1,154 results match your criteria: "Encephalitis Western Equine"

Western equine encephalitis is a zoonotic viral disease transmitted by the bite of an infected mosquito. Humans are terminal hosts and since they develop a very low and short lasting viremia, they are incapable of transmitting the disease. Most cases are asymptomatic, but it can present with high fever, myalgia and encephalitis or meningitis.

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We report the genomic analysis from early equine cases of the Western equine encephalitis virus outbreak during 2023-2024 in Uruguay. Sequences are related to a viral isolate from an outbreak in 1958 in Argentina. A viral origin from South America or continuous enzootic circulation with infrequent spillover is possible.

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Western equine encephalitis virus (WEEV) is a mosquito-borne arbovirus (genus , family ) that has re-emerged in South America in late 2023, causing severe disease in both horses and humans after a nearly 40-year intermission period. We here describe the virological, serological, pathological, and molecular features of WEEV infection in horses during the 2023-2024 outbreak in Argentina. WEEV-infected horses developed neurological signs with mild to severe encephalitis associated with minimal to abundant WEEV-infected cells, as demonstrated by WEEV-specific in situ hybridization.

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Equine Herpesvirus Type 1 ORF76 Encoding US9 as a Neurovirulence Factor in the Mouse Infection Model.

Pathogens

October 2024

Department of Applied Veterinary Sciences, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.

Equine herpesvirus type 1 (EHV-1) causes rhinopneumonitis, abortion, and neurological outbreaks (equine herpesvirus myeloencephalopathy, EHM) in horses. EHV-1 also causes lethal encephalitis in small laboratory animals such as mice and hamsters experimentally. EHV-1 ORF76 is a homolog of HSV-1 US9, which is a herpesvirus kinase.

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The VLDLR entry receptor is required for the pathogenesis of multiple encephalitic alphaviruses.

Cell Rep

October 2024

Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, St. Louis, MO 63110, USA; Center for Vaccines and Immunity to Microbial Pathogens, Washington University School of Medicine, Saint Louis, MO 63110, USA. Electronic address:

Article Synopsis
  • VLDLR has been identified as a receptor for several alphaviruses, including Western equine encephalitis virus (WEEV), and may play a role in their infection process.
  • Research shows that mice lacking VLDLR have reduced susceptibility to WEEV, EEEV, and Semliki Forest virus (SFV), indicating its importance in alphavirus pathogenesis.
  • The findings suggest that targeting VLDLR could be a potential strategy for developing treatments against various alphavirus infections.
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Article Synopsis
  • Western equine encephalitis (WEE) is a virus that primarily affects animals but can accidentally infect humans, particularly children who face a higher risk of serious symptoms.
  • A 13-year-old boy from Buenos Aires became severely ill with meningoencephalitis, and despite initial tests showing no common microorganisms, he tested positive for WEE virus antibodies in both his blood and cerebrospinal fluid.
  • This case highlights that WEE is often overlooked as a potential cause of encephalitis, making it important to consider even in urban settings.
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Article Synopsis
  • Western equine encephalitis virus (WEEV) caused a significant outbreak in Argentina and Uruguay from December 2023 to April 2024, with 217 human cases and 2,548 equine cases reported.
  • The investigation focused on the Rio Grande do Sul state border area between Argentina and Uruguay, utilizing epidemiologic, entomological, and genomic methods to analyze the outbreak.
  • A novel lineage of the virus, proposed as lineage C, was identified in three fatal equine cases, emphasizing the need for ongoing monitoring and equine vaccination to prevent future outbreaks.
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Western equine encephalitis, a report of two cases in pediatric patients.

Arch Argent Pediatr

August 2024

Department of Infectious Diseases; Clínica La Pequeña Familia, Junín, Argentina.

Article Synopsis
  • - Western equine encephalitis (WEE) is a viral infection transmitted through mosquitoes, affecting both horses and humans, with recent human cases reported in Argentina after a long absence since 1983.
  • - The report discusses two pediatric patients who exhibited brain-related symptoms and were diagnosed with WEE through cerebrospinal fluid analysis and serological testing showing specific antibodies.
  • - One patient fully recovered before discharge, while the other had temporary right hemiparesis that improved after two months, but continued to require anticonvulsant medication due to abnormal EEG readings.
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Article Synopsis
  • Western equine encephalitis virus (WEEV) used to cause significant outbreaks in humans and horses but has become less virulent over time, raising questions about the reasons for this change and the potential for re-emergence of deadly strains.
  • Researchers identified protocadherin 10 (PCDH10) as a key receptor for WEEV, which ancient strains could bind to, while contemporary strains show reduced binding abilities indicating a shift in the virus’s host adaptation.
  • The study suggests that PCDH10 not only facilitates infection in neurons but also that a soluble form can protect against WEEV, offering insights for future medical treatments and risk assessments of the virus.
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Article Synopsis
  • Molecular surveillance is crucial for tracking arboviruses, using techniques like genus-specific RT-qPCR, but issues like false negatives have hindered effective monitoring.
  • The study improved RT-qPCR tests to accurately detect various alphaviruses, including chikungunya, achieving high sensitivity and specificity.
  • The improved assay identified three chikungunya cases from a 2019 outbreak in Yunnan, suggesting that imported infections from nearby countries played a role in that outbreak.
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Background: West Nile Virus (WNV) is a zoonotic arbovirus worldwide spread. Seasonal WNV outbreaks occur in the Mediterranean basin since the late 1990's with ever-increasing incidence. In Southern Spain WNV is endemic, as disease foci - caused by WNV lineage 1 (WNV-L1) strains - occur every year.

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Article Synopsis
  • Venezuelan, eastern, and western equine encephalitis viruses are dangerous viruses that can cause severe illness in both horses and humans, but there are currently no approved vaccines or antiviral treatments for them.
  • Vaccine development requires FDA approval based on animal models that accurately reflect human disease, but existing mouse models do not do so effectively, as they result in different disease outcomes than in humans.
  • Recent studies indicate that using hamsters as a model for testing vaccines and therapies against these viruses is also ineffective, as their disease symptoms do not align with those seen in humans or non-human primates.
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Molecular epidemiology of Western equine encephalitis virus in Brazil, 2023-2024.

medRxiv

April 2024

Secretaria de Saúde do Estado do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.

Article Synopsis
  • A recent outbreak of western equine encephalitis virus (WEEV) has been reported in South America, particularly in Brazil, where three horses have died from the infection.
  • Researchers sequenced the WEEV strains and discovered a new lineage responsible for these fatalities.
  • To reduce the impact of WEEV, ongoing monitoring and vaccination of horses are essential.
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Article Synopsis
  • The study investigates the safety and effectiveness of a new vaccine, MVA-BN-WEV, designed to protect against three encephalitic alphaviruses (WEEV, EEEV, VEEV) in healthy adults.
  • Forty-five participants were given two doses of the vaccine at varying strengths, monitored for side effects and immune response over six months.
  • Results showed the vaccine was generally safe with mild side effects, and it successfully triggered strong immune responses against all three viruses, especially at higher doses.
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Article Synopsis
  • Researchers tested two vaccines for eastern equine encephalitis virus (EEEV) in cynomolgus macaques using an aerosol infection model.
  • Both vaccines, MVA-BN-EEEV (monovalent) and MVA-BN-WEV (multivalent), triggered strong and lasting immune responses that protected the monkeys against lethal EEEV exposure.
  • The results showed that the vaccinated macaques had nearly complete protection from viral presence in their bodies and no significant brain damage, suggesting the vaccines are effective against aerosolized EEEV infections.
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Japanese Encephalitis: Risk of Emergence in the United States and the Resulting Impact.

Viruses

December 2023

Quigley BioPharma LLC, 114 Water Tower Plaza No. 1042, Leominster, MA 01453, USA.

Japanese encephalitis virus is a mosquito-borne member of the family. JEV is the leading cause of viral encephalitis in Asia and is characterized by encephalitis, high lethality, and neurological sequelae in survivors. The virus also causes severe disease in swine, which are an amplifying host in the transmission cycle, and in horses.

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[Preparation of mouse monoclonal antibodies against the ectodomain of Western equine encephalitis virus E2 (E2ecto) protein].

Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi

January 2024

Department of Microbiology and Pathogenic Biology, Basic Medical Science Academy, Air Force Medical University, Xi'an 710032, China. *Corresponding authors, E-mail:

Objective To prepare mouse monoclonal antibodies against the ectodomain of E2 (E2ecto) glycoprotein of Western equine encephalitis virus (WEEV). Methods A prokaryotic expression plasmid pET-28a-WEEV E2ecto was constructed and transformed into BL21 (DE3) competent cells. E2ecto protein was expressed by IPTG induction and presented mainly as inclusion bodies.

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Article Synopsis
  • Researchers investigated the role of LDLR and other LDLR family members as entry factors for alphaviruses, discovering that blocking these receptors does not completely stop infection, indicating more unidentified factors are involved.
  • Using CRISPR-Cas9, they identified LDLR in mouse neuronal cells as a candidate receptor that aids in the infection of various alphaviruses like EEEV and Western equine encephalitis virus.
  • Their findings suggest that LDLR interacts weakly with virus proteins, and developing inhibitors using decoy proteins could provide a way to reduce alphavirus infections and related diseases.
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Severe Neurologic Disease in a Horse Caused by Tick-Borne Encephalitis Virus, Austria, 2021.

Viruses

September 2023

Viral Zoonoses, Emerging and Vector-Borne Infections Group, Institute of Virology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria.

Article Synopsis
  • *The study utilized various tests, including ELISA, RT-qPCR, and Sanger sequencing, to identify and confirm the presence of TBEV in horse brain tissue and serum samples.
  • *Findings indicated the Western European subtype of TBEV as the cause, emphasizing the importance of early diagnostic procedures after neurological signs appear to ensure accurate diagnosis and treatment.
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Vertebrate-class-specific binding modes of the alphavirus receptor MXRA8.

Cell

October 2023

Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Pathology & Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO 63110, USA; Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, Saint Louis, MO 63110, USA. Electronic address:

MXRA8 is a receptor for chikungunya (CHIKV) and other arthritogenic alphaviruses with mammalian hosts. However, mammalian MXRA8 does not bind to alphaviruses that infect humans and have avian reservoirs. Here, we show that avian, but not mammalian, MXRA8 can act as a receptor for Sindbis, western equine encephalitis (WEEV), and related alphaviruses with avian reservoirs.

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Identification and Molecular Characterization of Shamonda Virus in an Aborted Goat Fetus in South Africa.

Pathogens

August 2023

Zoonotic Arbo- and Respiratory Virus Research Program, Centre for Viral Zoonoses, Department of Medical Virology, University of Pretoria, Pretoria 0084, South Africa.

Viruses in the genus, family, are associated with encephalitis, birth defects and fatalities in animals, and some are zoonotic. Molecular diagnostic investigations of animals with neurological signs previously identified Shuni virus (SHUV) as the most significant orthobunyavirus in South Africa (SA). To determine if other orthobunyaviruses occur in SA, we screened clinical specimens from animals with neurological signs, abortions, and acute deaths from across SA in 2021 using a small (S) segment Simbu serogroup specific TaqMan real-time reverse transcription polymerase chain reaction (RT-PCR).

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While rodents are primary reservoirs of Venezuelan equine encephalitis virus (VEEV), their role in Madariaga virus (MADV) transmission remains uncertain, particularly given their overlapping geographic distribution. This study explores the interplay of alphavirus prevalence, rodent diversity, and land use within Darien and Western Panama provinces. A total of three locations were selected for rodent sampling in Darien province: Los Pavitos, El Real de Santa Maria and Santa Librada.

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A diverse group of RNA viruses including Rabies, Polio, La Crosse, West Nile, Zika, Nipah, Eastern and Western equine encephalitis, Venezuelan equine encephalitis, Japanese encephalitis, and tick-borne encephalitis viruses have the ability to gain access to and replicate in the central nervous system (CNS), causing severe neurological disease. Current treatment for these patients is generally limited to supportive care. To address the need for a generalizable antiviral, we utilized a strategy of mutagenesis to limit virus replication.

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