It is best known for causing reproductive failure in sows and central nervous system disease in horses. This medically important arbovirus is primarily spread from vertebrate hosts to humans by the mosquito vector culex tritaeniorhynchus. It is a leading cause of viral encephalitis in asia, with 3050,000 cases reported annually. Japanese encephalitis in india guidelines for prevention. This virus has caused widespread morbidity and mortality across the globe. Enveloped single stranded rna virus morphology not well defined history 1870s. Japanese encephalitis virus an overview sciencedirect. It is the leading cause of epidemic viral encephalitis worldwide. Japanese encephalitis is a potentially severe viral brain infection usually transmitted through the bite of an infected culex spp. Ravi v, desai as, shenoy pk, satishchandra p, chandramuki a, gouriedevi m. Japanese encephalitis and west nile viruses springerlink. Japanese encephalitis je is one of the most significant aetiological agents of viral encephalitis in asia. Japanese encephalitis disease directory travelers health. A form of encephalitis caused by a flavivirus japanese b encephalitis virus jbev and transmitted by mosquito bites.
This vaccine was approved in march 2009 for use in people aged 17 years and older and in may 20 for use in children 2 months through 16 years of age. Most infections occur without apparent symptoms or with mild symptoms such as fever and headache. The epidemiology of japanese encephalitis and risk to the traveler has changed and continues to evolve. Symptoms usually take 515 days to develop and include fever, headache, vomiting, confusion, and difficulty moving. Japanese encephalitis virus jev, the etiological agent of je, is the leading cause of epidemic encephalitis afflicting humans with 68,000 cases annually and 1050 %. Japanese encephalitis in india know what is japanese encephalitis, je situation in india, symptoms of the disease, guidelines for prevention and control of japanese encephalitis. Japanese encephalitis virus jev is a zoonotic mosquitoborne flavivirus which is the leading causative agent of viral encephalitis in endemic regions. Jul 24, 2019 japanese encephalitis virus jev, a flavivirus singlestranded ribonucleic acid rna, represents the most significant etiology of arboviral encephalitis worldwide. Rare clinical cases have also been reported in other species, such as cattle. Japanese encephalitis je is the most common form of viral encephalitis that appears in the form of frequent epidemics of brain fever throughout southeast asia, china and india. Japanese encephalitis virus belongs to the japanese encephalitis serocomplex, which is composed of 9 genetically and antigenically related viruses of the flaviviridae family. Some of the mosquitotransmitted viruses include dengue fever, yellow fever, zika virus, west nile virus and the japanese encephalitis virus.
In these cases, symptoms may include headache, vomiting, fever, confusion and seizures. Japanese encephalitis is a viral infection caused by rna viruses belonging to the flavivirus genus. Japanese encephalitis virus jev, a flavivirus singlestranded ribonucleic acid rna, represents the most significant etiology of arboviral encephalitis worldwide. Jul 24, 2019 japanese encephalitis virus, a flavivirus singlestranded ribonucleic acid rna, represents the most significant etiology of arboviral encephalitis worldwide. Japanese encephalitis virus jev, a flavivirus maintained in a zoonotic cycle and transmitted by the mosquito culex tritaeniorhynchus, causes epidemics of encephalitis throughout much of asia. Domestic pigs and japanese encephalitis virus infection. Jul 21, 2015 japanese encephalitis in india know what is japanese encephalitis, je situation in india, symptoms of the disease, guidelines for prevention and control of japanese encephalitis. The ratio of asymptomatic to symptomatic infection is estimated to be 100.
However, once symptoms develop, je is a serious viral encephalitis with a high mortality rate and high percentage of neuropsychiatric. Ardeid wading birds are the primary maintenance hosts, pigs are the main amplifying hosts, and culex mosquitoes are the primary mosquito vectors. The disease occurs mainly in the rural and agricultural areas of asia and the western pacific region. Japanese encephalitis virus tropism in experimentally. Japanese encephalitis virus jev is a major cause of viral encephalitis in southeast asia. About 20% of people develop a fever, headache, vomiting, or a rash. Japanese encephalitis vaccine for travellers passport health. Japanese encephalitis virus jev is endemic in much of asia and the.
Dengue virus denv and japanese encephalitis virus jev belong to the genus flavivirus, and infection with a virus within this genus induces antibodies that are crossreactive to other flaviviruses. Japanese encephalitis je is the main cause of viral encephalitis in many countries of asia. The disease occurs in large parts of asia and the pacific rim, usually in rural areas where rice cultivation and pig farming is common. Most cases are mild and asymptomatic but severe cases can lead to death. Most human infections with japanese encephalitis virus do not cause symptoms. The virus exists in a transmission cycle between mosquitoes, pigs andor water birds. Je virus enveloped virus closely related to west nile fever virus and st. Japanese encephalitis je is a vectorborne viral disease that occurs in south asia, southeast asia, east asia, and the pacific. Japanese encephalitis je virus is the leading cause of vaccinepreventable encephalitis in asia and the western pacific. It is closely related to other infections like west nile virus. Japanese encephalitis is a zoonotic disease caused by a mosquitoborne virus similar to west nile, dengue fever, st. An estimated 3 billion persons live in countries where the je virus is endemic, and the annual incidence of the disease is 30,00050,000 cases.
Classification of the causative agent resistance to. Japanese encephalitis virus is an important mosquitoborne human pathogen in much of asia including southeast asia, china, japan, the korean peninsula and adjacent areas of the russian federation, sri lanka, and portions of the indian subcontinent with recent incursions into the pacific islands and northern australia fig. Japanese encephalitis flaviviridae flavivirus the name is derived from. Pdf japanese encephalitis virus remains an important. It is a zoonosis an animal disease that can spread to humans primarily transmitted by evening biting culex mosquitoes that feed on infected birds, pigs and other mammals passing the infection to humans living and working in rural areas. The virulence to man of japanese encephalitis virus in thailand. Pdf japanese encephalitis virus remains an important cause.
It is an enveloped virus having single stranded rna as a genome which is infectious. Knowledge of the contemporary distribution of this vector species is lacking, and efforts to define areas of disease risk greatly depend on a thorough. The spread of japanese encephalitis virus into new environments, changes in agricultural practice and animal vectors, climate change, periurban growth, changes in international travel to asia, personal risk factors, mosquito vector free transmission, interactions with other. Aug 23, 2018 japanese encephalitis je is a dangerous form of brain inflammation caused by the japanese encephalitis virus, which is common in asia and the west pacific territories. Japanese encephalitis symptoms, diagnosis, treatments and. The genome is of 11kb with positive sense and a 5 cap but it lacks a 3 poly tail vashist et al. Japanese encephalitis is a leading cause of viral encephalitis in asia generally spread from western pacific region in east to pakistan in west and from korea in north to papua new guinea in south. Japanese encephalitis virus, a flavivirus singlestranded ribonucleic acid rna, represents the most significant etiology of arboviral encephalitis worldwide. Louis encephalitis, and murray valley encephalitis viruses. Japanese encephalitis is a mosquitoborne disease caused by the japanese encephalitis virus. The next documented epidemic in japan occurred in 1924 with 6,125 human cases resulting in 3,797 human deaths 62% casefatality rate.
Japanese encephalitis can be a very serious disease in people. Sep 29, 2017 this video is about japanese encephalitis virus introduction, history, geographic distribution, transmission cycles, signs and symptoms, viral structure. More detailed information about the symptoms, causes, and treatments of japanese encephalitis is available below. Japanese encephalitis je, caused by japanese encephalitis virus jev, is the most important form of viral encephalitis in asia. Symptoms that develop later include swelling around the brain and coma.
These antibody activities are considered central in. The virus that causes japanese encephalitis is called an arbovirus, which is an arthropodborne virus. Japanese encephalitis definition japanese encephalitis is an infection of the brain caused by a virus. Japanese encephalitis national health portal of india. The first historic mention of japanese encephalitis occurred during the summer encephalitis outbreaks in the late 1870s. It is a mosquitoborne flavivirus, meaning it is related to dengue, yellow fever and west nile viruses.
Japanese encephalitis is a neurologic infection closely related to st. Nucleotide changes responsible for loss of neuroinvasiveness in japanese encephalitis virus neutralizationresistant mutants. Japanese encephalitis is caused by a mosquitoeborne flavivirus and affects a wide range of species including ruminants, carnivores, birds and humans. Mutations in the envelope protein of japanese encephalitis virus affect entry into cultured cells and virulence in mice. The je virus is a flavivirus related to dengue, yellow fever and west nile viruses. It is the leading cause of epidemic viral encephalitis in humans worldwide.
The important mosquito vectors vary according to area. In the present study, the localization and kinetics of virus replication were investigated in. Encephalitis virus, japanese definition of encephalitis. Inactivated vero cell culturederived japanese encephalitis je vaccine manufactured as ixiaro is the only je vaccine licensed and available in the united states. Oct 18, 2016 dengue virus denv and japanese encephalitis virus jev belong to the genus flavivirus, and infection with a virus within this genus induces antibodies that are crossreactive to other flaviviruses. Only a single serotype of je virus has been identified and subtipification has been described. Although there is a single serotype of japanese encephalitis. Description the virus that causes japanese encephalitis is called an arbovirus, which is an arthropodborne virus. Japanese encephalitis virus epidemiology free 30day. It causes reproductive loses in pigs and encephalitis in horses. The majority of infections occur in children and are subclinical or have features limited to transient fever and gastrointestinal symptoms.
Mosquitoes in a number of regions carry this virus and are responsible for passing it along to humans. Pigs are considered to be the main amplifying host for japanese encephalitis virus jev, and their infection can correlate with human cases of disease. Virus is sensitive to heat, ultraviolet light and gamma irradiation. It is a leading cause of vaccinepreventable encephalitis inflammation of the brain in asia and the western pacific. Definition japanese encephalitis is an infection of the brain caused by a virus. In less than 1% of people, encephalitis or meningitis occurs, with associated neck stiffness, confusion, or seizures. Despite their importance in the ecology of the virus as it relates to human cases of encephalitis, the pathogenesis of jev in pigs remains obscure. The disease is caused by a flavivirus named japanese encephalitis virus that is spread to humans by mosquitoes. Aug 22, 2018 click here to view the thematic webpage of japanese encephalitis causative agent japanese encephalitis is a mosquitoborne disease caused by the japanese encephalitis virus. Recommendations of the advisory committee on immunization practices acip. The virus is maintained in an enzootic cycle between mosquitoes and amplifying vertebrate hosts mainly pigs. Overview economic impact history epidemiology transmission clinical signs diagnosis and treatment disease in humans prevention and control actions to takeprogram mode.
Japanese encephalitis je is a disease spread through mosquito bites. First human case of usutu virus neuroinvasive infection, italy, augsept 2009. The epidemiology of je has changed in the past 50 years and the area affected by jev has expanded to india, china, southeast asia and western pacific regions. Pathogenesis and clinical features of japanese encephalitis and west nile virus infections. Virus can be inactivated with 70% ethanol, 2% glutaraldehyde, 38% formaldehyde, 1% sodium hypochlorite, iodine, phenol iodophors and organic solventsdetergents. Most people infected with je do not have symptoms or have only mild symptoms. Japanese encephalitis is a serious mosquitoborne viral disease that affects horses, donkeys, pigs, and humans. Japanese encephalitis je virus was initially isolated in japan in 1935.
This video is about japanese encephalitis virus introduction, history, geographic distribution, transmission cycles, signs and symptoms, viral structure. Classification of the causative agent japanese encephalitis je virus is a member of the family flaviviridae, genus flavivirus. Japanese encephalitis je is an infection of the brain caused by the japanese encephalitis virus jev. Japanese encephalitis je is the most important cause of viral encephalitis in asia. The changing epidemiology of japanese encephalitis and new.
In about 80% of infections people have few or no symptoms. A mosquitoborne encephalitis caused by the japanese b encephalitis virus encephalitis virus, japanese occurring throughout eastern asia and australia. Persistence of japanese encephalitis virus in the human nervous system. The japanese encephalitis virus is an enveloped rna virus, flavivirus, which is a genus of viruses in the family flaviviridae. The prime method of spread of the west nile virus wnv is the female mosquito. The japanese encephalitis serological group of flaviviruses. Japanese encephalitis virus does not persist outside a living host. Japanese encephalitis virus jev is a mosquitoborne agent that can cause encephalitis in equids and humans and reproductive disease in pigs.
Japanese encephalitis and west nile viruses are members of the japanese encephalitis serological group of the genus. Usual adult dose for japanese encephalitis virus prophylaxis. The japanese encephalitis virus is present in asia, from japan to india and pakistan, and outbreaks are erratic and spatially and temporally limited phenomena, occurring quite unpredictably, even if all conditions appear to be present in a definite place. Japanese encephalitis virus an overview sciencedirect topics. Japanese encephalitis virus vector and reservoir involved. Japanese encephalitis virus belongs to the flaviviridae family, it is an rna virus measuring 4050 nm in diameter and structurally it is a spheroid having cubical symmetry. Japanese encephalitis je is an acute viral encephalitis transmitted by mosquitoes, mainly culex tritaeniorhyncus infected with je virus. Apr 10, 2015 je virus enveloped virus closely related to west nile fever virus and st. For most travelers to asia, the risk for je is very low but varies based on destination, length of travel, season, and activities.
Japanese encephalitis vaccine japanese encephalitis cdc. It is the most common cause of vaccinepreventable encephalitis in asia. Clinical features most infections occur without apparent symptoms or with mild symptoms such as fever and headache. While most infections result in little or no symptoms, occasional inflammation of the brain occurs. Suppression of jev disease in humans is generally considered to be best achieved through vaccination of humans or swine. Japanese encephalitis je is a dangerous form of brain inflammation caused by the japanese encephalitis virus, which is common in asia and the west pacific territories. West nile fever is an infection by the west nile virus, which is typically spread by mosquitoes. Japanese b encephalitis, arbovirus b, mosquitoborne encephalitis virus japanese encephalitis is a serious mosquitoborne viral disease that affects horses, donkeys, pigs, and humans. May 14, 2010 the first historic mention of japanese encephalitis occurred during the summer encephalitis outbreaks in the late 1870s. Humans get infected when bitten by an infected mosquito. Particularly in denv infection, antibodies to denv possess two competing activities.
Centre for health protection japanese encephalitis. If there are time constraints, three doses may be given on days 0, 7, and 14. Who recommends having strong prevention and control activities, including je immunization in all regions where the disease is a recognized public health problem. Japanese encephalitis is a disease caused by a flavi virus that affects the membranes around the brain. Japanese encephalitis virus jev, a main cause of severe viral encephalitis in humans, has a complex ecology, composed of a cycle involving primarily waterbirds and mosquitoes, as. In europe, cats were identified as being hosts for west nile virus.
Japanese encephalitis virus jev is endemic in much of asia and the western pacific. Japanese encephalitis is a mosquitoborne virus found throughout asia. Japanese encephalitis virus vaccine nakayama uses, side. Hasegawa h, yoshida m, shiosaka t, fujita s, kobayashi y. Japanese encephalitis virus vaccine dosing information. In symptomatic cases requiring hospitalisation, death rates are. Vectorfree transmission and persistence of japanese. Mosquitoes in a number of regions carry this virus. Travellers who are staying in regions with je for an extended period of time should be vaccinated against.
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