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Human Vaccines & Immunotherapeutics Jan 2018Japanese encephalitis (JE) is the most commonly diagnosed viral encephalitis in Asia. JE is caused by a virus called JE virus (JEV), a member of the genus Flavivirus,... (Review)
Review
Japanese encephalitis (JE) is the most commonly diagnosed viral encephalitis in Asia. JE is caused by a virus called JE virus (JEV), a member of the genus Flavivirus, family Flaviviridae, and is transmitted by Culex mosquitoes. Neutralising antibody to JEV protects against JE, and can be induced by vaccination. JE is a potential threat to travellers to endemic areas, which are most of South and Southeast Asia and some Pacific Islands. The risk of JE can be expected to increase with increasing mosquito exposure and time spent in regions and seasons of active transmission. JE is very rare in travellers, but mortality is high, around 1 in 3, and there is a high rate of lasting neurological damage. JE can therefore be a profoundly life changing event for a traveller. Travellers and their healthcare providers need to balance the low risk of disease against the very high severity of disease if it does occur. In order to make an informed decision, the severity of JE disease should be carefully explained to travellers to Asia.
Topics: Asia; Decision Making; Encephalitis Virus, Japanese; Encephalitis, Japanese; Endemic Diseases; Humans; Japanese Encephalitis Vaccines; Risk Assessment; Seasons; Severity of Illness Index; Travel-Related Illness; Vaccination
PubMed: 29244615
DOI: 10.1080/21645515.2017.1380756 -
Veterinary Microbiology Mar 2017Japanese encephalitis virus (JEV) is a significant cause of neurological disease in humans throughout Asia causing an estimated 70,000 human cases each year with... (Review)
Review
Japanese encephalitis virus (JEV) is a significant cause of neurological disease in humans throughout Asia causing an estimated 70,000 human cases each year with approximately 10,000 fatalities. The virus contains a positive sense RNA genome within a host-derived membrane and is classified within the family Flaviviridae. Like many flaviviruses, it is transmitted by mosquitoes, particularly those of the genus Culex in a natural cycle involving birds and some livestock species. Spill-over into domestic animals results in a spectrum of disease ranging from asymptomatic infection in some species to acute neurological signs in others. The impact of JEV infection is particularly apparent in pigs. Although infection in adult swine does not result in symptomatic disease, it is considered a significant reproductive problem causing abortion, still-birth and birth defects. Infected piglets can display fatal neurological disease. Equines are also infected, resulting in non-specific signs including pyrexia, but occasionally leading to overt neurological disease that in extreme cases can lead to death. Veterinary vaccination is available for both pigs and horses. This review of JEV disease in livestock considers the current diagnostic techniques available for detection of the virus. Options for disease control and prevention within the veterinary sector are discussed. Such measures are critical in breaking the link to zoonotic transmission into the human population where humans are dead-end hosts.
Topics: Animals; Animals, Domestic; Culex; Encephalitis Virus, Japanese; Encephalitis, Japanese; Humans; Insect Vectors; Livestock; Zoonoses
PubMed: 28284628
DOI: 10.1016/j.vetmic.2017.01.014 -
Expert Opinion on Biological Therapy Jul 2009Japanese encephalitis is the leading cause of viral encephalitis in Asia. Every year 30,000 - 50,000 cases and 10,000 deaths from Japanese encephalitis are reported, and... (Review)
Review
Japanese encephalitis is the leading cause of viral encephalitis in Asia. Every year 30,000 - 50,000 cases and 10,000 deaths from Japanese encephalitis are reported, and underreporting has been suggested. No effective antiviral therapy exists to treat this mosquito-borne flavivirus infection. For active immunization vaccines are available. The manufacturing of the only vaccine that was internationally licensed, JE-VAX, was ceased in 2005. Therefore a shortage of Japanese encephalitis vaccines might occur before new generation vaccines based on cell culture technology will be available. A promising new vaccine candidate is the inactivated whole-virus vaccine IXIARO (Strain SA(14)-14-2), developed by Intercell AG. Which was licensed in Europe, the USA and Australia in spring 2009. Recently, successful Phase III immunogenicity and tolerability studies were published, indicating that this vaccine will be an acceptable approach to active immunization against Japanese encephalitis. Cell-culture-based vaccines will not only be used in the population living in endemic areas where the risk of infection is high, but also by travelers and military personnel.
Topics: Animals; Clinical Trials as Topic; Cricetinae; Encephalitis, Japanese; Humans; Japanese Encephalitis Vaccines; Mice
PubMed: 19527110
DOI: 10.1517/14712590903042282 -
Zoonoses and Public Health Feb 2022Japanese encephalitis virus (JEV) infection has been recognized as a serious disease in humans. Wildlife animal infections due to JEV have not been well described. This...
Japanese encephalitis virus (JEV) infection has been recognized as a serious disease in humans. Wildlife animal infections due to JEV have not been well described. This study identified JEV infection in two deceased meerkats in Thailand, with clinical signs of neurological disease. Histopathology of brains revealed severe lymphoplasmacytic necrotizing meningoencephalitis, while similar inflammation was observed in the lung and liver. Partial JEV sequences were identified from the formalin-fixed paraffin-embedded-derived brain sections of two meerkats and were found to be genetically similar to a JEV strain detected in China but not from a local strain. Using immunohistochemistry, the virus was identified in neurons and glial cells, and also found in bronchial glands, Kupffer's cells in liver, lymphocytes in the spleen and pancreatic acini, which suggests extraneural infection. Transmission electron microscopy confirmed the presence of spheroid viral particles in the lungs. These findings may suggest that infection of extraneural organs in meerkats is similar to that described in JEV-infected humans. In conclusion, this study identified the first JEV infection in meerkats as an interesting case study. The JEV should be considered as an important differential diagnosis in meerkats with encephalitis. Further surveillance on JEV infection in meerkats and other wildlife species in a large cohort is needed in the future study.
Topics: Animals; Brain; China; Encephalitis Virus, Japanese; Encephalitis, Japanese; Humans; Immunohistochemistry
PubMed: 34254456
DOI: 10.1111/zph.12882 -
The Brazilian Journal of Infectious... 2012Japanese encephalitis virus (JEV) causes Japanese encephalitis, which is a leading form of viral encephalitis in Asia, with around 50,000 cases and 10,000 deaths per... (Review)
Review
Japanese encephalitis virus (JEV) causes Japanese encephalitis, which is a leading form of viral encephalitis in Asia, with around 50,000 cases and 10,000 deaths per year in children below 15 years of age. The JEV has shown a tendency to extend to other geographic regions. Case fatality averages 30% and a high percentage of the survivors are left with permanent neuropsychiatric sequelae. Currently, there is no cure for JEV, and treatment is mainly supportive. Patients are not infectious, but should avoid further mosquito bites. A number of antiviral agents have been investigated; however, none of these have convincingly been shown to improve the outcome of JEV. In this review, the current knowledge of the epidemiology and the pathogenesis of this deadly disease have been summarized.
Topics: Animals; Encephalitis Virus, Japanese; Encephalitis, Japanese; Humans; India; Insect Vectors; Japanese Encephalitis Vaccines; Risk Factors
PubMed: 23141974
DOI: 10.1016/j.bjid.2012.10.004 -
Reviews in Medical Virology Sep 2012Japanese encephalitis (JE), caused by Japanese encephalitis virus (JEV) infection, is the most important viral encephalitis in the world. Approximately 35,000-50,000... (Review)
Review
Japanese encephalitis (JE), caused by Japanese encephalitis virus (JEV) infection, is the most important viral encephalitis in the world. Approximately 35,000-50,000 people suffer from JE every year, with a mortality rate of 10,000-15,000 people per year. Although the safety and efficacy of JE vaccines (inactivated and attenuated) have been demonstrated, China still accounts for 50% of the reported JE cases worldwide. In this review, we provide information about the burden of JE in mainland China and the corresponding epidemiology from 1949 to 2010, including the morbidity and mortality of JE; the age, gender, and vocational distribution of JE cases; its regional and seasonal distribution; and JE immunization. In addition, we discuss the relationships among vectors, hosts, and JEV isolates from mainland China; the dominant vector species for JEV transmission; the variety of JEV genotypes and the different biological characteristics of the different JEV genotypes; and the molecular evolution of JEV.
Topics: China; Encephalitis Virus, Japanese; Encephalitis, Japanese; Evolution, Molecular; Genotype; Humans; Prevalence; Risk Factors; Seasons; Survival Analysis; Topography, Medical
PubMed: 22407526
DOI: 10.1002/rmv.1710 -
Medecine Tropicale : Revue Du Corps de... Sep 2005Japanese encephalitis is an arboviral disease due to a flavivirus transmitted by a mosquito of the genus Culex. It is a major public health problem in Southeast Asia... (Review)
Review
Japanese encephalitis is an arboviral disease due to a flavivirus transmitted by a mosquito of the genus Culex. It is a major public health problem in Southeast Asia where it is endemo-epidemic. The socio-economic impact of Japanese encephalitis is great since most cases occur in children and young adults and lead to death in 25 to 30 % and neurological sequelae in survivors. The tendency of Japanese encephalitis to spread geographically and the existence of imported cases are particularly important issues. The clinical features are the same as other viral encephalitis. Suspicion of imported Japanese encephalitis depends on awareness of the epidemiological setting (return from endemic areas). Diagnosis must be confirmed by serology using ELISA capture method to detect anti-viral antibodies in blood and cerebrospinal fluid. Unlike herpes encephalitis, there is currently no specific treatment for Japanese encephalitis. Only preventive measures can be effective against infection. At the present time the most widely used vaccine is Biken's lyophilized vaccine produced from a reference strain (Nakayama strain), but its high cost prevents mass vaccination in endemic areas. Recent progress in molecular biology has raised hope for the discovery of a genetically engineered vaccine to improve overall protection against Japanese encephalitis.
Topics: Encephalitis, Japanese; Humans
PubMed: 16548493
DOI: No ID Found -
Internal Medicine Journal Dec 2022
Topics: Humans; Encephalitis, Japanese; Australia
PubMed: 37133372
DOI: 10.1111/imj.15967 -
Microbes and Infection Apr 2011Japanese encephalitis virus (JEV) is an arbovirus belonging to the family Flaviviridae. It is maintained in a zoonotic cycle involving pigs, ardeid birds and Culex... (Review)
Review
Japanese encephalitis virus (JEV) is an arbovirus belonging to the family Flaviviridae. It is maintained in a zoonotic cycle involving pigs, ardeid birds and Culex species of mosquitoes. Humans are accidental/dead end hosts of JEV infection because they cannot sustain high viral titers. Factors affecting the clinical manifestations and pathogenesis of JEV infection are not well understood. Though, vaccines are currently available against JEV, it has to be further improved. Here we review the literature on the JEV life cycle, pathogenesis and host immune responses to JEV infection.
Topics: Animals; Encephalitis Virus, Japanese; Encephalitis, Japanese; Genome, Viral; Humans; Immunity; Virus Replication
PubMed: 21238600
DOI: 10.1016/j.micinf.2011.01.002 -
Viruses Feb 2023Japanese encephalitis virus (JEV) is an arboviral, encephalitogenic, zoonotic flavivirus characterized by its complex epidemiology whose transmission cycle involves...
Japanese encephalitis virus (JEV) is an arboviral, encephalitogenic, zoonotic flavivirus characterized by its complex epidemiology whose transmission cycle involves reservoir and amplifying hosts, competent vector species and optimal environmental conditions. Although typically endemic in Asia and parts of the Pacific Islands, unprecedented outbreaks in both humans and domestic pigs in southeastern Australia emphasize the virus' expanding geographical range. To estimate areas at highest risk of JEV transmission in Australia, ecological niche models of vectors and waterbirds, a sample of piggery coordinates and feral pig population density models were combined using mathematical and geospatial mapping techniques. These results highlight that both coastal and inland regions across the continent are estimated to have varying risks of enzootic and/or epidemic JEV transmission. We recommend increased surveillance of waterbirds, feral pigs and mosquito populations in areas where domestic pigs and human populations are present.
Topics: Humans; Animals; Encephalitis, Japanese; Mosquito Vectors; Encephalitis Virus, Japanese; Epidemics; Encephalitis Viruses, Japanese; Australia
PubMed: 36851664
DOI: 10.3390/v15020450