Venezuelan equine encephalitis vee is a mosquitoborne illness caused by an alphavirus of the togaviridae family. Definitive diagnosis can be made by isolating the virus in a laboratory or by testing blood for the. Sindbis virus is the prototype virus in this group. Eee was first recognized in massachusetts, united states, in 1831, when 75 horses died mysteriously of viral encephalitis. The pathogenesis of venezuelan equine encephalitis vee virus infection was compared in intraperitoneally inoculated mice n 24, 6 to 8 weeks old and hamsters n 9, 90110 g using histopathology and immunohistochemical localization of vee virus antigen. Eastern equine encephalitis virus eeev is a member of the genus alphavirus, family togaviridae. Venezuelan equine encephalitis and upper gastrointestinal. Wee, and venezuelan equine encephalomyelitis vee viruses are mosquitoborne pathogens that can cause nonspecific illnesses and encephalitis in equids horses, mules, burros, donkeys and zebras and humans in the americas. Molecular and cellular evidence of natural venezuelan. Genetically engineered, live, attenuated vaccines protect nonhuman primates against aerosol challenge with a virulent ie strain of venezuelan equine encephalitis virus douglas s.
Venezuelan equine encephalitis virus is an rna virus. Equine encephalids have high mortality rates and represent a significant zoonotic public health threat. Nov 29, 20 pathogenesis of venezuelan equine encephalitis. Venezuelan equine encephalitis epidemic cdc stacks. As the names suggest, eastern equine encephalitis eee most commonly occurs in the eastern united states and canada. Only a single serotype of je virus has been identified and subtipification has been described. Venezuelan equine encephalitis and upper gastrointestinal bleeding in child stalin vilcarromero, v. We strongly recommend that you talk with a trusted. Pdf venezuelan equine encephalitis virus veev remains a naturally emerging disease threat as well as a highly developed biological weapon. Pathogenesis of venezuelan equine encephalitis virus. Natural enzootic vectors of venezuelan equine encephalitis.
Venezuelan equine encephalitis virus and its replication. Nonhumanprimate models are needed to evaluate the efficacy of candidate vaccines. Kochel venezuelan equine encephalitis vee is reemerging in peru. The pathogenesis of venezuelan equine encephalitis vee virus infection was compared in intraperitoneally inoculated mice n 24, 6 to 8 weeks old and hamsters n 9, 90110 g using histopatho. The western equine encephalomyelitis virus complex contains western equine. Evolution and spread of venezuelan equine encephalitis. Venezuelan equine encephalitis genetic and rare diseases.
Venezuelan equine encephalitis virus cultures only 3. Assessment of listing and categorisation of animal diseases. Venezuelan equine encephalitis vee is an emerging zoonotic disease in the amazon region of peru. Novel antivirals for venezuelan equine encephalitis science.
Venezuelan equine encephalitis virus veev is a positivesense virus rna of the family togaviridae and the genus alphavirus, within this same group are the equine encephalitis viruses eev of the east and west, mayaro, madariaga, mucambo, and everglades 1,2. Aerosol infection of cynomolgus macaques with enzootic. Venezuelan equine encephalomyelitis vee viruses are taxonomically classified. Genetically engineered, live attenuated vaccines protect. Enzootic, equine avirulent, serotype id veev strains appear to alter their serotype to iab or ic, and. This map shows the distribution of eastern equine encephalitis virus neuroinvasive disease average annual incidence by county of residence from 2009 through 2018. Venezuelan equine encephalitis virus veev, western equine encephalitis virus weev, and eastern equine encephalitis virus eeev are nonsegmented, positivesense rna viruses of the genus alphavirus in the family togaviridae 1. Venezuelan equine encephalitis aetiology epidemiology diagnosis prevention and control references aetiology classification of the causative agent venezuelan equine encephalomyelitis vee viruses are taxonomically classified within the genus alphavirus of the family togaviridae formerly the group a arboviruses. Recurrent emergence of venezuelan equine encephalomyelitis. Highresolution functional mapping of the venezuelan. We used venezuelan equine encephalitis vee virus strain tc83 as a model to study the effects of chemical, thermal, and irradiation conditions on infectivity of singlestranded positive rna viruses. This is a pdf file of an unedited manuscript that has been.
Venezuelan equine encephalitis vee is an emerging zoonotic arboviral disease that affects equines and humans in the americas. Recently, progress has been made in understanding the complex ecological and viral genetic mechanisms that coincide in time and space to generate outbreaks. Vee virus subtype id in peru has not been previously. Research venezuelan equine encephalitis virus transmission. These include venezuelan equine encephalitis, western equine encephalitis, west nile equine encephalitis, african horse sickness, rabies, tetanus, and bacterial meningitis. Clinical and serological findings of madariaga and. A followup study of the 2010 outbreak was undertaken in 2015. Veev complex is a group of 14 antigenic varieties divided into 7 species.
Counties are shaded according to incidences ranging from less than 0. While endemic strains circulating in rodents are generally unable to cause disease in humans, mutations in certain veev subtypes can create an epizootic strain, carried by mosquitos, that is capable of infection. Venezuelan equine encephalitis virus from south florida. The safety and genetic stability of v4020, a novel venezuelan equine encephalitis virus veev vaccine based on the investigational veev tc83 strain, was evaluated in mice. Equine encephalitis fast fact iowa state university. Human and equine disease results from equine amplified, mosquitoborne outbreaks that expose hundreds of thousands of people to spillover infections.
Western equine encephalitis is a viral illness that is transmitted to people and horses through the bite of an infected mosquito. It is caused by the venezuelan equine encephalitis virus and is a significant disease in the americas. To assess the impact of continuing circulation of vee virus veev on human and animal populations, serologic and viral isolation studies were conducted in 2000 to 2001 in chiapas state. Our data showed that exposure of the virus to 65 degrees c for 515 min resulted in a 56 log reduction of virus infectivity. The virus is an alphavirus and is closely related to eastern equine encephalitis and venezuelan equine encephalitis viruses. Venezuelan equine encephalitis bioterrorism agent profiles. Venezuelan equine encephalitis virus was isolated three times from the culex melanoconion species of mosquitoes collected in south florida in june, july, and october, 1963. Venezuelan equine encephalitis virus an overview sciencedirect. There are at least 14 subtypes and varieties within the vee complex but only subtype i, varieties ab and c have been associated with major equine epizootics and epidemics aguilar et al. You can get a copy of the pdf viewer by clicking here. Molecular and cellular evidence of natural venezuelan equine. Jan 01, 2000 the venezuelan equine encephalitis vee complex is an antigenically related group of arboviruses in the family togaviridae, genus alphavirus. Veev is highly infectious in aerosol form and a known biowarfare agent that can cause severe encephalitis in humans.
Six subtypes containing 9 varieties of veevs have been identified by serology. Western equine encephalitis fact sheet minnesota dept. Venezuelan equine encephalitis definition of venezuelan. The veev nsp2 protease is a member of merops clan cn and characteristically contains a papainlike protease linked to an sadenosyllmethioninedependent rna methyltransferase sam. Dec 03, 2019 eastern equine encephalitis virus eeev is a member of the genus alphavirus, family togaviridae. The venezuelan equine encephalitis virus veev nonstructural protein 2 nsp2 cysteine protease ec 3. Nov 05, 2009 venezuelan equine encephalitis virus and its replication. Author summary the venezuelan equine encephalitis vee complex comprises a broadly distributed group of alphaviruses in the americas that have the potential to emerge and cause severe disease.
The viruses of the vee antigenic complex are currently classified into 6 antigenic subtypes by crossneutralization and hemagglutinationinhibition tests. Venezuelan equine encephalomyelitis vee, peste loca, venezuelan equine encephalitis, venezuelan encephalitis, venezuelan equine fever last updated. An outbreak of equine encephalitis occurred in venezuela in 1936, and a viruslater desig nated as venezuelan equine encephalitis vee viruswas. Kinetic, mutational, and structural studies of the. In addition, public health reporting of other emerging arboviral disease is encouraged. Historically, vee complex viruses have caused recurring outbreaks of human and equine encephalitis in central and south america as well as mexico, with at least one outbreak resulting in movement of the. The ia and ib strains are considered genetically indistinguishable and are thus classi. V4020 was generated from infectious dna, contains a stabilizing mutation in the e2120 glycoprotein, and includes rearrangement of structural genes. Specific antibody was present in 16 of 28 peromyscus gossypinus cotton mice and 3 of 16 sigmodon hispidus cotton rats sampled from one of the infected sites in january 1964. List of virus strains used in the study and known metadata. Venezuelan equine encephalitis virus was first isolated in 1938 from the brain of a horse that died of encephalitis 1,2. Depending on the subtype, veev maintains either an enzootic or an epizootic life cycle.
Human cases of madariaga virus madv infection were first detected during an outbreak in 2010 in eastern panama, where venezuelan equine encephalitis virus veev also circulates. Pdf venezuelan equine encephalitis juancarlos navarro. Endemic venezuelan equine encephalitis in the americas. Venezuelan equine encephalitis virus, southern mexico.
The alphavirus venezuelan equine encephalitis virus veev was first identified as the causative agent of an equine disease in 1938 and later was found to be a human pathogen. Humans are primarily exposed to vee through the bite of an infected mosquito. Novel antivirals for venezuelan equine encephalitis. Mar 28, 2018 the alphavirus venezuelan equine encephalitis virus veev was first identified as the causative agent of an equine disease in 1938 and later was found to be a human pathogen. Venezuelan equine encephalitis and 2 human deaths, peru cdc. Author summary the venezuelan equine encephalitis vee complex.
Venezuelan equine encephalitis virus veev is an important animal and human pathogen found only in the americas the new world. Venezuelan equine encephalitis virus veev, alphavirus in the togaviridae. Other medically important alphaviruses found in the americas include, venezuelan equine encephalitis virus veev, chikungunya virus chikv, mayaro virus mayv, and madariaga madv. Venezuelan equine encephalitis is an emerging infectious disease in latin america. The venezuelan equine encephalitis vee viru s com plex is a group ofserologically related arthropod borne viruses that are im portant pathogens ofhuman beings and horses in the americas. Equine epizootics of venezuelan equine encephalitis vee occurred in the southern mexican states of chiapas in 1993 and oaxaca in 1996. Venezuelan equine encephalitis virus pathogenesis and. Venezuelan equine encephalitis virus veev, alphavirus in the togaviridae family is an enveloped virus with a nonsegmented, positivesense rna genome of approximately 11. Eastern equine encephalitis eee, commonly called triple e or sleeping sickness not to be confused with african trypanosomiasis, is a disease caused by a zoonotic mosquito vectored togavirus that is present in north, central, and south america, and the caribbean. Venezuelan equine encephalitis virus is an alphavirus that was originally isolated from the brains of dead horses. Veev is actually a complex of 7 different species as well as multiple subtypes and varieties 3. Kinetic, mutational, and structural studies of the venezuelan.
These viruses belong to the alphavirus genus in the family togavir idae. Venezuelan equine encephalitis virus veev has caused sporadic outbreaks since the early part of the 20th century, with some epidemics affecting 100,000 persons. Guidelines for travel pandemic h1n1 in the last 18 years, epizootics of venezuelan equine encephalitis have not occurred in places with historic epidemic register in the guajira peninsula, colombia. Recently, progress has been made in understanding the. Apr 15, 2016 venezuelan equine encephalitis is an acute viral disease characterized by fever, chills, headache, nausea, vomiting, lumbosacral pain, and myalgia, which may progress to encephalitis. Venezuelan equine encephalitis bioterrorism agent profiles for health care workers causative agent. Western equine encephalitis fact sheet pdf what is western equine encephalitis. Venezuelan equine encephalitis virus veev is an alphavirus in the family togaviridae. Venezuelan equine encephalitis is the most important arboviral etiology of central nervous system disease in the americas. Because it can be easily weaponized, human venezuelan equine encephalitis virus disease is designated as reportable in missouri.
Mar 15, 2004 because venezuelan equine encephalitis viruses veevs are infectious by aerosol, they are considered to be a biologicalweapons threat. Venezuelan equine encephalitis virus nucleic acid can also be amplified from the blood or pharynx the eighth day of illness by pcr. During an outbreak of venezuelan equine encephalitis virus in venezuela and colombia in 1995, approximately 3000 cases of neurologic disease were reported. Association of tonate virus subtype iiib of the venezuelan. Little is known about the longterm consequences of either alphavirus infection. Venezuelan equine encephalitis viruses veevs are a group family, togaviridae. Western equine encephalitis wee has been isolated from argentina to western canada and in u. Venezuelan equine encephalitis virus is a mosquitoborne viral pathogen that causes venezuelan equine encephalitis or encephalomyelitis vee. Methods for inactivation of venezuelan equine encephalitis virus.
This is a pdf file of an unedited manuscript that has been accepted for publication. The 5 twothirds of the genome encodes four nonstructural proteins nsp1 to nsp4 that form an enzyme complex required for viral replication. The veev species include four antigenic varieties namely iab, ic, id, and ie, all of which cause human disease. Venezuelan equine encephalitis virus veev is a member of genus alphavirus in the family togaviridae. Pdf on jul 22, 20, katherine g taylor and others published pathogenesis of venezuelan equine encephalitis find, read and cite all the. Venezuelan equine encephalomyelitis vee is caused by the vee virus veev. Febrile illness and encephalitis pdf icon to the left to view a copy of this virus entry in pdf format. Venezuelan equine encephalitis is an acute viral disease characterized by fever, chills, headache, nausea, vomiting, lumbosacral pain, and myalgia, which may progress to encephalitis. Classification of the causative agent resistance to. Japanese encephalitis aetiology epidemiology diagnosis prevention and control references aetiology classification of the causative agent japanese encephalitis je virus is a member of the family flaviviridae, genus flavivirus.
Evolution and spread of venezuelan equine encephalitis complex. Enhanced vector infection from a single amino acid substitution in the envelope glycoprotein aaron c. Venezuelan equine encephalitis virus pathogenesis and vaccine. Pdf icon to the left to view a copy of this virus entry in pdf format. Eastern, western and venezuelan equine encephalomyelitis result from infection. Eastern equine encephalomyelitis the center for food security. Vaccines free fulltext advanced safety and genetic. Vector saliva enhances infection with many pathogens 18, and mosquito saliva is reported to enhance infec. Louis encephalitis, west nile, and western equine encephalitis. Schmaljohn the united states army medical research institute of infectious diseases, fort detrick, maryland, united states of america. Venezuelan equine encephalitis virus veev remains a naturally emerging disease threat as well as a highly developed biological weapon. Vee can affect all equine species, such as horses, donkeys, and zebras. Infected mice developed paralysis, and the majority died by 9 days after inoculation.
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