge with a subcutaneous inoculation of wild-type CHIKV, both vaccine can…

Human cases of Sindbis fever in South Africa, 2006-2010.

Sindbis virus (SINV), the prototype positive-sense RNA alphavirus, causes febrile arthritis and is present throughout Afro-Eurasia. Little is known of the epidemiology of Sindbis fever due to insufficient surveillance in most endemic countries. The epidemiological features of Sindbis fever in humans in South Africa are described here based on a retrospective study of suspected arbovirus cases submitted for laboratory investigation from 2006 to 2010. Cases were detected annually mostly during the late summer/early autumn months and an increase in cases was noted for 2010, coinciding with an out…

Transmission potential of two chimeric Chikungunya vaccine candidates in the urban mosquito vectors, Aedes aegypti and Ae. albopictus.

Chikungunya virus (CHIKV) is an emerging, mosquito-borne alphavirus that has caused major epidemics in Africa and Asia. We developed chimeric vaccine candidates using the non-structural protein genes of either Venezuelan equine encephalitis virus (VEEV) attenuated vaccine strain TC-83 or a naturally attenuated strain of eastern equine encephalitis virus (EEEV) and the structural genes of CHIKV. Because the transmission of genetically modified live vaccine strains is undesirable because of the potentially unpredictable evolution of these viruses as well as the potential for reversion, we evalua…